Gate forwarded-header trust behind trusted-proxy config (closes #88)

Every rate limiter keyed on httprate.KeyByRealIP, which believes
True-Client-IP, X-Real-IP and the first X-Forwarded-For entry from
any peer. A client could therefore mint a fresh bucket per request
by rotating a spoofed header, or drain another client's bucket by
claiming its address, which left the receiver, login and password
change limits with no value against a deliberate attacker.

The receiver, login and password change limiters now share one key
function: the connection's own address, unless the direct peer is
inside a network listed in the new TRUSTED_PROXIES CIDR list, in
which case the forwarded client address is used. The list is empty
by default, so nothing is trusted until an operator names their
proxy; a set-but-unparseable value aborts startup, matching the
handling of the other parsed variables.

X-Forwarded-For is the only forwarded header read, from any peer.
Reverse proxies append to it but pass other client headers through
verbatim, so believing a single-valued X-Real-IP or True-Client-IP
would hand a client behind the trusted proxy a fresh bucket per
request - the same bypass, inside the deployment TRUSTED_PROXIES
exists to serve. Within a trusted request the chain is walked right
to left, since the rightmost entry is the one the nearest proxy
appended, and the first hop that is not itself a trusted proxy is
taken as the client. A hop that is not a bare address - ip:port, a
bracketed IPv6 literal, the token unknown - ends the walk and the
peer address is used, rather than continuing left into entries the
client controls.

Trusted-proxy prefixes written in IPv4-mapped form are unmapped at
parse time, since peer addresses are unmapped before matching and
such a prefix would otherwise silently never match.

Also folds in two cleanups from the same review: the 429 responder
shared by all three limiters is extracted, and the
RECEIVER_RATE_LIMIT error-path tests now assert that the failure
names the variable and wraps ErrNonPositiveValue rather than only
that some error occurred.

README.md

@@ -89,9 +89,98 @@ TTY detection, and security headers are always applied.
 | `PORT`                  | HTTP listen port                    | `8080`   |
 | `DATA_DIR`              | Directory for all SQLite databases  | `/var/lib/webhooker` |
 | `DEBUG`                 | Enable debug logging                | `false`  |
+| `MAINTENANCE_MODE`      | Serve the maintenance page          | `false`  |
 | `METRICS_USERNAME`      | Basic auth username for `/metrics`  | `""`     |
 | `METRICS_PASSWORD`      | Basic auth password for `/metrics`  | `""`     |
 | `SENTRY_DSN`            | Sentry error reporting DSN          | `""`     |
+| `SESSION_IDLE_TIMEOUT`  | Idle session timeout (Go duration)  | `24h`    |
+| `RECEIVER_RATE_LIMIT`   | Receiver requests/minute per IP per entrypoint | `120` |
+| `TRUSTED_PROXIES`       | CIDRs whose forwarded headers are trusted | `""` (none) |
+
+#### Trusted proxies
+
+`TRUSTED_PROXIES` is a comma-separated list of CIDR blocks (a bare
+address such as `192.168.1.7` is accepted and treated as a single
+host), for example `192.168.1.7, 2001:db8::5`. It decides whose
+`X-Forwarded-For` header the rate limiters believe, so it should name
+the addresses of your reverse proxies and nothing else.
+
+`X-Forwarded-For` is honoured **only** when the connecting peer is
+inside one of these blocks; for every other peer the client identity is
+the connection's own address and the header is ignored. The default is
+the empty list, which trusts nobody — anything else would let any
+client pick its own rate limit bucket, minting a fresh one per request
+or draining someone else's. Set it to the address of your reverse
+proxy, and to nothing wider. A set but unparseable value aborts
+startup.
+
+`X-Real-IP` and `True-Client-IP` are **never** read, from any peer.
+Reverse proxies append to `X-Forwarded-For` but forward other client
+headers verbatim, so a single-valued header is client-controlled even
+behind a trusted proxy.
+
+Within a trusted request, `X-Forwarded-For` is read right to left,
+because the rightmost entry is the one the nearest proxy appended and
+everything left of it may have been written by the client. The first
+hop that is not itself a trusted proxy is taken as the client. A hop
+that is not a bare IP address — `ip:port`, a bracketed IPv6 literal,
+the token `unknown` — ends the walk and the peer address is used
+instead, since past such an entry the chain is not the shape assumed
+here. The peer address is likewise used when the header is absent or
+every hop in it is a trusted proxy.
+
+Two operator requirements follow:
+
+- Your proxy must **append** the peer address to `X-Forwarded-For`
+  (nginx `$proxy_add_x_forwarded_for`, HAProxy `option forwardfor`,
+  Caddy and AWS ALB by default), and must append a bare address with
+  no port.
+- List proxy hosts **only**. Any address inside `TRUSTED_PROXIES`
+  chooses its own rate-limit key: its `X-Forwarded-For` is walked, so
+  it can name a different address on every request to get a fresh
+  bucket each time, or name another client's address to drain that
+  client's bucket. Never list a block that also covers clients — a
+  broad `10.0.0.0/8` on a network where clients live in the same range
+  makes all three limits, including the unauthenticated webhook
+  receiver, silently bypassable by every client in the block.
+
+Sessions are bounded by two independent clocks, and end at whichever
+one runs out first:
+
+- **Idle expiry** (`SESSION_IDLE_TIMEOUT`, default `24h`) is a sliding
+  window. Every authenticated request pushes it forward, so a session
+  in continuous use never hits it, while an abandoned one expires a day
+  after its last use. Set it to `0` to disable idle expiry entirely;
+  the absolute cap below still applies. A set-but-unparseable value
+  aborts startup rather than silently falling back to the default.
+- **Absolute expiry** is a fixed 7 days from login. Activity does
+  **not** extend it: after a week, every session ends and the user
+  authenticates again.
+
+Only requests that authenticate with the session count as activity, so
+an unauthenticated request carrying the cookie cannot keep a session
+alive. The idle timestamp is rewritten at most once per tenth of the
+idle window rather than on every request, which means a session may
+expire up to 10% early relative to the user's true last request, but
+never late.
+
+#### Invalid values abort startup
+
+The defaults above apply **only** to variables that are unset (or set
+to an empty string). A variable that is set but cannot be parsed is a
+fatal configuration error: webhooker logs the offending variable and
+its value and refuses to start, rather than silently running with a
+substituted default. `PORT=eighty`, `DEBUG=ture`, and
+`RETENTION_SWEEP_INTERVAL=1 hour` all abort startup. `PORT` must
+additionally be a number in the range 1–65535,
+`RECEIVER_RATE_LIMIT` must be at least 1, and every entry in
+`TRUSTED_PROXIES` must be a CIDR block or a bare IP address.
+
+Boolean variables (`DEBUG`, `MAINTENANCE_MODE`) accept exactly the
+spellings Go's `strconv.ParseBool` accepts — `1`, `t`, `T`, `TRUE`,
+`true`, `True`, `0`, `f`, `F`, `FALSE`, `false`, `False` — and nothing
+else. `yes`, `on`, and `off` are rejected rather than quietly treated
+as false.
 
 On first startup, webhooker automatically generates a cryptographically
 secure session encryption key and stores it in the database. This key
@@ -307,13 +396,29 @@ event routing.
 | `user_id`        | UUID    | Foreign key → User |
 | `name`           | string  | Human-readable name |
 | `description`    | string  | Optional description |
-| `retention_days` | integer | Days to retain events (default: 30) |
+| `retention_days` | integer | Days to retain events (default: 30; 0 means retain forever) |
 
 **Relations:** Belongs to User. Has many Entrypoints. Has many Targets.
 
 The `retention_days` field controls how long event data is kept in the
 webhook's dedicated database before automatic cleanup.
 
+Setting `retention_days` to `0` means "retain events forever". Because
+the column carries a default of 30, a literal zero cannot survive an
+insert, so a zero is rewritten on save to a sentinel of `365 * 1000`
+days (`database.RetentionForeverDays`). The retention reaper recognises
+that sentinel and skips the webhook entirely, and the web UI displays
+such a webhook's retention as "forever" rather than as a day count.
+
+A *finite* retention is capped at `database.MaxFiniteRetentionDays`
+(106751 days, about 292 years), and a larger one is rejected with a
+400. The cap is not arbitrary: the reaper computes its cutoff as a
+`time.Duration`, an int64 nanosecond count, and a longer period
+overflows it. An overflowed cutoff lands in the future, where it
+matches every row, so the sweep would delete every event the webhook
+has instead of none. The reaper also clamps the value it is given, so a
+row written by an older version cannot trigger that either.
+
 #### Entrypoint
 
 A receiver URL where external services POST webhook events. Each
@@ -509,7 +614,7 @@ This separation provides:
   DB; the event database file is hard-deleted (permanently removed).
 - **Per-webhook retention** — the `retention_days` field on each webhook
   controls automatic cleanup of old events in that webhook's database
-  only.
+  only, or disables cleanup entirely when set to `0` (retain forever).
 - **Performance** — each webhook's database has its own WAL, its own
   page cache, and its own lock, so concurrent event ingestion across
   webhooks won't contend.
@@ -531,6 +636,36 @@ older than the expiry are pruned each time the archive is (re)opened. An
 archive write failure is never silent success: the delivery records a
 failed attempt with the error and is marked failed.
 
+Because reopens only happen on writes, an archive belonging to a webhook
+that has stopped receiving events would never be pruned. A background
+**archive sweeper** closes that gap: on the same interval as the event
+retention reaper (`RETENTION_SWEEP_INTERVAL`) it prunes every archive
+whose database target declares a positive expiry, whether or not the
+webhook is still receiving traffic. The sweep never creates an archive —
+a webhook whose archive file does not yet exist is skipped, not
+initialised — it takes the same per-webhook lock the write path uses, so
+it can never interleave with a write, and it leaves the archive closed
+afterwards so the move-the-file-away workflow keeps working. Archives
+with no expiry, or the expiry `never`, are not touched by the sweep at
+all.
+
+Note that a webhook has one archive file but may carry more than one
+`database` target, each with its own `expiry`. The shortest expiry
+configured on any of them therefore governs the whole archive, and the
+sweep applies it whether or not the webhook is still receiving events.
+Configure a single `database` target per webhook unless you intend that.
+
+Deleting a webhook releases its archive: the delivery engine's cached
+archive writer is dropped and its file handle closed, so nothing lingers
+after the webhook is gone. The archive **file itself is deliberately
+left on disk**. Unlike the event database — per-webhook working storage
+that is hard-deleted with the webhook — an archive is long-term storage
+an operator may still want to keep or move away for offline retention,
+and destroying it as a side effect of deleting a webhook would be
+unrecoverable. Removing `archive-{webhookID}.db` is the operator's call.
+Deleting a webhook's last `database` target releases the writer the same
+way, and for the same reason leaves the file alone.
+
 The **Slack target type** sends webhook events as formatted messages to
 any Slack-compatible incoming webhook URL (works with Slack, Mattermost,
 and other compatible services). Each message includes event metadata
@@ -636,6 +771,18 @@ This means:
    durable fallback that ensures no retry is permanently lost, even under
    extreme backpressure.
 
+**Changing a target's type does not migrate in-flight deliveries.** Only
+`http` and `slack` targets own durable retries; `database` and `log`
+targets are fire-and-forget and never produce a `retrying` delivery. If a
+target's `type` is edited from a retrying type to a non-retrying (or
+unknown) one while one of its deliveries is still `retrying`, both
+recovery paths above terminally mark that delivery `failed` and record a
+`DeliveryResult` naming the current target type as the reason, logging it
+at warn level. The delivery is not re-dispatched under the new type — the
+operator never asked for that delivery — and the event itself remains
+stored in the per-webhook event database, so it can be redelivered
+manually.
+
 ### Circuit Breaker (HTTP Targets with Retries)
 
 HTTP targets with `max_retries` > 0 are protected by a **per-target circuit breaker** that
@@ -689,17 +836,34 @@ just delayed until the target is healthy again.
 
 ### Rate Limiting
 
-Global rate limiting middleware (e.g., per-IP throttling applied at the
-router level) **must not** apply to webhook receiver endpoints. Webhook
-endpoints receive automated traffic from external services at
-unpredictable rates, and blanket rate limits would cause legitimate
-deliveries to be dropped.
+Global blanket rate limiting middleware (e.g., a per-IP throttle shared
+with the web UI) **must not** apply to webhook receiver endpoints.
+Webhook endpoints receive automated traffic from external services at
+unpredictable rates, and blanket limits shared with other routes would
+cause legitimate deliveries to be dropped.
 
-Instead, each webhook has its own individually configurable rate limit,
-applied within the webhook handler itself. By default, no rate limit is
-applied — webhook endpoints accept traffic as fast as it arrives. Rate
-limits can be configured per-webhook when needed (e.g., to protect
-against a misbehaving sender).
+The receiver instead has its own dedicated abuse limit, scoped to the
+`/webhook/{uuid}` route only and keyed per client IP per entrypoint: one
+misbehaving sender is throttled without affecting other senders of the
+same entrypoint or the same sender's other entrypoints. The limit is
+`RECEIVER_RATE_LIMIT` requests per minute (default 120, generous for
+legitimate webhook senders). Requests over the limit receive HTTP 429
+with a `Retry-After` header. A set-but-invalid `RECEIVER_RATE_LIMIT`
+value aborts startup rather than silently falling back to the default.
+
+Every limiter here — receiver, login, and password change — identifies
+the client the same way, through one shared key function: the
+connection's own address, unless the peer is listed in
+`TRUSTED_PROXIES`, in which case the forwarded client address is used
+instead. See [Trusted proxies](#trusted-proxies). Deployed without that
+variable set, a client behind a reverse proxy shares one bucket with
+every other client behind the same proxy, which is the safe direction
+to be wrong in: set `TRUSTED_PROXIES` to the proxy's address to get
+per-client limits back.
+
+Finer-grained per-webhook rate limits (configured in the web UI and
+enforced in the webhook handler) can layer on top of this env-level
+abuse limit later; they are tracked as future work.
 
 ### API Endpoints
 
@@ -867,9 +1031,17 @@ Applied to all routes in this order:
 8. **Sentry** — Error reporting to Sentry (if `SENTRY_DSN` is set;
    configured with `Repanic: true` so panics still reach Recoverer)
 
-Additionally, form endpoints (`/pages`, `/sources`, `/source/*`) apply a
-**MaxBodySize** middleware that limits POST/PUT/PATCH request bodies to
-1 MB using `http.MaxBytesReader`, preventing oversized form submissions.
+Additionally, form endpoints (`/pages`, `/user/*`, `/sources`,
+`/source/*`) apply a **MaxBodySize** middleware that limits
+POST/PUT/PATCH request bodies to 1 MB. It is registered ahead of the
+CSRF middleware in every one of those route groups, because
+gorilla/csrf parses the form; if the cap were installed after it, form
+parsing would run under net/http's 10 MB default and the 1 MB limit
+would never apply. A request that declares a `Content-Length` over the
+limit is answered with `413 Request Entity Too Large` before any other
+middleware or handler runs; a chunked request, or one that lies about
+its length, is hard-capped by `http.MaxBytesReader` and fails
+downstream at form-parse time.
 
 ### Authentication
 
@@ -891,7 +1063,8 @@ Additionally, form endpoints (`/pages`, `/sources`, `/source/*`) apply a
 - Production security headers on all responses: HSTS, X-Content-Type-Options
   (`nosniff`), X-Frame-Options (`DENY`), Content-Security-Policy, Referrer-Policy,
   and Permissions-Policy
-- Request body size limits (1 MB) on all form POST endpoints
+- Request body size limits (1 MB) on all form POST endpoints, enforced
+  by middleware that runs before CSRF parses the form
 - **CSRF protection** via [gorilla/csrf](https://github.com/gorilla/csrf)
   on all state-changing forms (cookie-based double-submit tokens with
   HMAC authentication). Applied to `/pages`, `/sources`, `/source`, and

TODO.md

@@ -10,24 +10,52 @@
 
 # Status
 
-pre-1.0. No git tags exist. main (afe88c6) is a working webhook proxy
+pre-1.0. No git tags exist. main (4f5ecb1) is a working webhook proxy
 with auth, CSRF/SSRF protections, login rate limiting, Slack target,
-policy compliance (#6), and pinned lint tooling (#55). Note: TODO.md was
+event retention (#63), the database archiving target (#43), the admin
+password change flow (#65), policy compliance (#6), pinned lint tooling
+(#55), and fail-loud configuration parsing (#80). Note: TODO.md was
 deliberately deleted from this repo in f9a9569 (2026-03-01, #6); its
 content was folded into the README TODO section, which this draft
 reconstructs as of 2026-07-06.
 
 # Next Step
 
-Implement automatic event retention cleanup based on retention_days: a
-periodic maintenance job that deletes Events, Deliveries, and
-DeliveryResults older than the parent webhook's retention_days from each
-per-webhook event database. The field exists on the Webhook model and
-the README promises the behavior, but nothing enforces it, so event
-databases currently grow without bound.
+Manual event redelivery from the web UI (replay is a core promised
+capability in the README rationale).
 
 # Completed Steps
 
+- 2026-08-11 Web UI cleanup: nav terminology unified on Webhooks, the
+  Profile settings placeholder removed, a progressive-enhancement copy
+  button for the entrypoint URL, and retention form copy that states the
+  actual policy (deletion by the reaper, 0 retains forever) (#57)
+- 2026-08-09 Inactivity-based session timeout: sliding idle expiry
+  (`SESSION_IDLE_TIMEOUT`, default `24h`) refreshed on authenticated
+  requests, with the 7-day absolute cap kept as an independent
+  backstop that activity never extends (#66)
+- 2026-08-09 Restart recovery and the 60s retry sweep terminally fail an
+  orphaned `retrying` delivery whose target type no longer supports
+  retries, recording a `DeliveryResult` with the reason instead of
+  leaving the delivery stuck forever (#82)
+- 2026-08-09 Root the delivery engine's worker pool and the retention
+  reaper's sweep loop at `context.Background()` rather than the fx
+  `OnStart` hook context (#97), which carries fx's 15s start timeout and
+  killed both roughly fifteen seconds after boot: the proxy silently
+  stopped delivering webhooks entirely, and the reaper never ran a
+  single sweep under its default one-hour interval
+- 2026-08-09 Archive writer lifecycle (#89): deleting a webhook (or its
+  last `database` target) evicts the cached archive writer and closes
+  its handle while deliberately leaving `archive-{webhookID}.db` on
+  disk, and a new `ArchiveSweeper` prunes idle archives on the existing
+  `RETENTION_SWEEP_INTERVAL` without ever creating an archive file
+- 2026-08-09 Configuration parsing fails loudly on set-but-unparseable
+  environment values: `envInt` removed in favour of `envPositiveInt`
+  plus a `PORT` range check, `envBool` now parses with
+  `strconv.ParseBool`, and defaults apply only to unset variables (#80)
+- 2026-08-07 Automatic event retention cleanup based on
+  `retention_days`, deleting expired events, deliveries, and delivery
+  results from each per-webhook event database (#63)
 - 2026-08-07 Update golangci-lint to v2.12.2 (Docker image digest in
   `Dockerfile`, release-archive sha256 pins in `script/bootstrap`),
   adopt the canonical `.golangci.yml` (v2 `linters.settings` layout so
@@ -56,8 +84,6 @@ databases currently grow without bound.
 
 # Future Steps
 
-- Manual event redelivery from the web UI (replay is a core promised
-  capability in the README rationale)
 - Delivery status and retry management UI
 - Per-webhook rate limiting in the receiver handler (per-webhook config
   plus handler enforcement; global limits must not apply to receiver
@@ -71,7 +97,7 @@ databases currently grow without bound.
     - event redelivery endpoint
     - OpenAPI specification
 - Analytics dashboard: success rates, response times, volume
-- Session expiration tuning and a remember-me option
+- A remember-me option at login
 - Password change and reset flow
 - Later, nice to have
     - email delivery target type

cmd/webhooker/main.go

@@ -40,9 +40,15 @@ func main() {
 			handlers.New,
 			middleware.New,
 			delivery.New,
+			delivery.NewArchiveSweeper,
 			// Wire *delivery.Engine as delivery.Notifier so the
 			// webhook handler can notify the engine of new deliveries.
 			func(e *delivery.Engine) delivery.Notifier { return e },
+			// Wire *delivery.Engine as delivery.WebhookEvictor so
+			// deleting a webhook releases its archive writer.
+			func(e *delivery.Engine) delivery.WebhookEvictor {
+				return e
+			},
 			server.New,
 		),
 		fx.Invoke(
@@ -50,6 +56,7 @@ func main() {
 				*server.Server,
 				*delivery.Engine,
 				*database.RetentionReaper,
+				*delivery.ArchiveSweeper,
 			) {
 			},
 		),

internal/config/config.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"log/slog"
+	"net/netip"
 	"os"
 	"strconv"
 	"strings"
@@ -31,12 +32,45 @@ const (
 	// defaultRetentionSweepInterval is how often the retention
 	// reaper deletes events older than each webhook's RetentionDays.
 	defaultRetentionSweepInterval = time.Hour
+
+	// defaultSessionIdleTimeout is how long a session may go without
+	// authenticated activity before it expires.
+	defaultSessionIdleTimeout = 24 * time.Hour
+
+	// defaultReceiverRateLimit is the default number of requests
+	// per minute each client IP may send to a single webhook
+	// receiver entrypoint. Generous for legitimate webhook
+	// senders while bounding abuse of the one unauthenticated,
+	// internet-exposed endpoint.
+	defaultReceiverRateLimit = 120
+
+	// maxPort is the highest valid TCP port number. The lower
+	// bound (at least 1) is enforced by envPositiveInt.
+	maxPort = 65535
+
+	// mappedV4Offset is the number of leading bits an IPv4-mapped
+	// IPv6 prefix spends on the ::ffff:0:0/96 wrapper, so a /104
+	// covers the same addresses as an IPv4 /8.
+	mappedV4Offset = 96
 )
 
 // ErrInvalidEnvironment is returned when WEBHOOKER_ENVIRONMENT
 // contains an unrecognised value.
 var ErrInvalidEnvironment = errors.New("invalid environment")
 
+// ErrNonPositiveValue is returned when an environment variable that
+// requires a positive integer is set to zero or a negative number.
+var ErrNonPositiveValue = errors.New("value must be positive")
+
+// ErrInvalidPort is returned when an environment variable holding a
+// TCP port number is set above the valid port range.
+var ErrInvalidPort = errors.New("invalid port")
+
+// ErrInvalidCIDR is returned when an environment variable holding a
+// list of CIDR blocks contains an entry that is neither a CIDR block
+// nor a bare IP address.
+var ErrInvalidCIDR = errors.New("invalid CIDR")
+
 //nolint:revive // ConfigParams is a standard fx naming convention.
 type ConfigParams struct {
 	fx.In
@@ -60,6 +94,25 @@ type Config struct {
 	// RetentionSweepInterval is how often the retention reaper runs.
 	RetentionSweepInterval time.Duration
 
+	// SessionIdleTimeout is the sliding inactivity window after
+	// which a session expires. Non-positive disables idle expiry.
+	SessionIdleTimeout time.Duration
+
+	// ReceiverRateLimit is the number of requests per minute each
+	// client IP may send to a single webhook receiver entrypoint.
+	ReceiverRateLimit int
+
+	// TrustedProxies is the set of networks whose members are
+	// allowed to speak for the client with X-Forwarded-For, the
+	// only forwarded header read. It is empty unless
+	// TRUSTED_PROXIES is set, and empty means no peer is
+	// trusted: forwarded headers are then ignored entirely and
+	// clients are identified by the connection's own address.
+	// Members can choose their own rate-limit key, so this must
+	// name proxy hosts only, never a block that also covers
+	// clients.
+	TrustedProxies []netip.Prefix
+
 	params *ConfigParams
 	log    *slog.Logger
 }
@@ -81,27 +134,81 @@ func envString(key string) string {
 }
 
 // envBool returns the value of the named environment variable
-// parsed as a boolean. Returns defaultValue if not set.
-func envBool(key string, defaultValue bool) bool {
-	if v := os.Getenv(key); v != "" {
-		return strings.EqualFold(v, "true") || v == "1"
+// parsed as a boolean. Returns defaultValue if not set. If the
+// variable is set but cannot be parsed, it returns a wrapped error
+// naming the key and the bad value, so startup fails loudly rather
+// than silently falling back to the default.
+//
+// Parsing is strconv.ParseBool, which accepts 1, t, T, TRUE, true,
+// True, 0, f, F, FALSE, false and False. Anything else — "yes",
+// "on", or a typo like "ture" — is an error rather than a silent
+// false.
+func envBool(key string, defaultValue bool) (bool, error) {
+	v := os.Getenv(key)
+	if v == "" {
+		return defaultValue, nil
 	}
 
-	return defaultValue
+	b, err := strconv.ParseBool(v)
+	if err != nil {
+		return false, fmt.Errorf(
+			"invalid boolean for %s: %q: %w", key, v, err,
+		)
+	}
+
+	return b, nil
 }
 
-// envInt returns the value of the named environment variable
-// parsed as an integer. Returns defaultValue if not set or
-// unparseable.
-func envInt(key string, defaultValue int) int {
-	if v := os.Getenv(key); v != "" {
-		i, err := strconv.Atoi(v)
-		if err == nil {
-			return i
-		}
+// envPositiveInt returns the value of the named environment variable
+// parsed as a positive integer. Returns defaultValue if not set. If
+// the variable is set but cannot be parsed, or parses to less than
+// one, it returns a wrapped error naming the key and the bad value,
+// so startup fails loudly rather than silently falling back to the
+// default.
+func envPositiveInt(
+	key string,
+	defaultValue int,
+) (int, error) {
+	v := os.Getenv(key)
+	if v == "" {
+		return defaultValue, nil
 	}
 
-	return defaultValue
+	i, err := strconv.Atoi(v)
+	if err != nil {
+		return 0, fmt.Errorf(
+			"invalid integer for %s: %q: %w", key, v, err,
+		)
+	}
+
+	if i < 1 {
+		return 0, fmt.Errorf(
+			"%w: %s must be at least 1, got %q",
+			ErrNonPositiveValue, key, v,
+		)
+	}
+
+	return i, nil
+}
+
+// envPort returns the value of the named environment variable parsed
+// as a TCP port number. Returns defaultValue if not set. A set value
+// that is unparseable, below 1, or above maxPort is a hard error
+// naming the key and the bad value.
+func envPort(key string, defaultValue int) (int, error) {
+	port, err := envPositiveInt(key, defaultValue)
+	if err != nil {
+		return 0, err
+	}
+
+	if port > maxPort {
+		return 0, fmt.Errorf(
+			"%w: %s must be at most %d, got %d",
+			ErrInvalidPort, key, maxPort, port,
+		)
+	}
+
+	return port, nil
 }
 
 // envDuration returns the value of the named environment variable
@@ -128,32 +235,117 @@ func envDuration(
 	return d, nil
 }
 
-// New creates a Config by reading environment variables.
+// parseCIDR parses one trusted-proxy list entry, which may be a
+// CIDR block ("10.0.0.0/8") or a bare address ("10.0.0.1", treated
+// as a single-host block).
 //
-//nolint:revive // lc parameter is required by fx even if unused.
-func New(lc fx.Lifecycle, params ConfigParams) (*Config, error) {
-	log := params.Logger.Get()
+// Both forms are unmapped, because peer addresses are unmapped
+// before they are matched against the list: an IPv4-mapped prefix
+// left in that form would silently never match.
+func parseCIDR(entry string) (netip.Prefix, error) {
+	if strings.Contains(entry, "/") {
+		prefix, err := netip.ParsePrefix(entry)
+		if err != nil {
+			return netip.Prefix{}, err //nolint:wrapcheck // wrapped by caller
+		}
 
-	// Determine environment from WEBHOOKER_ENVIRONMENT env var,
-	// default to dev
+		if addr := prefix.Addr(); addr.Is4In6() &&
+			prefix.Bits() >= mappedV4Offset {
+			prefix = netip.PrefixFrom(
+				addr.Unmap(), prefix.Bits()-mappedV4Offset,
+			)
+		}
+
+		return prefix.Masked(), nil
+	}
+
+	addr, err := netip.ParseAddr(entry)
+	if err != nil {
+		return netip.Prefix{}, err //nolint:wrapcheck // wrapped by caller
+	}
+
+	return netip.PrefixFrom(addr.Unmap(), addr.Unmap().BitLen()), nil
+}
+
+// envPrefixList returns the value of the named environment variable
+// parsed as a comma-separated list of CIDR blocks (bare addresses
+// allowed). An unset, empty, or blank value yields an empty list. A
+// set value containing an unparseable entry is a hard error naming
+// the key and the bad entry, so startup fails loudly rather than
+// silently running with a list the operator did not intend.
+func envPrefixList(key string) ([]netip.Prefix, error) {
+	v := strings.TrimSpace(os.Getenv(key))
+	if v == "" {
+		return nil, nil
+	}
+
+	var prefixes []netip.Prefix
+
+	for entry := range strings.SplitSeq(v, ",") {
+		entry = strings.TrimSpace(entry)
+		if entry == "" {
+			continue
+		}
+
+		prefix, err := parseCIDR(entry)
+		if err != nil {
+			return nil, fmt.Errorf(
+				"%w: %s: %q: %w", ErrInvalidCIDR, key, entry, err,
+			)
+		}
+
+		prefixes = append(prefixes, prefix)
+	}
+
+	return prefixes, nil
+}
+
+// resolveEnvironment reads WEBHOOKER_ENVIRONMENT, defaulting to
+// dev, and rejects unrecognised values.
+func resolveEnvironment() (string, error) {
 	environment := os.Getenv("WEBHOOKER_ENVIRONMENT")
 	if environment == "" {
 		environment = EnvironmentDev
 	}
 
-	// Validate environment
 	if environment != EnvironmentDev &&
 		environment != EnvironmentProd {
-		return nil, fmt.Errorf(
+		return "", fmt.Errorf(
 			"%w: WEBHOOKER_ENVIRONMENT must be '%s' or '%s', got '%s'",
 			ErrInvalidEnvironment,
 			EnvironmentDev, EnvironmentProd, environment,
 		)
 	}
 
-	// Parse the retention sweep interval; a set-but-unparseable value
-	// is a hard error so fx aborts startup rather than silently using
-	// the default.
+	return environment, nil
+}
+
+// loadFromEnv builds a Config from the environment. Every value that
+// needs parsing fails loudly when it is set but unparseable: the
+// documented defaults apply only to variables that are unset (or
+// empty), never as a substitute for a value the operator actually
+// provided.
+func loadFromEnv() (*Config, error) {
+	environment, err := resolveEnvironment()
+	if err != nil {
+		return nil, err
+	}
+
+	port, err := envPort("PORT", defaultPort)
+	if err != nil {
+		return nil, err
+	}
+
+	debug, err := envBool("DEBUG", false)
+	if err != nil {
+		return nil, err
+	}
+
+	maintenanceMode, err := envBool("MAINTENANCE_MODE", false)
+	if err != nil {
+		return nil, err
+	}
+
 	retentionSweepInterval, err := envDuration(
 		"RETENTION_SWEEP_INTERVAL",
 		defaultRetentionSweepInterval,
@@ -162,21 +354,60 @@ func New(lc fx.Lifecycle, params ConfigParams) (*Config, error) {
 		return nil, err
 	}
 
-	// Load configuration values from environment variables
-	s := &Config{
+	sessionIdleTimeout, err := envDuration(
+		"SESSION_IDLE_TIMEOUT",
+		defaultSessionIdleTimeout,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	receiverRateLimit, err := envPositiveInt(
+		"RECEIVER_RATE_LIMIT",
+		defaultReceiverRateLimit,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	trustedProxies, err := envPrefixList("TRUSTED_PROXIES")
+	if err != nil {
+		return nil, err
+	}
+
+	return &Config{
 		DataDir:                envString("DATA_DIR"),
-		Debug:                  envBool("DEBUG", false),
-		MaintenanceMode:        envBool("MAINTENANCE_MODE", false),
+		Debug:                  debug,
+		MaintenanceMode:        maintenanceMode,
 		Environment:            environment,
 		MetricsUsername:        envString("METRICS_USERNAME"),
 		MetricsPassword:        envString("METRICS_PASSWORD"),
-		Port:                   envInt("PORT", defaultPort),
+		Port:                   port,
 		SentryDSN:              envString("SENTRY_DSN"),
 		RetentionSweepInterval: retentionSweepInterval,
-		log:                    log,
-		params:                 &params,
+		SessionIdleTimeout:     sessionIdleTimeout,
+		ReceiverRateLimit:      receiverRateLimit,
+		TrustedProxies:         trustedProxies,
+	}, nil
+}
+
+// New creates a Config by reading environment variables.
+//
+//nolint:revive // lc parameter is required by fx even if unused.
+func New(lc fx.Lifecycle, params ConfigParams) (*Config, error) {
+	log := params.Logger.Get()
+
+	// A set-but-unparseable value anywhere in the environment is a
+	// hard error, so fx aborts startup rather than running with a
+	// silently substituted default.
+	s, err := loadFromEnv()
+	if err != nil {
+		return nil, err
 	}
 
+	s.log = log
+	s.params = &params
+
 	// Set default DataDir. All SQLite databases (main application
 	// DB and per-webhook event DBs) live here. The same default is
 	// used regardless of environment; override with DATA_DIR if
@@ -197,6 +428,8 @@ func New(lc fx.Lifecycle, params ConfigParams) (*Config, error) {
 		"maintenanceMode", s.MaintenanceMode,
 		"dataDir", s.DataDir,
 		"retentionSweepInterval", s.RetentionSweepInterval.String(),
+		"receiverRateLimit", s.ReceiverRateLimit,
+		"trustedProxies", len(s.TrustedProxies),
 		"hasSentryDSN", s.SentryDSN != "",
 		"hasMetricsAuth",
 		s.MetricsUsername != "" && s.MetricsPassword != "",

internal/config/config_test.go

@@ -14,6 +14,18 @@ import (
 	"sneak.berlin/go/webhooker/internal/logger"
 )
 
+// Shared subtest names for the env-parsing tables below, which all
+// exercise the same three cases against different variables.
+const (
+	caseUnsetUsesDefault = "unset uses default"
+	caseValidValueParsed = "valid value is parsed"
+	caseUnparseableFails = "unparseable value fails startup"
+
+	// cidrPrivateV4 is the sample trusted-proxy block the
+	// TRUSTED_PROXIES cases are built from.
+	cidrPrivateV4 = "10.0.0.0/8"
+)
+
 func TestEnvironmentConfig(t *testing.T) {
 	tests := []struct {
 		name        string
@@ -130,18 +142,18 @@ func TestRetentionSweepInterval(t *testing.T) {
 		expected    time.Duration
 	}{
 		{
-			name:     "unset uses default",
+			name:     caseUnsetUsesDefault,
 			set:      false,
 			expected: time.Hour,
 		},
 		{
-			name:     "valid value is parsed",
+			name:     caseValidValueParsed,
 			set:      true,
 			value:    "15m",
 			expected: 15 * time.Minute,
 		},
 		{
-			name:        "unparseable value fails startup",
+			name:        caseUnparseableFails,
 			set:         true,
 			value:       "not-a-duration",
 			expectError: true,
@@ -163,7 +175,7 @@ func TestRetentionSweepInterval(t *testing.T) {
 			}
 
 			if tt.expectError {
-				testRetentionSweepIntervalError(t)
+				expectStartupError(t)
 			} else {
 				testRetentionSweepIntervalSuccess(t, tt.expected)
 			}
@@ -171,7 +183,10 @@ func TestRetentionSweepInterval(t *testing.T) {
 	}
 }
 
-func testRetentionSweepIntervalError(t *testing.T) {
+// startupError builds the app config.New belongs to and returns
+// the error fx reports, which is non-nil whenever an environment
+// value is set but invalid.
+func startupError(t *testing.T) error {
 	t.Helper()
 
 	var cfg *config.Config
@@ -186,7 +201,33 @@ func testRetentionSweepIntervalError(t *testing.T) {
 		fx.Populate(&cfg),
 	)
 
-	assert.Error(t, app.Err())
+	return app.Err()
+}
+
+// expectStartupError asserts that fx refuses to build the app,
+// which is what a set-but-invalid environment value must cause.
+func expectStartupError(t *testing.T) {
+	t.Helper()
+
+	assert.Error(t, startupError(t))
+}
+
+// expectStartupErrorFor asserts that startup fails, that the error
+// names the offending variable so an operator can find it, and,
+// when sentinel is non-nil, that it wraps that sentinel.
+func expectStartupErrorFor(
+	t *testing.T,
+	key string,
+	sentinel error,
+) {
+	t.Helper()
+
+	err := startupError(t)
+	require.ErrorContains(t, err, key)
+
+	if sentinel != nil {
+		require.ErrorIs(t, err, sentinel)
+	}
 }
 
 func testRetentionSweepIntervalSuccess(
@@ -215,6 +256,82 @@ func testRetentionSweepIntervalSuccess(
 	assert.Equal(t, expected, cfg.RetentionSweepInterval)
 }
 
+func TestSessionIdleTimeout(t *testing.T) {
+	tests := []struct {
+		name        string
+		set         bool
+		value       string
+		expectError bool
+		expected    time.Duration
+	}{
+		{
+			name:     caseUnsetUsesDefault,
+			set:      false,
+			expected: 24 * time.Hour,
+		},
+		{
+			name:     caseValidValueParsed,
+			set:      true,
+			value:    "30m",
+			expected: 30 * time.Minute,
+		},
+		{
+			name:        caseUnparseableFails,
+			set:         true,
+			value:       "not-a-duration",
+			expectError: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Cannot use t.Parallel() here because t.Setenv
+			// is incompatible with parallel subtests.
+			t.Setenv("WEBHOOKER_ENVIRONMENT", "dev")
+
+			if tt.set {
+				t.Setenv("SESSION_IDLE_TIMEOUT", tt.value)
+			} else {
+				require.NoError(t, os.Unsetenv(
+					"SESSION_IDLE_TIMEOUT",
+				))
+			}
+
+			if tt.expectError {
+				expectStartupError(t)
+			} else {
+				testSessionIdleTimeoutSuccess(t, tt.expected)
+			}
+		})
+	}
+}
+
+func testSessionIdleTimeoutSuccess(
+	t *testing.T,
+	expected time.Duration,
+) {
+	t.Helper()
+
+	var cfg *config.Config
+
+	app := fxtest.New(
+		t,
+		fx.Provide(
+			globals.New,
+			logger.New,
+			config.New,
+		),
+		fx.Populate(&cfg),
+	)
+	require.NoError(t, app.Err())
+
+	app.RequireStart()
+
+	defer app.RequireStop()
+
+	assert.Equal(t, expected, cfg.SessionIdleTimeout)
+}
+
 func TestDefaultDataDir(t *testing.T) {
 	for _, env := range []string{"", "dev", "prod"} {
 		name := env
@@ -258,3 +375,212 @@ func TestDefaultDataDir(t *testing.T) {
 		})
 	}
 }
+
+func TestReceiverRateLimit(t *testing.T) {
+	tests := []struct {
+		name        string
+		set         bool
+		value       string
+		expectError bool
+		// sentinel, when set, must be wrapped by the startup
+		// error; every error case must additionally name the
+		// variable in its message.
+		sentinel error
+		expected int
+	}{
+		{
+			name:     caseUnsetUsesDefault,
+			set:      false,
+			expected: 120,
+		},
+		{
+			name:     caseValidValueParsed,
+			set:      true,
+			value:    "30",
+			expected: 30,
+		},
+		{
+			name:        caseUnparseableFails,
+			set:         true,
+			value:       "not-a-number",
+			expectError: true,
+		},
+		{
+			name:        "zero fails startup",
+			set:         true,
+			value:       "0",
+			expectError: true,
+			sentinel:    config.ErrNonPositiveValue,
+		},
+		{
+			name:        "negative fails startup",
+			set:         true,
+			value:       "-5",
+			expectError: true,
+			sentinel:    config.ErrNonPositiveValue,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Cannot use t.Parallel() here because t.Setenv
+			// is incompatible with parallel subtests.
+			t.Setenv("WEBHOOKER_ENVIRONMENT", "dev")
+
+			if tt.set {
+				t.Setenv("RECEIVER_RATE_LIMIT", tt.value)
+			} else {
+				require.NoError(t, os.Unsetenv(
+					"RECEIVER_RATE_LIMIT",
+				))
+			}
+
+			if tt.expectError {
+				expectStartupErrorFor(
+					t, "RECEIVER_RATE_LIMIT", tt.sentinel,
+				)
+			} else {
+				testReceiverRateLimitSuccess(t, tt.expected)
+			}
+		})
+	}
+}
+
+func testReceiverRateLimitSuccess(
+	t *testing.T,
+	expected int,
+) {
+	t.Helper()
+
+	var cfg *config.Config
+
+	app := fxtest.New(
+		t,
+		fx.Provide(
+			globals.New,
+			logger.New,
+			config.New,
+		),
+		fx.Populate(&cfg),
+	)
+	require.NoError(t, app.Err())
+
+	app.RequireStart()
+
+	defer app.RequireStop()
+
+	assert.Equal(t, expected, cfg.ReceiverRateLimit)
+}
+
+func TestTrustedProxies(t *testing.T) {
+	tests := []struct {
+		name        string
+		set         bool
+		value       string
+		expectError bool
+		expected    []string
+	}{
+		{
+			// The default must be "trust nobody": an empty list
+			// means forwarded headers are ignored, never that
+			// every peer may speak for the client.
+			name:     caseUnsetUsesDefault,
+			set:      false,
+			expected: []string{},
+		},
+		{
+			name:     "blank value trusts nothing",
+			set:      true,
+			value:    "  ",
+			expected: []string{},
+		},
+		{
+			name:  caseValidValueParsed,
+			set:   true,
+			value: cidrPrivateV4 + ", 192.168.1.7 ,2001:db8::/32",
+			expected: []string{
+				cidrPrivateV4, "192.168.1.7/32", "2001:db8::/32",
+			},
+		},
+		{
+			name:     "host bits are masked off",
+			set:      true,
+			value:    "10.1.2.3/8",
+			expected: []string{cidrPrivateV4},
+		},
+		{
+			// Peer addresses are unmapped before they are
+			// matched, so an IPv4-mapped prefix kept in that
+			// form could never match anything.
+			name:     "IPv4-mapped prefix is unmapped",
+			set:      true,
+			value:    "::ffff:10.0.0.0/104",
+			expected: []string{cidrPrivateV4},
+		},
+		{
+			name:        caseUnparseableFails,
+			set:         true,
+			value:       cidrPrivateV4 + ",not-an-address",
+			expectError: true,
+		},
+		{
+			name:        "out-of-range prefix length fails startup",
+			set:         true,
+			value:       "10.0.0.0/33",
+			expectError: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Cannot use t.Parallel() here because t.Setenv
+			// is incompatible with parallel subtests.
+			t.Setenv("WEBHOOKER_ENVIRONMENT", "dev")
+
+			if tt.set {
+				t.Setenv("TRUSTED_PROXIES", tt.value)
+			} else {
+				require.NoError(t, os.Unsetenv("TRUSTED_PROXIES"))
+			}
+
+			if tt.expectError {
+				expectStartupErrorFor(
+					t, "TRUSTED_PROXIES", config.ErrInvalidCIDR,
+				)
+			} else {
+				testTrustedProxiesSuccess(t, tt.expected)
+			}
+		})
+	}
+}
+
+func testTrustedProxiesSuccess(
+	t *testing.T,
+	expected []string,
+) {
+	t.Helper()
+
+	var cfg *config.Config
+
+	app := fxtest.New(
+		t,
+		fx.Provide(
+			globals.New,
+			logger.New,
+			config.New,
+		),
+		fx.Populate(&cfg),
+	)
+	require.NoError(t, app.Err())
+
+	app.RequireStart()
+
+	defer app.RequireStop()
+
+	got := make([]string, 0, len(cfg.TrustedProxies))
+	for _, prefix := range cfg.TrustedProxies {
+		got = append(got, prefix.String())
+	}
+
+	assert.Equal(t, expected, got)
+}

internal/config/env_test.go

@@ -0,0 +1,409 @@
+package config_test
+
+import (
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/fx"
+	"sneak.berlin/go/webhooker/internal/config"
+	"sneak.berlin/go/webhooker/internal/globals"
+	"sneak.berlin/go/webhooker/internal/logger"
+)
+
+// testEnvKey is a throwaway variable name used only by the helper
+// tables below, so they cannot disturb real configuration.
+const testEnvKey = "WEBHOOKER_TEST_VALUE"
+
+// Real configuration variables exercised by the config.New tests.
+const (
+	envKeyPort            = "PORT"
+	envKeyDebug           = "DEBUG"
+	envKeyMaintenanceMode = "MAINTENANCE_MODE"
+)
+
+// envBoolCase is one row of the envBool table.
+type envBoolCase struct {
+	name         string
+	set          bool
+	value        string
+	defaultValue bool
+	expectError  bool
+	expected     bool
+}
+
+// envBoolCases is the envBool table, kept out of the test body so
+// the test itself stays readable.
+func envBoolCases() []envBoolCase {
+	return []envBoolCase{
+		{
+			name:         "unset uses default false",
+			defaultValue: false,
+			expected:     false,
+		},
+		{
+			name:         "unset uses default true",
+			defaultValue: true,
+			expected:     true,
+		},
+		{
+			name:         "empty uses default true",
+			set:          true,
+			value:        "",
+			defaultValue: true,
+			expected:     true,
+		},
+		{
+			name:     "true is parsed",
+			set:      true,
+			value:    "true",
+			expected: true,
+		},
+		{
+			name:     "one is parsed",
+			set:      true,
+			value:    "1",
+			expected: true,
+		},
+		{
+			name:         "False is parsed",
+			set:          true,
+			value:        "False",
+			defaultValue: true,
+			expected:     false,
+		},
+		{
+			name:         "zero is parsed",
+			set:          true,
+			value:        "0",
+			defaultValue: true,
+			expected:     false,
+		},
+		{
+			name:        "yes is rejected",
+			set:         true,
+			value:       "yes",
+			expectError: true,
+		},
+		{
+			name:        "on is rejected",
+			set:         true,
+			value:       "on",
+			expectError: true,
+		},
+		{
+			name:        "typo is rejected",
+			set:         true,
+			value:       "ture",
+			expectError: true,
+		},
+	}
+}
+
+func TestEnvBool(t *testing.T) {
+	for _, tt := range envBoolCases() {
+		t.Run(tt.name, func(t *testing.T) {
+			// Cannot use t.Parallel() here because t.Setenv
+			// is incompatible with parallel subtests.
+			if tt.set {
+				t.Setenv(testEnvKey, tt.value)
+			} else {
+				require.NoError(t, os.Unsetenv(testEnvKey))
+			}
+
+			got, err := config.EnvBoolForTest(
+				testEnvKey, tt.defaultValue,
+			)
+
+			if tt.expectError {
+				require.Error(t, err)
+				assert.Contains(t, err.Error(), testEnvKey)
+				assert.Contains(t, err.Error(), tt.value)
+
+				return
+			}
+
+			require.NoError(t, err)
+			assert.Equal(t, tt.expected, got)
+		})
+	}
+}
+
+func TestEnvPositiveInt(t *testing.T) {
+	const defaultValue = 7
+
+	tests := []struct {
+		name        string
+		set         bool
+		value       string
+		expectError bool
+		errIs       error
+		expected    int
+	}{
+		{
+			name:     "unset returns the default integer",
+			expected: defaultValue,
+		},
+		{
+			name:     "empty returns the default integer",
+			set:      true,
+			value:    "",
+			expected: defaultValue,
+		},
+		{
+			name:     "positive value is parsed",
+			set:      true,
+			value:    "42",
+			expected: 42,
+		},
+		{
+			name:        "unparseable value is rejected",
+			set:         true,
+			value:       "not-a-number",
+			expectError: true,
+		},
+		{
+			name:        "zero is rejected",
+			set:         true,
+			value:       "0",
+			expectError: true,
+			errIs:       config.ErrNonPositiveValue,
+		},
+		{
+			name:        "negative is rejected",
+			set:         true,
+			value:       "-5",
+			expectError: true,
+			errIs:       config.ErrNonPositiveValue,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Cannot use t.Parallel() here because t.Setenv
+			// is incompatible with parallel subtests.
+			if tt.set {
+				t.Setenv(testEnvKey, tt.value)
+			} else {
+				require.NoError(t, os.Unsetenv(testEnvKey))
+			}
+
+			got, err := config.EnvPositiveIntForTest(
+				testEnvKey, defaultValue,
+			)
+
+			if tt.expectError {
+				require.Error(t, err)
+				assert.Contains(t, err.Error(), testEnvKey)
+				assert.Contains(t, err.Error(), tt.value)
+
+				if tt.errIs != nil {
+					require.ErrorIs(t, err, tt.errIs)
+				}
+
+				return
+			}
+
+			require.NoError(t, err)
+			assert.Equal(t, tt.expected, got)
+		})
+	}
+}
+
+func TestEnvPort(t *testing.T) {
+	const defaultValue = 8080
+
+	tests := []struct {
+		name        string
+		set         bool
+		value       string
+		expectError bool
+		errIs       error
+		expected    int
+	}{
+		{
+			name:     "unset returns the default port",
+			expected: defaultValue,
+		},
+		{
+			name:     "valid port is parsed",
+			set:      true,
+			value:    "9000",
+			expected: 9000,
+		},
+		{
+			name:     "highest port is accepted",
+			set:      true,
+			value:    "65535",
+			expected: 65535,
+		},
+		{
+			name:        "unparseable value is rejected",
+			set:         true,
+			value:       "not-a-port",
+			expectError: true,
+		},
+		{
+			name:        "zero is rejected",
+			set:         true,
+			value:       "0",
+			expectError: true,
+			errIs:       config.ErrNonPositiveValue,
+		},
+		{
+			name:        "above the port range is rejected",
+			set:         true,
+			value:       "65536",
+			expectError: true,
+			errIs:       config.ErrInvalidPort,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Cannot use t.Parallel() here because t.Setenv
+			// is incompatible with parallel subtests.
+			if tt.set {
+				t.Setenv(testEnvKey, tt.value)
+			} else {
+				require.NoError(t, os.Unsetenv(testEnvKey))
+			}
+
+			got, err := config.EnvPortForTest(
+				testEnvKey, defaultValue,
+			)
+
+			if tt.expectError {
+				require.Error(t, err)
+				assert.Contains(t, err.Error(), testEnvKey)
+
+				if tt.errIs != nil {
+					require.ErrorIs(t, err, tt.errIs)
+				}
+
+				return
+			}
+
+			require.NoError(t, err)
+			assert.Equal(t, tt.expected, got)
+		})
+	}
+}
+
+// buildConfig constructs a Config through fx exactly as the
+// application does, returning the config and any construction error.
+func buildConfig(t *testing.T) (*config.Config, error) {
+	t.Helper()
+
+	var cfg *config.Config
+
+	app := fx.New(
+		fx.NopLogger,
+		fx.Provide(
+			globals.New,
+			logger.New,
+			config.New,
+		),
+		fx.Populate(&cfg),
+	)
+
+	return cfg, app.Err()
+}
+
+func TestNewRejectsBadEnvValues(t *testing.T) {
+	tests := []struct {
+		name        string
+		key         string
+		value       string
+		expectError bool
+		check       func(t *testing.T, cfg *config.Config)
+	}{
+		{
+			name:  "valid PORT is used",
+			key:   envKeyPort,
+			value: "9001",
+			check: func(t *testing.T, cfg *config.Config) {
+				t.Helper()
+				assert.Equal(t, 9001, cfg.Port)
+			},
+		},
+		{
+			name:        "unparseable PORT aborts startup",
+			key:         envKeyPort,
+			value:       "eighty-eighty",
+			expectError: true,
+		},
+		{
+			name:        "out-of-range PORT aborts startup",
+			key:         envKeyPort,
+			value:       "70000",
+			expectError: true,
+		},
+		{
+			name:  "valid DEBUG is used",
+			key:   envKeyDebug,
+			value: "true",
+			check: func(t *testing.T, cfg *config.Config) {
+				t.Helper()
+				assert.True(t, cfg.Debug)
+			},
+		},
+		{
+			name:        "unparseable DEBUG aborts startup",
+			key:         envKeyDebug,
+			value:       "ture",
+			expectError: true,
+		},
+		{
+			name:        "unparseable MAINTENANCE_MODE aborts startup",
+			key:         envKeyMaintenanceMode,
+			value:       "sometimes",
+			expectError: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Cannot use t.Parallel() here because t.Setenv
+			// is incompatible with parallel subtests.
+			t.Setenv("WEBHOOKER_ENVIRONMENT", "dev")
+			t.Setenv(tt.key, tt.value)
+
+			cfg, err := buildConfig(t)
+
+			if tt.expectError {
+				require.Error(t, err)
+				assert.Contains(t, err.Error(), tt.key)
+				assert.Contains(t, err.Error(), tt.value)
+
+				return
+			}
+
+			require.NoError(t, err)
+			require.NotNil(t, cfg)
+			tt.check(t, cfg)
+		})
+	}
+}
+
+// TestNewUsesDefaultsWhenUnset proves the fail-loud behaviour did not
+// break the legitimate unset case: absent variables still get their
+// documented defaults.
+func TestNewUsesDefaultsWhenUnset(t *testing.T) {
+	t.Setenv("WEBHOOKER_ENVIRONMENT", "dev")
+
+	for _, key := range []string{
+		envKeyPort, envKeyDebug, envKeyMaintenanceMode,
+	} {
+		require.NoError(t, os.Unsetenv(key))
+	}
+
+	cfg, err := buildConfig(t)
+	require.NoError(t, err)
+	require.NotNil(t, cfg)
+
+	assert.Equal(t, 8080, cfg.Port)
+	assert.False(t, cfg.Debug)
+	assert.False(t, cfg.MaintenanceMode)
+}

internal/config/export_test.go

@@ -0,0 +1,20 @@
+package config
+
+// This file exposes the unexported environment parsing helpers to
+// the external config_test package so each helper can be covered by
+// its own table-driven test without weakening the package API.
+
+// EnvBoolForTest exposes envBool.
+func EnvBoolForTest(key string, defaultValue bool) (bool, error) {
+	return envBool(key, defaultValue)
+}
+
+// EnvPositiveIntForTest exposes envPositiveInt.
+func EnvPositiveIntForTest(key string, defaultValue int) (int, error) {
+	return envPositiveInt(key, defaultValue)
+}
+
+// EnvPortForTest exposes envPort.
+func EnvPortForTest(key string, defaultValue int) (int, error) {
+	return envPort(key, defaultValue)
+}

internal/database/database_test.go

@@ -18,6 +18,11 @@ const (
 	testVersion = "test"
 	// testContentType is the event content type used in tests.
 	testContentType = "application/json"
+	// testWebhookName is the Webhook.Name used in tests.
+	testWebhookName = "test-webhook"
+	// testForeverLabel is Webhook.RetentionLabel for a retain-forever
+	// webhook.
+	testForeverLabel = "forever"
 )
 
 func setupTestDB(

internal/database/export_test.go

@@ -5,6 +5,8 @@ import (
 	"log/slog"
 	"os"
 	"time"
+
+	"go.uber.org/fx"
 )
 
 // NewTestRetentionReaper builds a RetentionReaper backed by the given
@@ -29,3 +31,26 @@ func NewTestRetentionReaper(
 func (r *RetentionReaper) ExportSweep(ctx context.Context) {
 	r.sweep(ctx)
 }
+
+// ExportRegisterHooks registers the reaper's real fx lifecycle hooks
+// on a lifecycle supplied by a test, so a test can drive the exact
+// OnStart/OnStop functions the application runs and hand OnStart the
+// kind of context fx actually supplies.
+func (r *RetentionReaper) ExportRegisterHooks(lc fx.Lifecycle) {
+	r.registerHooks(lc)
+}
+
+// ExportStart starts the reaper's background loop for tests.
+func (r *RetentionReaper) ExportStart() {
+	r.start()
+}
+
+// ExportStop stops the reaper's background loop for tests.
+func (r *RetentionReaper) ExportStop() {
+	r.stop()
+}
+
+// ExportSetInterval overrides the sweep interval for tests.
+func (r *RetentionReaper) ExportSetInterval(d time.Duration) {
+	r.interval = d
+}

internal/database/model_webhook.go

@@ -1,6 +1,59 @@
 package database
 
+import (
+	"math"
+	"strconv"
+	"time"
+
+	"gorm.io/gorm"
+)
+
+const (
+	// DefaultRetentionDays is the event retention period applied to a
+	// webhook created without an explicit retention value. It is the
+	// single source of truth for that policy and must stay in sync
+	// with the `gorm:"default:30"` column default on
+	// Webhook.RetentionDays below; a struct tag cannot reference a
+	// constant, so a test asserts the two agree.
+	DefaultRetentionDays = 30
+
+	// RetentionForeverDays is the sentinel RetentionDays value meaning
+	// "retain events forever". Users express that intent as 0, which
+	// Webhook.BeforeSave rewrites to this value: the column default
+	// substitutes DefaultRetentionDays for a zero value at insert
+	// time, so a zero can never survive a round trip to the database.
+	// Nothing outside this file may hardcode the number.
+	RetentionForeverDays = 365 * 1000
+
+	// MaxFiniteRetentionDays is the largest finite retention period the
+	// reaper's cutoff arithmetic can represent, and therefore the
+	// largest one a caller may request. It is derived from that
+	// arithmetic rather than picked: retentionCutoff computes
+	// retentionDays * hoursPerDay * time.Hour, and a time.Duration is
+	// an int64 nanosecond count, so math.MaxInt64 nanoseconds divided
+	// by an hour and then by a day is the exact ceiling — 106751 days,
+	// a little over 292 years.
+	//
+	// One day more overflows int64, wraps the product negative, and
+	// turns the cutoff into a timestamp in the far future that matches
+	// every row in the webhook's database. That is why this bound is
+	// enforced on input and why retentionCutoff saturates underneath
+	// it. Note that RetentionForeverDays deliberately sits above this
+	// ceiling: such webhooks are skipped before any cutoff is
+	// computed, and never reach the arithmetic at all.
+	MaxFiniteRetentionDays = int(
+		math.MaxInt64 / int64(time.Hour) / hoursPerDay,
+	)
+)
+
 // Webhook represents a webhook processing unit that groups entrypoints and targets
+//
+// Every method below takes a pointer receiver. BeforeSave has to,
+// because it mutates the record and GORM only invokes hooks declared
+// that way; the display helpers follow suit so the receiver kinds do
+// not mix. Handlers therefore put a *Webhook into template data:
+// html/template cannot call a pointer method on a value held in a map,
+// because a map element is not addressable.
 type Webhook struct {
 	BaseModel
 
@@ -8,7 +61,9 @@ type Webhook struct {
 	Name        string `gorm:"not null"           json:"name"`
 	Description string `json:"description"`
 
-	// RetentionDays is the number of days to retain events.
+	// RetentionDays is the number of days to retain events. A value of
+	// RetentionForeverDays means retain forever. The column default
+	// must equal DefaultRetentionDays.
 	RetentionDays int `gorm:"default:30" json:"retentionDays"`
 
 	// Relations
@@ -16,3 +71,55 @@ type Webhook struct {
 	Entrypoints []Entrypoint `json:"entrypoints,omitempty"`
 	Targets     []Target     `json:"targets,omitempty"`
 }
+
+// BeforeSave normalises RetentionDays on every insert and update. A
+// non-positive value is the user's way of asking for "retain forever",
+// which is stored as the RetentionForeverDays sentinel.
+//
+// This has to happen in a hook rather than at the call sites. GORM
+// substitutes the column default (DefaultRetentionDays) for a zero
+// value while building the insert statement, which runs after
+// BeforeSave; rewriting any later than this loses that race and the
+// row lands at 30 days. Living on the model also means a future call
+// site — a REST API, a fixture, a migration — cannot bypass it.
+func (w *Webhook) BeforeSave(_ *gorm.DB) error {
+	if w.RetentionDays <= 0 {
+		w.RetentionDays = RetentionForeverDays
+	}
+
+	return nil
+}
+
+// retainsForever reports whether a stored RetentionDays value means
+// "keep events indefinitely". It is the single definition of that
+// question, shared by Webhook.RetainsForever and by the reaper's
+// cutoff computation so the two cannot disagree about which webhooks
+// are exempt from reaping.
+//
+// It accepts the RetentionForeverDays sentinel written by BeforeSave
+// and, defensively, the non-positive values that rows written before
+// the sentinel existed may still carry.
+func retainsForever(retentionDays int) bool {
+	return retentionDays <= 0 ||
+		retentionDays >= RetentionForeverDays
+}
+
+// RetainsForever reports whether this webhook's events are kept
+// indefinitely.
+func (w *Webhook) RetainsForever() bool {
+	return retainsForever(w.RetentionDays)
+}
+
+// RetentionLabel returns the webhook's retention policy as display
+// text, so that no template has to know about the sentinel value.
+func (w *Webhook) RetentionLabel() string {
+	if w.RetainsForever() {
+		return "forever"
+	}
+
+	if w.RetentionDays == 1 {
+		return "1 day"
+	}
+
+	return strconv.Itoa(w.RetentionDays) + " days"
+}

internal/database/model_webhook_test.go

@@ -0,0 +1,222 @@
+package database_test
+
+import (
+	"context"
+	"reflect"
+	"strconv"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+	"sneak.berlin/go/webhooker/internal/database"
+)
+
+// startedTestDB returns a started main database for model-level tests.
+func startedTestDB(t *testing.T) *gorm.DB {
+	t.Helper()
+
+	db, lc := setupTestDB(t)
+
+	ctx := context.Background()
+	require.NoError(t, lc.Start(ctx))
+	t.Cleanup(func() { require.NoError(t, lc.Stop(ctx)) })
+
+	return db.DB()
+}
+
+// storedRetention reads the retention_days column straight out of the
+// row, so the assertion is about what was persisted rather than about
+// whatever the in-memory struct happens to hold.
+func storedRetention(t *testing.T, db *gorm.DB, id string) int {
+	t.Helper()
+
+	var got int
+
+	require.NoError(
+		t,
+		db.Model(&database.Webhook{}).
+			Where("id = ?", id).
+			Pluck("retention_days", &got).Error,
+	)
+
+	return got
+}
+
+// newWebhookWithRetention creates a webhook through the ordinary Create
+// path, so the BeforeSave hook and the GORM column default both apply
+// exactly as they do in production.
+func newWebhookWithRetention(
+	t *testing.T,
+	db *gorm.DB,
+	wh *database.Webhook,
+) string {
+	t.Helper()
+
+	wh.UserID = uuid.New().String()
+	wh.Name = testWebhookName
+
+	require.NoError(
+		t,
+		db.Omit(clause.Associations).Create(wh).Error,
+	)
+
+	return wh.ID
+}
+
+func TestWebhookBeforeSave_ZeroBecomesForeverSentinel(t *testing.T) {
+	t.Parallel()
+
+	db := startedTestDB(t)
+
+	wh := &database.Webhook{RetentionDays: 0}
+	id := newWebhookWithRetention(t, db, wh)
+
+	assert.Equal(
+		t,
+		database.RetentionForeverDays,
+		storedRetention(t, db, id),
+		"a zero retention must be stored as the sentinel, "+
+			"not replaced by the column default",
+	)
+}
+
+func TestWebhookBeforeSave_NegativeBecomesForeverSentinel(t *testing.T) {
+	t.Parallel()
+
+	db := startedTestDB(t)
+
+	wh := &database.Webhook{RetentionDays: -5}
+	id := newWebhookWithRetention(t, db, wh)
+
+	assert.Equal(
+		t,
+		database.RetentionForeverDays,
+		storedRetention(t, db, id),
+	)
+}
+
+func TestWebhookBeforeSave_PositiveIsPreserved(t *testing.T) {
+	t.Parallel()
+
+	db := startedTestDB(t)
+
+	wh := &database.Webhook{RetentionDays: 7}
+	id := newWebhookWithRetention(t, db, wh)
+
+	assert.Equal(t, 7, storedRetention(t, db, id))
+}
+
+// TestWebhookBeforeSave_UpdateToZeroBecomesSentinel proves the hook
+// fires on update as well as insert, via the same Save call the edit
+// handler makes.
+func TestWebhookBeforeSave_UpdateToZeroBecomesSentinel(t *testing.T) {
+	t.Parallel()
+
+	db := startedTestDB(t)
+
+	wh := &database.Webhook{RetentionDays: 30}
+	id := newWebhookWithRetention(t, db, wh)
+	require.Equal(t, 30, storedRetention(t, db, id))
+
+	wh.RetentionDays = 0
+	require.NoError(t, db.Omit(clause.Associations).Save(wh).Error)
+
+	assert.Equal(
+		t,
+		database.RetentionForeverDays,
+		storedRetention(t, db, id),
+	)
+}
+
+// TestWebhookRetentionColumnDefaultMatchesConstant guards the one place
+// the default lives twice: a struct tag cannot reference a constant, so
+// this asserts the tag and DefaultRetentionDays agree.
+func TestWebhookRetentionColumnDefaultMatchesConstant(t *testing.T) {
+	t.Parallel()
+
+	field, ok := reflect.TypeFor[database.Webhook]().
+		FieldByName("RetentionDays")
+	require.True(t, ok, "Webhook.RetentionDays must exist")
+
+	assert.Equal(
+		t,
+		"default:"+strconv.Itoa(database.DefaultRetentionDays),
+		field.Tag.Get("gorm"),
+	)
+}
+
+// TestMaxFiniteRetentionDaysIsTheOverflowCeiling asserts that the
+// constant is exactly where the cutoff arithmetic stops working, which
+// is what makes it a derived bound rather than a round number someone
+// liked. One day more wraps the int64 nanosecond count negative, and a
+// negative span is precisely what turned a cutoff into a future
+// timestamp that matched — and deleted — every row.
+//
+// The multiplications are done through variables on purpose: as
+// constant expressions the overflowing one would not compile.
+func TestMaxFiniteRetentionDaysIsTheOverflowCeiling(t *testing.T) {
+	t.Parallel()
+
+	const hoursPerDay = 24
+
+	atCeiling := database.MaxFiniteRetentionDays
+	overCeiling := database.MaxFiniteRetentionDays + 1
+
+	assert.Positive(
+		t,
+		time.Duration(atCeiling*hoursPerDay)*time.Hour,
+		"the ceiling itself must still be representable",
+	)
+	assert.Negative(
+		t,
+		time.Duration(overCeiling*hoursPerDay)*time.Hour,
+		"one day past the ceiling must overflow",
+	)
+
+	assert.Less(
+		t,
+		database.MaxFiniteRetentionDays,
+		database.RetentionForeverDays,
+		"the sentinel sits above the ceiling and is only safe "+
+			"because retain-forever webhooks skip the arithmetic",
+	)
+}
+
+func TestWebhookRetainsForeverAndLabel(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct {
+		name    string
+		days    int
+		forever bool
+		label   string
+	}{
+		{
+			"sentinel",
+			database.RetentionForeverDays, true, testForeverLabel,
+		},
+		{
+			"above sentinel",
+			database.RetentionForeverDays + 1, true, testForeverLabel,
+		},
+		{"legacy zero", 0, true, testForeverLabel},
+		{"legacy negative", -1, true, testForeverLabel},
+		{"default", database.DefaultRetentionDays, false, "30 days"},
+		{"one day", 1, false, "1 day"},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			wh := database.Webhook{RetentionDays: tc.days}
+
+			assert.Equal(t, tc.forever, wh.RetainsForever())
+			assert.Equal(t, tc.label, wh.RetentionLabel())
+		})
+	}
+}

internal/database/retention.go

@@ -56,9 +56,20 @@ func NewRetentionReaper(
 		interval:  params.Config.RetentionSweepInterval,
 	}
 
+	r.registerHooks(lc)
+
+	return r
+}
+
+// registerHooks wires the reaper's start and stop into the fx
+// lifecycle. The start hook's context is deliberately ignored: see
+// start for why the sweep loop must not inherit it.
+func (r *RetentionReaper) registerHooks(lc fx.Lifecycle) {
 	lc.Append(fx.Hook{
-		OnStart: func(ctx context.Context) error {
-			r.start(ctx)
+		//nolint:contextcheck // Not inheriting the hook context is
+		// the point: see start.
+		OnStart: func(_ context.Context) error {
+			r.start()
 
 			return nil
 		},
@@ -68,12 +79,20 @@ func NewRetentionReaper(
 			return nil
 		},
 	})
-
-	return r
 }
 
-func (r *RetentionReaper) start(ctx context.Context) {
-	ctx, cancel := context.WithCancel(ctx)
+// start launches the background sweep loop.
+//
+// The loop's context is derived from context.Background(), NOT from
+// the fx OnStart hook context. The hook context carries fx's start
+// timeout (15s by default) and is cancelled once the start phase
+// completes, so a loop derived from it dies 45 minutes before its
+// first tick under the default one-hour sweep interval, leaving a
+// reaper that never reaps. A long-lived goroutine must outlive the
+// startup phase, so its lifetime is bounded by OnStop instead: stop
+// cancels this context and waits on the WaitGroup.
+func (r *RetentionReaper) start() {
+	ctx, cancel := context.WithCancel(context.Background())
 	r.cancel = cancel
 
 	r.wg.Add(1)
@@ -114,7 +133,8 @@ func (r *RetentionReaper) run(ctx context.Context) {
 }
 
 // sweep lists every webhook from the main database and reaps expired
-// rows from each per-webhook database whose RetentionDays is positive.
+// rows from each per-webhook database that has a finite retention
+// policy. Webhooks set to retain forever are skipped entirely.
 func (r *RetentionReaper) sweep(ctx context.Context) {
 	var webhooks []Webhook
 
@@ -139,8 +159,13 @@ func (r *RetentionReaper) sweep(ctx context.Context) {
 
 		wh := webhooks[i]
 
-		// RetentionDays of zero or less means retain forever.
-		if wh.RetentionDays <= 0 {
+		// Skip retain-forever webhooks before building any query.
+		// RetainsForever covers both the RetentionForeverDays
+		// sentinel and the non-positive values that predate it: the
+		// sentinel is a positive number, so without this the reaper
+		// would compute a cutoff a thousand years in the past and
+		// issue a DELETE matching nothing on every single sweep.
+		if wh.RetainsForever() {
 			continue
 		}
 
@@ -171,9 +196,10 @@ func (r *RetentionReaper) reapWebhook(
 		return
 	}
 
-	cutoff := time.Now().Add(
-		-time.Duration(retentionDays*hoursPerDay) * time.Hour,
-	)
+	cutoff, ok := retentionCutoff(time.Now(), retentionDays)
+	if !ok {
+		return
+	}
 
 	deleted, err := reapExpired(db, cutoff)
 	if err != nil {
@@ -196,6 +222,37 @@ func (r *RetentionReaper) reapWebhook(
 	}
 }
 
+// retentionCutoff returns the timestamp before which a webhook's
+// events have expired, and whether any cutoff applies at all. It
+// reports false for a retain-forever policy, so no DELETE is issued.
+//
+// The day count is clamped to MaxFiniteRetentionDays first. This is
+// defense in depth rather than decoration: a time.Duration is an int64
+// nanosecond count, so an unclamped multiplication overflows above
+// that ceiling and wraps the span negative. Subtracting a negative
+// span moves the cutoff into the far future, where it matches every
+// row in the database: the sweep then deletes every event, delivery,
+// and delivery result, including ones created seconds ago. Rejecting
+// out-of-range input at the form is the primary guard; saturating here
+// means an old row, a migration, or a future call site cannot turn a
+// too-large retention into total data loss.
+func retentionCutoff(
+	now time.Time,
+	retentionDays int,
+) (time.Time, bool) {
+	if retainsForever(retentionDays) {
+		return time.Time{}, false
+	}
+
+	if retentionDays > MaxFiniteRetentionDays {
+		retentionDays = MaxFiniteRetentionDays
+	}
+
+	return now.Add(
+		-time.Duration(retentionDays*hoursPerDay) * time.Hour,
+	), true
+}
+
 // reapExpired hard-deletes, in foreign-key-safe order, the delivery
 // results, deliveries, and events associated with events older than
 // cutoff. Deletes are unscoped so rows are physically removed rather

internal/database/retention_lifecycle_test.go

@@ -0,0 +1,209 @@
+package database_test
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/fx"
+	"gorm.io/gorm"
+	"sneak.berlin/go/webhooker/internal/database"
+)
+
+const (
+	// reaperTestInterval is the sweep interval a lifecycle test
+	// runs the reaper at, so a loop that survives startup produces
+	// an observable sweep quickly.
+	reaperTestInterval = 10 * time.Millisecond
+
+	// reaperStopTimeout bounds how long a lifecycle test waits for
+	// the reaper's OnStop hook to return before declaring the
+	// shutdown hung.
+	reaperStopTimeout = 10 * time.Second
+
+	// reaperTestRetentionDays is the retention policy the lifecycle
+	// tests give their webhook.
+	reaperTestRetentionDays = 30
+)
+
+// recordingLifecycle is a minimal fx.Lifecycle that records the
+// hooks a component registers, so a test can invoke the real
+// OnStart/OnStop functions with a context of its choosing.
+type recordingLifecycle struct {
+	hooks []fx.Hook
+}
+
+func (l *recordingLifecycle) Append(h fx.Hook) {
+	l.hooks = append(l.hooks, h)
+}
+
+// startReaperViaHook drives the genuine fx hooks the application
+// registers for the reaper, handing OnStart a context that is
+// already done. It returns the recorded lifecycle so the caller
+// can drive OnStop too.
+func startReaperViaHook(
+	t *testing.T, r *database.RetentionReaper,
+) *recordingLifecycle {
+	t.Helper()
+
+	lc := &recordingLifecycle{}
+	r.ExportRegisterHooks(lc)
+	require.Len(t, lc.hooks, 1)
+
+	// fx hands OnStart a context carrying the application start
+	// timeout, and cancels it when the start phase ends. An
+	// already-cancelled context is that same defect taken to its
+	// limit, and unlike a plain context.Background() it actually
+	// distinguishes a correctly rooted loop from a broken one.
+	hookCtx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	require.NoError(t, lc.hooks[0].OnStart(hookCtx))
+
+	return lc
+}
+
+// eventGone reports whether an event row has been removed. It
+// takes no *testing.T because it is polled from an
+// assert.Eventually condition, which runs off the test goroutine
+// where testify assertions must not be used.
+func eventGone(db *gorm.DB, eventID string) bool {
+	var n int64
+
+	err := db.Unscoped().Model(&database.Event{}).
+		Where("id = ?", eventID).Count(&n).Error
+	if err != nil {
+		return false
+	}
+
+	return n == 0
+}
+
+// seedExpiredWebhook creates a webhook with a finite retention
+// policy plus one long-expired event chain, and returns the
+// webhook's database and the chain's event ID.
+func seedExpiredWebhook(
+	t *testing.T, env *retentionTestEnv,
+) (*gorm.DB, string) {
+	t.Helper()
+
+	webhookID := createWebhook(
+		t, env.mainDB.DB(), reaperTestRetentionDays,
+	)
+
+	db, err := env.mgr.GetDB(webhookID)
+	require.NoError(t, err)
+
+	chain := seedEventChain(
+		t, db, webhookID,
+		time.Now().Add(-365*24*time.Hour),
+	)
+
+	return db, chain.eventID
+}
+
+// TestRetentionReaper_LoopOutlivesStartHookContext is the
+// regression test for a reaper that never reaped. fx calls
+// OnStart with a context carrying the application's start timeout
+// (15s by default) and cancels it when the start phase ends, so a
+// sweep loop rooted in it is dead three quarters of an hour
+// before its first tick under the default one-hour interval, and
+// per-webhook event databases grow without bound exactly as they
+// did before retention existed.
+//
+// Driving OnStart with an already-cancelled context is that
+// defect taken to its limit: a loop that inherits the hook
+// context never ticks once, while a correctly rooted loop keeps
+// sweeping for as long as the process lives.
+func TestRetentionReaper_LoopOutlivesStartHookContext(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupRetentionTest(t)
+
+	db, eventID := seedExpiredWebhook(t, env)
+
+	env.reaper.ExportSetInterval(reaperTestInterval)
+
+	lc := startReaperViaHook(t, env.reaper)
+	t.Cleanup(func() {
+		_ = lc.hooks[0].OnStop(context.Background())
+	})
+
+	assert.Eventually(
+		t,
+		func() bool { return eventGone(db, eventID) },
+		5*time.Second,
+		reaperTestInterval,
+		"the sweep loop must keep running after the start "+
+			"hook's context is done; it reaped nothing, so it "+
+			"inherited the hook context and died",
+	)
+}
+
+// TestRetentionReaper_StopHookStopsLoop proves the fix did not
+// trade a startup bug for a shutdown hang: now that the sweep
+// loop no longer observes the start hook's cancellation, OnStop
+// is the only thing that can stop it, and it must both return
+// promptly and actually leave the loop stopped.
+func TestRetentionReaper_StopHookStopsLoop(t *testing.T) {
+	t.Parallel()
+
+	env := setupRetentionTest(t)
+
+	db, eventID := seedExpiredWebhook(t, env)
+
+	env.reaper.ExportSetInterval(reaperTestInterval)
+
+	lc := startReaperViaHook(t, env.reaper)
+
+	// Let the loop prove it is running before stopping it, so a
+	// fast OnStop cannot pass by stopping something already dead.
+	require.Eventually(
+		t,
+		func() bool { return eventGone(db, eventID) },
+		5*time.Second,
+		reaperTestInterval,
+	)
+
+	var stopErr error
+
+	stopped := make(chan struct{})
+
+	go func() {
+		defer close(stopped)
+
+		// stop blocks on the loop's WaitGroup, so returning at all
+		// proves the goroutine observed the cancellation.
+		stopErr = lc.hooks[0].OnStop(context.Background())
+	}()
+
+	select {
+	case <-stopped:
+	case <-time.After(reaperStopTimeout):
+		t.Fatal(
+			"OnStop did not return: the retention reaper's " +
+				"WaitGroup is still waiting on a loop that never " +
+				"observed cancellation",
+		)
+	}
+
+	require.NoError(t, stopErr)
+
+	// With the loop gone, a newly expired chain must survive.
+	survivor := seedEventChain(
+		t, db, "stopped-webhook",
+		time.Now().Add(-365*24*time.Hour),
+	)
+
+	time.Sleep(20 * reaperTestInterval)
+
+	assert.False(
+		t,
+		eventGone(db, survivor.eventID),
+		"a stopped reaper must not sweep anything",
+	)
+}

internal/database/retention_test.go

@@ -77,7 +77,7 @@ func createWebhook(
 
 	wh := &database.Webhook{
 		UserID:        uuid.New().String(),
-		Name:          "test-webhook",
+		Name:          testWebhookName,
 		RetentionDays: retentionDays,
 	}
 	require.NoError(
@@ -85,10 +85,11 @@ func createWebhook(
 		db.Omit(clause.Associations).Create(wh).Error,
 	)
 
-	// The RetentionDays column carries a GORM default of 30, so a
-	// zero (or negative) value passed to Create is replaced by that
-	// default. Force the requested value explicitly so the
-	// retain-forever (<= 0) path can be exercised.
+	// Webhook.BeforeSave rewrites a non-positive RetentionDays to the
+	// retain-forever sentinel, and the column's GORM default would
+	// otherwise substitute 30. Force the requested value with a
+	// column-level update so tests can plant legacy rows that predate
+	// the sentinel and still carry a literal 0 or negative value.
 	require.NoError(
 		t,
 		db.Model(wh).
@@ -98,6 +99,30 @@ func createWebhook(
 	return wh.ID
 }
 
+// createWebhookNormally inserts a webhook through the ordinary Create
+// path, with no column-level forcing, so Webhook.BeforeSave applies
+// exactly as it does in production. Passing 0 therefore yields a row
+// holding the RetentionForeverDays sentinel.
+func createWebhookNormally(
+	t *testing.T,
+	db *gorm.DB,
+	retentionDays int,
+) string {
+	t.Helper()
+
+	wh := &database.Webhook{
+		UserID:        uuid.New().String(),
+		Name:          testWebhookName,
+		RetentionDays: retentionDays,
+	}
+	require.NoError(
+		t,
+		db.Omit(clause.Associations).Create(wh).Error,
+	)
+
+	return wh.ID
+}
+
 // eventChain is the set of row IDs seeded for a single event.
 type eventChain struct {
 	eventID    string
@@ -256,12 +281,111 @@ func TestRetentionReaper_ReapsExpiredKeepsRecent(t *testing.T) {
 	assertChainPresent(t, db, recent)
 }
 
+// TestRetentionReaper_SkipsSentinelReapsFiniteInSameSweep covers the
+// end-to-end retain-forever path: a webhook created the normal way with
+// a requested retention of 0 lands on the RetentionForeverDays
+// sentinel, and the reaper leaves its ancient events alone while still
+// reaping a finite-retention webhook in the very same sweep.
+func TestRetentionReaper_SkipsSentinelReapsFiniteInSameSweep(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupRetentionTest(t)
+
+	foreverID := createWebhookNormally(t, env.mainDB.DB(), 0)
+
+	var stored database.Webhook
+
+	require.NoError(
+		t,
+		env.mainDB.DB().Where("id = ?", foreverID).
+			First(&stored).Error,
+	)
+	require.Equal(
+		t,
+		database.RetentionForeverDays,
+		stored.RetentionDays,
+		"a requested retention of 0 must persist as the sentinel",
+	)
+
+	finiteID := createWebhookNormally(t, env.mainDB.DB(), 30)
+
+	foreverDB, err := env.mgr.GetDB(foreverID)
+	require.NoError(t, err)
+
+	finiteDB, err := env.mgr.GetDB(finiteID)
+	require.NoError(t, err)
+
+	ancient := time.Now().Add(-365 * 24 * time.Hour)
+	kept := seedEventChain(t, foreverDB, foreverID, ancient)
+	doomed := seedEventChain(t, finiteDB, finiteID, ancient)
+
+	env.reaper.ExportSweep(context.Background())
+
+	assertChainPresent(t, foreverDB, kept)
+	assertChainGone(t, finiteDB, doomed)
+}
+
+// TestRetentionReaper_HugeFiniteRetentionRetainsRecentEvents pins the
+// overflow that made a large finite retention destroy everything.
+//
+// The cutoff is a time.Duration, an int64 nanosecond count. A day
+// count above MaxFiniteRetentionDays multiplied out unclamped wraps
+// negative, so subtracting it moves the cutoff into the far future,
+// where "created_at < cutoff" matches every row: an event created a
+// moment ago, and its delivery and delivery result, were all deleted
+// on the first sweep. 200000 is inside that band and below the
+// retain-forever sentinel, so it is treated as a finite policy and
+// really does reach the arithmetic.
+//
+// The row is planted at the column level because such a value can no
+// longer be submitted through the form; the point of the test is that
+// a row from an older version, or a future call site, still cannot
+// trigger the wipe.
+func TestRetentionReaper_HugeFiniteRetentionRetainsRecentEvents(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupRetentionTest(t)
+
+	const overflowingRetentionDays = 200000
+
+	require.Greater(
+		t,
+		overflowingRetentionDays,
+		database.MaxFiniteRetentionDays,
+		"the test value must exceed what the cutoff can represent",
+	)
+	require.Less(
+		t,
+		overflowingRetentionDays,
+		database.RetentionForeverDays,
+		"the test value must not be rescued by the forever skip",
+	)
+
+	webhookID := createWebhook(
+		t, env.mainDB.DB(), overflowingRetentionDays,
+	)
+
+	db, err := env.mgr.GetDB(webhookID)
+	require.NoError(t, err)
+
+	fresh := seedEventChain(t, db, webhookID, time.Now())
+
+	env.reaper.ExportSweep(context.Background())
+
+	assertChainPresent(t, db, fresh)
+}
+
 func TestRetentionReaper_RetainsForeverWhenNonPositive(t *testing.T) {
 	t.Parallel()
 
 	env := setupRetentionTest(t)
 
-	// RetentionDays of zero means retain forever.
+	// A legacy row written before the sentinel existed still carries a
+	// literal 0; the <= 0 guard must keep honouring it.
 	webhookID := createWebhook(t, env.mainDB.DB(), 0)
 
 	db, err := env.mgr.GetDB(webhookID)

internal/delivery/archive_sweeper.go

@@ -0,0 +1,229 @@
+package delivery
+
+import (
+	"context"
+	"errors"
+	"log/slog"
+	"sync"
+	"time"
+
+	"go.uber.org/fx"
+	"sneak.berlin/go/webhooker/internal/config"
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/logger"
+)
+
+// ArchiveSweeperParams holds the fx dependencies for the
+// ArchiveSweeper.
+type ArchiveSweeperParams struct {
+	fx.In
+
+	Config   *config.Config
+	Database *database.Database
+	Engine   *Engine
+	Logger   *logger.Logger
+}
+
+// ArchiveSweeper periodically prunes expired rows from
+// per-webhook archive databases whose database target carries a
+// positive expiry.
+//
+// Without it, pruning happens only when an archive is
+// (re)opened, and archives are only ever reopened by writes: an
+// archive belonging to a webhook that has stopped receiving
+// events would keep its expired rows forever. The sweep closes
+// that gap without changing anything for archives whose expiry
+// is unset or "never".
+//
+// It reuses Config.RetentionSweepInterval rather than
+// introducing a second interval: this is a retention sweep with
+// the same semantics as the event retention reaper.
+type ArchiveSweeper struct {
+	db       *database.Database
+	eng      *Engine
+	log      *slog.Logger
+	interval time.Duration
+	cancel   context.CancelFunc
+	wg       sync.WaitGroup
+}
+
+// NewArchiveSweeper creates the archive sweeper and registers
+// its fx lifecycle hooks. The background sweep loop starts on
+// OnStart and stops cleanly on OnStop via context cancellation.
+func NewArchiveSweeper(
+	lc fx.Lifecycle,
+	params ArchiveSweeperParams,
+) *ArchiveSweeper {
+	s := &ArchiveSweeper{
+		db:       params.Database,
+		eng:      params.Engine,
+		log:      params.Logger.Get(),
+		interval: params.Config.RetentionSweepInterval,
+	}
+
+	s.registerHooks(lc)
+
+	return s
+}
+
+// registerHooks wires the sweeper's start and stop into the fx
+// lifecycle. Both hook contexts are deliberately ignored: see
+// start for why the background loop must not inherit the start
+// hook's context, and stop for why shutdown blocks on the loop
+// rather than on the stop hook's deadline.
+func (s *ArchiveSweeper) registerHooks(lc fx.Lifecycle) {
+	lc.Append(fx.Hook{
+		//nolint:contextcheck // Not passing the hook context is
+		// the point: see start.
+		OnStart: func(_ context.Context) error {
+			s.start()
+
+			return nil
+		},
+		OnStop: func(_ context.Context) error {
+			s.stop()
+
+			return nil
+		},
+	})
+}
+
+// start launches the background sweep loop.
+//
+// The loop's context is derived from context.Background(), NOT
+// from the fx OnStart hook context. The hook context carries
+// fx's start timeout (15s by default), so a loop derived from it
+// is cancelled 15 seconds after the application starts — long
+// before the first tick under the default one-hour sweep
+// interval, leaving a sweeper that never sweeps. A long-lived
+// goroutine must outlive the startup phase, so its lifetime is
+// bounded by OnStop instead: stop cancels this context and waits
+// on the WaitGroup.
+func (s *ArchiveSweeper) start() {
+	ctx, cancel := context.WithCancel(context.Background())
+	s.cancel = cancel
+
+	s.wg.Add(1)
+
+	go s.run(ctx)
+
+	s.log.Info(
+		"archive sweeper started",
+		"interval", s.interval.String(),
+	)
+}
+
+func (s *ArchiveSweeper) stop() {
+	s.log.Info("archive sweeper stopping")
+
+	if s.cancel != nil {
+		s.cancel()
+	}
+
+	s.wg.Wait()
+	s.log.Info("archive sweeper stopped")
+}
+
+func (s *ArchiveSweeper) run(ctx context.Context) {
+	defer s.wg.Done()
+
+	ticker := time.NewTicker(s.interval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			s.sweep(ctx)
+		}
+	}
+}
+
+// sweep prunes every archive whose database target declares a
+// positive expiry. Targets belonging to a deleted webhook are
+// soft-deleted along with it, so GORM's default scope already
+// excludes them.
+//
+// A failure for one webhook is logged and the sweep continues,
+// matching how the write path already treats a prune error as
+// non-fatal.
+func (s *ArchiveSweeper) sweep(ctx context.Context) {
+	var targets []database.Target
+
+	err := s.db.DB().
+		Model(&database.Target{}).
+		Where("type = ?", database.TargetTypeDatabase).
+		Find(&targets).Error
+	if err != nil {
+		s.log.Error(
+			"archive sweep: failed to list database targets",
+			"error", err,
+		)
+
+		return
+	}
+
+	for i := range targets {
+		select {
+		case <-ctx.Done():
+			return
+		default:
+		}
+
+		s.sweepTarget(&targets[i])
+	}
+}
+
+// sweepTarget prunes the archive of a single database target.
+// A missing, empty, or "never" expiry parses as a zero duration
+// and is skipped entirely, so those archives keep exactly the
+// behaviour they had before the sweep existed.
+func (s *ArchiveSweeper) sweepTarget(target *database.Target) {
+	expiry, err := parseArchiveExpiry(target.Config)
+	if err != nil {
+		s.log.Error(
+			"archive sweep: invalid database target config",
+			"webhook_id", target.WebhookID,
+			"target_id", target.ID,
+			"error", err,
+		)
+
+		return
+	}
+
+	if expiry <= 0 {
+		return
+	}
+
+	if s.eng == nil || s.eng.dbTarget == nil {
+		return
+	}
+
+	err = s.eng.dbTarget.sweepWebhook(target.WebhookID, expiry)
+	if err == nil {
+		return
+	}
+
+	// A writer evicted underneath the sweep means the operator
+	// deleted the webhook (or its last database target) while the
+	// sweep was walking the target list. That is an ordinary
+	// interleaving, not a failure, so it must not produce an
+	// error line.
+	if errors.Is(err, errArchiveWriterEvicted) {
+		s.log.Debug(
+			"archive sweep: writer evicted mid-sweep",
+			"webhook_id", target.WebhookID,
+			"target_id", target.ID,
+		)
+
+		return
+	}
+
+	s.log.Error(
+		"archive sweep: failed to prune archive",
+		"webhook_id", target.WebhookID,
+		"target_id", target.ID,
+		"error", err,
+	)
+}

internal/delivery/archive_sweeper_test.go

@@ -0,0 +1,930 @@
+package delivery_test
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"net/http"
+	"os"
+	"path/filepath"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/fx"
+	"gorm.io/driver/sqlite"
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+	_ "modernc.org/sqlite" // Pure Go SQLite driver.
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/delivery"
+)
+
+const (
+	// sweepRowOld and sweepRowNew are the event ids
+	// seedArchiveRows assigns to the first and second seeded
+	// rows.
+	sweepRowOld = "ev-0"
+	sweepRowNew = "ev-1"
+
+	// sweepConcurrentWrites is how many deliveries the
+	// concurrent write-plus-sweep test races against the sweep.
+	sweepConcurrentWrites = 20
+)
+
+// sweeperEnv bundles the pieces an archive sweep test drives:
+// a main configuration database holding webhooks and targets, a
+// delivery engine owning the archive writer registry, and the
+// data directory the archive files live in.
+type sweeperEnv struct {
+	sweeper *delivery.ArchiveSweeper
+	eng     *delivery.Engine
+	mainDB  *database.Database
+	dataDir string
+}
+
+func setupSweeperTest(t *testing.T) *sweeperEnv {
+	t.Helper()
+
+	dataDir := t.TempDir()
+	log := archiveTestLogger()
+
+	sqlDB, err := sql.Open(
+		"sqlite",
+		fmt.Sprintf(
+			"file:%s?mode=rwc",
+			filepath.Join(dataDir, "main.db"),
+		),
+	)
+	require.NoError(t, err)
+
+	t.Cleanup(func() { _ = sqlDB.Close() })
+
+	gdb, err := gorm.Open(
+		sqlite.Dialector{Conn: sqlDB}, &gorm.Config{},
+	)
+	require.NoError(t, err)
+
+	mainDB := database.NewTestDatabase(gdb)
+	require.NoError(t, mainDB.Migrate())
+
+	eng := delivery.NewTestEngineWithDB(
+		mainDB,
+		database.NewTestWebhookDBManager(dataDir),
+		log,
+		&http.Client{Timeout: 5 * time.Second},
+		1,
+	)
+
+	return &sweeperEnv{
+		sweeper: delivery.NewTestArchiveSweeper(
+			mainDB, eng, log,
+		),
+		eng:     eng,
+		mainDB:  mainDB,
+		dataDir: dataDir,
+	}
+}
+
+// archivePath returns where the engine keeps a webhook's
+// archive file.
+func (env *sweeperEnv) archivePath(webhookID string) string {
+	return filepath.Join(
+		env.dataDir, fmt.Sprintf("archive-%s.db", webhookID),
+	)
+}
+
+// seedDatabaseTarget creates a webhook with one database target
+// carrying the given target config JSON, and returns the
+// webhook id.
+func (env *sweeperEnv) seedDatabaseTarget(
+	t *testing.T, configJSON string,
+) string {
+	t.Helper()
+
+	wh := &database.Webhook{
+		UserID: uuid.New().String(),
+		Name:   "sweep-test",
+	}
+	require.NoError(
+		t,
+		env.mainDB.DB().
+			Omit(clause.Associations).
+			Create(wh).Error,
+	)
+
+	tgt := &database.Target{
+		WebhookID: wh.ID,
+		Name:      "archive",
+		Type:      database.TargetTypeDatabase,
+		Active:    true,
+		Config:    configJSON,
+	}
+	require.NoError(
+		t,
+		env.mainDB.DB().
+			Omit(clause.Associations).
+			Create(tgt).Error,
+	)
+
+	return wh.ID
+}
+
+// seedArchiveRows creates the archive file for a webhook and
+// inserts one row per supplied archived-at timestamp, returning
+// the archive path. The handle is closed before returning, so
+// the archive is idle exactly as it would be with no traffic.
+func (env *sweeperEnv) seedArchiveRows(
+	t *testing.T, webhookID string, archivedAt ...time.Time,
+) string {
+	t.Helper()
+
+	path := env.archivePath(webhookID)
+
+	sqlDB, err := sql.Open(
+		"sqlite", fmt.Sprintf("file:%s?mode=rwc", path),
+	)
+	require.NoError(t, err)
+
+	gdb, err := gorm.Open(
+		sqlite.Dialector{Conn: sqlDB}, &gorm.Config{},
+	)
+	require.NoError(t, err)
+
+	require.NoError(
+		t, gdb.AutoMigrate(&delivery.ExportArchivedEvent{}),
+	)
+
+	for i, at := range archivedAt {
+		row := delivery.ExportArchivedEvent{
+			EventID:    fmt.Sprintf("ev-%d", i),
+			WebhookID:  webhookID,
+			Method:     http.MethodPost,
+			Body:       `{"seeded":true}`,
+			ArchivedAt: at,
+		}
+		require.NoError(t, gdb.Create(&row).Error)
+	}
+
+	require.NoError(t, sqlDB.Close())
+
+	return path
+}
+
+// archivedEventIDs returns the event ids currently stored in an
+// archive file, read through a separate read-only handle.
+func archivedEventIDs(
+	t *testing.T, path string,
+) []string {
+	t.Helper()
+
+	var rows []delivery.ExportArchivedEvent
+
+	rdb := openArchiveDBForRead(t, path)
+	require.NoError(t, rdb.Order("event_id").Find(&rows).Error)
+
+	ids := make([]string, 0, len(rows))
+	for i := range rows {
+		ids = append(ids, rows[i].EventID)
+	}
+
+	return ids
+}
+
+// countArchivedRows counts the rows in an archive file without
+// asserting anything, so it is safe to poll from an
+// assert.Eventually condition (which runs off the test
+// goroutine, where testify assertions must not be used).
+func countArchivedRows(path string) (int64, error) {
+	sqlDB, err := sql.Open(
+		"sqlite", fmt.Sprintf("file:%s?mode=ro", path),
+	)
+	if err != nil {
+		return 0, err
+	}
+
+	defer func() { _ = sqlDB.Close() }()
+
+	gdb, err := gorm.Open(
+		sqlite.Dialector{Conn: sqlDB}, &gorm.Config{},
+	)
+	if err != nil {
+		return 0, err
+	}
+
+	var count int64
+
+	err = gdb.Model(&delivery.ExportArchivedEvent{}).
+		Count(&count).Error
+	if err != nil {
+		return 0, err
+	}
+
+	return count, nil
+}
+
+// captureLifecycle is a minimal fx.Lifecycle that records the
+// hooks a component registers, so a test can invoke the real
+// OnStart/OnStop functions with a context of its choosing.
+type captureLifecycle struct {
+	hooks []fx.Hook
+}
+
+func (l *captureLifecycle) Append(h fx.Hook) {
+	l.hooks = append(l.hooks, h)
+}
+
+// TestArchiveSweeper_LoopOutlivesStartHookContext is the
+// regression test for a sweeper that never swept. fx calls
+// OnStart with a context carrying the application's start
+// timeout (15 seconds by default), so a background loop whose
+// context is derived from it is cancelled 15 seconds into the
+// process — three quarters of an hour before the first tick
+// under the default one-hour sweep interval.
+//
+// The hook context here is already cancelled, which is the same
+// defect taken to its limit: a loop that inherits it never runs
+// a single tick, while a correctly rooted loop keeps sweeping
+// for as long as the process lives. Handing the hook a plain
+// context.Background() would assert nothing at all.
+func TestArchiveSweeper_LoopOutlivesStartHookContext(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSweeperTest(t)
+
+	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+
+	now := time.Now()
+	path := env.seedArchiveRows(
+		t, webhookID,
+		now.Add(-48*time.Hour),
+		now.Add(-time.Minute),
+	)
+
+	env.sweeper.ExportSetInterval(10 * time.Millisecond)
+
+	// Drive the genuine fx hooks the application registers,
+	// rather than a test-only entry point.
+	lc := &captureLifecycle{}
+	env.sweeper.ExportRegisterHooks(lc)
+	require.Len(t, lc.hooks, 1)
+
+	hookCtx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	require.NoError(t, lc.hooks[0].OnStart(hookCtx))
+
+	t.Cleanup(func() {
+		_ = lc.hooks[0].OnStop(context.Background())
+	})
+
+	assert.Eventually(
+		t,
+		func() bool {
+			count, err := countArchivedRows(path)
+
+			return err == nil && count == 1
+		},
+		5*time.Second,
+		10*time.Millisecond,
+		"the sweep loop must keep running after the start "+
+			"hook's context is done; it pruned nothing, so it "+
+			"inherited the hook context and died",
+	)
+}
+
+// TestArchiveSweep_DoesNotResurrectEvictedWriter covers the
+// interleaving where a sweep tick has already listed a webhook's
+// target when the webhook is deleted and its writer evicted. The
+// sweep must not put a writer back into the registry: nothing
+// would ever evict it again, which is precisely the leak this
+// change exists to close.
+func TestArchiveSweep_DoesNotResurrectEvictedWriter(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSweeperTest(t)
+
+	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	env.seedArchiveRows(
+		t, webhookID, time.Now().Add(-48*time.Hour),
+	)
+
+	// Prime the registry the way a delivery would, then evict as
+	// the deletion path does. The target row is deliberately left
+	// in place: this is the tick that listed the webhook before
+	// the deletion committed.
+	_, err := env.eng.ExportEnsureArchiveWriter(webhookID)
+	require.NoError(t, err)
+
+	env.eng.EvictWebhook(webhookID)
+	require.False(t, env.eng.ExportHasArchiveWriter(webhookID))
+
+	env.sweeper.ExportSweep(context.Background())
+
+	assert.False(
+		t, env.eng.ExportHasArchiveWriter(webhookID),
+		"a sweep must never re-register a writer for a webhook "+
+			"whose registry entry has already been released",
+	)
+}
+
+// TestArchiveSweep_LeavesNoRegistryEntry states the same
+// invariant in its general form: sweeping an archive whose
+// webhook has no cached writer must not leave one behind, so the
+// registry keeps holding only writers a delivery created and an
+// eviction can reach.
+func TestArchiveSweep_LeavesNoRegistryEntry(t *testing.T) {
+	t.Parallel()
+
+	env := setupSweeperTest(t)
+
+	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	path := env.seedArchiveRows(
+		t, webhookID,
+		time.Now().Add(-48*time.Hour),
+		time.Now().Add(-time.Minute),
+	)
+
+	require.False(t, env.eng.ExportHasArchiveWriter(webhookID))
+
+	env.sweeper.ExportSweep(context.Background())
+
+	assert.Equal(
+		t, []string{sweepRowNew}, archivedEventIDs(t, path),
+		"the sweep must still prune an idle archive",
+	)
+	assert.False(
+		t, env.eng.ExportHasArchiveWriter(webhookID),
+		"the sweep must release the registry entry it created",
+	)
+}
+
+// TestArchiveSweep_KeepsWriterAdoptedByDelivery is the other
+// half of that invariant: an entry the sweep created but a
+// delivery then claimed belongs to the registry and must survive
+// the sweep, or the delivery would be left holding a detached
+// writer with an open handle that no eviction can reach.
+func TestArchiveSweep_KeepsWriterAdoptedByDelivery(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSweeperTest(t)
+
+	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	env.seedArchiveRows(
+		t, webhookID, time.Now().Add(-48*time.Hour),
+	)
+
+	webhookDB := testWebhookDB(t)
+	event := seedEvent(t, webhookDB, `{"n":1}`)
+	event.WebhookID = webhookID
+	d := seedDatabaseTargetDelivery(
+		t, webhookDB, event, `{"expiry":"1h"}`,
+	)
+
+	env.sweeper.ExportSweep(context.Background())
+	require.False(t, env.eng.ExportHasArchiveWriter(webhookID))
+
+	env.eng.ExportDeliverDatabase(webhookDB, d)
+
+	assert.True(
+		t, env.eng.ExportHasArchiveWriter(webhookID),
+		"a delivery's writer must stay registered",
+	)
+
+	env.sweeper.ExportSweep(context.Background())
+
+	assert.True(
+		t, env.eng.ExportHasArchiveWriter(webhookID),
+		"a sweep must not drop a writer a delivery owns",
+	)
+}
+
+// TestArchiveSweep_KeepsWriterAdoptedDuringSweep covers the one
+// interleaving the sweepOwned flag exists for, which
+// TestArchiveSweep_KeepsWriterAdoptedByDelivery cannot reach: a
+// delivery adopting the sweep's own entry WHILE that sweep is
+// still running.
+//
+// The registry operations are driven directly, in the order the
+// sweep and a concurrent delivery perform them, so the window is
+// exercised deterministically rather than hoped for:
+//
+//  1. the sweep finds no cached writer and registers one of its
+//     own, marked sweep-owned;
+//  2. a delivery arrives, is handed that very writer, clears the
+//     flag and opens the archive handle;
+//  3. the sweep finishes and releases what it created.
+//
+// Step 3 must leave the entry alone. Dropping it would detach a
+// writer that is holding an open archive handle inside its
+// debounce window, and no eviction could ever reach it again —
+// exactly the process-lifetime handle leak this change exists to
+// close. The eviction at the end proves the entry is still
+// reachable.
+func TestArchiveSweep_KeepsWriterAdoptedDuringSweep(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSweeperTest(t)
+
+	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	env.seedArchiveRows(
+		t, webhookID, time.Now().Add(-48*time.Hour),
+	)
+
+	sweepWriter, created, err := env.eng.ExportSweepWriterFor(
+		webhookID,
+	)
+	require.NoError(t, err)
+	require.True(
+		t, created,
+		"the sweep must have created the registry entry itself",
+	)
+
+	// The delivery lands mid-sweep and adopts the entry.
+	webhookDB := testWebhookDB(t)
+	event := seedEvent(t, webhookDB, `{"n":1}`)
+	event.WebhookID = webhookID
+	d := seedDatabaseTargetDelivery(
+		t, webhookDB, event, `{"expiry":"1h"}`,
+	)
+
+	env.eng.ExportDeliverDatabase(webhookDB, d)
+
+	adopted := env.eng.ExportArchiveWriterFor(webhookID)
+	require.NotNil(t, adopted)
+	require.True(
+		t, sweepWriter.Same(adopted),
+		"the delivery must have adopted the sweep's writer",
+	)
+	require.True(
+		t, env.eng.ExportArchiveHandleOpen(webhookID),
+		"the delivery leaves the archive handle open",
+	)
+
+	// The sweep finishes.
+	env.eng.ExportReleaseSweepWriter(webhookID, sweepWriter)
+
+	require.True(
+		t, env.eng.ExportHasArchiveWriter(webhookID),
+		"a writer adopted by a delivery during a sweep must "+
+			"stay registered, or its open handle is unreachable",
+	)
+
+	env.eng.EvictWebhook(webhookID)
+
+	assert.False(
+		t, env.eng.ExportHasArchiveWriter(webhookID),
+		"the adopted writer must still be evictable",
+	)
+	assert.False(
+		t, sweepWriter.HandleOpen(),
+		"eviction must have closed the adopted writer's handle",
+	)
+}
+
+// TestArchiveSweep_ContinuesAfterPerWebhookFailure proves a
+// failure for one webhook does not abort the sweep for the
+// others: an unparseable expiry and an unreadable archive both
+// have to be logged and stepped over.
+func TestArchiveSweep_ContinuesAfterPerWebhookFailure(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSweeperTest(t)
+
+	// Seeded first so the sweep reaches them before the healthy
+	// webhook: targets come back in insertion order.
+	badConfigID := env.seedDatabaseTarget(t, `{"expiry":"!!!"}`)
+	env.seedArchiveRows(
+		t, badConfigID, time.Now().Add(-48*time.Hour),
+	)
+
+	corruptID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	require.NoError(t, os.WriteFile(
+		env.archivePath(corruptID),
+		[]byte("this is not a sqlite database"),
+		0o600,
+	))
+
+	healthyID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	healthyPath := env.seedArchiveRows(
+		t, healthyID,
+		time.Now().Add(-48*time.Hour),
+		time.Now().Add(-time.Minute),
+	)
+
+	env.sweeper.ExportSweep(context.Background())
+
+	assert.Equal(
+		t, []string{sweepRowNew},
+		archivedEventIDs(t, healthyPath),
+		"a failure for an earlier webhook must not stop the "+
+			"sweep from pruning the ones after it",
+	)
+}
+
+// TestArchiveSweep_OpenExistingDoesNotCreateFile pins the second
+// of the two no-create guards. The first is the stat in
+// sweepWebhook; this one is the SQLite open mode, which is what
+// protects the window between that stat and the open. Flipping
+// the sweep's mode to create-if-missing makes this fail.
+func TestArchiveSweep_OpenExistingDoesNotCreateFile(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	dir := t.TempDir()
+	path := filepath.Join(dir, "archive-absent.db")
+
+	w := delivery.NewExportArchiveWriter(
+		path, archiveTestLogger(), 0,
+	)
+
+	err := w.OpenExisting(time.Hour)
+
+	require.Error(
+		t, err,
+		"opening a missing archive without create permission "+
+			"must fail rather than conjure the file",
+	)
+
+	for _, suffix := range archiveFileSuffixes() {
+		assert.NoFileExists(t, path+suffix)
+	}
+}
+
+// TestArchiveSweep_PrunesIdleArchive is the core regression
+// test for this issue: an archive that receives no further
+// writes must still lose its expired rows. Before the sweeper
+// existed, pruning only ever ran on a write-triggered reopen,
+// so an idle archive kept expired rows forever.
+func TestArchiveSweep_PrunesIdleArchive(t *testing.T) {
+	t.Parallel()
+
+	env := setupSweeperTest(t)
+
+	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+
+	now := time.Now()
+	path := env.seedArchiveRows(
+		t, webhookID,
+		now.Add(-48*time.Hour),
+		now.Add(-time.Minute),
+	)
+
+	require.Equal(
+		t, []string{sweepRowOld, sweepRowNew},
+		archivedEventIDs(t, path),
+	)
+
+	env.sweeper.ExportSweep(context.Background())
+
+	assert.Equal(
+		t, []string{sweepRowNew}, archivedEventIDs(t, path),
+		"the sweep should prune rows older than the expiry "+
+			"from an idle archive and keep the rest",
+	)
+}
+
+// TestArchiveSweep_LeavesArchiveClosed proves the sweep does
+// not hold the archive open afterwards, so an operator can
+// still move the file away for offline retention.
+//
+// The assertion is made on a writer the test holds a reference
+// to, and the handle is proven OPEN before the sweep runs, so the
+// test observes the sweep closing it rather than a writer that
+// merely never opened anything. Asking the registry instead would
+// be vacuous here: the sweep releases an entry it created, and a
+// missing entry reports "not open" whether or not anything was
+// closed.
+func TestArchiveSweep_LeavesArchiveClosed(t *testing.T) {
+	t.Parallel()
+
+	env := setupSweeperTest(t)
+
+	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	path := env.seedArchiveRows(
+		t, webhookID, time.Now().Add(-48*time.Hour),
+	)
+
+	w := delivery.NewExportArchiveWriter(
+		path, archiveTestLogger(), 0,
+	)
+
+	require.NoError(t, w.OpenExisting(time.Hour))
+	require.True(
+		t, w.HandleOpen(),
+		"the writer must hold an open handle before the sweep",
+	)
+
+	require.NoError(t, w.SweepExpired(time.Hour))
+
+	assert.False(
+		t, w.HandleOpen(),
+		"an idle archive must end the sweep closed",
+	)
+}
+
+// TestArchiveSweep_ClosesHandleOfRegisteredWriter states the same
+// guarantee end to end, through the real sweeper and a writer the
+// registry keeps.
+//
+// The delivery leaves the archive handle open inside its debounce
+// window and makes the entry delivery-owned, so the sweep finds a
+// cached writer (created is false, nothing is released) and the
+// registry query afterwards is answered by a writer that really
+// exists. A handle left open here would be doubly wrong: it also
+// blocks the operator's move-the-file-away workflow.
+func TestArchiveSweep_ClosesHandleOfRegisteredWriter(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSweeperTest(t)
+
+	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	env.seedArchiveRows(
+		t, webhookID, time.Now().Add(-48*time.Hour),
+	)
+
+	webhookDB := testWebhookDB(t)
+	event := seedEvent(t, webhookDB, `{"n":1}`)
+	event.WebhookID = webhookID
+	d := seedDatabaseTargetDelivery(
+		t, webhookDB, event, `{"expiry":"1h"}`,
+	)
+
+	env.eng.ExportDeliverDatabase(webhookDB, d)
+
+	require.True(
+		t, env.eng.ExportArchiveHandleOpen(webhookID),
+		"the delivery must leave the archive handle open",
+	)
+
+	env.sweeper.ExportSweep(context.Background())
+
+	require.True(
+		t, env.eng.ExportHasArchiveWriter(webhookID),
+		"the delivery's registry entry must survive the sweep",
+	)
+	assert.False(
+		t, env.eng.ExportArchiveHandleOpen(webhookID),
+		"the sweep must leave the archive closed",
+	)
+}
+
+// TestArchiveSweep_NeverExpiryUntouched proves the sweep is a
+// no-op for the default retention policy, so archives with no
+// expiry (or the literal "never") behave exactly as before.
+func TestArchiveSweep_NeverExpiryUntouched(t *testing.T) {
+	t.Parallel()
+
+	for _, configJSON := range []string{
+		`{"expiry":"never"}`,
+		`{"expiry":""}`,
+		"",
+	} {
+		env := setupSweeperTest(t)
+
+		webhookID := env.seedDatabaseTarget(t, configJSON)
+		path := env.seedArchiveRows(
+			t, webhookID,
+			time.Now().Add(-10000*time.Hour),
+		)
+
+		env.sweeper.ExportSweep(context.Background())
+
+		assert.Equal(
+			t, []string{sweepRowOld}, archivedEventIDs(t, path),
+			"config %q must keep rows forever", configJSON,
+		)
+		assert.False(
+			t, env.eng.ExportHasArchiveWriter(webhookID),
+			"config %q must leave no registry entry behind",
+			configJSON,
+		)
+	}
+}
+
+// TestArchiveSweep_NeverExpirySkipsBeforeOpening pins the
+// expiry <= 0 boundary in sweepTarget, which the row assertions
+// above cannot reach: pruning is separately gated on a positive
+// expiry, so a "never" archive keeps its rows even if the sweep
+// does open it.
+//
+// The spec is stronger than that — a "never" archive is skipped
+// before any file is touched — so the archive here exists but has
+// never been migrated. Opening it at all would run AutoMigrate
+// and create the archive table, which is exactly what must not
+// happen.
+func TestArchiveSweep_NeverExpirySkipsBeforeOpening(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSweeperTest(t)
+
+	webhookID := env.seedDatabaseTarget(t, `{"expiry":"never"}`)
+	path := env.archivePath(webhookID)
+
+	seedUnmigratedArchive(t, path)
+	require.False(t, archiveTableExists(t, path))
+
+	env.sweeper.ExportSweep(context.Background())
+
+	assert.False(
+		t, archiveTableExists(t, path),
+		"a never-expiry archive must not be opened at all",
+	)
+}
+
+// seedUnmigratedArchive creates an archive file that exists but
+// carries no archive schema, so any open of it is observable: the
+// archive table appears only if something ran AutoMigrate.
+func seedUnmigratedArchive(t *testing.T, path string) {
+	t.Helper()
+
+	sqlDB, err := sql.Open(
+		"sqlite", fmt.Sprintf("file:%s?mode=rwc", path),
+	)
+	require.NoError(t, err)
+
+	_, err = sqlDB.ExecContext(
+		t.Context(), "CREATE TABLE placeholder (id INTEGER)",
+	)
+	require.NoError(t, err)
+
+	require.NoError(t, sqlDB.Close())
+}
+
+// archiveTableExists reports whether an archive file has had the
+// archive schema migrated into it.
+func archiveTableExists(t *testing.T, path string) bool {
+	t.Helper()
+
+	return openArchiveDBForRead(t, path).
+		Migrator().
+		HasTable(&delivery.ExportArchivedEvent{})
+}
+
+// TestArchiveSweep_DoesNotCreateArchiveFile proves the sweep
+// never conjures an archive: a webhook with a database target
+// that has never received an event must still have no archive
+// file (nor SQLite sidecar) after a sweep.
+func TestArchiveSweep_DoesNotCreateArchiveFile(t *testing.T) {
+	t.Parallel()
+
+	env := setupSweeperTest(t)
+
+	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	path := env.archivePath(webhookID)
+
+	require.NoFileExists(t, path)
+
+	env.sweeper.ExportSweep(context.Background())
+
+	for _, suffix := range archiveFileSuffixes() {
+		assert.NoFileExists(
+			t, path+suffix,
+			"the sweep must not create an archive file",
+		)
+	}
+}
+
+// TestArchiveSweep_DoesNotCreateAfterWriterExists covers the
+// same guarantee once a writer is cached in the registry but
+// the file itself is still absent (for instance because the
+// operator moved the archive away).
+func TestArchiveSweep_DoesNotCreateAfterWriterExists(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSweeperTest(t)
+
+	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+
+	path, err := env.eng.ExportEnsureArchiveWriter(webhookID)
+	require.NoError(t, err)
+	require.NoFileExists(t, path)
+
+	env.sweeper.ExportSweep(context.Background())
+
+	assert.NoFileExists(t, path)
+}
+
+// TestArchiveSweep_SkipsDeletedWebhookTargets proves that the
+// sweep ignores targets soft-deleted along with their webhook,
+// so a deleted webhook's archive is never reopened.
+func TestArchiveSweep_SkipsDeletedWebhookTargets(t *testing.T) {
+	t.Parallel()
+
+	env := setupSweeperTest(t)
+
+	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	path := env.seedArchiveRows(
+		t, webhookID, time.Now().Add(-48*time.Hour),
+	)
+
+	require.NoError(
+		t,
+		env.mainDB.DB().
+			Where("webhook_id = ?", webhookID).
+			Delete(&database.Target{}).Error,
+	)
+
+	env.sweeper.ExportSweep(context.Background())
+
+	assert.Equal(
+		t, []string{sweepRowOld}, archivedEventIDs(t, path),
+		"a deleted target's archive must be left alone",
+	)
+}
+
+// TestArchiveSweep_ConcurrentWrites proves the sweep serialises
+// against writes through the per-webhook writer mutex. Run
+// under -race, an unsynchronised sweep would be caught here.
+func TestArchiveSweep_ConcurrentWrites(t *testing.T) {
+	t.Parallel()
+
+	env := setupSweeperTest(t)
+
+	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+
+	webhookDB := testWebhookDB(t)
+
+	// The deliveries are seeded up front, on the test's own
+	// goroutine: the seed helpers assert, and testify assertions
+	// must not run off the test goroutine.
+	deliveries := make(
+		[]*database.Delivery, 0, sweepConcurrentWrites,
+	)
+
+	for range sweepConcurrentWrites {
+		event := seedEvent(t, webhookDB, `{"n":1}`)
+		event.WebhookID = webhookID
+
+		deliveries = append(
+			deliveries,
+			seedDatabaseTargetDelivery(
+				t, webhookDB, event, `{"expiry":"1h"}`,
+			),
+		)
+	}
+
+	var wg sync.WaitGroup
+
+	wg.Add(2)
+
+	go func() {
+		defer wg.Done()
+
+		for _, d := range deliveries {
+			env.eng.ExportDeliverDatabase(webhookDB, d)
+		}
+	}()
+
+	go func() {
+		defer wg.Done()
+
+		for range sweepConcurrentWrites {
+			env.sweeper.ExportSweep(context.Background())
+		}
+	}()
+
+	wg.Wait()
+
+	assert.FileExists(t, env.archivePath(webhookID))
+}
+
+// TestArchiveSweeper_StopsCleanly proves the background loop
+// exits on OnStop rather than leaking a goroutine.
+func TestArchiveSweeper_StopsCleanly(t *testing.T) {
+	t.Parallel()
+
+	env := setupSweeperTest(t)
+
+	webhookID := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
+	env.seedArchiveRows(
+		t, webhookID, time.Now().Add(-48*time.Hour),
+	)
+
+	env.sweeper.ExportSetInterval(time.Millisecond)
+	env.sweeper.ExportStart()
+
+	// stop blocks on the loop's WaitGroup, so returning at all
+	// proves the loop observed the cancellation and exited.
+	env.sweeper.ExportStop()
+}

internal/delivery/engine.go

@@ -94,6 +94,23 @@ type Notifier interface {
 	Notify(tasks []Task)
 }
 
+// WebhookEvictor releases the delivery engine's per-webhook
+// state for a webhook that no longer needs it — currently the
+// cached archive writer of the database target, whose open
+// file handle would otherwise outlive the webhook.
+//
+// It is deliberately separate from Notifier and deliberately
+// one method wide: archiving lifecycle is not notification, and
+// a single-method interface keeps the handlers package free of
+// any dependency on the engine's internals while staying
+// trivially fakeable in tests.
+//
+// EvictWebhook never deletes an archive file. It is idempotent
+// and is a no-op for a webhook with no engine state.
+type WebhookEvictor interface {
+	EvictWebhook(webhookID string)
+}
+
 // EngineParams are the fx dependencies for the delivery
 // engine.
 type EngineParams struct {
@@ -127,6 +144,10 @@ type Engine struct {
 	// httpTarget is retained so tests can reach the HTTP
 	// target's shared client and circuit breakers.
 	httpTarget *httpTarget
+
+	// dbTarget is retained so the engine can reach the archive
+	// writer registry for webhook eviction and the idle sweep.
+	dbTarget *databaseTarget
 }
 
 // New creates and registers the delivery engine with the
@@ -149,18 +170,7 @@ func New(
 		Transport: NewSSRFSafeTransport(),
 	})
 
-	lc.Append(fx.Hook{
-		OnStart: func(ctx context.Context) error {
-			e.start(ctx)
-
-			return nil
-		},
-		OnStop: func(_ context.Context) error {
-			e.stop()
-
-			return nil
-		},
-	})
+	e.registerHooks(lc)
 
 	return e
 }
@@ -182,6 +192,19 @@ func (e *Engine) Notify(tasks []Task) {
 	}
 }
 
+// EvictWebhook implements WebhookEvictor. It releases the
+// engine's per-webhook archiving state: the database target's
+// cached archive writer is dropped from the registry and its
+// file handle closed. The archive file itself is left on disk
+// — it is long-term storage the operator owns.
+func (e *Engine) EvictWebhook(webhookID string) {
+	if e.dbTarget == nil {
+		return
+	}
+
+	e.dbTarget.evict(webhookID)
+}
+
 // ScheduleRetry schedules a task to be re-enqueued onto the
 // retry channel after delay. It implements the Scheduler
 // interface the targets use to own their durable retries.
@@ -210,8 +233,40 @@ func (e *Engine) ScheduleRetry(
 	})
 }
 
-func (e *Engine) start(ctx context.Context) {
-	ctx, cancel := context.WithCancel(ctx)
+// registerHooks wires the engine's start and stop into the fx
+// lifecycle. The start hook's context is deliberately ignored:
+// see start for why the worker pool must not inherit it.
+func (e *Engine) registerHooks(lc fx.Lifecycle) {
+	lc.Append(fx.Hook{
+		//nolint:contextcheck // Not inheriting the hook context
+		// is the point: see start.
+		OnStart: func(_ context.Context) error {
+			e.start()
+
+			return nil
+		},
+		OnStop: func(_ context.Context) error {
+			e.stop()
+
+			return nil
+		},
+	})
+}
+
+// start launches the worker pool, restart recovery, and the
+// periodic retry sweep.
+//
+// Their context is derived from context.Background(), NOT from
+// the fx OnStart hook context. The hook context carries fx's
+// start timeout (15s by default) and is cancelled once the start
+// phase completes, so goroutines derived from it stop a few
+// seconds into the process: every worker would return and the
+// engine would silently stop delivering webhooks entirely. A
+// long-lived goroutine must outlive the startup phase, so its
+// lifetime is bounded by OnStop instead: stop cancels this
+// context and waits on the WaitGroup.
+func (e *Engine) start() {
+	ctx, cancel := context.WithCancel(context.Background())
 	e.cancel = cancel
 
 	for range e.workers {
@@ -453,8 +508,9 @@ func (e *Engine) recoverRetryingDeliveries(
 // recoverSingleRetry hands an orphaned retrying delivery back
 // to its target to recompute the remaining backoff, then
 // reschedules it. Targets that do not own durable retries
-// (fire-and-forget) never produce retrying deliveries, so
-// they are skipped.
+// (fire-and-forget) never produce retrying deliveries, so a
+// delivery found in that state has had its target's type
+// changed underneath it and is terminally failed.
 func (e *Engine) recoverSingleRetry(
 	webhookDB *gorm.DB,
 	webhookID string,
@@ -475,6 +531,10 @@ func (e *Engine) recoverSingleRetry(
 
 	rs, ok := e.targets[target.Type].(rescheduler)
 	if !ok {
+		e.failUnretryableRetry(
+			webhookDB, webhookID, d, &target,
+		)
+
 		return
 	}
 
@@ -649,8 +709,8 @@ func (e *Engine) sweepWebhookRetries(
 
 // sweepSingleRetry re-enqueues an orphaned retrying delivery
 // whose backoff window has elapsed, delegating the backoff
-// decision to the delivery's target. Targets that do not own
-// durable retries are skipped.
+// decision to the delivery's target. A delivery whose target
+// no longer owns durable retries is terminally failed.
 func (e *Engine) sweepSingleRetry(
 	webhookDB *gorm.DB,
 	webhookID string,
@@ -670,6 +730,10 @@ func (e *Engine) sweepSingleRetry(
 
 	rs, ok := e.targets[target.Type].(rescheduler)
 	if !ok {
+		e.failUnretryableRetry(
+			webhookDB, webhookID, d, &target,
+		)
+
 		return
 	}
 
@@ -710,6 +774,59 @@ func (e *Engine) sweepSingleRetry(
 	}
 }
 
+// failUnretryableRetry terminally fails an orphaned retrying
+// delivery whose target type no longer supports retries. Both
+// restart recovery and the periodic sweep call it, so the
+// terminal transition exists once.
+//
+// This is only reachable when a target's type has been changed
+// out from under an in-flight retrying delivery (or the type is
+// unknown to the registry): fire-and-forget targets never set
+// status retrying themselves. Re-dispatching under the new type
+// would be a delivery the operator never asked for, and leaving
+// the row retrying strands it forever, so the delivery is
+// failed with a recorded reason and can be redelivered
+// manually. Logged at warn, not error: this is operator-caused
+// state, not a system fault.
+func (e *Engine) failUnretryableRetry(
+	webhookDB *gorm.DB,
+	webhookID string,
+	d *database.Delivery,
+	target *database.Target,
+) {
+	e.log.Warn(
+		"failing orphaned retrying delivery: target "+
+			"type no longer supports retries",
+		"webhook_id", webhookID,
+		"delivery_id", d.ID,
+		"target_id", target.ID,
+		"target_name", target.Name,
+		"target_type", target.Type,
+	)
+
+	reason := fmt.Sprintf(
+		"target type %q does not support retries; "+
+			"delivery was left retrying by a previous "+
+			"target type and has been failed terminally",
+		target.Type,
+	)
+
+	e.recordResult(
+		webhookDB,
+		d,
+		e.countAttempts(webhookDB, d.ID)+1,
+		false,
+		0,
+		"",
+		reason,
+		0,
+	)
+
+	e.updateDeliveryStatus(
+		webhookDB, d, database.DeliveryStatusFailed,
+	)
+}
+
 // processDelivery dispatches a delivery to the target that
 // owns its type. Unknown target types fail the delivery.
 func (e *Engine) processDelivery(

internal/delivery/engine_integration_test.go

@@ -476,7 +476,7 @@ func TestWorkerLifecycle_StartStop(t *testing.T) {
 	t.Parallel()
 
 	s := newISetup(t)
-	s.Engine.ExportStart(context.Background())
+	s.Engine.ExportStart()
 
 	event := iSeedEvent(
 		t, s.WebhookDB, s.WebhookID,
@@ -499,21 +499,17 @@ func TestWorkerLifecycle_StartStop(t *testing.T) {
 
 	s.Engine.Notify([]delivery.Task{task})
 
-	iWaitForStatus(
-		t, s.WebhookDB, d.ID,
-		database.DeliveryStatusDelivered,
-	)
+	iWaitForDelivered(t, s.WebhookDB, d.ID)
 
 	s.Engine.ExportStop()
 }
 
-// iWaitForStatus polls until the delivery reaches the
-// expected status.
-func iWaitForStatus(
+// iWaitForDelivered polls until the delivery reaches the
+// delivered status.
+func iWaitForDelivered(
 	t *testing.T,
 	db *gorm.DB,
 	deliveryID string,
-	expected database.DeliveryStatus,
 ) {
 	t.Helper()
 
@@ -527,7 +523,7 @@ func iWaitForStatus(
 			return false
 		}
 
-		return d.Status == expected
+		return d.Status == database.DeliveryStatusDelivered
 	}, 5*time.Second, 50*time.Millisecond)
 }
 
@@ -558,7 +554,7 @@ func TestWorkerLifecycle_ProcessesRetryChannel(
 		database.DeliveryStatusRetrying,
 	)
 
-	s.Engine.ExportStart(context.Background())
+	s.Engine.ExportStart()
 
 	bodyStr := event.Body
 	cfg := iHTTPConfig(ts.URL)
@@ -569,10 +565,7 @@ func TestWorkerLifecycle_ProcessesRetryChannel(
 
 	s.Engine.ExportRetryCh() <- task
 
-	iWaitForStatus(
-		t, s.WebhookDB, d.ID,
-		database.DeliveryStatusDelivered,
-	)
+	iWaitForDelivered(t, s.WebhookDB, d.ID)
 
 	s.Engine.ExportStop()
 }
@@ -748,6 +741,193 @@ func TestRecoverWebhookDeliveries_RetryingDeliveries(
 	case <-time.After(5 * time.Second):
 		t.Fatal("expected retry task from recovery")
 	}
+
+	// Regression guard: a target that still supports retries
+	// must be rescheduled, never terminally failed, and must
+	// not gain a synthetic result row.
+	iAssertStatus(
+		t, s.WebhookDB, d.ID,
+		database.DeliveryStatusRetrying,
+	)
+
+	assert.Len(t, iResults(t, s.WebhookDB, d.ID), 1)
+}
+
+// --- Retrying deliveries whose target type changed ---
+
+// iSeedRetryingWithType seeds a retrying delivery with one
+// recorded failed attempt against a target of the given type,
+// standing in for a target whose type was edited in the main
+// database while the delivery was still retrying.
+func iSeedRetryingWithType(
+	t *testing.T,
+	s iSetup,
+	targetType database.TargetType,
+) string {
+	t.Helper()
+
+	targetID := uuid.New().String()
+
+	iCreateTarget(t, s.MainDB, targetID,
+		s.WebhookID, "mutated-target", targetType,
+		iHTTPConfig("http://example.com/hook"), 5,
+	)
+
+	event := iSeedEvent(
+		t, s.WebhookDB, s.WebhookID,
+		`{"orphaned":"retry"}`,
+	)
+
+	d := iSeedDelivery(
+		t, s.WebhookDB, event.ID, targetID,
+		database.DeliveryStatusRetrying,
+	)
+
+	iSeedFailedResult(t, s.WebhookDB, d.ID)
+
+	return d.ID
+}
+
+// iResults loads a delivery's results in attempt order.
+func iResults(
+	t *testing.T, db *gorm.DB, deliveryID string,
+) []database.DeliveryResult {
+	t.Helper()
+
+	var results []database.DeliveryResult
+
+	require.NoError(t, db.
+		Where("delivery_id = ?", deliveryID).
+		Order("attempt_num").
+		Find(&results).Error)
+
+	return results
+}
+
+// iAssertTerminallyFailed asserts the delivery ended failed
+// with a result row recording why, and was not rescheduled.
+func iAssertTerminallyFailed(
+	t *testing.T,
+	s iSetup,
+	deliveryID string,
+	targetType database.TargetType,
+) {
+	t.Helper()
+
+	iAssertStatus(
+		t, s.WebhookDB, deliveryID,
+		database.DeliveryStatusFailed,
+	)
+
+	results := iResults(t, s.WebhookDB, deliveryID)
+	require.Len(t, results, 2)
+
+	last := results[1]
+
+	assert.False(t, last.Success)
+	assert.Equal(t, 2, last.AttemptNum)
+
+	assert.Contains(
+		t, last.Error, string(targetType),
+	)
+
+	assert.Contains(
+		t, last.Error, "does not support retries",
+	)
+
+	assert.Empty(t, s.Engine.ExportRetryCh())
+}
+
+func TestRecoverSingleRetry_TypeNoLongerRetries(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	s := newISetup(t)
+
+	iCreateWebhook(
+		t, s.MainDB, s.WebhookID, "mutated-type",
+	)
+
+	deliveryID := iSeedRetryingWithType(
+		t, s, database.TargetTypeLog,
+	)
+
+	s.Engine.ExportRecoverWebhookDeliveries(
+		context.Background(), s.WebhookID,
+	)
+
+	iAssertTerminallyFailed(
+		t, s, deliveryID, database.TargetTypeLog,
+	)
+}
+
+func TestSweepSingleRetry_TypeNoLongerRetries(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	s := newISetup(t)
+
+	iCreateWebhook(
+		t, s.MainDB, s.WebhookID, "mutated-type-sweep",
+	)
+
+	deliveryID := iSeedRetryingWithType(
+		t, s, database.TargetTypeDatabase,
+	)
+
+	s.Engine.ExportSweepWebhookRetries(
+		context.Background(), s.WebhookID,
+	)
+
+	iAssertTerminallyFailed(
+		t, s, deliveryID, database.TargetTypeDatabase,
+	)
+}
+
+func TestRecoverSingleRetry_UnknownTargetType(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	s := newISetup(t)
+
+	iCreateWebhook(
+		t, s.MainDB, s.WebhookID, "unknown-type",
+	)
+
+	unknown := database.TargetType("not-a-target-type")
+
+	deliveryID := iSeedRetryingWithType(t, s, unknown)
+
+	s.Engine.ExportRecoverWebhookDeliveries(
+		context.Background(), s.WebhookID,
+	)
+
+	iAssertTerminallyFailed(t, s, deliveryID, unknown)
+}
+
+func TestSweepSingleRetry_UnknownTargetType(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	s := newISetup(t)
+
+	iCreateWebhook(
+		t, s.MainDB, s.WebhookID, "unknown-type-sweep",
+	)
+
+	unknown := database.TargetType("not-a-target-type")
+
+	deliveryID := iSeedRetryingWithType(t, s, unknown)
+
+	s.Engine.ExportSweepWebhookRetries(
+		context.Background(), s.WebhookID,
+	)
+
+	iAssertTerminallyFailed(t, s, deliveryID, unknown)
 }
 
 // iSeedFailedResult creates a failed delivery result.

internal/delivery/engine_lifecycle_test.go

@@ -0,0 +1,199 @@
+package delivery_test
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/fx"
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/delivery"
+)
+
+const (
+	// hookStopTimeout bounds how long a lifecycle test waits for
+	// the engine's OnStop hook to return before declaring the
+	// shutdown hung.
+	hookStopTimeout = 10 * time.Second
+
+	// hookSettleDelay is how long startEngineViaHook waits after
+	// OnStart before the caller may enqueue work. A worker pool
+	// wrongly rooted in the already-done hook context has nothing
+	// but ctx.Done() ready in its select, so it is deterministically
+	// gone by the end of this window. Without the wait, Notify would
+	// race the pool's very first select, in which a ready ctx.Done()
+	// and a ready deliveryCh are chosen between at random and a
+	// doomed pool still delivers.
+	hookSettleDelay = 250 * time.Millisecond
+)
+
+// recordingLifecycle is a minimal fx.Lifecycle that records the
+// hooks a component registers, so a test can invoke the real
+// OnStart/OnStop functions with a context of its choosing.
+type recordingLifecycle struct {
+	hooks []fx.Hook
+}
+
+func (l *recordingLifecycle) Append(h fx.Hook) {
+	l.hooks = append(l.hooks, h)
+}
+
+// startEngineViaHook drives the genuine fx hooks the application
+// registers for the engine, handing OnStart a context that is
+// already done, and returns only once a pool that inherited that
+// context would have exited. It returns the recorded lifecycle so
+// the caller can drive OnStop too.
+//
+// Callers must not seed pending or retrying deliveries before
+// calling this: restart recovery enqueues those during startup,
+// which would put work in the queue while the pool is still
+// racing its first select.
+func startEngineViaHook(
+	t *testing.T, eng *delivery.Engine,
+) *recordingLifecycle {
+	t.Helper()
+
+	lc := &recordingLifecycle{}
+	eng.ExportRegisterHooks(lc)
+	require.Len(t, lc.hooks, 1)
+
+	// fx hands OnStart a context carrying the application start
+	// timeout, and cancels it when the start phase ends. An
+	// already-cancelled context is that same defect taken to its
+	// limit, and unlike a plain context.Background() it actually
+	// distinguishes a correctly rooted loop from a broken one.
+	hookCtx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	require.NoError(t, lc.hooks[0].OnStart(hookCtx))
+
+	time.Sleep(hookSettleDelay)
+
+	return lc
+}
+
+// seedLogTask seeds a pending delivery for a log target and
+// returns its ID together with the task that drives it. The log
+// target needs no network, so a delivery completing proves only
+// that a worker picked the task up.
+func seedLogTask(
+	t *testing.T, s iSetup,
+) (string, delivery.Task) {
+	t.Helper()
+
+	event := iSeedEvent(
+		t, s.WebhookDB, s.WebhookID,
+		`{"lifecycle":"hook-context"}`,
+	)
+	targetID := uuid.New().String()
+
+	d := iSeedDelivery(
+		t, s.WebhookDB, event.ID, targetID,
+		database.DeliveryStatusPending,
+	)
+
+	bodyStr := event.Body
+	task := iTask(
+		d, event, s.WebhookID, targetID,
+		"hook-context-test", "", 0, 1, &bodyStr,
+	)
+	task.TargetType = database.TargetTypeLog
+
+	return d.ID, task
+}
+
+// TestEngine_WorkersOutliveStartHookContext is the regression
+// test for a delivery engine that stopped delivering roughly
+// fifteen seconds after boot. fx calls OnStart with a context
+// carrying the application's start timeout (15s by default) and
+// cancels it when the start phase ends, so a worker pool rooted
+// in it exits shortly after startup: the process keeps accepting
+// and persisting events while nothing at all forwards them.
+//
+// Driving OnStart with an already-cancelled context is that
+// defect taken to its limit. A pool that inherits the hook
+// context is gone before the task is even enqueued; a correctly
+// rooted pool keeps working for as long as the process lives.
+func TestEngine_WorkersOutliveStartHookContext(t *testing.T) {
+	t.Parallel()
+
+	s := newISetup(t)
+
+	lc := startEngineViaHook(t, s.Engine)
+	t.Cleanup(func() {
+		_ = lc.hooks[0].OnStop(context.Background())
+	})
+
+	// Seeded only after the pool has settled, so restart recovery
+	// cannot enqueue it during startup.
+	deliveryID, task := seedLogTask(t, s)
+
+	s.Engine.Notify([]delivery.Task{task})
+
+	iWaitForDelivered(t, s.WebhookDB, deliveryID)
+}
+
+// TestEngine_StopHookStopsWorkers proves the fix did not trade a
+// startup bug for a shutdown hang: now that the worker pool no
+// longer observes the start hook's cancellation, OnStop is the
+// only thing that can stop it, and it must both return promptly
+// and actually leave the pool drained.
+func TestEngine_StopHookStopsWorkers(t *testing.T) {
+	t.Parallel()
+
+	s := newISetup(t)
+
+	lc := startEngineViaHook(t, s.Engine)
+
+	// Let the pool prove it is running before stopping it, so a
+	// fast OnStop cannot pass by stopping something already dead.
+	firstID, firstTask := seedLogTask(t, s)
+	s.Engine.Notify([]delivery.Task{firstTask})
+	iWaitForDelivered(t, s.WebhookDB, firstID)
+
+	var stopErr error
+
+	stopped := make(chan struct{})
+
+	go func() {
+		defer close(stopped)
+
+		// stop blocks on the workers' WaitGroup, so returning at
+		// all proves every goroutine observed the cancellation.
+		stopErr = lc.hooks[0].OnStop(context.Background())
+	}()
+
+	select {
+	case <-stopped:
+	case <-time.After(hookStopTimeout):
+		t.Fatal(
+			"OnStop did not return: the delivery engine's " +
+				"WaitGroup is still waiting on a goroutine that " +
+				"never observed cancellation",
+		)
+	}
+
+	require.NoError(t, stopErr)
+
+	// With every worker gone, a freshly notified task must sit
+	// untouched in the queue rather than being delivered.
+	secondID, secondTask := seedLogTask(t, s)
+	s.Engine.Notify([]delivery.Task{secondTask})
+
+	time.Sleep(200 * time.Millisecond)
+
+	var after database.Delivery
+
+	require.NoError(
+		t,
+		s.WebhookDB.First(&after, "id = ?", secondID).Error,
+	)
+	require.Equal(
+		t,
+		database.DeliveryStatusPending,
+		after.Status,
+		"a stopped engine must not deliver anything",
+	)
+}

internal/delivery/export_test.go

@@ -7,10 +7,17 @@ import (
 	"net/http"
 	"time"
 
+	"go.uber.org/fx"
 	"gorm.io/gorm"
 	"sneak.berlin/go/webhooker/internal/database"
 )
 
+// ErrExportArchiveWriterEvicted exposes the sentinel returned by
+// an evicted archive writer. It carries the Err prefix rather
+// than this file's usual Export one because it is a sentinel
+// error.
+var ErrExportArchiveWriterEvicted = errArchiveWriterEvicted
+
 // Exported constants for test access.
 const (
 	ExportDeliveryChannelSize     = deliveryChannelSize
@@ -188,9 +195,24 @@ func (e *Engine) ExportRecoverInFlight(
 	e.recoverInFlight(ctx)
 }
 
+// ExportSweepWebhookRetries exposes sweepWebhookRetries.
+func (e *Engine) ExportSweepWebhookRetries(
+	ctx context.Context, webhookID string,
+) {
+	e.sweepWebhookRetries(ctx, webhookID)
+}
+
 // ExportStart exposes start for testing.
-func (e *Engine) ExportStart(ctx context.Context) {
-	e.start(ctx)
+func (e *Engine) ExportStart() {
+	e.start()
+}
+
+// ExportRegisterHooks registers the engine's real fx lifecycle
+// hooks on a lifecycle supplied by a test, so a test can drive
+// the exact OnStart/OnStop functions the application runs and
+// hand OnStart the kind of context fx actually supplies.
+func (e *Engine) ExportRegisterHooks(lc fx.Lifecycle) {
+	e.registerHooks(lc)
 }
 
 // ExportStop exposes stop for testing.
@@ -328,6 +350,183 @@ func (e *ExportArchiveWriter) DB() *gorm.DB {
 	return e.w.db
 }
 
+// Path returns the archive file the writer owns.
+func (e *ExportArchiveWriter) Path() string {
+	return e.w.path
+}
+
+// OpenExisting opens the archive without permitting creation,
+// the way the idle sweep does.
+func (e *ExportArchiveWriter) OpenExisting(
+	expiry time.Duration,
+) error {
+	return e.w.openMode(archiveModeExisting, expiry)
+}
+
+// SweepExpired runs an idle sweep of the archive.
+func (e *ExportArchiveWriter) SweepExpired(
+	expiry time.Duration,
+) error {
+	return e.w.sweepExpired(expiry)
+}
+
+// Evict marks the writer evicted and closes its handle, exactly
+// as leaving the registry does.
+func (e *ExportArchiveWriter) Evict() {
+	e.w.evict()
+}
+
+// HandleOpen reports whether the writer currently holds an open
+// archive handle.
+func (e *ExportArchiveWriter) HandleOpen() bool {
+	e.w.mu.Lock()
+	defer e.w.mu.Unlock()
+
+	return e.w.db != nil
+}
+
+// Same reports whether both wrappers refer to the very same
+// underlying archive writer, so a test can prove a registry entry
+// is the writer it was handed rather than a replacement.
+func (e *ExportArchiveWriter) Same(
+	other *ExportArchiveWriter,
+) bool {
+	return other != nil && e.w == other.w
+}
+
+// ExportArchiveWriterFor returns the archive writer the registry
+// currently caches for a webhook, or nil when none is cached. It
+// never creates one, so a test can hold a reference to the very
+// writer an eviction is about to detach.
+func (e *Engine) ExportArchiveWriterFor(
+	webhookID string,
+) *ExportArchiveWriter {
+	e.dbTarget.mu.Lock()
+	defer e.dbTarget.mu.Unlock()
+
+	w, ok := e.dbTarget.writers[webhookID]
+	if !ok {
+		return nil
+	}
+
+	return &ExportArchiveWriter{w: w}
+}
+
+// ExportHasArchiveWriter reports whether the database target
+// currently caches an archive writer for a webhook.
+func (e *Engine) ExportHasArchiveWriter(
+	webhookID string,
+) bool {
+	e.dbTarget.mu.Lock()
+	defer e.dbTarget.mu.Unlock()
+
+	_, ok := e.dbTarget.writers[webhookID]
+
+	return ok
+}
+
+// ExportArchiveHandleOpen reports whether the cached archive
+// writer for a webhook holds an open database handle. It
+// returns false when no writer is cached.
+func (e *Engine) ExportArchiveHandleOpen(
+	webhookID string,
+) bool {
+	e.dbTarget.mu.Lock()
+	w, ok := e.dbTarget.writers[webhookID]
+	e.dbTarget.mu.Unlock()
+
+	if !ok {
+		return false
+	}
+
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	return w.db != nil
+}
+
+// ExportEnsureArchiveWriter creates (if needed) and returns the
+// archive file path of the cached writer for a webhook, so a
+// test can prime the registry the way a delivery would.
+func (e *Engine) ExportEnsureArchiveWriter(
+	webhookID string,
+) (string, error) {
+	w, err := e.dbTarget.writerFor(webhookID)
+	if err != nil {
+		return "", err
+	}
+
+	return w.path, nil
+}
+
+// ExportSweepWriterFor takes a webhook's registry writer exactly
+// as the idle sweep does, reporting whether the sweep had to
+// create the entry. It lets a test drive the registry through the
+// sweep's own entry point instead of choreographing goroutines.
+func (e *Engine) ExportSweepWriterFor(
+	webhookID string,
+) (*ExportArchiveWriter, bool, error) {
+	w, created, err := e.dbTarget.sweepWriterFor(webhookID)
+	if err != nil {
+		return nil, false, err
+	}
+
+	return &ExportArchiveWriter{w: w}, created, nil
+}
+
+// ExportReleaseSweepWriter releases a sweep-created registry entry
+// exactly as a finished sweep does.
+func (e *Engine) ExportReleaseSweepWriter(
+	webhookID string, w *ExportArchiveWriter,
+) {
+	e.dbTarget.releaseSweepWriter(webhookID, w.w)
+}
+
+// NewTestArchiveSweeper builds an ArchiveSweeper backed by the
+// given main database and engine, without the fx lifecycle.
+// Intended for tests.
+func NewTestArchiveSweeper(
+	db *database.Database,
+	eng *Engine,
+	log *slog.Logger,
+) *ArchiveSweeper {
+	return &ArchiveSweeper{
+		db:       db,
+		eng:      eng,
+		log:      log,
+		interval: time.Hour,
+	}
+}
+
+// ExportSweep runs a single archive sweep synchronously for
+// tests.
+func (s *ArchiveSweeper) ExportSweep(ctx context.Context) {
+	s.sweep(ctx)
+}
+
+// ExportStart starts the sweeper's background loop for tests.
+func (s *ArchiveSweeper) ExportStart() {
+	s.start()
+}
+
+// ExportRegisterHooks registers the sweeper's real fx lifecycle
+// hooks on a lifecycle supplied by a test, so a test can drive
+// the exact OnStart/OnStop functions the application runs and
+// hand OnStart the kind of context fx actually supplies.
+func (s *ArchiveSweeper) ExportRegisterHooks(lc fx.Lifecycle) {
+	s.registerHooks(lc)
+}
+
+// ExportStop stops the sweeper's background loop for tests.
+func (s *ArchiveSweeper) ExportStop() {
+	s.stop()
+}
+
+// ExportSetInterval overrides the sweep interval for tests.
+func (s *ArchiveSweeper) ExportSetInterval(d time.Duration) {
+	s.interval = d
+}
+
 // ExportParseArchiveExpiry exposes parseArchiveExpiry.
 func ExportParseArchiveExpiry(
 	configJSON string,

internal/delivery/ssrf.go

@@ -92,7 +92,12 @@ func ValidateTargetURL(
 ) error {
 	parsed, err := url.Parse(targetURL)
 	if err != nil {
-		return fmt.Errorf("invalid URL: %w", err)
+		// url.Parse embeds the whole URL in its error, and
+		// this one is logged and shown; mask it. Every other
+		// branch below reports only the hostname.
+		return fmt.Errorf(
+			"invalid URL: %w", maskURLError(err),
+		)
 	}
 
 	err = validateScheme(parsed.Scheme)

internal/delivery/target.go

@@ -90,12 +90,15 @@ func (e *Engine) initTargets(client *http.Client) {
 		client:   client,
 	}
 
+	dbT := &databaseTarget{eng: e}
+
 	e.httpTarget = httpT
+	e.dbTarget = dbT
 
 	e.targets = map[database.TargetType]Target{
 		database.TargetTypeHTTP:     httpT,
 		database.TargetTypeSlack:    slackT,
-		database.TargetTypeDatabase: &databaseTarget{eng: e},
+		database.TargetTypeDatabase: dbT,
 		database.TargetTypeLog:      &logTarget{eng: e},
 	}
 }

internal/delivery/target_config_view.go

@@ -0,0 +1,202 @@
+package delivery
+
+import (
+	"encoding/json"
+	"fmt"
+	"strconv"
+
+	"sneak.berlin/go/webhooker/internal/database"
+)
+
+// configUnavailable is what a target's configuration renders
+// as when it is absent, of an unknown type, or does not
+// parse. The stored blob is never shown as a fallback: it can
+// hold a credential (a Slack incoming webhook URL is a bearer
+// token) and a UI that prints it leaks that credential into
+// browser history, screenshots and screen shares.
+const configUnavailable = "(unavailable)"
+
+// ConfigField is one labelled, display-safe value derived
+// from a target's stored configuration.
+type ConfigField struct {
+	Label string
+	Value string
+}
+
+// TargetView is the display-safe projection of a target for
+// the UI. It deliberately has no raw configuration field, so
+// no template — present or future — can render the stored
+// blob.
+type TargetView struct {
+	ID     string
+	Name   string
+	Type   database.TargetType
+	Active bool
+	Config []ConfigField
+}
+
+// NewTargetViews projects targets for rendering, replacing
+// each stored configuration blob with named, display-safe
+// fields.
+func NewTargetViews(
+	targets []database.Target,
+) []TargetView {
+	views := make([]TargetView, 0, len(targets))
+
+	for i := range targets {
+		t := &targets[i]
+
+		views = append(views, TargetView{
+			ID:     t.ID,
+			Name:   t.Name,
+			Type:   t.Type,
+			Active: t.Active,
+			Config: targetConfigFields(t),
+		})
+	}
+
+	return views
+}
+
+// targetConfigFields returns the display-safe fields for a
+// target's configuration. Anything it cannot parse becomes
+// the neutral placeholder.
+func targetConfigFields(
+	t *database.Target,
+) []ConfigField {
+	switch t.Type {
+	case database.TargetTypeSlack:
+		return slackConfigFields(t.Config)
+	case database.TargetTypeHTTP:
+		return httpConfigFields(t)
+	case database.TargetTypeDatabase:
+		return databaseConfigFields(t.Config)
+	case database.TargetTypeLog:
+		// The log target takes no configuration.
+		return nil
+	default:
+		return unavailableConfigFields()
+	}
+}
+
+// unavailableConfigFields is the neutral placeholder shown
+// for a configuration that could not be presented.
+func unavailableConfigFields() []ConfigField {
+	return []ConfigField{{
+		Label: "Configuration",
+		Value: configUnavailable,
+	}}
+}
+
+// slackConfigFields describes a Slack target. Only the masked
+// webhook URL is shown; the full URL is the credential.
+func slackConfigFields(configJSON string) []ConfigField {
+	cfg, err := parseSlackConfig(configJSON)
+	if err != nil {
+		return unavailableConfigFields()
+	}
+
+	return []ConfigField{{
+		Label: "Webhook URL",
+		Value: cfg.MaskedWebhookURL(),
+	}}
+}
+
+// httpConfigFields describes an HTTP target: its destination
+// and its retry settings. Header values are not shown — they
+// routinely carry authorization tokens — only how many are
+// configured.
+func httpConfigFields(t *database.Target) []ConfigField {
+	cfg, err := parseHTTPConfig(t.Config)
+	if err != nil {
+		return unavailableConfigFields()
+	}
+
+	fields := []ConfigField{{
+		Label: "Destination URL",
+		Value: cfg.URL,
+	}}
+
+	if cfg.Timeout > 0 {
+		fields = append(fields, ConfigField{
+			Label: "Timeout",
+			Value: strconv.Itoa(cfg.Timeout) + "s",
+		})
+	}
+
+	if len(cfg.Headers) > 0 {
+		fields = append(fields, ConfigField{
+			Label: "Headers",
+			Value: fmt.Sprintf(
+				"%d configured", len(cfg.Headers),
+			),
+		})
+	}
+
+	return append(fields, retryFields(t)...)
+}
+
+// retryFields describes a target's retry settings, which live
+// on the target row rather than in its configuration blob.
+func retryFields(t *database.Target) []ConfigField {
+	retries := strconv.Itoa(t.MaxRetries)
+	if t.MaxRetries == 0 {
+		retries += " (fire-and-forget)"
+	}
+
+	fields := []ConfigField{{
+		Label: "Max Retries",
+		Value: retries,
+	}}
+
+	if t.MaxQueueSize > 0 {
+		fields = append(fields, ConfigField{
+			Label: "Max Queue Size",
+			Value: strconv.Itoa(t.MaxQueueSize),
+		})
+	}
+
+	return fields
+}
+
+// databaseConfigFields describes an archive target. Its
+// configuration is optional, and an absent or empty expiry
+// means the archive is kept forever. An expiry that is set
+// but not a valid duration is reported as unavailable rather
+// than echoed back.
+func databaseConfigFields(configJSON string) []ConfigField {
+	expiry := archiveExpiryNever
+
+	if configJSON != "" {
+		var cfg databaseTargetConfig
+
+		err := json.Unmarshal([]byte(configJSON), &cfg)
+		if err != nil {
+			return unavailableConfigFields()
+		}
+
+		if cfg.Expiry != "" {
+			if ValidateArchiveExpiry(cfg.Expiry) != nil {
+				return unavailableConfigFields()
+			}
+
+			expiry = cfg.Expiry
+		}
+	}
+
+	return []ConfigField{{
+		Label: "Archive Expiry",
+		Value: expiry,
+	}}
+}
+
+// MaskedWebhookURL returns the Slack webhook URL reduced to
+// its scheme and host, with the path, query and any userinfo
+// elided. The path segments are the credential, so none of
+// them is shown: the field accepts an arbitrary URL, so no
+// segment can be assumed non-secret. A URL that does not
+// parse into a scheme and host yields the neutral
+// placeholder, never the raw string.
+func (c *SlackTargetConfig) MaskedWebhookURL() string {
+	return MaskURL(c.WebhookURL)
+}

internal/delivery/target_config_view_test.go

@@ -0,0 +1,299 @@
+package delivery_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/delivery"
+)
+
+const (
+	// slackSecretPath is the credential-bearing part of a
+	// Slack incoming webhook URL: everything after the host.
+	slackSecretPath = "/services/T00000000/B00000000/" +
+		"XXXXXXXXXXXXXXXXXXXXXXXX"
+	slackWebhookURL = "https://hooks.slack.com" +
+		slackSecretPath
+
+	viewExampleOrigin = "https://example.com"
+	viewExampleHook   = viewExampleOrigin + "/hook"
+	viewUnavailable   = "(unavailable)"
+	viewExpiryNever   = "never"
+)
+
+func TestMaskedWebhookURL(t *testing.T) {
+	t.Parallel()
+
+	tests := map[string]struct {
+		url  string
+		want string
+	}{
+		"slack webhook": {
+			url:  slackWebhookURL,
+			want: "https://hooks.slack.com/...",
+		},
+		"query string dropped": {
+			url:  viewExampleOrigin + "/a?token=secret",
+			want: viewExampleOrigin + "/...",
+		},
+		// Fabricated userinfo in a test URL, not a real
+		// credential.
+		//nolint:gosec // G101
+		"userinfo dropped": {
+			url:  "https://user:pw@example.com/a/b",
+			want: viewExampleOrigin + "/...",
+		},
+		"no path": {
+			url:  viewExampleOrigin,
+			want: viewExampleOrigin,
+		},
+		"root path": {
+			url:  viewExampleOrigin + "/",
+			want: viewExampleOrigin,
+		},
+		"not a url": {
+			url:  "definitely not a url",
+			want: viewUnavailable,
+		},
+		"empty": {
+			url:  "",
+			want: viewUnavailable,
+		},
+	}
+
+	for name, tc := range tests {
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			cfg := &delivery.SlackTargetConfig{
+				WebhookURL: tc.url,
+			}
+
+			assert.Equal(
+				t, tc.want, cfg.MaskedWebhookURL(),
+			)
+		})
+	}
+}
+
+// TestMaskedWebhookURL_NeverLeaksPath is the direct
+// expression of the rule: whatever the input, the masked
+// value never contains a path segment of it.
+func TestMaskedWebhookURL_NeverLeaksPath(t *testing.T) {
+	t.Parallel()
+
+	cfg := &delivery.SlackTargetConfig{
+		WebhookURL: slackWebhookURL,
+	}
+
+	masked := cfg.MaskedWebhookURL()
+
+	assert.NotContains(t, masked, "T00000000")
+	assert.NotContains(t, masked, "B00000000")
+	assert.NotContains(
+		t, masked, "XXXXXXXXXXXXXXXXXXXXXXXX",
+	)
+	assert.NotContains(t, masked, slackSecretPath)
+}
+
+// fieldMap turns a view's config fields into a lookup so
+// assertions read by label.
+func fieldMap(fields []delivery.ConfigField) map[string]string {
+	out := make(map[string]string, len(fields))
+	for _, f := range fields {
+		out[f.Label] = f.Value
+	}
+
+	return out
+}
+
+// viewFor projects a single target and returns its view.
+func viewFor(
+	t *testing.T,
+	target database.Target,
+) delivery.TargetView {
+	t.Helper()
+
+	views := delivery.NewTargetViews(
+		[]database.Target{target},
+	)
+	require.Len(t, views, 1)
+
+	return views[0]
+}
+
+func TestNewTargetViews_Slack(t *testing.T) {
+	t.Parallel()
+
+	view := viewFor(t, database.Target{
+		Name:   "slack-target",
+		Type:   database.TargetTypeSlack,
+		Active: true,
+		Config: `{"webhookUrl":"` +
+			slackWebhookURL + `"}`,
+	})
+
+	assert.Equal(t, "slack-target", view.Name)
+	assert.Equal(
+		t,
+		map[string]string{
+			"Webhook URL": "https://hooks.slack.com/...",
+		},
+		fieldMap(view.Config),
+	)
+}
+
+func TestNewTargetViews_HTTP(t *testing.T) {
+	t.Parallel()
+
+	view := viewFor(t, database.Target{
+		Type: database.TargetTypeHTTP,
+		Config: `{"url":"` + viewExampleHook + `",` +
+			`"timeout":30,` +
+			`"headers":{"Authorization":"Bearer sekrit"}}`,
+		MaxRetries:   5,
+		MaxQueueSize: 100,
+	})
+
+	fields := fieldMap(view.Config)
+
+	assert.Equal(
+		t,
+		map[string]string{
+			"Destination URL": viewExampleHook,
+			"Timeout":         "30s",
+			"Headers":         "1 configured",
+			"Max Retries":     "5",
+			"Max Queue Size":  "100",
+		},
+		fields,
+	)
+
+	// Header values can be credentials and are never shown.
+	for _, v := range fields {
+		assert.NotContains(t, v, "sekrit")
+	}
+}
+
+func TestNewTargetViews_HTTPFireAndForget(t *testing.T) {
+	t.Parallel()
+
+	view := viewFor(t, database.Target{
+		Type:   database.TargetTypeHTTP,
+		Config: `{"url":"` + viewExampleHook + `"}`,
+	})
+
+	assert.Equal(
+		t,
+		map[string]string{
+			"Destination URL": viewExampleHook,
+			"Max Retries":     "0 (fire-and-forget)",
+		},
+		fieldMap(view.Config),
+	)
+}
+
+func TestNewTargetViews_Database(t *testing.T) {
+	t.Parallel()
+
+	tests := map[string]struct {
+		config string
+		want   string
+	}{
+		"empty config": {config: "", want: viewExpiryNever},
+		"empty expiry": {config: `{}`, want: viewExpiryNever},
+		"explicit": {
+			config: `{"expiry":"720h"}`,
+			want:   "720h",
+		},
+		"never literal": {
+			config: `{"expiry":"` + viewExpiryNever + `"}`,
+			want:   viewExpiryNever,
+		},
+	}
+
+	for name, tc := range tests {
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			view := viewFor(t, database.Target{
+				Type:   database.TargetTypeDatabase,
+				Config: tc.config,
+			})
+
+			assert.Equal(
+				t,
+				map[string]string{"Archive Expiry": tc.want},
+				fieldMap(view.Config),
+			)
+		})
+	}
+}
+
+func TestNewTargetViews_Log(t *testing.T) {
+	t.Parallel()
+
+	view := viewFor(t, database.Target{
+		Type:   database.TargetTypeLog,
+		Config: "",
+	})
+
+	assert.Empty(t, view.Config)
+}
+
+// TestNewTargetViews_Unpresentable proves that no config the
+// view cannot present falls back to the stored blob.
+func TestNewTargetViews_Unpresentable(t *testing.T) {
+	t.Parallel()
+
+	const blob = `{"webhookUrl":"https://hooks.slack.com` +
+		slackSecretPath + `"`
+
+	tests := map[string]database.Target{
+		"unknown target type": {
+			Type:   database.TargetType("carrier-pigeon"),
+			Config: blob,
+		},
+		"unparseable json": {
+			Type:   database.TargetTypeSlack,
+			Config: blob,
+		},
+		"empty slack config": {
+			Type: database.TargetTypeSlack,
+		},
+		"slack config without url": {
+			Type:   database.TargetTypeSlack,
+			Config: `{}`,
+		},
+		"unparseable http json": {
+			Type:   database.TargetTypeHTTP,
+			Config: `{"url":`,
+		},
+		"unparseable archive json": {
+			Type:   database.TargetTypeDatabase,
+			Config: `{"expiry":`,
+		},
+		"invalid archive expiry": {
+			Type:   database.TargetTypeDatabase,
+			Config: `{"expiry":"a fortnight"}`,
+		},
+	}
+
+	for name, target := range tests {
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			view := viewFor(t, target)
+
+			assert.Equal(
+				t,
+				map[string]string{
+					"Configuration": viewUnavailable,
+				},
+				fieldMap(view.Config),
+			)
+		})
+	}
+}

internal/delivery/target_database.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"path/filepath"
 	"sync"
+	"time"
 
 	"gorm.io/gorm"
 	"sneak.berlin/go/webhooker/internal/database"
@@ -111,15 +112,11 @@ func (t *databaseTarget) archive(d *database.Delivery) error {
 func (t *databaseTarget) writerFor(
 	webhookID string,
 ) (*archiveWriter, error) {
-	if t.eng.dbManager == nil {
-		return nil, errArchiveNoDataDir
+	path, err := t.archivePath(webhookID)
+	if err != nil {
+		return nil, err
 	}
 
-	dir := filepath.Dir(t.eng.dbManager.DBPath(webhookID))
-	path := filepath.Join(
-		dir, fmt.Sprintf("archive-%s.db", webhookID),
-	)
-
 	t.mu.Lock()
 	defer t.mu.Unlock()
 
@@ -133,5 +130,166 @@ func (t *databaseTarget) writerFor(
 		t.writers[webhookID] = w
 	}
 
+	// A delivery claims the entry: even if the idle sweep created
+	// it moments ago, it now belongs to the registry proper and
+	// the sweep must leave it in place when it finishes.
+	w.sweepOwned = false
+
 	return w, nil
 }
+
+// sweepWriterFor returns the archive writer the idle sweep should
+// prune a webhook through, together with whether the sweep itself
+// created the registry entry.
+//
+// The sweep must route its prune through the registered writer so
+// the writer's mutex orders it against concurrent writes, but it
+// must never leave a registry entry behind: a sweep that ran
+// concurrently with the webhook's deletion would otherwise
+// re-create an entry that nothing will ever evict again, which is
+// exactly the leak eviction exists to prevent. An entry the sweep
+// creates is therefore marked sweep-owned and handed back to
+// releaseSweepWriter when the sweep is done.
+func (t *databaseTarget) sweepWriterFor(
+	webhookID string,
+) (*archiveWriter, bool, error) {
+	path, err := t.archivePath(webhookID)
+	if err != nil {
+		return nil, false, err
+	}
+
+	t.mu.Lock()
+	defer t.mu.Unlock()
+
+	if t.writers == nil {
+		t.writers = make(map[string]*archiveWriter)
+	}
+
+	w, ok := t.writers[webhookID]
+	if ok {
+		return w, false, nil
+	}
+
+	w = newArchiveWriter(path, t.eng.log)
+	w.sweepOwned = true
+	t.writers[webhookID] = w
+
+	return w, true, nil
+}
+
+// releaseSweepWriter drops a registry entry that the idle sweep
+// created, so a sweep leaves the registry exactly as it found it.
+//
+// The entry is removed only if it is still the very writer the
+// sweep installed and no delivery has claimed it in the meantime
+// (writerFor clears sweepOwned when it hands a writer to the
+// write path). Both conditions are evaluated under the registry
+// lock, so an eviction that raced the sweep — which removes the
+// entry outright — simply finds nothing left to do here, and a
+// delivery that adopted the writer keeps a registered, evictable
+// one.
+func (t *databaseTarget) releaseSweepWriter(
+	webhookID string, w *archiveWriter,
+) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+
+	cur, ok := t.writers[webhookID]
+	if !ok || cur != w || !cur.sweepOwned {
+		return
+	}
+
+	delete(t.writers, webhookID)
+}
+
+// archivePath returns the archive file path for a webhook: it
+// lives beside the per-webhook event database in the data
+// directory. It does not touch the filesystem.
+func (t *databaseTarget) archivePath(
+	webhookID string,
+) (string, error) {
+	if t.eng.dbManager == nil {
+		return "", errArchiveNoDataDir
+	}
+
+	dir := filepath.Dir(t.eng.dbManager.DBPath(webhookID))
+
+	return filepath.Join(
+		dir, fmt.Sprintf("archive-%s.db", webhookID),
+	), nil
+}
+
+// evict drops a webhook's archive writer from the registry and
+// closes its handle, so a deleted webhook does not leave a
+// writer (and an open archive handle within its debounce
+// window) alive for the process lifetime.
+//
+// The map entry is removed under the registry lock, which is
+// then released before the handle is closed under the writer's
+// own lock: that ordering keeps the registry available to other
+// webhooks while an in-flight write on this one drains, and
+// closing under the writer's lock means eviction can never race
+// a write.
+//
+// Eviction is idempotent and silent for a webhook with no
+// writer, which is the common case: a webhook with no database
+// target never creates one. It never deletes the archive file.
+func (t *databaseTarget) evict(webhookID string) {
+	t.mu.Lock()
+
+	w, ok := t.writers[webhookID]
+	if ok {
+		delete(t.writers, webhookID)
+	}
+
+	t.mu.Unlock()
+
+	if !ok {
+		return
+	}
+
+	w.evict()
+
+	t.eng.log.Info(
+		"evicted archive writer",
+		"webhook_id", webhookID,
+		"path", w.path,
+	)
+}
+
+// sweepWebhook prunes one webhook's archive of rows older than
+// expiry, without requiring a write. It returns nil (nothing to
+// do) when the archive file does not exist, so a sweep never
+// creates an archive for a webhook that has a database target
+// but has never received an event.
+//
+// It also never leaves a registry entry behind: an entry it had
+// to create to reach the writer's mutex is released again once
+// the prune is done, so a sweep racing a webhook deletion cannot
+// resurrect the writer the eviction just dropped.
+func (t *databaseTarget) sweepWebhook(
+	webhookID string, expiry time.Duration,
+) error {
+	path, err := t.archivePath(webhookID)
+	if err != nil {
+		return err
+	}
+
+	// Check before taking a writer at all: a webhook whose
+	// archive has never been created gets no writer, no handle,
+	// and no file.
+	if !fileExists(path) {
+		return nil
+	}
+
+	w, created, err := t.sweepWriterFor(webhookID)
+	if err != nil {
+		return err
+	}
+
+	if created {
+		defer t.releaseSweepWriter(webhookID, w)
+	}
+
+	return w.sweepExpired(expiry)
+}

internal/delivery/target_database_archive.go

@@ -24,6 +24,20 @@ const archiveExpiryNever = "never"
 // offline archiving, but never more than once per this window.
 const archiveReopenDebounce = time.Second
 
+const (
+	// archiveModeCreate is the SQLite URI mode used by the write
+	// path: open the archive file, creating it if missing, so a
+	// first write (or a write after the operator moved the file
+	// away) recreates it.
+	archiveModeCreate = "rwc"
+
+	// archiveModeExisting is the SQLite URI mode used by the idle
+	// sweep: open read-write but never create. A sweep must never
+	// conjure an empty archive file for a webhook that has a
+	// database target but has never received an event.
+	archiveModeExisting = "rw"
+)
+
 var (
 	// errArchiveMissingWebhookID is returned when an event to
 	// archive has no webhook id to key its archive file on.
@@ -44,6 +58,15 @@ var (
 	errArchiveExpiryNotPositive = errors.New(
 		"expiry must be a positive duration or \"never\"",
 	)
+
+	// errArchiveWriterEvicted is returned when a writer that has
+	// been evicted (its webhook was deleted, or its last database
+	// target was removed) is used again. An evicted writer is no
+	// longer in the registry, so reopening its file would leak a
+	// handle nothing owns.
+	errArchiveWriterEvicted = errors.New(
+		"archive writer has been evicted",
+	)
 )
 
 // databaseTargetConfig is the optional per-target JSON config
@@ -161,6 +184,25 @@ type archiveWriter struct {
 	db         *gorm.DB
 	lastReopen time.Time
 	reopens    int
+
+	// evicted marks a writer that has been removed from the
+	// per-webhook registry. Its handle is closed and it must
+	// never open the file again: nothing holds it any more, so a
+	// reopen would leak the handle for the process lifetime.
+	evicted bool
+
+	// sweepOwned marks a registry entry that the idle sweep
+	// created because no writer was cached for the webhook. The
+	// sweep removes such an entry again when it is done, so a
+	// sweep can never leave — or resurrect — a registry entry
+	// for a webhook that has been deleted. A delivery that adopts
+	// the writer clears the flag, handing the entry to the
+	// registry proper.
+	//
+	// Unlike every other field here it is guarded by
+	// databaseTarget.mu, not by this writer's mu: it describes the
+	// registry entry rather than the file.
+	sweepOwned bool
 }
 
 // newArchiveWriter builds an archiveWriter for a file path with
@@ -185,6 +227,12 @@ func (w *archiveWriter) write(
 	w.mu.Lock()
 	defer w.mu.Unlock()
 
+	if w.evicted {
+		return fmt.Errorf(
+			"%w: %s", errArchiveWriterEvicted, w.path,
+		)
+	}
+
 	if w.db == nil || !fileExists(w.path) {
 		err := w.reopen(expiry)
 		if err != nil {
@@ -212,7 +260,19 @@ func (w *archiveWriter) write(
 // its schema, records the reopen time, and prunes expired rows
 // when expiry is positive.
 func (w *archiveWriter) open(expiry time.Duration) error {
-	dbURL := fmt.Sprintf("file:%s?mode=rwc", w.path)
+	return w.openMode(archiveModeCreate, expiry)
+}
+
+// openMode opens the archive file with the given SQLite URI
+// mode, migrates its schema, records the reopen time, and
+// prunes expired rows when expiry is positive. The write path
+// passes archiveModeCreate so a missing file is recreated; the
+// idle sweep passes archiveModeExisting so a missing file is an
+// error rather than a newly conjured empty archive.
+func (w *archiveWriter) openMode(
+	mode string, expiry time.Duration,
+) error {
+	dbURL := fmt.Sprintf("file:%s?mode=%s", w.path, mode)
 
 	sqlDB, err := sql.Open("sqlite", dbURL)
 	if err != nil {
@@ -275,11 +335,70 @@ func (w *archiveWriter) close() {
 	w.db = nil
 }
 
+// sweepExpired prunes an archive that may have gone idle, with
+// no write to trigger the usual on-reopen prune. It takes the
+// writer's own mutex for the whole operation, so a sweep is
+// ordered against concurrent writes rather than reaching around
+// them to the file.
+//
+// It never creates the archive file: a missing file is skipped,
+// and the reopen uses archiveModeExisting so SQLite itself
+// refuses to create one if the file disappears between the
+// check and the open.
+//
+// The archive is left CLOSED afterwards. An idle archive holding
+// no handle is what keeps the operator's move-the-file-away
+// workflow working; the next write reopens (and recreates) the
+// file as it always has.
+func (w *archiveWriter) sweepExpired(expiry time.Duration) error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	if w.evicted {
+		return fmt.Errorf(
+			"%w: %s", errArchiveWriterEvicted, w.path,
+		)
+	}
+
+	if !fileExists(w.path) {
+		return nil
+	}
+
+	// Drop any live handle first so the prune runs against a
+	// freshly opened file, matching the write path's semantics.
+	w.close()
+
+	err := w.openMode(archiveModeExisting, expiry)
+	if err != nil {
+		return err
+	}
+
+	w.close()
+
+	return nil
+}
+
+// evict closes the writer's handle and marks it unusable. It is
+// called when the writer leaves the registry, either because the
+// webhook was deleted or because its last database target was
+// removed. The archive FILE is deliberately left on disk: it is
+// long-term storage an operator may still want.
+func (w *archiveWriter) evict() {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	w.evicted = true
+
+	w.close()
+}
+
 // prune deletes archived rows older than expiry, measured from
-// each row's archived time. It runs on every (re)open, and
-// because the file is reopened after writes this keeps the
-// archive swept without a separate background sweeper. Failures
-// are logged, not fatal: a prune error must not stop archiving.
+// each row's archived time. It runs on every (re)open, so a
+// steadily written archive is swept by its own write traffic. An
+// archive that goes idle receives no further reopens, which is
+// why ArchiveSweeper exists to drive sweepExpired on a timer.
+// Failures are logged, not fatal: a prune error must not stop
+// archiving.
 func (w *archiveWriter) prune(expiry time.Duration) {
 	cutoff := time.Now().Add(-expiry)
 

internal/delivery/target_database_evict_test.go

@@ -0,0 +1,363 @@
+package delivery_test
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+	"os"
+	"path/filepath"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/delivery"
+)
+
+// evictTestEngine builds an engine backed by a temporary data
+// directory and returns it along with that directory.
+func evictTestEngine(t *testing.T) (*delivery.Engine, string) {
+	t.Helper()
+
+	dataDir := t.TempDir()
+
+	eng := delivery.NewTestEngineWithDB(
+		nil,
+		database.NewTestWebhookDBManager(dataDir),
+		archiveTestLogger(),
+		&http.Client{Timeout: 5 * time.Second},
+		1,
+	)
+
+	return eng, dataDir
+}
+
+// TestEvictWebhook_ClosesAndRemovesWriter proves that evicting
+// a webhook drops its archive writer from the registry and
+// closes the open archive handle, rather than leaving both
+// alive for the process lifetime.
+func TestEvictWebhook_ClosesAndRemovesWriter(t *testing.T) {
+	t.Parallel()
+
+	eng, dataDir := evictTestEngine(t)
+
+	webhookDB := testWebhookDB(t)
+	event := seedEvent(t, webhookDB, `{"archived":true}`)
+	d := seedDatabaseTargetDelivery(t, webhookDB, event, "")
+
+	eng.ExportDeliverDatabase(webhookDB, d)
+
+	webhookID := event.WebhookID
+
+	require.True(
+		t, eng.ExportHasArchiveWriter(webhookID),
+		"a delivery should have cached an archive writer",
+	)
+	require.True(
+		t, eng.ExportArchiveHandleOpen(webhookID),
+		"the writer should hold an open handle after a write",
+	)
+
+	eng.EvictWebhook(webhookID)
+
+	assert.False(
+		t, eng.ExportHasArchiveWriter(webhookID),
+		"eviction should remove the registry entry",
+	)
+	assert.False(
+		t, eng.ExportArchiveHandleOpen(webhookID),
+		"eviction should close the archive handle",
+	)
+
+	archivePath := filepath.Join(
+		dataDir, fmt.Sprintf("archive-%s.db", webhookID),
+	)
+	assert.FileExists(
+		t, archivePath,
+		"eviction must not delete the archive file",
+	)
+}
+
+// TestEvictWebhook_UnknownWebhookIsNoOp proves eviction is safe
+// for the common case of a webhook that never had a database
+// target, and that repeating it does not panic.
+func TestEvictWebhook_UnknownWebhookIsNoOp(t *testing.T) {
+	t.Parallel()
+
+	eng, _ := evictTestEngine(t)
+
+	assert.NotPanics(t, func() {
+		eng.EvictWebhook("no-such-webhook")
+		eng.EvictWebhook("no-such-webhook")
+	})
+
+	assert.False(
+		t, eng.ExportHasArchiveWriter("no-such-webhook"),
+		"eviction must not create a writer",
+	)
+}
+
+// evictTestRow builds an archive row for the eviction tests.
+func evictTestRow(eventID string) delivery.ExportArchivedEvent {
+	return delivery.ExportArchivedEvent{
+		EventID:   eventID,
+		WebhookID: "wh-evict",
+		Method:    http.MethodPost,
+		Body:      `{"seeded":true}`,
+	}
+}
+
+// TestEvictedWriter_WriteDoesNotReopenFile is the direct test of
+// the evicted guard on the write path. A writer that has left
+// the registry is held by nobody, so a handle it opened could
+// never be closed again: it must refuse the write outright
+// rather than recreate the archive behind the registry's back.
+//
+// The archive file is removed before the eviction, so an
+// unguarded write is unmistakable — it recreates the file.
+func TestEvictedWriter_WriteDoesNotReopenFile(t *testing.T) {
+	t.Parallel()
+
+	path := filepath.Join(t.TempDir(), "archive-evicted.db")
+
+	w := delivery.NewExportArchiveWriter(
+		path, archiveTestLogger(), 0,
+	)
+
+	require.NoError(t, w.Write(evictTestRow("ev-1"), 0))
+	require.FileExists(t, path)
+
+	// The operator moves the archive away for offline retention,
+	// which the write path would ordinarily undo on the next
+	// write by recreating the file.
+	require.NoError(t, os.Remove(path))
+
+	w.Evict()
+
+	err := w.Write(evictTestRow("ev-2"), 0)
+
+	require.ErrorIs(
+		t, err, delivery.ErrExportArchiveWriterEvicted,
+		"an evicted writer must refuse writes",
+	)
+	assert.NoFileExists(
+		t, path,
+		"an evicted writer must not reopen (or recreate) the "+
+			"archive file",
+	)
+	assert.False(
+		t, w.HandleOpen(),
+		"an evicted writer must hold no handle",
+	)
+}
+
+// TestEvictedWriter_SweepDoesNotReopenFile is the same test for
+// the sweep path: an idle sweep that reaches a writer already
+// evicted underneath it must return the sentinel rather than
+// reopen a file nothing owns.
+func TestEvictedWriter_SweepDoesNotReopenFile(t *testing.T) {
+	t.Parallel()
+
+	path := filepath.Join(t.TempDir(), "archive-evicted.db")
+
+	w := delivery.NewExportArchiveWriter(
+		path, archiveTestLogger(), 0,
+	)
+
+	require.NoError(t, w.Write(evictTestRow("ev-1"), 0))
+	require.FileExists(t, path)
+
+	w.Evict()
+
+	err := w.SweepExpired(time.Hour)
+
+	require.ErrorIs(
+		t, err, delivery.ErrExportArchiveWriterEvicted,
+		"an evicted writer must refuse an idle sweep",
+	)
+	assert.False(
+		t, w.HandleOpen(),
+		"a refused sweep must not leave a handle open",
+	)
+}
+
+// racingWrites drives a pack of goroutines writing to one
+// archive writer until each is refused, so an eviction on the
+// test goroutine has to take the writer's mutex away from writes
+// that are already contending for it.
+type racingWrites struct {
+	wg         sync.WaitGroup
+	mu         sync.Mutex
+	sawEvicted bool
+	otherErr   error
+	started    chan struct{}
+}
+
+// racingWriteGoroutines is how many goroutines contend for the
+// writer's mutex while the eviction lands.
+const racingWriteGoroutines = 4
+
+// startRacingWrites launches the writing goroutines. Each writes
+// in a loop and stops at its first error, recording whether that
+// error was the eviction sentinel. The deadline is a backstop
+// against a hang, not a timing assumption: the first write after
+// the eviction is refused.
+func startRacingWrites(
+	w *delivery.ExportArchiveWriter,
+) *racingWrites {
+	r := &racingWrites{
+		started: make(chan struct{}, racingWriteGoroutines),
+	}
+
+	deadline := time.Now().Add(10 * time.Second)
+
+	r.wg.Add(racingWriteGoroutines)
+
+	for i := range racingWriteGoroutines {
+		go func() {
+			defer r.wg.Done()
+
+			first := true
+
+			for time.Now().Before(deadline) {
+				err := w.Write(
+					evictTestRow(fmt.Sprintf("ev-%d", i)), 0,
+				)
+
+				if first {
+					r.started <- struct{}{}
+
+					first = false
+				}
+
+				if err == nil {
+					continue
+				}
+
+				r.record(err)
+
+				return
+			}
+		}()
+	}
+
+	return r
+}
+
+// record classifies the error that stopped one goroutine.
+func (r *racingWrites) record(err error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	if errors.Is(err, delivery.ErrExportArchiveWriterEvicted) {
+		r.sawEvicted = true
+
+		return
+	}
+
+	r.otherErr = err
+}
+
+// awaitFirstWrite blocks until at least one write has run, so
+// the eviction that follows is a genuine race.
+func (r *racingWrites) awaitFirstWrite() {
+	<-r.started
+}
+
+// wait joins the goroutines and reports whether any write was
+// refused with the eviction sentinel, plus any unexpected error.
+func (r *racingWrites) wait() (bool, error) {
+	r.wg.Wait()
+
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	return r.sawEvicted, r.otherErr
+}
+
+// TestEvictWebhook_RacingWriteDoesNotReopenHandle exercises the
+// interleaving the evicted flag exists for: writes already
+// contending for the writer's mutex when the eviction takes it.
+// The write that wins the mutex after the eviction must abandon
+// its work rather than reopen the archive, leaving the writer
+// permanently handle-free. Run under -race.
+func TestEvictWebhook_RacingWriteDoesNotReopenHandle(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	eng, _ := evictTestEngine(t)
+
+	webhookDB := testWebhookDB(t)
+	event := seedEvent(t, webhookDB, `{"archived":true}`)
+	d := seedDatabaseTargetDelivery(t, webhookDB, event, "")
+
+	// Prime the registry so the test can hold the very writer the
+	// eviction is about to detach.
+	eng.ExportDeliverDatabase(webhookDB, d)
+
+	w := eng.ExportArchiveWriterFor(event.WebhookID)
+	require.NotNil(t, w)
+	require.True(t, w.HandleOpen())
+
+	race := startRacingWrites(w)
+
+	// Evict only once writes are genuinely in flight, so the
+	// eviction has to contend for the writer's mutex.
+	race.awaitFirstWrite()
+
+	eng.EvictWebhook(event.WebhookID)
+
+	sawEvicted, otherErr := race.wait()
+
+	require.NoError(t, otherErr)
+	assert.True(
+		t, sawEvicted,
+		"a write after eviction must be refused",
+	)
+	assert.False(
+		t, w.HandleOpen(),
+		"no write may reopen the archive once the writer has "+
+			"been evicted",
+	)
+	assert.False(
+		t, eng.ExportHasArchiveWriter(event.WebhookID),
+		"the registry entry must stay gone",
+	)
+}
+
+// TestEvictWebhook_LaterDeliveryRecreatesWriter proves eviction
+// does not break archiving for a webhook that is still alive: a
+// subsequent delivery gets a brand new writer from the registry.
+// It says nothing about the evicted writer itself — that is what
+// TestEvictedWriter_WriteDoesNotReopenFile covers.
+func TestEvictWebhook_LaterDeliveryRecreatesWriter(t *testing.T) {
+	t.Parallel()
+
+	eng, _ := evictTestEngine(t)
+
+	webhookDB := testWebhookDB(t)
+	event := seedEvent(t, webhookDB, `{"archived":true}`)
+	d := seedDatabaseTargetDelivery(t, webhookDB, event, "")
+
+	eng.ExportDeliverDatabase(webhookDB, d)
+	require.True(
+		t, eng.ExportHasArchiveWriter(event.WebhookID),
+	)
+
+	eng.EvictWebhook(event.WebhookID)
+
+	// A fresh delivery for the same webhook gets a brand new
+	// writer from the registry, so archiving keeps working.
+	second := seedDatabaseTargetDelivery(
+		t, webhookDB, event, "",
+	)
+	eng.ExportDeliverDatabase(webhookDB, second)
+
+	assert.True(
+		t, eng.ExportHasArchiveWriter(event.WebhookID),
+		"a later delivery should recreate the writer",
+	)
+}

internal/delivery/target_database_test.go

@@ -50,6 +50,13 @@ func openArchiveDBForRead(
 	return gdb
 }
 
+// archiveFileSuffixes returns the archive file itself and the
+// SQLite sidecars that accompany an open database. A test that
+// asserts no archive was created has to check all of them.
+func archiveFileSuffixes() []string {
+	return []string{"", "-wal", "-shm"}
+}
+
 // removeArchiveFiles simulates an operator moving the archive
 // away by deleting the SQLite file and its sidecar files.
 func removeArchiveFiles(t *testing.T, path string) {

internal/delivery/target_http.go

@@ -363,7 +363,8 @@ func (t *httpTarget) doHTTPRequest(
 	)
 	if reqErr != nil {
 		return 0, "", 0, fmt.Errorf(
-			"creating request: %w", reqErr,
+			"creating request: %w",
+			maskURLError(reqErr),
 		)
 	}
 
@@ -492,8 +493,19 @@ func applyRequestHeaders(
 // executeHTTPRequest sends an HTTP request using the provided
 // client. URLs are validated by the config parsers and the
 // SSRF-safe transport before reaching here.
+//
+// Transport failures are masked here, at the single point
+// where every target's request errors are born, because the
+// caller stores them in DeliveryResult.Error: an unmasked
+// *url.Error would write the target URL — the credential for
+// a Slack incoming webhook — into the per-webhook database.
 func executeHTTPRequest(
 	client *http.Client, req *http.Request,
 ) (*http.Response, error) {
-	return client.Do(req) //#nosec G704 -- validated URL, SSRF-safe transport
+	resp, err := client.Do(req) //#nosec G704 -- validated URL, SSRF-safe transport
+	if err != nil {
+		return nil, maskURLError(err)
+	}
+
+	return resp, nil
 }

internal/delivery/target_slack.go

@@ -125,7 +125,7 @@ func (t *slackTarget) attempt(
 	if err != nil {
 		return attemptResult{
 			success: false,
-			errMsg:  err.Error(),
+			errMsg:  maskURLError(err).Error(),
 		}
 	}
 

internal/delivery/url_mask.go

@@ -0,0 +1,61 @@
+package delivery
+
+import (
+	"errors"
+	"net/url"
+)
+
+// urlPathElision stands in for a URL's elided path.
+const urlPathElision = "/..."
+
+// MaskURL renders a URL as scheme plus host with everything
+// that can carry a secret removed. A delivery target URL is
+// itself a credential — a Slack incoming webhook URL is a
+// bearer token — so the path, query and userinfo are never
+// reproduced, in a page, a log line or a stored error. A URL
+// that does not parse into a scheme and host yields the
+// neutral placeholder, never the raw string.
+func MaskURL(raw string) string {
+	parsed, err := url.Parse(raw)
+	if err != nil || parsed.Scheme == "" ||
+		parsed.Host == "" {
+		return configUnavailable
+	}
+
+	masked := parsed.Scheme + "://" + parsed.Host
+
+	if parsed.Path != "" && parsed.Path != "/" {
+		masked += urlPathElision
+	}
+
+	return masked
+}
+
+// maskURLError strips the credential from an error raised
+// against a request URL. The net/http and net/url packages
+// embed the full request URL in every *url.Error they return,
+// so an unmodified transport error persisted into
+// DeliveryResult.Error writes the credential to disk.
+//
+// The masked error keeps the operation and the wrapped cause,
+// so a DNS failure still reads differently from a refused
+// connection, a TLS handshake failure or a timeout, and Is,
+// As, Timeout and Temporary keep working on it. Only the
+// path, query and userinfo of the URL are dropped. Errors
+// that carry no URL are returned unchanged.
+//
+// Call it where the error is raised, before any wrapping: it
+// replaces the *url.Error itself, so any context wrapped
+// around it first would be discarded.
+func maskURLError(err error) error {
+	var urlErr *url.Error
+	if !errors.As(err, &urlErr) {
+		return err
+	}
+
+	return &url.Error{
+		Op:  urlErr.Op,
+		URL: MaskURL(urlErr.URL),
+		Err: urlErr.Err,
+	}
+}

internal/delivery/url_mask_test.go

@@ -0,0 +1,196 @@
+package delivery_test
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/gorm"
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/delivery"
+)
+
+// The path of a Slack incoming webhook URL is the credential:
+// whoever holds these segments can post to the channel
+// forever. None of them may reach a stored delivery error,
+// which lives on disk in the per-webhook database and is
+// serialized by the JSON tag on DeliveryResult.Error.
+const (
+	maskSecretPath = "/services/T00000000/B00000000/" +
+		"XXXXXXXXXXXXXXXXXXXXXXXX"
+)
+
+// assertNoCredential fails if the whole path or any single
+// segment of it survived into the message, so a partial leak
+// fails the test too.
+func assertNoCredential(t *testing.T, msg string) {
+	t.Helper()
+
+	segments := []string{
+		maskSecretPath,
+		"services",
+		"T00000000",
+		"B00000000",
+		"XXXXXXXXXXXXXXXXXXXXXXXX",
+	}
+
+	for _, segment := range segments {
+		assert.NotContains(t, msg, segment)
+	}
+}
+
+// storedDeliveryError returns the error string persisted for a
+// delivery, which is what an operator and any future API read.
+func storedDeliveryError(
+	t *testing.T, db *gorm.DB, deliveryID string,
+) string {
+	t.Helper()
+
+	var result database.DeliveryResult
+
+	require.NoError(t, db.Where(
+		"delivery_id = ?", deliveryID,
+	).First(&result).Error)
+
+	return result.Error
+}
+
+// deliverSlackTo runs a Slack delivery against webhookURL and
+// returns the error string it persisted.
+func deliverSlackTo(
+	t *testing.T, webhookURL string,
+) string {
+	t.Helper()
+
+	db := testWebhookDB(t)
+	e := testEngine(t, 1)
+	targetID := uuid.New().String()
+
+	slackCfg, err := json.Marshal(
+		delivery.SlackTargetConfig{
+			WebhookURL: webhookURL,
+		},
+	)
+	require.NoError(t, err)
+
+	event := seedEvent(t, db, `{"test":true}`)
+
+	dlv := seedDelivery(
+		t, db, event.ID, targetID,
+		database.DeliveryStatusPending,
+	)
+
+	d := buildSlackDelivery(
+		dlv, event, targetID,
+		"test-slack-mask", string(slackCfg),
+	)
+
+	e.ExportDeliverSlack(context.TODO(), db, d)
+
+	assertDeliveryStatus(t, db, dlv.ID,
+		database.DeliveryStatusFailed,
+	)
+
+	return storedDeliveryError(t, db, dlv.ID)
+}
+
+// TestDeliverSlack_TransportErrorMasksWebhookURL is the
+// load-bearing regression test: a transport failure must not
+// persist the webhook URL's credential into the database, and
+// must still say what went wrong and where.
+func TestDeliverSlack_TransportErrorMasksWebhookURL(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	// A server closed before use gives a deterministic
+	// transport failure against a known host.
+	ts := httptest.NewServer(http.NewServeMux())
+	host := ts.URL
+
+	ts.Close()
+
+	errMsg := deliverSlackTo(t, host+maskSecretPath)
+
+	require.NotEmpty(t, errMsg)
+	assertNoCredential(t, errMsg)
+
+	// The diagnostic value survives: the operation, the host
+	// and the transport failure are all still reported, and
+	// only the path is elided.
+	assert.Contains(t, errMsg, "sending request")
+	assert.Contains(t, errMsg, "Post")
+	assert.Contains(t, errMsg, host+"/...")
+	assert.Contains(t, errMsg, "connection refused")
+}
+
+// TestDeliverSlack_UnparsableURLMasksWebhookURL covers the
+// other error path out of a Slack attempt: url.Parse also
+// embeds the whole URL in the error it returns.
+func TestDeliverSlack_UnparsableURLMasksWebhookURL(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	errMsg := deliverSlackTo(
+		t,
+		"https://hooks.slack.com"+maskSecretPath+"\n",
+	)
+
+	require.NotEmpty(t, errMsg)
+	assertNoCredential(t, errMsg)
+	assert.Contains(t, errMsg, "invalid control character")
+}
+
+// TestDoHTTPRequest_TransportErrorMasksURL proves the HTTP
+// target's transport errors are masked too; its destination
+// URL can carry a token in a query string.
+func TestDoHTTPRequest_TransportErrorMasksURL(t *testing.T) {
+	t.Parallel()
+
+	ts := httptest.NewServer(http.NewServeMux())
+	host := ts.URL
+
+	ts.Close()
+
+	e := testEngine(t, 1)
+
+	cfg, err := e.ExportParseHTTPConfig(
+		newHTTPTargetConfig(host + maskSecretPath),
+	)
+	require.NoError(t, err)
+
+	statusCode, _, _, reqErr := e.ExportDoHTTPRequest(
+		context.TODO(), cfg,
+		&database.Event{Body: `{"test":true}`},
+	)
+	require.Error(t, reqErr)
+	assert.Zero(t, statusCode)
+
+	assertNoCredential(t, reqErr.Error())
+	assert.Contains(t, reqErr.Error(), host+"/...")
+	assert.Contains(
+		t, reqErr.Error(), "connection refused",
+	)
+}
+
+// TestValidateTargetURL_UnparsableURLIsMasked proves the SSRF
+// validator's error does not carry the submitted URL, which
+// the handler both logs and shows.
+func TestValidateTargetURL_UnparsableURLIsMasked(t *testing.T) {
+	t.Parallel()
+
+	err := delivery.ValidateTargetURL(
+		context.TODO(),
+		"https://hooks.slack.com"+maskSecretPath+"\n",
+	)
+	require.Error(t, err)
+
+	assertNoCredential(t, err.Error())
+	assert.Contains(t, err.Error(), "invalid URL")
+}

internal/handlers/auth.go

@@ -29,10 +29,8 @@ func (h *Handlers) HandleLoginPage() http.HandlerFunc {
 // HandleLoginSubmit handles the login form submission (POST)
 func (h *Handlers) HandleLoginSubmit() http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		// Limit request body to prevent memory exhaustion
-		r.Body = http.MaxBytesReader(w, r.Body, 1<<maxBodyShift)
-
-		// Parse form data
+		// The body size cap is enforced by the MaxBodySize
+		// middleware, which runs before CSRF parses the form.
 		err := r.ParseForm()
 		if err != nil {
 			h.log.Error("failed to parse form", "error", err)

internal/handlers/handlers.go

@@ -26,8 +26,6 @@ const (
 	maxBodyShift = 20
 	// recentEventLimit is the number of recent events to show.
 	recentEventLimit = 20
-	// defaultRetentionDays is the default event retention period.
-	defaultRetentionDays = 30
 	// paginationPerPage is the number of items per page.
 	paginationPerPage = 25
 
@@ -51,6 +49,7 @@ type HandlersParams struct {
 	Healthcheck  *healthcheck.Healthcheck
 	Session      *session.Session
 	Notifier     delivery.Notifier
+	Evictor      delivery.WebhookEvictor
 }
 
 // Handlers provides HTTP handler methods for all application
@@ -63,6 +62,7 @@ type Handlers struct {
 	dbMgr     *database.WebhookDBManager
 	session   *session.Session
 	notifier  delivery.Notifier
+	evictor   delivery.WebhookEvictor
 	templates map[string]*template.Template
 }
 
@@ -97,6 +97,7 @@ func New(
 	s.dbMgr = params.WebhookDBMgr
 	s.session = params.Session
 	s.notifier = params.Notifier
+	s.evictor = params.Evictor
 
 	// Parse all page templates once at startup
 	s.templates = map[string]*template.Template{

internal/handlers/handlers_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"net/http"
 	"net/http/httptest"
+	"sync"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -24,6 +25,32 @@ type noopNotifier struct{}
 
 func (n *noopNotifier) Notify([]delivery.Task) {}
 
+// recordingEvictor is a delivery.WebhookEvictor that records
+// the webhook ids it was asked to evict, so a test can prove
+// that a deletion path reached the delivery engine.
+type recordingEvictor struct {
+	mu      sync.Mutex
+	evicted []string
+}
+
+func (r *recordingEvictor) EvictWebhook(webhookID string) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	r.evicted = append(r.evicted, webhookID)
+}
+
+// Evicted returns a copy of the recorded webhook ids.
+func (r *recordingEvictor) Evicted() []string {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	out := make([]string, len(r.evicted))
+	copy(out, r.evicted)
+
+	return out
+}
+
 func newTestApp(
 	t *testing.T,
 	targets ...any,
@@ -47,6 +74,12 @@ func newTestApp(
 			func() delivery.Notifier {
 				return &noopNotifier{}
 			},
+			func() *recordingEvictor {
+				return &recordingEvictor{}
+			},
+			func(r *recordingEvictor) delivery.WebhookEvictor {
+				return r
+			},
 			handlers.New,
 		),
 		fx.Populate(targets...),

internal/handlers/profile.go

@@ -31,9 +31,8 @@ func (h *Handlers) HandlePasswordChange() http.HandlerFunc {
 			return
 		}
 
-		// Limit request body to prevent memory exhaustion.
-		r.Body = http.MaxBytesReader(w, r.Body, 1<<maxBodyShift)
-
+		// The body size cap is enforced by the MaxBodySize
+		// middleware, which runs before CSRF parses the form.
 		err := r.ParseForm()
 		if err != nil {
 			h.log.Error("failed to parse form", "error", err)

internal/handlers/source_delete_test.go

@@ -0,0 +1,356 @@
+package handlers_test
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/go-chi/chi"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/gorm/clause"
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/handlers"
+	"sneak.berlin/go/webhooker/internal/session"
+)
+
+const (
+	deleteTestUserID   = "test-user-id"
+	deleteTestUsername = "testuser"
+
+	// paramSourceID and paramTargetID are the chi URL parameter
+	// names the deletion handlers read.
+	paramSourceID = "sourceID"
+	paramTargetID = "targetID"
+)
+
+// seedWebhook inserts a webhook owned by the test user and
+// returns it.
+func seedWebhook(
+	t *testing.T,
+	db *database.Database,
+) *database.Webhook {
+	t.Helper()
+
+	wh := &database.Webhook{
+		UserID: deleteTestUserID,
+		Name:   "delete-me",
+	}
+
+	require.NoError(
+		t,
+		db.DB().Omit(clause.Associations).Create(wh).Error,
+	)
+
+	return wh
+}
+
+// seedTarget inserts a target of the given type for a webhook
+// and returns it.
+func seedTarget(
+	t *testing.T,
+	db *database.Database,
+	webhookID string,
+	targetType database.TargetType,
+) *database.Target {
+	t.Helper()
+
+	tgt := &database.Target{
+		WebhookID: webhookID,
+		Name:      "t-" + string(targetType),
+		Type:      targetType,
+		Active:    true,
+	}
+
+	require.NoError(
+		t,
+		db.DB().Omit(clause.Associations).Create(tgt).Error,
+	)
+
+	return tgt
+}
+
+// archivePathFor returns the archive database path the
+// delivery engine would use for a webhook: beside the webhook's
+// event database in the data directory.
+func archivePathFor(
+	t *testing.T,
+	mgr *database.WebhookDBManager,
+	webhookID string,
+) string {
+	t.Helper()
+
+	return filepath.Join(
+		filepath.Dir(mgr.DBPath(webhookID)),
+		"archive-"+webhookID+".db",
+	)
+}
+
+// writeArchivePlaceholder creates a stand-in archive file so a
+// test can assert the file survives webhook deletion.
+func writeArchivePlaceholder(path string) error {
+	return os.WriteFile(path, []byte("archive"), 0o600)
+}
+
+// postRequest builds an authenticated POST request carrying the
+// given chi URL parameters.
+func postRequest(
+	path string,
+	cookies []*http.Cookie,
+	params map[string]string,
+) *http.Request {
+	req := httptest.NewRequestWithContext(
+		context.Background(), http.MethodPost, path, nil,
+	)
+
+	for _, c := range cookies {
+		req.AddCookie(c)
+	}
+
+	rctx := chi.NewRouteContext()
+	for k, v := range params {
+		rctx.URLParams.Add(k, v)
+	}
+
+	return req.WithContext(
+		context.WithValue(req.Context(), chi.RouteCtxKey, rctx),
+	)
+}
+
+// TestHandleSourceDelete_EvictsArchiveWriter proves that
+// deleting a webhook reaches the delivery engine and releases
+// the webhook's archive writer, exercised through the real
+// deletion handler rather than by calling the evictor directly.
+func TestHandleSourceDelete_EvictsArchiveWriter(t *testing.T) {
+	t.Parallel()
+
+	var (
+		h    *handlers.Handlers
+		sess *session.Session
+		db   *database.Database
+		ev   *recordingEvictor
+	)
+
+	app := newTestApp(t, &h, &sess, &db, &ev)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	wh := seedWebhook(t, db)
+	seedTarget(t, db, wh.ID, database.TargetTypeDatabase)
+
+	cookies := authenticatedCookies(
+		t, sess, deleteTestUserID, deleteTestUsername,
+	)
+
+	req := postRequest(
+		"/source/"+wh.ID+"/delete",
+		cookies,
+		map[string]string{paramSourceID: wh.ID},
+	)
+	w := httptest.NewRecorder()
+
+	h.HandleSourceDelete().ServeHTTP(w, req)
+
+	require.Equal(t, http.StatusSeeOther, w.Code)
+	assert.Equal(
+		t, []string{wh.ID}, ev.Evicted(),
+		"deleting a webhook should evict its archive writer",
+	)
+}
+
+// TestHandleSourceDelete_KeepsArchiveFile proves that deleting
+// a webhook does not remove its archive database file: the
+// archive is long-term storage the operator owns.
+func TestHandleSourceDelete_KeepsArchiveFile(t *testing.T) {
+	t.Parallel()
+
+	var (
+		h    *handlers.Handlers
+		sess *session.Session
+		db   *database.Database
+		mgr  *database.WebhookDBManager
+	)
+
+	app := newTestApp(t, &h, &sess, &db, &mgr)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	wh := seedWebhook(t, db)
+
+	// Place an archive file where the delivery engine would.
+	archivePath := archivePathFor(t, mgr, wh.ID)
+	require.NoError(
+		t,
+		writeArchivePlaceholder(archivePath),
+	)
+
+	cookies := authenticatedCookies(
+		t, sess, deleteTestUserID, deleteTestUsername,
+	)
+
+	req := postRequest(
+		"/source/"+wh.ID+"/delete",
+		cookies,
+		map[string]string{paramSourceID: wh.ID},
+	)
+	w := httptest.NewRecorder()
+
+	h.HandleSourceDelete().ServeHTTP(w, req)
+
+	require.Equal(t, http.StatusSeeOther, w.Code)
+	assert.FileExists(
+		t, archivePath,
+		"webhook deletion must not destroy the archive file",
+	)
+}
+
+// TestHandleTargetDelete_EvictsWhenLastDatabaseTargetGone
+// proves that removing the last database target releases the
+// archive writer.
+func TestHandleTargetDelete_EvictsWhenLastDatabaseTargetGone(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	var (
+		h    *handlers.Handlers
+		sess *session.Session
+		db   *database.Database
+		ev   *recordingEvictor
+	)
+
+	app := newTestApp(t, &h, &sess, &db, &ev)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	wh := seedWebhook(t, db)
+	tgt := seedTarget(
+		t, db, wh.ID, database.TargetTypeDatabase,
+	)
+
+	cookies := authenticatedCookies(
+		t, sess, deleteTestUserID, deleteTestUsername,
+	)
+
+	req := postRequest(
+		"/source/"+wh.ID+"/targets/"+tgt.ID+"/delete",
+		cookies,
+		map[string]string{
+			paramSourceID: wh.ID,
+			paramTargetID: tgt.ID,
+		},
+	)
+	w := httptest.NewRecorder()
+
+	h.HandleTargetDelete().ServeHTTP(w, req)
+
+	require.Equal(t, http.StatusSeeOther, w.Code)
+	assert.Equal(
+		t, []string{wh.ID}, ev.Evicted(),
+		"removing the last database target should evict",
+	)
+}
+
+// TestHandleTargetDelete_KeepsWriterWhenDatabaseTargetRemains
+// proves that deleting one of several database targets leaves
+// the still-needed archive writer alone: the surviving target
+// keeps archiving to the same file, so the writer must stay.
+func TestHandleTargetDelete_KeepsWriterWhenDatabaseTargetRemains(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	var (
+		h    *handlers.Handlers
+		sess *session.Session
+		db   *database.Database
+		ev   *recordingEvictor
+	)
+
+	app := newTestApp(t, &h, &sess, &db, &ev)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	wh := seedWebhook(t, db)
+	doomed := seedTarget(
+		t, db, wh.ID, database.TargetTypeDatabase,
+	)
+	seedTarget(t, db, wh.ID, database.TargetTypeDatabase)
+
+	cookies := authenticatedCookies(
+		t, sess, deleteTestUserID, deleteTestUsername,
+	)
+
+	req := postRequest(
+		"/source/"+wh.ID+"/targets/"+doomed.ID+"/delete",
+		cookies,
+		map[string]string{
+			paramSourceID: wh.ID,
+			paramTargetID: doomed.ID,
+		},
+	)
+	w := httptest.NewRecorder()
+
+	h.HandleTargetDelete().ServeHTTP(w, req)
+
+	require.Equal(t, http.StatusSeeOther, w.Code)
+	assert.Empty(
+		t, ev.Evicted(),
+		"a second database target still needs the writer",
+	)
+}
+
+// TestHandleTargetDelete_KeepsWriterWhenOtherTypeDeleted proves
+// that deleting a target of an unrelated type leaves a
+// still-needed archive writer alone: the webhook's database
+// target is untouched, so its writer must stay.
+func TestHandleTargetDelete_KeepsWriterWhenOtherTypeDeleted(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	var (
+		h    *handlers.Handlers
+		sess *session.Session
+		db   *database.Database
+		ev   *recordingEvictor
+	)
+
+	app := newTestApp(t, &h, &sess, &db, &ev)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	wh := seedWebhook(t, db)
+	seedTarget(t, db, wh.ID, database.TargetTypeDatabase)
+	other := seedTarget(t, db, wh.ID, database.TargetTypeLog)
+
+	cookies := authenticatedCookies(
+		t, sess, deleteTestUserID, deleteTestUsername,
+	)
+
+	req := postRequest(
+		"/source/"+wh.ID+"/targets/"+other.ID+"/delete",
+		cookies,
+		map[string]string{
+			paramSourceID: wh.ID,
+			paramTargetID: other.ID,
+		},
+	)
+	w := httptest.NewRecorder()
+
+	h.HandleTargetDelete().ServeHTTP(w, req)
+
+	require.Equal(t, http.StatusSeeOther, w.Code)
+	assert.Empty(
+		t, ev.Evicted(),
+		"a surviving database target must keep its writer",
+	)
+}

internal/handlers/source_detail_test.go

@@ -0,0 +1,187 @@
+package handlers_test
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/go-chi/chi"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/gorm/clause"
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/handlers"
+	"sneak.berlin/go/webhooker/internal/session"
+)
+
+// The secret path segments of a Slack incoming webhook URL.
+// Holding them is enough to post to the channel forever, so
+// they must never reach the rendered page.
+const (
+	slackSecretPath = "/services/T00000000/B00000000/" +
+		"XXXXXXXXXXXXXXXXXXXXXXXX"
+	slackWebhookURL = "https://hooks.slack.com" +
+		slackSecretPath
+)
+
+// seedConfiguredTarget inserts a target with a stored config
+// blob and returns it.
+func seedConfiguredTarget(
+	t *testing.T,
+	db *database.Database,
+	webhookID string,
+	targetType database.TargetType,
+	config string,
+) *database.Target {
+	t.Helper()
+
+	tgt := &database.Target{
+		WebhookID: webhookID,
+		Name:      "t-" + string(targetType),
+		Type:      targetType,
+		Active:    true,
+		Config:    config,
+	}
+
+	require.NoError(
+		t,
+		db.DB().Omit(clause.Associations).Create(tgt).Error,
+	)
+
+	return tgt
+}
+
+// renderSourceDetailPage runs the real source detail handler
+// for a webhook and returns the rendered HTML.
+func renderSourceDetailPage(
+	t *testing.T,
+	h *handlers.Handlers,
+	sess *session.Session,
+	webhookID string,
+) string {
+	t.Helper()
+
+	req := httptest.NewRequestWithContext(
+		context.Background(),
+		http.MethodGet,
+		"/source/"+webhookID,
+		nil,
+	)
+
+	for _, c := range authenticatedCookies(
+		t, sess, deleteTestUserID, deleteTestUsername,
+	) {
+		req.AddCookie(c)
+	}
+
+	rctx := chi.NewRouteContext()
+	rctx.URLParams.Add(paramSourceID, webhookID)
+
+	req = req.WithContext(
+		context.WithValue(
+			req.Context(), chi.RouteCtxKey, rctx,
+		),
+	)
+
+	w := httptest.NewRecorder()
+	h.HandleSourceDetail().ServeHTTP(w, req)
+
+	require.Equal(t, http.StatusOK, w.Code)
+
+	return w.Body.String()
+}
+
+// TestHandleSourceDetail_MasksSlackWebhookURL is the
+// load-bearing regression test for the credential leak: the
+// rendered page must show the Slack target without any of the
+// secret path segments of its webhook URL.
+func TestHandleSourceDetail_MasksSlackWebhookURL(t *testing.T) {
+	t.Parallel()
+
+	var (
+		h    *handlers.Handlers
+		sess *session.Session
+		db   *database.Database
+	)
+
+	app := newTestApp(t, &h, &sess, &db)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	wh := seedWebhook(t, db)
+	seedConfiguredTarget(
+		t, db, wh.ID,
+		database.TargetTypeSlack,
+		`{"webhookUrl":"`+slackWebhookURL+`"}`,
+	)
+
+	body := renderSourceDetailPage(t, h, sess, wh.ID)
+
+	assert.NotContains(t, body, slackSecretPath)
+	assert.NotContains(t, body, "T00000000")
+	assert.NotContains(t, body, "B00000000")
+	assert.NotContains(
+		t, body, "XXXXXXXXXXXXXXXXXXXXXXXX",
+	)
+	assert.NotContains(t, body, "webhookUrl")
+
+	assert.Contains(t, body, "Webhook URL")
+	assert.Contains(t, body, "https://hooks.slack.com/...")
+}
+
+// TestHandleSourceDetail_RendersNamedTargetFields proves the
+// other target types render labelled fields rather than the
+// stored blob.
+func TestHandleSourceDetail_RendersNamedTargetFields(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	var (
+		h    *handlers.Handlers
+		sess *session.Session
+		db   *database.Database
+	)
+
+	app := newTestApp(t, &h, &sess, &db)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	wh := seedWebhook(t, db)
+
+	seedConfiguredTarget(
+		t, db, wh.ID,
+		database.TargetTypeHTTP,
+		`{"url":"https://example.com/hook","timeout":30,`+
+			`"headers":{"Authorization":"Bearer sekrit"}}`,
+	)
+	seedConfiguredTarget(
+		t, db, wh.ID,
+		database.TargetTypeDatabase,
+		`{"expiry":"720h"}`,
+	)
+	seedConfiguredTarget(
+		t, db, wh.ID,
+		database.TargetType("carrier-pigeon"),
+		`{"beak":"sharp"}`,
+	)
+
+	body := renderSourceDetailPage(t, h, sess, wh.ID)
+
+	assert.Contains(t, body, "Destination URL")
+	assert.Contains(t, body, "https://example.com/hook")
+	assert.Contains(t, body, "Timeout")
+	assert.Contains(t, body, "1 configured")
+	assert.NotContains(t, body, "sekrit")
+
+	assert.Contains(t, body, "Archive Expiry")
+	assert.Contains(t, body, "720h")
+
+	// An unknown type gets the neutral placeholder, never the
+	// stored blob.
+	assert.Contains(t, body, "(unavailable)")
+	assert.NotContains(t, body, "beak")
+}

internal/handlers/source_logs_test.go

@@ -0,0 +1,134 @@
+package handlers_test
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/go-chi/chi"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/gorm/clause"
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/handlers"
+	"sneak.berlin/go/webhooker/internal/session"
+)
+
+// seedDeliveredEvent records an event and a delivery for it in
+// the webhook's own database, so the log page has a delivery
+// to render against the target.
+func seedDeliveredEvent(
+	t *testing.T,
+	dbMgr *database.WebhookDBManager,
+	webhookID, targetID string,
+) {
+	t.Helper()
+
+	webhookDB, err := dbMgr.GetDB(webhookID)
+	require.NoError(t, err)
+
+	event := &database.Event{
+		WebhookID:   webhookID,
+		Method:      http.MethodPost,
+		Body:        `{"test":true}`,
+		ContentType: "application/json",
+	}
+
+	require.NoError(t, webhookDB.Omit(
+		clause.Associations,
+	).Create(event).Error)
+
+	dlv := &database.Delivery{
+		EventID:  event.ID,
+		TargetID: targetID,
+		Status:   database.DeliveryStatusDelivered,
+	}
+
+	require.NoError(t, webhookDB.Omit(
+		clause.Associations,
+	).Create(dlv).Error)
+}
+
+// renderSourceLogsPage runs the real event log handler for a
+// webhook and returns the rendered HTML.
+func renderSourceLogsPage(
+	t *testing.T,
+	h *handlers.Handlers,
+	sess *session.Session,
+	webhookID string,
+) string {
+	t.Helper()
+
+	req := httptest.NewRequestWithContext(
+		context.Background(),
+		http.MethodGet,
+		"/source/"+webhookID+"/logs",
+		nil,
+	)
+
+	for _, c := range authenticatedCookies(
+		t, sess, deleteTestUserID, deleteTestUsername,
+	) {
+		req.AddCookie(c)
+	}
+
+	rctx := chi.NewRouteContext()
+	rctx.URLParams.Add(paramSourceID, webhookID)
+
+	req = req.WithContext(
+		context.WithValue(
+			req.Context(), chi.RouteCtxKey, rctx,
+		),
+	)
+
+	w := httptest.NewRecorder()
+	h.HandleSourceLogs().ServeHTTP(w, req)
+
+	require.Equal(t, http.StatusOK, w.Code)
+
+	return w.Body.String()
+}
+
+// TestHandleSourceLogs_MasksSlackWebhookURL proves the event
+// log page is handed a display-safe projection of each target
+// rather than the stored row, so the credential cannot be
+// rendered from its template data.
+func TestHandleSourceLogs_MasksSlackWebhookURL(t *testing.T) {
+	t.Parallel()
+
+	var (
+		h     *handlers.Handlers
+		sess  *session.Session
+		db    *database.Database
+		dbMgr *database.WebhookDBManager
+	)
+
+	app := newTestApp(t, &h, &sess, &db, &dbMgr)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	wh := seedWebhook(t, db)
+	tgt := seedConfiguredTarget(
+		t, db, wh.ID,
+		database.TargetTypeSlack,
+		`{"webhookUrl":"`+slackWebhookURL+`"}`,
+	)
+
+	seedDeliveredEvent(t, dbMgr, wh.ID, tgt.ID)
+
+	body := renderSourceLogsPage(t, h, sess, wh.ID)
+
+	assert.NotContains(t, body, slackSecretPath)
+	assert.NotContains(t, body, "T00000000")
+	assert.NotContains(t, body, "B00000000")
+	assert.NotContains(
+		t, body, "XXXXXXXXXXXXXXXXXXXXXXXX",
+	)
+	assert.NotContains(t, body, "webhookUrl")
+
+	// The page still identifies the delivery's target.
+	assert.Contains(t, body, tgt.Name)
+	assert.Contains(t, body, "delivered")
+}

internal/handlers/source_management.go

@@ -25,11 +25,88 @@ type WebhookListItem struct {
 // errMissingURL signals that a required URL was not provided.
 var errMissingURL = errors.New("missing URL")
 
+// errInvalidRetention signals a retention_days form value that is not
+// a non-negative whole number.
+var errInvalidRetention = errors.New("invalid retention days")
+
+// errRetentionTooLarge signals a retention_days form value that is a
+// whole number but larger than the reaper's cutoff arithmetic can
+// represent. It is distinguished from errInvalidRetention so the form
+// can tell the user the actual ceiling instead of implying their input
+// was not a number.
+var errRetentionTooLarge = errors.New("retention days out of range")
+
+// retentionErrorMessage returns the message the create and edit forms
+// show the user for a rejected retention_days value. Any error other
+// than errRetentionTooLarge falls back to the generic wording, so an
+// unrecognised parse failure still produces a sensible 400 rather than
+// an empty alert.
+func retentionErrorMessage(err error) string {
+	if errors.Is(err, errRetentionTooLarge) {
+		return "Retention must be at most " +
+			strconv.Itoa(database.MaxFiniteRetentionDays) +
+			" days, or 0 to retain events forever."
+	}
+
+	return "Retention must be a whole number of days, or 0 to " +
+		"retain events forever."
+}
+
+// parseRetentionDays interprets a retention_days form value.
+//
+// An empty value yields fallback, which lets the create path apply the
+// default and the edit path leave the stored value unchanged. A value
+// of 0 is returned as 0 and is rewritten to the retain-forever
+// sentinel by database.Webhook's BeforeSave hook. Anything unparseable
+// or negative is an error rather than a silently substituted default.
+//
+// The upper bound is not cosmetic. The reaper computes its cutoff as a
+// time.Duration, an int64 nanosecond count, so a day count above
+// database.MaxFiniteRetentionDays overflows, puts the cutoff in the
+// future, and deletes every event the webhook has. A finite value
+// above that ceiling is therefore a 400.
+//
+// A value at or above the retain-forever sentinel is not out of range:
+// it is what the edit form pre-fills for a retain-forever webhook, so
+// submitting the form back unchanged has to keep meaning "forever"
+// rather than being rejected.
+func parseRetentionDays(raw string, fallback int) (int, error) {
+	raw = strings.TrimSpace(raw)
+	if raw == "" {
+		return fallback, nil
+	}
+
+	v, err := strconv.Atoi(raw)
+	if err != nil || v < 0 {
+		return 0, errInvalidRetention
+	}
+
+	if v >= database.RetentionForeverDays {
+		return database.RetentionForeverDays, nil
+	}
+
+	if v > database.MaxFiniteRetentionDays {
+		return 0, errRetentionTooLarge
+	}
+
+	return v, nil
+}
+
 // EventWithDeliveries holds an event and its deliveries.
 type EventWithDeliveries struct {
 	database.Event
 
-	Deliveries []database.Delivery
+	Deliveries []DeliveryView
+}
+
+// DeliveryView is the display-safe projection of a delivery
+// for the event log page. Its target is a TargetView, so the
+// stored configuration blob — which holds the target's
+// credential — has no path to the template.
+type DeliveryView struct {
+	ID     string
+	Status database.DeliveryStatus
+	Target delivery.TargetView
 }
 
 // HandleSourceList shows a list of user's webhooks.
@@ -106,11 +183,30 @@ func (h *Handlers) buildWebhookListItems(
 // HandleSourceCreate shows the form to create a new webhook.
 func (h *Handlers) HandleSourceCreate() http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		data := map[string]any{
-			tmplKeyError: "",
-		}
+		h.renderTemplate(
+			w, r, "sources_new.html",
+			newSourceFormData("", "", ""),
+		)
+	}
+}
 
-		h.renderTemplate(w, r, "sources_new.html", data)
+// newSourceFormData builds the template data for the webhook creation
+// form.
+//
+// It carries the retention default so the pre-filled value comes from
+// database.DefaultRetentionDays rather than being a third hardcoded
+// copy of the same policy, and it carries the submitted name and
+// description so that re-rendering the form after a validation failure
+// gives the user their input back instead of a blank form. The edit
+// form already behaves that way; create now matches it.
+func newSourceFormData(
+	errMsg, name, description string,
+) map[string]any {
+	return map[string]any{
+		tmplKeyError:           errMsg,
+		"Name":                 name,
+		"Description":          description,
+		"DefaultRetentionDays": database.DefaultRetentionDays,
 	}
 }
 
@@ -127,10 +223,8 @@ func (h *Handlers) HandleSourceCreateSubmit() http.HandlerFunc {
 			return
 		}
 
-		r.Body = http.MaxBytesReader(
-			w, r.Body, 1<<maxBodyShift,
-		)
-
+		// The body size cap is enforced by the MaxBodySize
+		// middleware, which runs before CSRF parses the form.
 		err := r.ParseForm()
 		if err != nil {
 			http.Error(
@@ -145,23 +239,31 @@ func (h *Handlers) HandleSourceCreateSubmit() http.HandlerFunc {
 		retentionStr := r.FormValue("retention_days")
 
 		if name == "" {
-			data := map[string]any{
-				tmplKeyError: "Name is required",
-			}
-
 			w.WriteHeader(http.StatusBadRequest)
-			h.renderTemplate(w, r, "sources_new.html", data)
+			h.renderTemplate(
+				w, r, "sources_new.html",
+				newSourceFormData(
+					"Name is required", name, description,
+				),
+			)
 
 			return
 		}
 
-		retentionDays := defaultRetentionDays
+		retentionDays, retErr := parseRetentionDays(
+			retentionStr, database.DefaultRetentionDays,
+		)
+		if retErr != nil {
+			w.WriteHeader(http.StatusBadRequest)
+			h.renderTemplate(
+				w, r, "sources_new.html",
+				newSourceFormData(
+					retentionErrorMessage(retErr),
+					name, description,
+				),
+			)
 
-		if retentionStr != "" {
-			v, convErr := strconv.Atoi(retentionStr)
-			if convErr == nil && v > 0 {
-				retentionDays = v
-			}
+			return
 		}
 
 		h.createWebhookWithEntrypoint(
@@ -315,12 +417,17 @@ func (h *Handlers) renderSourceDetail(
 		scheme = fwdProto
 	}
 
+	// The template calls Webhook methods, which take pointer
+	// receivers; html/template cannot address a value stored in a map.
 	data := map[string]any{
-		tmplKeyWebhook: webhook,
+		tmplKeyWebhook: &webhook,
 		"Entrypoints":  entrypoints,
-		"Targets":      targets,
-		"Events":       events,
-		"BaseURL":      scheme + "://" + host,
+		// Targets are projected to a display-safe view: the
+		// stored config blob holds credentials and must never
+		// reach a template.
+		"Targets": delivery.NewTargetViews(targets),
+		"Events":  events,
+		"BaseURL": scheme + "://" + host,
 	}
 
 	h.renderTemplate(w, r, "source_detail.html", data)
@@ -352,7 +459,7 @@ func (h *Handlers) HandleSourceEdit() http.HandlerFunc {
 		}
 
 		data := map[string]any{
-			tmplKeyWebhook: webhook,
+			tmplKeyWebhook: &webhook,
 			tmplKeyError:   "",
 		}
 
@@ -386,10 +493,8 @@ func (h *Handlers) HandleSourceEditSubmit() http.HandlerFunc {
 			return
 		}
 
-		r.Body = http.MaxBytesReader(
-			w, r.Body, 1<<maxBodyShift,
-		)
-
+		// The body size cap is enforced by the MaxBodySize
+		// middleware, which runs before CSRF parses the form.
 		err = r.ParseForm()
 		if err != nil {
 			http.Error(
@@ -409,14 +514,12 @@ func (h *Handlers) applyWebhookEdit(
 	r *http.Request,
 	webhook *database.Webhook,
 ) {
-	r.Body = http.MaxBytesReader(
-		w, r.Body, 1<<maxBodyShift,
-	)
-
+	// The body size cap is enforced by the MaxBodySize middleware,
+	// which runs before CSRF parses the form.
 	name := r.FormValue("name")
 	if name == "" {
 		data := map[string]any{
-			tmplKeyWebhook: *webhook,
+			tmplKeyWebhook: webhook,
 			tmplKeyError:   "Name is required",
 		}
 
@@ -428,7 +531,25 @@ func (h *Handlers) applyWebhookEdit(
 
 	webhook.Name = name
 	webhook.Description = r.FormValue("description")
-	h.parseRetention(r, webhook)
+
+	// An empty field falls back to the stored value, so submitting the
+	// form without touching retention leaves the policy alone.
+	retentionDays, retErr := parseRetentionDays(
+		r.FormValue("retention_days"), webhook.RetentionDays,
+	)
+	if retErr != nil {
+		data := map[string]any{
+			tmplKeyWebhook: webhook,
+			tmplKeyError:   retentionErrorMessage(retErr),
+		}
+
+		w.WriteHeader(http.StatusBadRequest)
+		h.renderTemplate(w, r, "source_edit.html", data)
+
+		return
+	}
+
+	webhook.RetentionDays = retentionDays
 
 	err := h.db.DB().Save(webhook).Error
 	if err != nil {
@@ -442,23 +563,6 @@ func (h *Handlers) applyWebhookEdit(
 	)
 }
 
-// parseRetention parses and applies retention_days from the
-// form.
-func (h *Handlers) parseRetention(
-	r *http.Request,
-	webhook *database.Webhook,
-) {
-	retStr := r.FormValue("retention_days")
-	if retStr == "" {
-		return
-	}
-
-	v, err := strconv.Atoi(retStr)
-	if err == nil && v > 0 {
-		webhook.RetentionDays = v
-	}
-}
-
 // HandleSourceDelete handles webhook deletion.
 func (h *Handlers) HandleSourceDelete() http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
@@ -533,6 +637,13 @@ func (h *Handlers) deleteWebhookResources(
 		return
 	}
 
+	// Release the delivery engine's per-webhook archiving state
+	// so a deleted webhook's archive writer (and any handle open
+	// within its debounce window) does not linger for the
+	// process lifetime. The archive file itself is deliberately
+	// left on disk; see evictArchiveWriter.
+	h.evictArchiveWriter(webhook.ID)
+
 	err = h.dbMgr.DeleteDB(webhook.ID)
 	if err != nil {
 		h.log.Error(
@@ -551,6 +662,64 @@ func (h *Handlers) deleteWebhookResources(
 	http.Redirect(w, r, "/sources", http.StatusSeeOther)
 }
 
+// evictArchiveWriter asks the delivery engine to drop its
+// cached archive writer for a webhook, closing the archive file
+// handle.
+//
+// The archive database file is NOT deleted. Unlike the event
+// database — which is per-webhook working storage and is
+// hard-deleted with the webhook — an archive is explicitly
+// long-term storage that an operator may want to keep or move
+// away for offline retention. Destroying it as a side effect of
+// deleting a webhook would be a surprising and unrecoverable
+// data loss, so the file is left for the operator to handle.
+func (h *Handlers) evictArchiveWriter(webhookID string) {
+	if h.evictor == nil {
+		return
+	}
+
+	h.evictor.EvictWebhook(webhookID)
+}
+
+// evictArchiveWriterIfUnused releases a webhook's archive
+// writer once the webhook has no database target left to feed
+// it.
+//
+// It is called after any child resource of a webhook is
+// deleted, and is correct without knowing which kind was: it
+// evicts only when no database target remains, so deleting one
+// of several database targets — or deleting an unrelated
+// target type — leaves a still-needed writer alone. When no
+// database target ever existed there is no writer and eviction
+// is a no-op. Soft-deleted targets are excluded by GORM's
+// default scope, so the row just deleted is not counted.
+func (h *Handlers) evictArchiveWriterIfUnused(webhookID string) {
+	var remaining int64
+
+	err := h.db.DB().
+		Model(&database.Target{}).
+		Where(
+			"webhook_id = ? AND type = ?",
+			webhookID, database.TargetTypeDatabase,
+		).
+		Count(&remaining).Error
+	if err != nil {
+		h.log.Error(
+			"failed to count remaining database targets",
+			"webhook_id", webhookID,
+			"error", err,
+		)
+
+		return
+	}
+
+	if remaining > 0 {
+		return
+	}
+
+	h.evictArchiveWriter(webhookID)
+}
+
 // HandleSourceLogs shows the request/response logs for a
 // webhook.
 func (h *Handlers) HandleSourceLogs() http.HandlerFunc {
@@ -590,7 +759,7 @@ func (h *Handlers) HandleSourceLogs() http.HandlerFunc {
 		}
 
 		data := map[string]any{
-			tmplKeyWebhook: webhook,
+			tmplKeyWebhook: &webhook,
 			"Events":       evts,
 			"Page":         page,
 			"TotalPages":   totalPages,
@@ -605,22 +774,27 @@ func (h *Handlers) HandleSourceLogs() http.HandlerFunc {
 	}
 }
 
-// loadTargetMap loads targets into a map keyed by target ID.
+// loadTargetMap loads targets into a map of display-safe
+// views keyed by target ID. The projection happens here so
+// that no caller can hand a raw target, configuration blob
+// and all, to a template.
 func (h *Handlers) loadTargetMap(
 	webhookID string,
-) map[string]database.Target {
+) map[string]delivery.TargetView {
 	var targets []database.Target
 
 	h.db.DB().Where(
 		"webhook_id = ?", webhookID,
 	).Find(&targets)
 
+	views := delivery.NewTargetViews(targets)
+
 	targetMap := make(
-		map[string]database.Target, len(targets),
+		map[string]delivery.TargetView, len(views),
 	)
 
-	for _, t := range targets {
-		targetMap[t.ID] = t
+	for _, v := range views {
+		targetMap[v.ID] = v
 	}
 
 	return targetMap
@@ -645,7 +819,7 @@ func (h *Handlers) parsePage(r *http.Request) int {
 func (h *Handlers) loadEventsWithDeliveries(
 	w http.ResponseWriter,
 	webhook database.Webhook,
-	targetMap map[string]database.Target,
+	targetMap map[string]delivery.TargetView,
 	page int,
 ) ([]EventWithDeliveries, int64) {
 	var totalEvents int64
@@ -684,22 +858,39 @@ func (h *Handlers) loadEventsWithDeliveries(
 	for i := range events {
 		result[i].Event = events[i]
 
+		var deliveries []database.Delivery
+
 		webhookDB.Where(
 			"event_id = ?", events[i].ID,
-		).Find(&result[i].Deliveries)
+		).Find(&deliveries)
 
-		for j := range result[i].Deliveries {
-			tid := result[i].Deliveries[j].TargetID
-
-			if target, ok := targetMap[tid]; ok {
-				result[i].Deliveries[j].Target = target
-			}
-		}
+		result[i].Deliveries = newDeliveryViews(
+			deliveries, targetMap,
+		)
 	}
 
 	return result, totalEvents
 }
 
+// newDeliveryViews projects deliveries for rendering,
+// resolving each one's target to its display-safe view.
+func newDeliveryViews(
+	deliveries []database.Delivery,
+	targetMap map[string]delivery.TargetView,
+) []DeliveryView {
+	views := make([]DeliveryView, len(deliveries))
+
+	for i := range deliveries {
+		views[i] = DeliveryView{
+			ID:     deliveries[i].ID,
+			Status: deliveries[i].Status,
+			Target: targetMap[deliveries[i].TargetID],
+		}
+	}
+
+	return views
+}
+
 // HandleEntrypointCreate handles adding a new entrypoint.
 func (h *Handlers) HandleEntrypointCreate() http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
@@ -725,10 +916,8 @@ func (h *Handlers) HandleEntrypointCreate() http.HandlerFunc {
 			return
 		}
 
-		r.Body = http.MaxBytesReader(
-			w, r.Body, 1<<maxBodyShift,
-		)
-
+		// The body size cap is enforced by the MaxBodySize
+		// middleware, which runs before CSRF parses the form.
 		err = r.ParseForm()
 		if err != nil {
 			http.Error(
@@ -785,10 +974,8 @@ func (h *Handlers) HandleTargetCreate() http.HandlerFunc {
 			return
 		}
 
-		r.Body = http.MaxBytesReader(
-			w, r.Body, 1<<maxBodyShift,
-		)
-
+		// The body size cap is enforced by the MaxBodySize
+		// middleware, which runs before CSRF parses the form.
 		err = r.ParseForm()
 		if err != nil {
 			http.Error(
@@ -808,10 +995,8 @@ func (h *Handlers) processTargetCreate(
 	r *http.Request,
 	webhook database.Webhook,
 ) {
-	r.Body = http.MaxBytesReader(
-		w, r.Body, 1<<maxBodyShift,
-	)
-
+	// The body size cap is enforced by the MaxBodySize middleware,
+	// which runs before CSRF parses the form.
 	name := r.FormValue("name")
 	targetType := database.TargetType(r.FormValue("type"))
 	targetURL := r.FormValue("url")
@@ -949,9 +1134,12 @@ func (h *Handlers) buildURLTargetConfig(
 		r.Context(), targetURL,
 	)
 	if err != nil {
+		// The submitted URL can be a credential (a Slack
+		// incoming webhook URL is a bearer token), so the log
+		// records only its scheme and host.
 		h.log.Warn(
 			"target URL blocked by SSRF protection",
-			"url", targetURL,
+			"url", delivery.MaskURL(targetURL),
 			"error", err,
 		)
 		http.Error(
@@ -1024,23 +1212,31 @@ func (h *Handlers) HandleEntrypointDelete() http.HandlerFunc {
 	return h.deleteChildResource(
 		"entrypointID", &database.Entrypoint{},
 		"failed to delete entrypoint",
+		nil,
 	)
 }
 
-// HandleTargetDelete handles deleting a target.
+// HandleTargetDelete handles deleting a target. Deleting the
+// last database target of a webhook leaves its archive writer
+// with nothing to write, so the writer is evicted and its
+// handle closed; the archive file is left on disk.
 func (h *Handlers) HandleTargetDelete() http.HandlerFunc {
 	return h.deleteChildResource(
 		"targetID", &database.Target{},
 		"failed to delete target",
+		h.evictArchiveWriterIfUnused,
 	)
 }
 
 // deleteChildResource returns a handler that deletes a child
-// resource (entrypoint or target) belonging to a webhook.
+// resource (entrypoint or target) belonging to a webhook. The
+// optional afterDelete hook runs with the webhook's id once the
+// delete has succeeded, before the redirect.
 func (h *Handlers) deleteChildResource(
 	idParam string,
 	model any,
 	errMsg string,
+	afterDelete func(webhookID string),
 ) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		userID, ok := h.getUserID(r)
@@ -1080,6 +1276,10 @@ func (h *Handlers) deleteChildResource(
 			return
 		}
 
+		if afterDelete != nil {
+			afterDelete(webhook.ID)
+		}
+
 		http.Redirect(
 			w, r,
 			"/source/"+webhook.ID,

internal/handlers/source_management_test.go

@@ -0,0 +1,589 @@
+package handlers_test
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strconv"
+	"strings"
+	"testing"
+
+	"github.com/go-chi/chi"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/gorm/clause"
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/handlers"
+	"sneak.berlin/go/webhooker/internal/session"
+)
+
+const (
+	// sourceTestUserID is the session user id used by the webhook
+	// management tests.
+	sourceTestUserID = "source-test-user"
+	// sourceIDParam is the chi URL parameter naming a webhook.
+	sourceIDParam = "sourceID"
+)
+
+// formRequest builds an urlencoded POST to path carrying the given
+// cookies, plus any chi URL parameters the handler reads.
+func formRequest(
+	path string,
+	cookies []*http.Cookie,
+	form url.Values,
+	urlParams map[string]string,
+) *http.Request {
+	req := httptest.NewRequestWithContext(
+		context.Background(),
+		http.MethodPost,
+		path,
+		strings.NewReader(form.Encode()),
+	)
+	req.Header.Set(
+		"Content-Type", "application/x-www-form-urlencoded",
+	)
+
+	for _, c := range cookies {
+		req.AddCookie(c)
+	}
+
+	rctx := chi.NewRouteContext()
+	for k, v := range urlParams {
+		rctx.URLParams.Add(k, v)
+	}
+
+	return req.WithContext(
+		context.WithValue(req.Context(), chi.RouteCtxKey, rctx),
+	)
+}
+
+// getRequest builds a GET to path carrying the given cookies, plus any
+// chi URL parameters the handler reads.
+func getRequest(
+	t *testing.T,
+	path string,
+	cookies []*http.Cookie,
+	urlParams map[string]string,
+) *http.Request {
+	t.Helper()
+
+	req := httptest.NewRequestWithContext(
+		context.Background(), http.MethodGet, path, nil,
+	)
+
+	for _, c := range cookies {
+		req.AddCookie(c)
+	}
+
+	rctx := chi.NewRouteContext()
+	for k, v := range urlParams {
+		rctx.URLParams.Add(k, v)
+	}
+
+	return req.WithContext(
+		context.WithValue(req.Context(), chi.RouteCtxKey, rctx),
+	)
+}
+
+// submitCreate posts the webhook creation form with the given
+// retention_days value (omitted entirely when retention is nil) and
+// returns the recorder.
+func submitCreate(
+	t *testing.T,
+	h *handlers.Handlers,
+	cookies []*http.Cookie,
+	name string,
+	retention *string,
+) *httptest.ResponseRecorder {
+	t.Helper()
+
+	form := url.Values{}
+	form.Set("name", name)
+
+	if retention != nil {
+		form.Set("retention_days", *retention)
+	}
+
+	req := formRequest("/sources/new", cookies, form, nil)
+	w := httptest.NewRecorder()
+
+	h.HandleSourceCreateSubmit().ServeHTTP(w, req)
+
+	return w
+}
+
+// onlyWebhook loads the single webhook belonging to the test user.
+func onlyWebhook(
+	t *testing.T,
+	db *database.Database,
+) database.Webhook {
+	t.Helper()
+
+	var webhooks []database.Webhook
+
+	require.NoError(
+		t,
+		db.DB().Where("user_id = ?", sourceTestUserID).
+			Find(&webhooks).Error,
+	)
+	require.Len(t, webhooks, 1)
+
+	return webhooks[0]
+}
+
+// seedWebhookWithRetention inserts a webhook owned by the test user
+// with an exact stored retention value, bypassing Webhook.BeforeSave
+// via a column-level update so that legacy rows can be planted too.
+func seedWebhookWithRetention(
+	t *testing.T,
+	db *database.Database,
+	retentionDays int,
+) database.Webhook {
+	t.Helper()
+
+	wh := &database.Webhook{
+		UserID:        sourceTestUserID,
+		Name:          "seeded",
+		RetentionDays: retentionDays,
+	}
+	require.NoError(
+		t,
+		db.DB().Omit(clause.Associations).Create(wh).Error,
+	)
+	require.NoError(
+		t,
+		db.DB().Model(wh).
+			Update("retention_days", retentionDays).Error,
+	)
+
+	wh.RetentionDays = retentionDays
+
+	return *wh
+}
+
+// storedRetentionDays reads the retention_days column for a webhook.
+func storedRetentionDays(
+	t *testing.T,
+	db *database.Database,
+	id string,
+) int {
+	t.Helper()
+
+	var got int
+
+	require.NoError(
+		t,
+		db.DB().Model(&database.Webhook{}).
+			Where("id = ?", id).
+			Pluck("retention_days", &got).Error,
+	)
+
+	return got
+}
+
+// sourceTestEnv bundles the handler, session, and database a webhook
+// management test drives.
+type sourceTestEnv struct {
+	handlers *handlers.Handlers
+	db       *database.Database
+	cookies  []*http.Cookie
+}
+
+func setupSourceTest(t *testing.T) *sourceTestEnv {
+	t.Helper()
+
+	var h *handlers.Handlers
+
+	var sess *session.Session
+
+	var db *database.Database
+
+	app := newTestApp(t, &h, &sess, &db)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	return &sourceTestEnv{
+		handlers: h,
+		db:       db,
+		cookies: authenticatedCookies(
+			t, sess, sourceTestUserID, "sourceuser",
+		),
+	}
+}
+
+// TestHandleSourceCreateSubmit_ZeroRetentionPersistsForever is the core
+// regression test for the bug: the create form's 0 must reach the
+// database as the retain-forever sentinel rather than being replaced by
+// the column's default of 30.
+func TestHandleSourceCreateSubmit_ZeroRetentionPersistsForever(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+	zero := "0"
+
+	w := submitCreate(t, env.handlers, env.cookies, "forever", &zero)
+	require.Equal(t, http.StatusSeeOther, w.Code)
+
+	wh := onlyWebhook(t, env.db)
+	assert.Equal(
+		t,
+		database.RetentionForeverDays,
+		storedRetentionDays(t, env.db, wh.ID),
+	)
+	assert.True(t, wh.RetainsForever())
+}
+
+func TestHandleSourceCreateSubmit_OmittedRetentionUsesDefault(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+
+	w := submitCreate(t, env.handlers, env.cookies, "defaulted", nil)
+	require.Equal(t, http.StatusSeeOther, w.Code)
+
+	wh := onlyWebhook(t, env.db)
+	assert.Equal(
+		t,
+		database.DefaultRetentionDays,
+		storedRetentionDays(t, env.db, wh.ID),
+	)
+}
+
+// TestHandleSourceCreate_PrefillsDefaultFromConstant keeps the create
+// form's pre-filled retention from becoming a third hardcoded copy of
+// the 30-day policy.
+func TestHandleSourceCreate_PrefillsDefaultFromConstant(t *testing.T) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+
+	w := httptest.NewRecorder()
+	env.handlers.HandleSourceCreate().ServeHTTP(
+		w, getRequest(t, "/sources/new", env.cookies, nil),
+	)
+
+	require.Equal(t, http.StatusOK, w.Code)
+
+	body := w.Body.String()
+
+	assert.Contains(
+		t, body,
+		`value="`+strconv.Itoa(database.DefaultRetentionDays)+`"`,
+	)
+	assert.NotContains(
+		t, body, `max="365"`,
+		"a max below the sentinel would block retain-forever",
+	)
+	assert.Contains(t, body, `min="0"`)
+}
+
+func TestHandleSourceCreateSubmit_InvalidRetentionIsRejected(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	for _, raw := range []string{"abc", "-1", "3.5"} {
+		t.Run(raw, func(t *testing.T) {
+			t.Parallel()
+
+			env := setupSourceTest(t)
+
+			w := submitCreate(
+				t, env.handlers, env.cookies, "bad", &raw,
+			)
+
+			assert.Equal(t, http.StatusBadRequest, w.Code)
+			assert.Contains(
+				t, w.Body.String(), "Retention must be",
+			)
+
+			var count int64
+
+			require.NoError(
+				t,
+				env.db.DB().Model(&database.Webhook{}).
+					Where("user_id = ?", sourceTestUserID).
+					Count(&count).Error,
+			)
+			assert.Zero(
+				t, count,
+				"no webhook may be created from a rejected form",
+			)
+		})
+	}
+}
+
+// TestHandleSourceCreateSubmit_OverflowingRetentionIsRejected covers
+// the data-loss path directly: a finite retention above the largest one
+// the reaper's cutoff arithmetic can represent must never reach the
+// database, because the sweep would compute a future cutoff and delete
+// every event the webhook has.
+func TestHandleSourceCreateSubmit_OverflowingRetentionIsRejected(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	tooBig := strconv.Itoa(database.MaxFiniteRetentionDays + 1)
+
+	env := setupSourceTest(t)
+
+	w := submitCreate(t, env.handlers, env.cookies, "huge", &tooBig)
+
+	assert.Equal(t, http.StatusBadRequest, w.Code)
+	assert.Contains(
+		t, w.Body.String(),
+		strconv.Itoa(database.MaxFiniteRetentionDays),
+		"the form tells the user the actual ceiling",
+	)
+
+	var count int64
+
+	require.NoError(
+		t,
+		env.db.DB().Model(&database.Webhook{}).
+			Where("user_id = ?", sourceTestUserID).
+			Count(&count).Error,
+	)
+	assert.Zero(
+		t, count,
+		"no webhook may be created from a rejected form",
+	)
+}
+
+// TestHandleSourceCreateSubmit_SentinelIsAcceptedAsForever guards the
+// boundary between "too large to represent" and "retain forever": the
+// sentinel is above MaxFiniteRetentionDays, but it is the value the
+// edit form pre-fills, so it must be accepted rather than rejected as
+// out of range.
+func TestHandleSourceCreateSubmit_SentinelIsAcceptedAsForever(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+	sentinel := strconv.Itoa(database.RetentionForeverDays)
+
+	w := submitCreate(t, env.handlers, env.cookies, "forever", &sentinel)
+	require.Equal(t, http.StatusSeeOther, w.Code)
+
+	wh := onlyWebhook(t, env.db)
+	assert.Equal(
+		t,
+		database.RetentionForeverDays,
+		storedRetentionDays(t, env.db, wh.ID),
+	)
+}
+
+// TestHandleSourceCreateSubmit_RejectedFormKeepsUserInput checks that a
+// validation failure hands the user's typing back, matching what the
+// edit form already does. Losing a long description to a mistyped
+// retention value is the kind of thing that makes people give up on a
+// form.
+func TestHandleSourceCreateSubmit_RejectedFormKeepsUserInput(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+
+	const (
+		name        = "kept-name"
+		description = "a description worth not losing"
+	)
+
+	form := url.Values{}
+	form.Set("name", name)
+	form.Set("description", description)
+	form.Set("retention_days", "nonsense")
+
+	req := formRequest("/sources/new", env.cookies, form, nil)
+	w := httptest.NewRecorder()
+
+	env.handlers.HandleSourceCreateSubmit().ServeHTTP(w, req)
+
+	require.Equal(t, http.StatusBadRequest, w.Code)
+
+	body := w.Body.String()
+
+	assert.Contains(t, body, `value="`+name+`"`)
+	assert.Contains(t, body, description)
+}
+
+// submitEdit posts the webhook edit form for the given webhook.
+func submitEdit(
+	t *testing.T,
+	env *sourceTestEnv,
+	wh database.Webhook,
+	retention string,
+) *httptest.ResponseRecorder {
+	t.Helper()
+
+	form := url.Values{}
+	form.Set("name", wh.Name)
+	form.Set("description", wh.Description)
+	form.Set("retention_days", retention)
+
+	req := formRequest(
+		"/source/"+wh.ID+"/edit",
+		env.cookies,
+		form,
+		map[string]string{sourceIDParam: wh.ID},
+	)
+	w := httptest.NewRecorder()
+
+	env.handlers.HandleSourceEditSubmit().ServeHTTP(w, req)
+
+	return w
+}
+
+func TestHandleSourceEditSubmit_ZeroRetentionPersistsForever(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+	wh := seedWebhookWithRetention(
+		t, env.db, database.DefaultRetentionDays,
+	)
+
+	w := submitEdit(t, env, wh, "0")
+	require.Equal(t, http.StatusSeeOther, w.Code)
+
+	assert.Equal(
+		t,
+		database.RetentionForeverDays,
+		storedRetentionDays(t, env.db, wh.ID),
+	)
+}
+
+func TestHandleSourceEditSubmit_InvalidRetentionIsRejected(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+	wh := seedWebhookWithRetention(
+		t, env.db, database.DefaultRetentionDays,
+	)
+
+	w := submitEdit(t, env, wh, "not-a-number")
+
+	assert.Equal(t, http.StatusBadRequest, w.Code)
+	assert.Contains(t, w.Body.String(), "Retention must be")
+	assert.Equal(
+		t,
+		database.DefaultRetentionDays,
+		storedRetentionDays(t, env.db, wh.ID),
+		"a rejected form must not change the stored retention",
+	)
+}
+
+func TestHandleSourceEditSubmit_EmptyRetentionLeavesValueUnchanged(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+	wh := seedWebhookWithRetention(t, env.db, 7)
+
+	w := submitEdit(t, env, wh, "")
+	require.Equal(t, http.StatusSeeOther, w.Code)
+
+	assert.Equal(t, 7, storedRetentionDays(t, env.db, wh.ID))
+}
+
+// TestSourceEditForm_ForeverWebhookRoundTrips walks the exact path that
+// the removed max="365" cap used to break: render the edit form for a
+// retain-forever webhook, confirm the pre-filled sentinel is not capped
+// by browser validation, then submit that pre-filled value straight
+// back and confirm the retention policy survives untouched.
+func TestSourceEditForm_ForeverWebhookRoundTrips(t *testing.T) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+	wh := seedWebhookWithRetention(
+		t, env.db, database.RetentionForeverDays,
+	)
+
+	req := getRequest(
+		t, "/source/"+wh.ID+"/edit", env.cookies,
+		map[string]string{sourceIDParam: wh.ID},
+	)
+	w := httptest.NewRecorder()
+	env.handlers.HandleSourceEdit().ServeHTTP(w, req)
+
+	require.Equal(t, http.StatusOK, w.Code)
+
+	sentinel := strconv.Itoa(database.RetentionForeverDays)
+	body := w.Body.String()
+
+	assert.Contains(
+		t, body, `value="`+sentinel+`"`,
+		"the edit form pre-fills the stored retention",
+	)
+	assert.NotContains(
+		t, body, `max="365"`,
+		"a max below the sentinel would block saving any edit",
+	)
+	// "Currently forever." is the rendered RetentionLabel, not the
+	// static hint below the input, which says "Enter 0 to retain events
+	// forever." A bare Contains of "forever" would pass for any
+	// webhook and would assert nothing about this one.
+	assert.Contains(
+		t, body, "Currently forever.",
+		"the form reports this webhook's policy as forever",
+	)
+
+	// Submit the pre-filled value back, exactly as a browser would.
+	post := submitEdit(t, env, wh, sentinel)
+	require.Equal(t, http.StatusSeeOther, post.Code)
+
+	assert.Equal(
+		t,
+		database.RetentionForeverDays,
+		storedRetentionDays(t, env.db, wh.ID),
+	)
+}
+
+// TestSourceListAndDetail_ShowForeverNotTheSentinelNumber checks that
+// the retain-forever value is never rendered to the user as a raw day
+// count on either read-only view.
+func TestSourceListAndDetail_ShowForeverNotTheSentinelNumber(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+	wh := seedWebhookWithRetention(
+		t, env.db, database.RetentionForeverDays,
+	)
+	sentinel := strconv.Itoa(database.RetentionForeverDays)
+
+	listW := httptest.NewRecorder()
+	env.handlers.HandleSourceList().ServeHTTP(
+		listW, getRequest(t, "/sources", env.cookies, nil),
+	)
+
+	require.Equal(t, http.StatusOK, listW.Code)
+	assert.Contains(t, listW.Body.String(), "Retention: forever")
+	assert.NotContains(t, listW.Body.String(), sentinel)
+
+	detailW := httptest.NewRecorder()
+	env.handlers.HandleSourceDetail().ServeHTTP(
+		detailW,
+		getRequest(
+			t, "/source/"+wh.ID, env.cookies,
+			map[string]string{sourceIDParam: wh.ID},
+		),
+	)
+
+	require.Equal(t, http.StatusOK, detailW.Code)
+	assert.Contains(t, detailW.Body.String(), "Retention: forever")
+	assert.NotContains(t, detailW.Body.String(), sentinel)
+}

internal/handlers/ui_copy_test.go

@@ -0,0 +1,299 @@
+package handlers_test
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/delivery"
+	"sneak.berlin/go/webhooker/internal/handlers"
+	"sneak.berlin/go/webhooker/internal/session"
+)
+
+// Template data keys the page templates read. The handlers package has
+// its own unexported constants for these; this is the external test
+// package, so it needs its own.
+const (
+	dataKeyWebhook = "Webhook"
+	dataKeyError   = "Error"
+)
+
+// testWebhookID is the identifier given to the webhook under test on
+// pages that render one.
+const testWebhookID = "wh-1"
+
+// renderPage renders a page template through the real template set as
+// an authenticated user and returns the resulting HTML.
+func renderPage(
+	t *testing.T,
+	h *handlers.Handlers,
+	sess *session.Session,
+	page string,
+	data map[string]any,
+) string {
+	t.Helper()
+
+	cookies := authenticatedCookies(t, sess, "test-user-id", "testuser")
+
+	req := httptest.NewRequestWithContext(
+		context.Background(), http.MethodGet, "/", nil,
+	)
+	for _, c := range cookies {
+		req.AddCookie(c)
+	}
+
+	w := httptest.NewRecorder()
+	h.RenderTemplateForTest(w, req, page, data)
+
+	return w.Body.String()
+}
+
+// TestNavbarUsesWebhookTerminology pins the user-visible navigation
+// label to "Webhooks". The /sources route is deliberately unchanged, so
+// the assertion targets the link text rather than the href.
+func TestNavbarUsesWebhookTerminology(t *testing.T) {
+	t.Parallel()
+
+	var h *handlers.Handlers
+
+	var sess *session.Session
+
+	app := newTestApp(t, &h, &sess)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	// One item, so the list body renders too: it calls
+	// WebhookListItem.RetentionLabel, promoted from the embedded
+	// Webhook and therefore a pointer method. An empty list would
+	// skip that call and hide a template error behind the
+	// navigation assertions below.
+	item := handlers.WebhookListItem{}
+	item.Name = "wh"
+	item.ID = testWebhookID
+	item.RetentionDays = 14
+
+	body := renderPage(t, h, sess, "sources_list.html", map[string]any{
+		"Webhooks": []handlers.WebhookListItem{item},
+	})
+
+	assert.Contains(t, body, "Retention: 14 days")
+	assert.Contains(t, body, `class="btn-text">Webhooks</a>`)
+	assert.Contains(
+		t, body, `class="btn-text w-full text-left">Webhooks</a>`,
+	)
+	assert.Contains(
+		t, body,
+		`<h1 class="text-2xl font-medium text-gray-900">Webhooks</h1>`,
+	)
+	assert.NotContains(
+		t, body, ">Sources<",
+		"no user-visible element may still be labelled Sources",
+	)
+	assert.Contains(
+		t, body, `href="/sources"`,
+		"the /sources route itself must not change",
+	)
+}
+
+// TestEditPageUsesWebhookTerminology pins the edit page's heading and
+// its back link. The link's href still points at /source/{id}, which is
+// intentional: only user-visible copy changes.
+func TestEditPageUsesWebhookTerminology(t *testing.T) {
+	t.Parallel()
+
+	var h *handlers.Handlers
+
+	var sess *session.Session
+
+	app := newTestApp(t, &h, &sess)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	// The webhook goes in as a pointer because source_edit.html calls
+	// Webhook.RetentionLabel, a pointer method: a map element is not
+	// addressable, so a value here renders an error instead of the
+	// page.
+	webhook := &database.Webhook{Name: "wh", RetentionDays: 14}
+	webhook.ID = testWebhookID
+
+	body := renderPage(t, h, sess, "source_edit.html", map[string]any{
+		dataKeyWebhook: webhook,
+		dataKeyError:   "",
+	})
+
+	assert.Contains(t, body, "Edit Webhook")
+	assert.NotContains(t, body, ">Sources<")
+	assert.Contains(t, body, `href="/source/wh-1"`)
+}
+
+// TestCreateFormRetentionCopyMatchesBehaviour pins the create form's
+// retention copy to what the code does: the reaper permanently deletes
+// events past the cutoff, an empty field falls back to
+// DefaultRetentionDays, and 0 is rewritten to the retain-forever
+// sentinel by Webhook.BeforeSave.
+func TestCreateFormRetentionCopyMatchesBehaviour(t *testing.T) {
+	t.Parallel()
+
+	var h *handlers.Handlers
+
+	var sess *session.Session
+
+	app := newTestApp(t, &h, &sess)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	body := renderPage(t, h, sess, "sources_new.html", map[string]any{
+		"Name":                 "",
+		"Description":          "",
+		"DefaultRetentionDays": database.DefaultRetentionDays,
+		dataKeyError:           "",
+	})
+
+	assert.Contains(
+		t, body,
+		"permanently deletes events older than this",
+		"the form must say retention is enforced by deletion",
+	)
+	assert.Contains(t, body, "Enter 0 to retain events forever")
+	assert.Contains(
+		t, body,
+		"leave blank to use the default of "+
+			strconv.Itoa(database.DefaultRetentionDays)+" days",
+		"blank means the default, not forever",
+	)
+}
+
+// TestEditFormRetentionCopyMatchesBehaviour pins the edit form's
+// retention copy, including that it states the stored policy via
+// RetentionLabel and that an empty field leaves that policy unchanged
+// rather than meaning forever.
+func TestEditFormRetentionCopyMatchesBehaviour(t *testing.T) {
+	t.Parallel()
+
+	var h *handlers.Handlers
+
+	var sess *session.Session
+
+	app := newTestApp(t, &h, &sess)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	finite := &database.Webhook{Name: "wh", RetentionDays: 14}
+	finite.ID = testWebhookID
+
+	body := renderPage(t, h, sess, "source_edit.html", map[string]any{
+		dataKeyWebhook: finite,
+		dataKeyError:   "",
+	})
+
+	assert.Contains(t, body, "Currently 14 days.")
+	assert.Contains(
+		t, body,
+		"permanently deletes events older than this",
+	)
+	assert.Contains(t, body, "Enter 0 to retain events forever")
+	assert.Contains(
+		t, body,
+		"leave blank to keep the current setting",
+		"blank means unchanged, not forever",
+	)
+
+	forever := &database.Webhook{
+		Name:          "wh",
+		RetentionDays: database.RetentionForeverDays,
+	}
+	forever.ID = "wh-2"
+
+	foreverBody := renderPage(
+		t, h, sess, "source_edit.html", map[string]any{
+			dataKeyWebhook: forever,
+			dataKeyError:   "",
+		},
+	)
+
+	assert.Contains(
+		t, foreverBody, "Currently forever.",
+		"a retain-forever webhook must not read as a day count",
+	)
+	assert.Contains(
+		t, foreverBody,
+		"No events are deleted while retention is set to forever",
+	)
+	assert.NotContains(
+		t, foreverBody,
+		"permanently deletes events older than this",
+		"the reaper skips retain-forever webhooks, so the form "+
+			"must not claim it deletes their events",
+	)
+}
+
+// TestEntrypointCopyButtonIsProgressiveEnhancement proves the copy
+// affordance degrades: the button ships with the hidden attribute, so a
+// browser that never runs app.js shows no dead control, and the URL is
+// rendered as ordinary selectable text either way.
+func TestEntrypointCopyButtonIsProgressiveEnhancement(t *testing.T) {
+	t.Parallel()
+
+	var h *handlers.Handlers
+
+	var sess *session.Session
+
+	app := newTestApp(t, &h, &sess)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	entrypoint := database.Entrypoint{Path: "abc123"}
+	entrypoint.ID = "ep-1"
+
+	// The webhook goes in as a pointer because source_detail.html
+	// calls Webhook.RetentionLabel, a pointer method: a map element
+	// is not addressable, so a value here aborts execution partway
+	// down the page, after the copy button has already been flushed
+	// to the response.
+	webhook := &database.Webhook{Name: "wh", RetentionDays: 14}
+	webhook.ID = testWebhookID
+	webhook.CreatedAt = time.Date(
+		2026, time.January, 2, 3, 4, 5, 0, time.UTC,
+	)
+
+	body := renderPage(t, h, sess, "source_detail.html", map[string]any{
+		dataKeyWebhook: webhook,
+		"Entrypoints":  []database.Entrypoint{entrypoint},
+		// The handler passes delivery.NewTargetViews(targets), never
+		// raw targets, so the test data has to have that same shape.
+		"Targets": delivery.NewTargetViews(nil),
+		"Events":  []database.Event{},
+		"BaseURL": "https://hooks.example.com",
+	})
+
+	assert.Contains(
+		t, body,
+		`<code id="entrypoint-url-ep-1"`,
+	)
+	assert.Contains(t, body, "https://hooks.example.com/webhook/abc123")
+	assert.Contains(
+		t, body,
+		`hidden data-copy-target="entrypoint-url-ep-1"`,
+		"the button must start hidden and be revealed by script",
+	)
+
+	// renderTemplate streams to the ResponseWriter, so an abort
+	// midway still leaves everything above it in the body. This pins
+	// content from the last line of the template, which is below the
+	// assertions above: without it, a page that renders the copy
+	// button and then 500s passes.
+	assert.Contains(
+		t, body, "Retention: 14 days",
+		"the page must render to completion, not abort partway",
+	)
+}

internal/middleware/middleware.go

@@ -186,6 +186,10 @@ func (s *Middleware) RequireAuth() func(http.Handler) http.Handler {
 				return
 			}
 
+			// IsAuthenticated also enforces both session expiry
+			// deadlines, so an idle-expired or absolutely-expired
+			// session lands here and is sent back to the login
+			// page.
 			if !s.session.IsAuthenticated(sess) {
 				s.log.Debug(
 					"auth middleware: unauthenticated request",
@@ -199,6 +203,26 @@ func (s *Middleware) RequireAuth() func(http.Handler) http.Handler {
 				return
 			}
 
+			// This request authenticated with the session, so it
+			// counts as activity: push the idle deadline forward.
+			// This is the only place sessions are refreshed, which
+			// is what keeps an unauthenticated request from
+			// extending someone else's session. Touch advances the
+			// idle clock only -- the absolute cap is untouched --
+			// and reports false when nothing changed, so most
+			// requests do not re-issue the cookie. Save before the
+			// handler runs, while the headers are still ours to
+			// write.
+			if s.session.Touch(sess) {
+				err = s.session.Save(r, w, sess)
+				if err != nil {
+					s.log.Error(
+						"auth middleware: failed to refresh session",
+						"error", err,
+					)
+				}
+			}
+
 			next.ServeHTTP(w, r)
 		})
 	}
@@ -285,10 +309,36 @@ func (s *Middleware) NoCache() func(http.Handler) http.Handler {
 	}
 }
 
-// MaxBodySize returns middleware that limits the request body size
-// for POST requests. If the body exceeds the given limit in
-// bytes, the server returns 413 Request Entity Too Large. This
-// prevents clients from sending arbitrarily large form bodies.
+// bodyLimitedMethod reports whether the request method carries a
+// body that the MaxBodySize middleware should cap.
+func bodyLimitedMethod(method string) bool {
+	return method == http.MethodPost ||
+		method == http.MethodPut ||
+		method == http.MethodPatch
+}
+
+// MaxBodySize returns middleware that limits the size of
+// POST/PUT/PATCH request bodies to maxBytes. It must be registered
+// before any middleware that parses the body — notably CSRF, which
+// calls r.PostFormValue — so that form parsing happens under this
+// cap rather than net/http's 10 MB default.
+//
+// Two enforcement paths exist, because http.MaxBytesReader alone
+// cannot produce a 413: it reports the overflow as an error from
+// Read, by which point the body parser downstream has already
+// converted that error into its own response.
+//
+//   - Declared oversize: the request announces a Content-Length
+//     greater than maxBytes. The middleware answers 413 Request
+//     Entity Too Large immediately and does not call the next
+//     handler, so neither CSRF nor the endpoint handler runs.
+//   - Undeclared oversize: the request is chunked (Content-Length
+//     of -1) or lies about its Content-Length. There is nothing to
+//     check up front, so http.MaxBytesReader hard-caps the body at
+//     maxBytes and the request fails downstream — the form parse
+//     errors out and CSRF rejects it with 403. The response is less
+//     precise than a 413, but the body is still never buffered
+//     beyond the cap, which is the property that matters.
 func (s *Middleware) MaxBodySize(
 	maxBytes int64,
 ) func(http.Handler) http.Handler {
@@ -297,14 +347,31 @@ func (s *Middleware) MaxBodySize(
 			w http.ResponseWriter,
 			r *http.Request,
 		) {
-			if r.Method == http.MethodPost ||
-				r.Method == http.MethodPut ||
-				r.Method == http.MethodPatch {
-				r.Body = http.MaxBytesReader(
-					w, r.Body, maxBytes,
-				)
+			if !bodyLimitedMethod(r.Method) {
+				next.ServeHTTP(w, r)
+
+				return
 			}
 
+			if r.ContentLength > maxBytes {
+				s.log.Warn(
+					"request body exceeds limit",
+					"method", r.Method,
+					"path", r.URL.Path,
+					"content_length", r.ContentLength,
+					"limit", maxBytes,
+				)
+				http.Error(
+					w,
+					"Request Entity Too Large",
+					http.StatusRequestEntityTooLarge,
+				)
+
+				return
+			}
+
+			r.Body = http.MaxBytesReader(w, r.Body, maxBytes)
+
 			next.ServeHTTP(w, r)
 		})
 	}

internal/middleware/middleware_test.go

@@ -3,11 +3,14 @@ package middleware_test
 import (
 	"context"
 	"encoding/base64"
+	"io"
 	"log/slog"
 	"net/http"
 	"net/http/httptest"
 	"os"
+	"strings"
 	"testing"
+	"time"
 
 	"github.com/gorilla/sessions"
 	"github.com/stretchr/testify/assert"
@@ -28,13 +31,30 @@ func testMiddleware(
 ) (*middleware.Middleware, *session.Session) {
 	t.Helper()
 
+	m, s, _ := testMiddlewareWithSessionClock(t, env, 0, nil)
+
+	return m, s
+}
+
+// testMiddlewareWithSessionClock is testMiddleware with a
+// configurable session idle timeout and a manually advanced clock,
+// for the session-expiry tests. A nil clock uses the real one.
+func testMiddlewareWithSessionClock(
+	t *testing.T,
+	env string,
+	idleTimeout time.Duration,
+	clock *fakeClock,
+) (*middleware.Middleware, *session.Session, *fakeClock) {
+	t.Helper()
+
 	log := slog.New(slog.NewTextHandler(
 		os.Stderr,
 		&slog.HandlerOptions{Level: slog.LevelDebug},
 	))
 
 	cfg := &config.Config{
-		Environment: env,
+		Environment:        env,
+		SessionIdleTimeout: idleTimeout,
 	}
 
 	// Create a real session manager with a known key
@@ -53,11 +73,40 @@ func testMiddleware(
 		SameSite: http.SameSiteLaxMode,
 	}
 
-	sessManager := session.NewForTest(store, cfg, log, key)
+	var now func() time.Time
+
+	if clock != nil {
+		now = clock.Now
+	}
+
+	sessManager := session.NewForTest(store, cfg, log, key, now)
 
 	m := middleware.NewForTest(log, cfg, sessManager)
 
-	return m, sessManager
+	return m, sessManager, clock
+}
+
+// fakeClock is a manually advanced clock, so session expiry can be
+// tested without sleeping.
+type fakeClock struct {
+	t time.Time
+}
+
+func (c *fakeClock) Now() time.Time {
+	return c.t
+}
+
+func (c *fakeClock) Advance(d time.Duration) {
+	c.t = c.t.Add(d)
+}
+
+// newFakeClock returns a clock started at a fixed instant.
+func newFakeClock() *fakeClock {
+	return &fakeClock{
+		t: time.Date(
+			2026, time.January, 2, 3, 4, 5, 0, time.UTC,
+		),
+	}
 }
 
 // --- Logging Middleware Tests ---
@@ -387,6 +436,181 @@ func TestRequireAuth_UnauthenticatedSession_RedirectsToLogin(
 	assert.Equal(t, "/pages/login", w.Header().Get("Location"))
 }
 
+// --- RequireAuth Session Expiry Tests ---
+
+// loginCookies authenticates a new session and returns the cookies
+// a browser would then send back.
+func loginCookies(
+	t *testing.T,
+	sessManager *session.Session,
+) []*http.Cookie {
+	t.Helper()
+
+	req := httptest.NewRequestWithContext(
+		context.Background(), http.MethodGet, "/login", nil)
+	w := httptest.NewRecorder()
+
+	sess, err := sessManager.Get(req)
+	require.NoError(t, err)
+	sessManager.SetUser(sess, "user-123", "testuser")
+	require.NoError(t, sessManager.Save(req, w, sess))
+
+	cookies := w.Result().Cookies()
+	require.NotEmpty(t, cookies, "session cookie should be set")
+
+	return cookies
+}
+
+// runAuthed sends a request carrying cookies through RequireAuth
+// and reports whether the protected handler ran, plus the response.
+func runAuthed(
+	t *testing.T,
+	m *middleware.Middleware,
+	cookies []*http.Cookie,
+) (bool, *httptest.ResponseRecorder) {
+	t.Helper()
+
+	var called bool
+
+	handler := m.RequireAuth()(http.HandlerFunc(
+		func(_ http.ResponseWriter, _ *http.Request) {
+			called = true
+		},
+	))
+
+	req := httptest.NewRequestWithContext(
+		context.Background(),
+		http.MethodGet, "/dashboard", nil,
+	)
+
+	for _, c := range cookies {
+		req.AddCookie(c)
+	}
+
+	w := httptest.NewRecorder()
+	handler.ServeHTTP(w, req)
+
+	return called, w
+}
+
+// sessionCookies filters a response's cookies down to the session
+// cookie, so tests can tell whether the session was re-issued.
+func sessionCookies(
+	w *httptest.ResponseRecorder,
+) []*http.Cookie {
+	var out []*http.Cookie
+
+	for _, c := range w.Result().Cookies() {
+		if c.Name == session.SessionName {
+			out = append(out, c)
+		}
+	}
+
+	return out
+}
+
+func TestRequireAuth_IdleExpiredSession_RedirectsToLogin(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	idle := time.Hour
+
+	m, sessManager, clock := testMiddlewareWithSessionClock(
+		t, config.EnvironmentDev, idle, newFakeClock(),
+	)
+
+	cookies := loginCookies(t, sessManager)
+
+	clock.Advance(idle)
+
+	called, w := runAuthed(t, m, cookies)
+
+	assert.False(
+		t, called,
+		"handler should not run for an idle-expired session",
+	)
+	assert.Equal(t, http.StatusSeeOther, w.Code)
+	assert.Equal(t, "/pages/login", w.Header().Get("Location"))
+	assert.Empty(
+		t, sessionCookies(w),
+		"an expired session must not be refreshed",
+	)
+}
+
+func TestRequireAuth_RefreshesIdleDeadlineOnActivity(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	idle := time.Hour
+
+	m, sessManager, clock := testMiddlewareWithSessionClock(
+		t, config.EnvironmentDev, idle, newFakeClock(),
+	)
+
+	cookies := loginCookies(t, sessManager)
+
+	// Activity halfway through the idle window.
+	clock.Advance(idle / 2)
+
+	called, w := runAuthed(t, m, cookies)
+	require.True(t, called, "handler should run while valid")
+
+	refreshed := sessionCookies(w)
+	require.NotEmpty(
+		t, refreshed,
+		"activity should re-issue the session cookie",
+	)
+
+	// Past the original deadline. The refreshed cookie is still
+	// good; the original one is not.
+	clock.Advance(idle - time.Second)
+
+	calledRefreshed, _ := runAuthed(t, m, refreshed)
+	assert.True(
+		t, calledRefreshed,
+		"refreshed session should outlive the original deadline",
+	)
+
+	calledStale, staleW := runAuthed(t, m, cookies)
+	assert.False(
+		t, calledStale,
+		"the pre-refresh cookie carries the old idle deadline",
+	)
+	assert.Equal(t, http.StatusSeeOther, staleW.Code)
+}
+
+func TestRequireAuth_UnauthenticatedRequestDoesNotRefresh(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	m, sessManager, _ := testMiddlewareWithSessionClock(
+		t, config.EnvironmentDev, time.Hour, newFakeClock(),
+	)
+
+	// A session cookie that exists but was never authenticated.
+	req := httptest.NewRequestWithContext(
+		context.Background(), http.MethodGet, "/setup", nil)
+	setupW := httptest.NewRecorder()
+
+	sess, err := sessManager.Get(req)
+	require.NoError(t, err)
+	require.NoError(t, sessManager.Save(req, setupW, sess))
+
+	cookies := setupW.Result().Cookies()
+	require.NotEmpty(t, cookies)
+
+	called, w := runAuthed(t, m, cookies)
+
+	assert.False(t, called)
+	assert.Empty(
+		t, sessionCookies(w),
+		"an unauthenticated request must not stamp the session",
+	)
+}
+
 // --- NoCache Middleware Tests ---
 
 func TestNoCache_SetsHeaders(t *testing.T) {
@@ -426,6 +650,153 @@ func TestNoCache_SetsHeaders(t *testing.T) {
 	)
 }
 
+// --- MaxBodySize Middleware Tests ---
+
+const testBodyLimit int64 = 64
+
+// maxBodySizeHandler wraps a sentinel handler in MaxBodySize with
+// testBodyLimit. The sentinel records whether it ran and how much of
+// the body it managed to read, so tests can distinguish "never
+// reached" from "reached but truncated".
+type maxBodySizeResult struct {
+	called   bool
+	read     int
+	readErr  error
+	response *httptest.ResponseRecorder
+}
+
+func runMaxBodySize(
+	t *testing.T,
+	req *http.Request,
+) *maxBodySizeResult {
+	t.Helper()
+
+	m, _ := testMiddleware(t, config.EnvironmentDev)
+	res := &maxBodySizeResult{response: httptest.NewRecorder()}
+
+	handler := m.MaxBodySize(testBodyLimit)(http.HandlerFunc(
+		func(w http.ResponseWriter, r *http.Request) {
+			res.called = true
+
+			body, err := io.ReadAll(r.Body)
+			res.read = len(body)
+			res.readErr = err
+
+			w.WriteHeader(http.StatusOK)
+		},
+	))
+
+	handler.ServeHTTP(res.response, req)
+
+	return res
+}
+
+// postWithBody builds a POST request whose Content-Length is
+// accurate for the given payload size.
+func postWithBody(size int) *http.Request {
+	req := httptest.NewRequestWithContext(
+		context.Background(),
+		http.MethodPost, "/pages/login",
+		strings.NewReader(strings.Repeat("a", size)),
+	)
+	req.Header.Set(
+		"Content-Type", "application/x-www-form-urlencoded",
+	)
+
+	return req
+}
+
+func TestMaxBodySize_DeclaredOversize_413AndHandlerNotReached(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	res := runMaxBodySize(t, postWithBody(int(testBodyLimit)+1))
+
+	assert.False(
+		t, res.called,
+		"handler must not be reached for an oversized body",
+	)
+	assert.Equal(
+		t, http.StatusRequestEntityTooLarge, res.response.Code,
+	)
+}
+
+func TestMaxBodySize_AtLimit_PassesThrough(t *testing.T) {
+	t.Parallel()
+
+	res := runMaxBodySize(t, postWithBody(int(testBodyLimit)))
+
+	assert.True(
+		t, res.called,
+		"handler should be reached for a body at the limit",
+	)
+	require.NoError(t, res.readErr)
+	assert.Equal(t, int(testBodyLimit), res.read)
+	assert.Equal(t, http.StatusOK, res.response.Code)
+}
+
+func TestMaxBodySize_UnderLimit_PassesThrough(t *testing.T) {
+	t.Parallel()
+
+	res := runMaxBodySize(t, postWithBody(1))
+
+	assert.True(t, res.called)
+	require.NoError(t, res.readErr)
+	assert.Equal(t, 1, res.read)
+	assert.Equal(t, http.StatusOK, res.response.Code)
+}
+
+func TestMaxBodySize_GetWithOversizeBody_NotCapped(t *testing.T) {
+	t.Parallel()
+
+	req := httptest.NewRequestWithContext(
+		context.Background(),
+		http.MethodGet, "/pages/login",
+		strings.NewReader(
+			strings.Repeat("a", int(testBodyLimit)+1),
+		),
+	)
+
+	res := runMaxBodySize(t, req)
+
+	assert.True(
+		t, res.called,
+		"GET requests are not subject to the POST body cap",
+	)
+	require.NoError(t, res.readErr)
+	assert.Equal(t, int(testBodyLimit)+1, res.read)
+}
+
+// TestMaxBodySize_UndeclaredOversize_TruncatedAtCap covers the
+// chunked / lying-Content-Length case: there is nothing to check up
+// front, so the request reaches the handler but MaxBytesReader
+// hard-caps the body and the read fails at the limit.
+func TestMaxBodySize_UndeclaredOversize_TruncatedAtCap(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	req := postWithBody(int(testBodyLimit) + 1)
+	// Simulate a chunked request: no declared length.
+	req.ContentLength = -1
+
+	res := runMaxBodySize(t, req)
+
+	assert.True(
+		t, res.called,
+		"an undeclared oversize body cannot be rejected up front",
+	)
+	require.Error(
+		t, res.readErr,
+		"reading past the cap must fail",
+	)
+	assert.Equal(
+		t, int(testBodyLimit), res.read,
+		"the handler must not see more than the cap",
+	)
+}
+
 // --- Helper Tests ---
 
 func TestIpFromHostPort(t *testing.T) {
@@ -479,7 +850,7 @@ func metricsAuthMiddleware(
 	store := sessions.NewCookieStore(key)
 	store.Options = &sessions.Options{Path: "/", MaxAge: 86400}
 
-	sessManager := session.NewForTest(store, cfg, log, key)
+	sessManager := session.NewForTest(store, cfg, log, key, nil)
 
 	return middleware.NewForTest(log, cfg, sessManager)
 }

internal/middleware/ratelimit.go

@@ -2,6 +2,9 @@ package middleware
 
 import (
 	"net/http"
+	"net/netip"
+	"slices"
+	"strings"
 	"time"
 
 	"github.com/go-chi/httprate"
@@ -24,15 +27,127 @@ const (
 	// passwordChangeRateInterval is the time window for the
 	// password change rate limit.
 	passwordChangeRateInterval = 1 * time.Minute
+
+	// receiverRateInterval is the time window for the webhook
+	// receiver rate limit. The configured limit is expressed in
+	// requests per minute.
+	receiverRateInterval = 1 * time.Minute
 )
 
+// normalizeAddr strips the IPv4-in-IPv6 wrapper and any zone from
+// addr so that comparisons and bucket keys are canonical.
+func normalizeAddr(addr netip.Addr) netip.Addr {
+	return addr.Unmap().WithZone("")
+}
+
+// isTrustedProxy reports whether addr belongs to a network the
+// operator listed in TRUSTED_PROXIES. The list is empty by default,
+// so by default nothing is trusted.
+func (m *Middleware) isTrustedProxy(addr netip.Addr) bool {
+	for _, prefix := range m.params.Config.TrustedProxies {
+		if prefix.Contains(addr) {
+			return true
+		}
+	}
+
+	return false
+}
+
+// forwardedClientAddr returns the client address named by this
+// request's X-Forwarded-For chain. It is consulted only for requests
+// whose direct peer is a trusted proxy.
+//
+// X-Forwarded-For is the only header read. X-Real-IP and
+// True-Client-IP are deliberately ignored: the reverse proxies in
+// common use append to X-Forwarded-For and pass any other header the
+// client sent through untouched, so believing a single-valued header
+// would let a client behind the trusted proxy name its own bucket —
+// the very bypass this gating exists to close.
+//
+// The chain is walked right to left, because the rightmost entry is
+// the one the nearest proxy appended and everything to its left may
+// have been written by the client. The first hop that is not itself
+// a trusted proxy is the client. A hop that cannot be read as a bare
+// address ends the walk: past it the chain is not the shape assumed
+// here, so the caller falls back to the peer address.
+func (m *Middleware) forwardedClientAddr(
+	r *http.Request,
+) (netip.Addr, bool) {
+	hops := strings.Split(
+		strings.Join(r.Header.Values("X-Forwarded-For"), ","), ",",
+	)
+
+	for _, hop := range slices.Backward(hops) {
+		hop = strings.TrimSpace(hop)
+		if hop == "" {
+			continue
+		}
+
+		addr, err := netip.ParseAddr(hop)
+		if err != nil {
+			return netip.Addr{}, false
+		}
+
+		if addr = normalizeAddr(addr); !m.isTrustedProxy(addr) {
+			return addr, true
+		}
+	}
+
+	return netip.Addr{}, false
+}
+
+// rateLimitKey is the client identity every rate limiter in this
+// package buckets on. Forwarded headers are honoured only when the
+// direct peer (RemoteAddr) is inside the configured trusted-proxy
+// set; otherwise the peer address itself is the key. Without that
+// gate any client could mint a fresh bucket per request, or starve
+// another client's bucket, by picking an X-Forwarded-For value —
+// which makes every limit here decorative against a deliberate
+// attacker.
+func (m *Middleware) rateLimitKey(r *http.Request) (string, error) {
+	return m.clientKey(r), nil
+}
+
+// clientKey computes the bucket key described on rateLimitKey.
+func (m *Middleware) clientKey(r *http.Request) string {
+	peer, err := netip.ParseAddr(ipFromHostPort(r.RemoteAddr))
+	if err != nil {
+		// Not an address we can reason about; key on the raw
+		// value rather than collapsing such peers into one
+		// shared bucket.
+		return r.RemoteAddr
+	}
+
+	peer = normalizeAddr(peer)
+	if !m.isTrustedProxy(peer) {
+		return peer.String()
+	}
+
+	if addr, ok := m.forwardedClientAddr(r); ok {
+		return addr.String()
+	}
+
+	return peer.String()
+}
+
+// tooManyRequests returns the 429 handler shared by every limiter:
+// it logs the rejection with logMessage and answers with
+// responseMessage. httprate adds the Retry-After header (RFC 6585).
+func (m *Middleware) tooManyRequests(
+	logMessage, responseMessage string,
+) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		m.log.Warn(logMessage, "path", r.URL.Path)
+		http.Error(w, responseMessage, http.StatusTooManyRequests)
+	}
+}
+
 // LoginRateLimit returns middleware that enforces per-IP rate
 // limiting on login attempts using go-chi/httprate. Only POST
 // requests are rate-limited; GET requests (rendering the login
 // form) pass through unaffected. When the rate limit is exceeded,
-// a 429 Too Many Requests response is returned. IP extraction
-// honours X-Forwarded-For, X-Real-IP, and True-Client-IP headers
-// for reverse-proxy setups.
+// a 429 Too Many Requests response is returned. Clients are
+// identified by rateLimitKey.
 func (m *Middleware) LoginRateLimit() func(http.Handler) http.Handler {
 	return m.postRateLimit(
 		loginRateLimit,
@@ -61,9 +176,7 @@ func (m *Middleware) PasswordChangeRateLimit() func(http.Handler) http.Handler {
 // limit on POST requests only; all other methods pass through
 // unaffected. Requests over the limit receive a 429 with the
 // given response message, and each rejection is logged with the
-// given log message. IP extraction honours X-Forwarded-For,
-// X-Real-IP, and True-Client-IP headers for reverse-proxy
-// setups.
+// given log message. Clients are identified by rateLimitKey.
 func (m *Middleware) postRateLimit(
 	limit int,
 	interval time.Duration,
@@ -72,19 +185,10 @@ func (m *Middleware) postRateLimit(
 	limiter := httprate.Limit(
 		limit,
 		interval,
-		httprate.WithKeyFuncs(httprate.KeyByRealIP),
-		httprate.WithLimitHandler(http.HandlerFunc(
-			func(w http.ResponseWriter, r *http.Request) {
-				m.log.Warn(logMessage,
-					"path", r.URL.Path,
-				)
-				http.Error(
-					w,
-					responseMessage,
-					http.StatusTooManyRequests,
-				)
-			},
-		)),
+		httprate.WithKeyFuncs(m.rateLimitKey),
+		httprate.WithLimitHandler(
+			m.tooManyRequests(logMessage, responseMessage),
+		),
 	)
 
 	return func(next http.Handler) http.Handler {
@@ -105,3 +209,25 @@ func (m *Middleware) postRateLimit(
 		})
 	}
 }
+
+// ReceiverRateLimit returns middleware that rate-limits the
+// public webhook receiver endpoint per client IP per request
+// path (the path contains the entrypoint UUID, so each sender
+// is limited per entrypoint without affecting other senders or
+// other entrypoints). The limit is Config.ReceiverRateLimit
+// requests per minute. Requests over the limit receive a 429.
+// Clients are identified by rateLimitKey.
+func (m *Middleware) ReceiverRateLimit() func(http.Handler) http.Handler {
+	return httprate.Limit(
+		m.params.Config.ReceiverRateLimit,
+		receiverRateInterval,
+		httprate.WithKeyFuncs(
+			m.rateLimitKey,
+			httprate.KeyByEndpoint,
+		),
+		httprate.WithLimitHandler(m.tooManyRequests(
+			"webhook receiver rate limit exceeded",
+			"Too many requests. Please slow down.",
+		)),
+	)
+}

internal/middleware/ratelimit_test.go

@@ -2,8 +2,12 @@ package middleware_test
 
 import (
 	"context"
+	"fmt"
+	"log/slog"
 	"net/http"
 	"net/http/httptest"
+	"net/netip"
+	"os"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -179,3 +183,429 @@ func TestLoginRateLimit_IndependentPerIP(t *testing.T) {
 		"different IP should not be affected",
 	)
 }
+
+// okHandler is the terminal handler the limiter middleware wraps
+// in these tests: it answers 200 to anything that reaches it.
+func okHandler() http.Handler {
+	return http.HandlerFunc(
+		func(w http.ResponseWriter, _ *http.Request) {
+			w.WriteHeader(http.StatusOK)
+		},
+	)
+}
+
+// rateLimitMiddleware builds a Middleware around cfg, whose
+// TrustedProxies field is what the rate limit key function gates
+// forwarded-header trust on.
+func rateLimitMiddleware(
+	t *testing.T, cfg *config.Config,
+) *middleware.Middleware {
+	t.Helper()
+
+	log := slog.New(slog.NewTextHandler(
+		os.Stderr,
+		&slog.HandlerOptions{Level: slog.LevelDebug},
+	))
+
+	return middleware.NewForTest(log, cfg, nil)
+}
+
+// trustedProxies parses CIDR strings for a test Config.
+func trustedProxies(cidrs ...string) []netip.Prefix {
+	prefixes := make([]netip.Prefix, 0, len(cidrs))
+	for _, cidr := range cidrs {
+		prefixes = append(prefixes, netip.MustParsePrefix(cidr))
+	}
+
+	return prefixes
+}
+
+// postWithHeaders sends one POST to the handler from peer with the
+// given headers set and returns the recorder.
+func postWithHeaders(
+	handler http.Handler,
+	peer, path string,
+	headers map[string]string,
+) *httptest.ResponseRecorder {
+	req := httptest.NewRequestWithContext(
+		context.Background(), http.MethodPost, path, nil,
+	)
+	req.RemoteAddr = peer
+
+	for name, value := range headers {
+		req.Header.Set(name, value)
+	}
+
+	w := httptest.NewRecorder()
+	handler.ServeHTTP(w, req)
+
+	return w
+}
+
+// receiverLimitedHandler builds a ReceiverRateLimit-wrapped
+// handler with the given per-minute limit and no trusted proxies.
+func receiverLimitedHandler(
+	t *testing.T, limit int,
+) http.Handler {
+	t.Helper()
+
+	m := rateLimitMiddleware(
+		t, &config.Config{ReceiverRateLimit: limit},
+	)
+
+	return m.ReceiverRateLimit()(okHandler())
+}
+
+// receiverPost sends one POST to the handler from the given IP
+// and path and returns the recorder.
+func receiverPost(
+	handler http.Handler, ip, path string,
+) *httptest.ResponseRecorder {
+	req := httptest.NewRequestWithContext(
+		context.Background(),
+		http.MethodPost, path, nil,
+	)
+	req.RemoteAddr = ip
+
+	w := httptest.NewRecorder()
+	handler.ServeHTTP(w, req)
+
+	return w
+}
+
+func TestReceiverRateLimit_LimitsPerIPAndPath(t *testing.T) {
+	t.Parallel()
+
+	const limit = 3
+
+	handler := receiverLimitedHandler(t, limit)
+
+	// The first limit requests from one IP to one entrypoint
+	// pass.
+	for i := range limit {
+		w := receiverPost(
+			handler, "9.9.9.9:1234", "/webhook/uuid-a",
+		)
+		assert.Equal(
+			t, http.StatusOK, w.Code,
+			"request %d should pass", i,
+		)
+	}
+
+	// The next request over the limit is rejected with a 429
+	// carrying a Retry-After header.
+	w := receiverPost(
+		handler, "9.9.9.9:1234", "/webhook/uuid-a",
+	)
+	assert.Equal(t, http.StatusTooManyRequests, w.Code)
+	assert.NotEmpty(
+		t, w.Header().Get("Retry-After"),
+		"429 must carry a Retry-After header",
+	)
+
+	// The same IP is not limited on a different entrypoint.
+	w = receiverPost(
+		handler, "9.9.9.9:1234", "/webhook/uuid-b",
+	)
+	assert.Equal(
+		t, http.StatusOK, w.Code,
+		"a different entrypoint must not be affected",
+	)
+
+	// A different IP is not limited on the same entrypoint.
+	w = receiverPost(
+		handler, "8.8.8.8:1234", "/webhook/uuid-a",
+	)
+	assert.Equal(
+		t, http.StatusOK, w.Code,
+		"a different client IP must not be affected",
+	)
+}
+
+// TestReceiverRateLimit_CountsEveryMethod proves the receiver
+// limit counts non-POST requests too: a GET shares the bucket
+// with a POST and is itself rejected once over the limit.
+func TestReceiverRateLimit_CountsEveryMethod(t *testing.T) {
+	t.Parallel()
+
+	const (
+		limit = 2
+		ip    = "7.7.7.7:1234"
+		path  = "/webhook/uuid-c"
+	)
+
+	handler := receiverLimitedHandler(t, limit)
+
+	get := func() *httptest.ResponseRecorder {
+		req := httptest.NewRequestWithContext(
+			context.Background(), http.MethodGet, path, nil,
+		)
+		req.RemoteAddr = ip
+
+		w := httptest.NewRecorder()
+		handler.ServeHTTP(w, req)
+
+		return w
+	}
+
+	// One POST plus one GET fill the bucket, so the GET must
+	// have been counted.
+	assert.Equal(
+		t, http.StatusOK, receiverPost(handler, ip, path).Code,
+	)
+	assert.Equal(t, http.StatusOK, get().Code)
+
+	assert.Equal(
+		t, http.StatusTooManyRequests, get().Code,
+		"a GET over the limit must be rate-limited",
+	)
+}
+
+const (
+	loginPath  = "/pages/login"
+	headerXFF  = "X-Forwarded-For"
+	headerReal = "X-Real-IP"
+	headerTrue = "True-Client-IP"
+)
+
+// assertSharedBucket drives the login limiter from peer with the
+// trusted-proxy set proxies, sending one more request than the limit
+// allows and varying the headers on each with headers(i). Every
+// request must land in the same bucket, so the last one is rejected:
+// if any of the varying header values reached the key, the run would
+// have minted fresh buckets and nothing would be rejected.
+func assertSharedBucket(
+	t *testing.T,
+	proxies []netip.Prefix,
+	peer string,
+	headers func(i int) map[string]string,
+	msg string,
+) {
+	t.Helper()
+
+	m := rateLimitMiddleware(
+		t, &config.Config{TrustedProxies: proxies},
+	)
+	handler := m.LoginRateLimit()(okHandler())
+
+	for i := range middleware.LoginRateLimitConst {
+		w := postWithHeaders(handler, peer, loginPath, headers(i))
+		assert.Equal(
+			t, http.StatusOK, w.Code,
+			"request %d should pass", i,
+		)
+	}
+
+	w := postWithHeaders(
+		handler, peer, loginPath,
+		headers(middleware.LoginRateLimitConst),
+	)
+	assert.Equal(t, http.StatusTooManyRequests, w.Code, msg)
+}
+
+// TestRateLimitKey_SpoofedForwardedFromUntrustedPeer is the test
+// this gating exists for: with no trusted proxies configured (the
+// default), a client that rotates a forwarded header on every
+// request must stay in one bucket. If forwarded headers were
+// trusted unconditionally, each spoofed value would mint a fresh
+// bucket and the limit would stop no one.
+func TestRateLimitKey_SpoofedForwardedFromUntrustedPeer(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	for _, header := range []string{
+		headerXFF, headerReal, headerTrue,
+	} {
+		t.Run(header, func(t *testing.T) {
+			t.Parallel()
+
+			assertSharedBucket(
+				t, nil, "203.0.113.9:44444",
+				func(i int) map[string]string {
+					return map[string]string{
+						header: fmt.Sprintf(
+							"198.51.100.%d", i+1,
+						),
+					}
+				},
+				"a spoofed "+header+" from an untrusted peer "+
+					"must not mint a fresh bucket",
+			)
+		})
+	}
+}
+
+// TestRateLimitKey_SingleValuedHeadersIgnoredFromTrustedPeer is the
+// regression test for the bypass hiding inside the trusted case.
+// Real reverse proxies (nginx, HAProxy, Caddy, ALB) set only
+// X-Forwarded-For and pass every other client header through
+// verbatim, so a client behind the configured proxy can send its own
+// X-Real-IP or True-Client-IP. Reading either would hand that client
+// a fresh bucket per request from inside exactly the deployment
+// TRUSTED_PROXIES exists to serve, so neither header is read at all.
+func TestRateLimitKey_SingleValuedHeadersIgnoredFromTrustedPeer(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	for _, header := range []string{headerReal, headerTrue} {
+		t.Run(header, func(t *testing.T) {
+			t.Parallel()
+
+			assertSharedBucket(
+				t, trustedProxies("10.0.0.0/8"),
+				"10.0.0.1:44444",
+				func(i int) map[string]string {
+					return map[string]string{
+						header: fmt.Sprintf(
+							"198.51.100.%d", i+1,
+						),
+					}
+				},
+				header+" from a trusted peer must not mint a "+
+					"fresh bucket: only X-Forwarded-For is read",
+			)
+		})
+	}
+}
+
+// TestRateLimitKey_MalformedRightmostHopFallsBackToPeer covers the
+// other end of the chain walk. The rightmost X-Forwarded-For entry
+// is the one the trusted proxy appended; if it cannot be read as an
+// address the chain is not the shape the walk assumes, and every
+// entry to its left may have come from the client. The walk must
+// stop and fall back to the peer rather than select one of them.
+func TestRateLimitKey_MalformedRightmostHopFallsBackToPeer(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	// Forms seen in the wild: host:port (Azure Application
+	// Gateway, IIS ARR), a bracketed IPv6 literal, and the
+	// RFC 7239 placeholder token.
+	for _, tail := range []string{
+		"198.51.100.7:1234", "[2001:db8::1]", "unknown",
+	} {
+		t.Run(tail, func(t *testing.T) {
+			t.Parallel()
+
+			assertSharedBucket(
+				t, trustedProxies("10.0.0.0/8"),
+				"10.0.0.1:44444",
+				func(i int) map[string]string {
+					return map[string]string{
+						headerXFF: fmt.Sprintf(
+							"9.9.9.%d, %s", i+1, tail,
+						),
+					}
+				},
+				"an unparseable rightmost hop must fall back "+
+					"to the peer address, not select a "+
+					"client-controlled entry",
+			)
+		})
+	}
+}
+
+// TestRateLimitKey_ForwardedHonouredFromTrustedPeer checks the
+// other half: when the direct peer is a configured trusted proxy,
+// the forwarded client address is what buckets are keyed on, so
+// one sender behind the proxy cannot exhaust another's limit.
+func TestRateLimitKey_ForwardedHonouredFromTrustedPeer(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	m := rateLimitMiddleware(t, &config.Config{
+		TrustedProxies: trustedProxies("10.0.0.0/8"),
+	})
+	handler := m.LoginRateLimit()(okHandler())
+
+	const peer = "10.0.0.1:44444"
+
+	first := map[string]string{headerXFF: "198.51.100.7"}
+
+	for range middleware.LoginRateLimitConst {
+		postWithHeaders(handler, peer, loginPath, first)
+	}
+
+	w := postWithHeaders(handler, peer, loginPath, first)
+	assert.Equal(
+		t, http.StatusTooManyRequests, w.Code,
+		"the forwarded client's own bucket must fill up",
+	)
+
+	w = postWithHeaders(
+		handler, peer, loginPath,
+		map[string]string{headerXFF: "198.51.100.8"},
+	)
+	assert.Equal(
+		t, http.StatusOK, w.Code,
+		"a forwarded header from a trusted peer must be honoured",
+	)
+}
+
+// TestRateLimitKey_ChainWalkSkipsClientPrepended covers the
+// residual spoofing route behind a trusted proxy: the client
+// controls the leftmost X-Forwarded-For entries, so the key is the
+// rightmost hop that is not itself trusted. Rotating the prepended
+// entry must not create new buckets.
+func TestRateLimitKey_ChainWalkSkipsClientPrepended(t *testing.T) {
+	t.Parallel()
+
+	assertSharedBucket(
+		t, trustedProxies("10.0.0.0/8"), "10.0.0.1:44444",
+		func(i int) map[string]string {
+			return map[string]string{
+				headerXFF: fmt.Sprintf(
+					"9.9.9.%d, 198.51.100.7, 10.0.0.2", i+1,
+				),
+			}
+		},
+		"a client-prepended X-Forwarded-For entry must not "+
+			"mint a fresh bucket",
+	)
+}
+
+// TestReceiverRateLimit_IgnoresForwardedFromUntrustedPeer proves
+// the receiver limiter uses the same gated key function as the
+// POST limiters.
+func TestReceiverRateLimit_IgnoresForwardedFromUntrustedPeer(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	const (
+		limit = 3
+		peer  = "203.0.113.10:44444"
+		path  = "/webhook/uuid-d"
+	)
+
+	handler := receiverLimitedHandler(t, limit)
+
+	for i := range limit {
+		w := postWithHeaders(
+			handler, peer, path,
+			map[string]string{
+				headerXFF: fmt.Sprintf(
+					"198.51.100.%d", i+1,
+				),
+			},
+		)
+		assert.Equal(
+			t, http.StatusOK, w.Code,
+			"request %d should pass", i,
+		)
+	}
+
+	w := postWithHeaders(
+		handler, peer, path,
+		map[string]string{headerXFF: "198.51.100.200"},
+	)
+	assert.Equal(
+		t, http.StatusTooManyRequests, w.Code,
+		"a spoofed X-Forwarded-For from an untrusted peer must "+
+			"not mint a fresh receiver bucket",
+	)
+}

internal/server/export_test.go

@@ -0,0 +1,36 @@
+package server
+
+import (
+	"log/slog"
+	"net/http"
+
+	"sneak.berlin/go/webhooker/internal/config"
+	"sneak.berlin/go/webhooker/internal/handlers"
+	"sneak.berlin/go/webhooker/internal/middleware"
+)
+
+// MaxFormBodySizeForTest exposes the form body cap so tests can
+// build requests that sit exactly at, below, and above it.
+const MaxFormBodySizeForTest = maxFormBodySize
+
+// NewRouterForTest builds the real route tree via SetupRoutes with
+// the supplied middleware and handlers, bypassing the fx lifecycle
+// and the HTTP listener. Tests use it so that route-group middleware
+// registration order is exercised exactly as it ships, rather than
+// against a hand-rebuilt chain that could drift from routes.go.
+func NewRouterForTest(
+	log *slog.Logger,
+	cfg *config.Config,
+	mw *middleware.Middleware,
+	h *handlers.Handlers,
+) http.Handler {
+	s := &Server{
+		log:    log,
+		mw:     mw,
+		h:      h,
+		params: ServerParams{Config: cfg},
+	}
+	s.SetupRoutes()
+
+	return s.router
+}

internal/server/routes.go

@@ -90,9 +90,11 @@ func (s *Server) setupRoutes() {
 
 func (s *Server) setupPageRoutes() {
 	s.router.Route("/pages", func(r chi.Router) {
+		// MaxBodySize must precede CSRF: gorilla/csrf parses the
+		// form, so the cap has to be installed before it runs.
+		r.Use(s.mw.MaxBodySize(maxFormBodySize))
 		r.Use(s.mw.CSRF())
 		r.Use(s.mw.NoCache())
-		r.Use(s.mw.MaxBodySize(maxFormBodySize))
 
 		r.Group(func(r chi.Router) {
 			r.Use(s.mw.LoginRateLimit())
@@ -106,6 +108,9 @@ func (s *Server) setupPageRoutes() {
 
 func (s *Server) setupUserRoutes() {
 	s.router.Route("/user/{username}", func(r chi.Router) {
+		// MaxBodySize must precede CSRF: gorilla/csrf parses the
+		// form, so the cap has to be installed before it runs.
+		r.Use(s.mw.MaxBodySize(maxFormBodySize))
 		r.Use(s.mw.CSRF())
 		r.Use(s.mw.NoCache())
 		r.Use(s.mw.RequireAuth())
@@ -118,20 +123,24 @@ func (s *Server) setupUserRoutes() {
 
 func (s *Server) setupSourceRoutes() {
 	s.router.Route("/sources", func(r chi.Router) {
+		// MaxBodySize must precede CSRF: gorilla/csrf parses the
+		// form, so the cap has to be installed before it runs.
+		r.Use(s.mw.MaxBodySize(maxFormBodySize))
 		r.Use(s.mw.CSRF())
 		r.Use(s.mw.NoCache())
 		r.Use(s.mw.RequireAuth())
-		r.Use(s.mw.MaxBodySize(maxFormBodySize))
 		r.Get("/", s.h.HandleSourceList())
 		r.Get("/new", s.h.HandleSourceCreate())
 		r.Post("/new", s.h.HandleSourceCreateSubmit())
 	})
 
 	s.router.Route("/source/{sourceID}", func(r chi.Router) {
+		// MaxBodySize must precede CSRF: gorilla/csrf parses the
+		// form, so the cap has to be installed before it runs.
+		r.Use(s.mw.MaxBodySize(maxFormBodySize))
 		r.Use(s.mw.CSRF())
 		r.Use(s.mw.NoCache())
 		r.Use(s.mw.RequireAuth())
-		r.Use(s.mw.MaxBodySize(maxFormBodySize))
 		r.Get("/", s.h.HandleSourceDetail())
 		r.Get("/edit", s.h.HandleSourceEdit())
 		r.Post("/edit", s.h.HandleSourceEditSubmit())
@@ -162,7 +171,7 @@ func (s *Server) setupSourceRoutes() {
 }
 
 func (s *Server) setupWebhookRoutes() {
-	s.router.HandleFunc(
+	s.router.With(s.mw.ReceiverRateLimit()).HandleFunc(
 		"/webhook/{uuid}",
 		s.h.HandleWebhook(),
 	)

internal/server/routes_test.go

@@ -0,0 +1,383 @@
+package server_test
+
+import (
+	"context"
+	"html"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"regexp"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/fx"
+	"go.uber.org/fx/fxtest"
+	"sneak.berlin/go/webhooker/internal/config"
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/delivery"
+	"sneak.berlin/go/webhooker/internal/globals"
+	"sneak.berlin/go/webhooker/internal/handlers"
+	"sneak.berlin/go/webhooker/internal/healthcheck"
+	"sneak.berlin/go/webhooker/internal/logger"
+	"sneak.berlin/go/webhooker/internal/middleware"
+	"sneak.berlin/go/webhooker/internal/server"
+	"sneak.berlin/go/webhooker/internal/session"
+)
+
+// csrfCookieName is the cookie gorilla/csrf issues when it runs. Its
+// presence or absence on a response is how these tests tell whether
+// the CSRF middleware executed.
+const csrfCookieName = "_gorilla_csrf"
+
+type noopNotifier struct{}
+
+func (n *noopNotifier) Notify([]delivery.Task) {}
+
+// noopEvictor satisfies handlers.New's delivery.WebhookEvictor
+// dependency. These tests never delete a webhook, so there is
+// nothing to record.
+type noopEvictor struct{}
+
+func (e *noopEvictor) EvictWebhook(string) {}
+
+// testEnv is the real router from routes.go plus the collaborators
+// tests need to seed users and forge sessions.
+type testEnv struct {
+	router http.Handler
+	sess   *session.Session
+	db     *database.Database
+}
+
+// newTestEnv wires the dependency graph with fx and builds the
+// production route tree, so middleware registration order is
+// exercised exactly as it ships.
+func newTestEnv(t *testing.T) *testEnv {
+	t.Helper()
+
+	var (
+		log  *logger.Logger
+		cfg  *config.Config
+		mw   *middleware.Middleware
+		hnd  *handlers.Handlers
+		sess *session.Session
+		db   *database.Database
+	)
+
+	app := fxtest.New(
+		t,
+		fx.Provide(
+			globals.New,
+			logger.New,
+			func() *config.Config {
+				return &config.Config{
+					DataDir:     t.TempDir(),
+					Environment: config.EnvironmentDev,
+				}
+			},
+			database.New,
+			database.NewWebhookDBManager,
+			healthcheck.New,
+			session.New,
+			func() delivery.Notifier { return &noopNotifier{} },
+			func() delivery.WebhookEvictor { return &noopEvictor{} },
+			middleware.New,
+			handlers.New,
+		),
+		fx.Populate(&log, &cfg, &mw, &hnd, &sess, &db),
+	)
+	app.RequireStart()
+	t.Cleanup(app.RequireStop)
+
+	return &testEnv{
+		router: server.NewRouterForTest(log.Get(), cfg, mw, hnd),
+		sess:   sess,
+		db:     db,
+	}
+}
+
+// oversizeValue returns a form value one byte past the route-group
+// body cap, so an encoded form containing it is guaranteed oversize.
+func oversizeValue() string {
+	return strings.Repeat("a", int(server.MaxFormBodySizeForTest)+1)
+}
+
+// csrfCookieSet reports whether the response issued a gorilla/csrf
+// cookie, which only happens if the CSRF middleware ran.
+func csrfCookieSet(w *httptest.ResponseRecorder) bool {
+	for _, c := range w.Result().Cookies() {
+		if c.Name == csrfCookieName {
+			return true
+		}
+	}
+
+	return false
+}
+
+// get issues a GET through the router with the supplied cookies.
+func (e *testEnv) get(
+	path string,
+	cookies []*http.Cookie,
+) *httptest.ResponseRecorder {
+	req := httptest.NewRequestWithContext(
+		context.Background(), http.MethodGet, path, nil,
+	)
+
+	for _, c := range cookies {
+		req.AddCookie(c)
+	}
+
+	w := httptest.NewRecorder()
+	e.router.ServeHTTP(w, req)
+
+	return w
+}
+
+// post issues a urlencoded form POST through the router. The body is
+// a strings.Reader, so the request carries an accurate
+// Content-Length — the signal MaxBodySize checks up front.
+func (e *testEnv) post(
+	path string,
+	form url.Values,
+	cookies []*http.Cookie,
+) *httptest.ResponseRecorder {
+	req := httptest.NewRequestWithContext(
+		context.Background(), http.MethodPost, path,
+		strings.NewReader(form.Encode()),
+	)
+	req.Header.Set(
+		"Content-Type", "application/x-www-form-urlencoded",
+	)
+
+	for _, c := range cookies {
+		req.AddCookie(c)
+	}
+
+	w := httptest.NewRecorder()
+	e.router.ServeHTTP(w, req)
+
+	return w
+}
+
+// csrfFrom renders the page at path and returns the CSRF token from
+// its form together with every cookie needed for the follow-up POST.
+func (e *testEnv) csrfFrom(
+	t *testing.T,
+	path string,
+	cookies []*http.Cookie,
+) (string, []*http.Cookie) {
+	t.Helper()
+
+	w := e.get(path, cookies)
+	require.Equal(t, http.StatusOK, w.Code)
+
+	pattern := regexp.MustCompile(
+		`name="csrf_token" value="([^"]+)"`,
+	)
+
+	match := pattern.FindStringSubmatch(w.Body.String())
+	require.Len(t, match, 2, "form must embed a CSRF token")
+
+	// html/template escapes "+" and "=" in attribute values, and
+	// gorilla/csrf tokens are standard base64, so the value read
+	// out of the markup has to be unescaped before it is submitted.
+	token := html.UnescapeString(match[1])
+
+	combined := make([]*http.Cookie, 0, len(cookies))
+	combined = append(combined, cookies...)
+	combined = append(combined, w.Result().Cookies()...)
+
+	return token, combined
+}
+
+// authCookies forges an authenticated session for the given user.
+func (e *testEnv) authCookies(
+	t *testing.T,
+	userID, username string,
+) []*http.Cookie {
+	t.Helper()
+
+	req := httptest.NewRequestWithContext(
+		context.Background(), http.MethodGet, "/setup", nil,
+	)
+	w := httptest.NewRecorder()
+
+	s, err := e.sess.Get(req)
+	require.NoError(t, err)
+
+	e.sess.SetUser(s, userID, username)
+	require.NoError(t, e.sess.Save(req, w, s))
+
+	cookies := w.Result().Cookies()
+	require.NotEmpty(t, cookies, "session cookie should be set")
+
+	return cookies
+}
+
+// seedUser creates a user with the given password and returns the
+// stored hash so tests can assert whether it later changed.
+func (e *testEnv) seedUser(
+	t *testing.T,
+	username, password string,
+) (string, string) {
+	t.Helper()
+
+	hash, err := database.HashPassword(password)
+	require.NoError(t, err)
+
+	user := &database.User{Username: username, Password: hash}
+	require.NoError(t, e.db.DB().Create(user).Error)
+
+	return user.ID, hash
+}
+
+// storedHash reads the current password hash for a username.
+func (e *testEnv) storedHash(t *testing.T, username string) string {
+	t.Helper()
+
+	var user database.User
+
+	require.NoError(t,
+		e.db.DB().Where("username = ?", username).
+			First(&user).Error,
+	)
+
+	return user.Password
+}
+
+// --- /pages group ---
+
+// TestPagesLogin_OversizeBody_RejectedBeforeCSRF proves the cap runs
+// ahead of gorilla/csrf: the response is a clean 413 and no CSRF
+// cookie was issued, so neither the CSRF middleware nor the login
+// handler ran.
+func TestPagesLogin_OversizeBody_RejectedBeforeCSRF(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	form := url.Values{}
+	form.Set("username", oversizeValue())
+	form.Set("password", "irrelevant")
+
+	w := env.post("/pages/login", form, nil)
+
+	assert.Equal(
+		t, http.StatusRequestEntityTooLarge, w.Code,
+	)
+	assert.False(
+		t, csrfCookieSet(w),
+		"CSRF middleware must not run for an oversized body",
+	)
+}
+
+// TestPagesLogin_UnderLimit_NoToken_CSRFRejects is the control for
+// the test above: an identically shaped but under-limit POST does
+// reach gorilla/csrf, which rejects it and issues its cookie. Without
+// this, the missing-cookie assertion above would prove nothing.
+func TestPagesLogin_UnderLimit_NoToken_CSRFRejects(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	form := url.Values{}
+	form.Set("username", "someone")
+	form.Set("password", "irrelevant")
+
+	w := env.post("/pages/login", form, nil)
+
+	assert.Equal(t, http.StatusForbidden, w.Code)
+	assert.True(
+		t, csrfCookieSet(w),
+		"CSRF middleware should run for an under-limit body",
+	)
+}
+
+// TestPagesLogin_UnderLimit_ValidToken_ReachesHandler proves the
+// reorder did not break CSRF token handling: a token harvested from
+// the rendered login form is still accepted and the request lands in
+// the handler.
+func TestPagesLogin_UnderLimit_ValidToken_ReachesHandler(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	token, cookies := env.csrfFrom(t, "/pages/login", nil)
+
+	form := url.Values{}
+	form.Set("csrf_token", token)
+	form.Set("username", "nosuchuser")
+	form.Set("password", "wrongpassword")
+
+	w := env.post("/pages/login", form, cookies)
+
+	assert.Equal(t, http.StatusUnauthorized, w.Code)
+	assert.Contains(
+		t, w.Body.String(), "Invalid username or password",
+		"request should reach the login handler",
+	)
+}
+
+// --- /user/{username} group ---
+
+// TestPasswordChange_OversizeBody_RejectedAndPasswordUnchanged
+// covers the route that previously had no middleware body cap at
+// all. The request carries a valid session and a valid CSRF token,
+// so the only thing that can stop it is the size cap; the unchanged
+// password hash is the observable proof the handler never ran.
+func TestPasswordChange_OversizeBody_RejectedAndPasswordUnchanged(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	userID, originalHash := env.seedUser(t, "pwuser", "oldpassword")
+	cookies := env.authCookies(t, userID, "pwuser")
+	token, cookies := env.csrfFrom(t, "/user/pwuser/", cookies)
+
+	form := url.Values{}
+	form.Set("csrf_token", token)
+	form.Set("current_password", "oldpassword")
+	form.Set("new_password", oversizeValue())
+	form.Set("confirm_password", oversizeValue())
+
+	w := env.post("/user/pwuser/password", form, cookies)
+
+	assert.Equal(
+		t, http.StatusRequestEntityTooLarge, w.Code,
+	)
+	assert.Equal(
+		t, originalHash, env.storedHash(t, "pwuser"),
+		"handler must not run, so the password must be unchanged",
+	)
+}
+
+// TestPasswordChange_UnderLimit_Succeeds proves that adding the cap
+// to the /user/{username} group did not break the route it guards.
+func TestPasswordChange_UnderLimit_Succeeds(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	userID, originalHash := env.seedUser(t, "okuser", "oldpassword")
+	cookies := env.authCookies(t, userID, "okuser")
+	token, cookies := env.csrfFrom(t, "/user/okuser/", cookies)
+
+	form := url.Values{}
+	form.Set("csrf_token", token)
+	form.Set("current_password", "oldpassword")
+	form.Set("new_password", "brandnewpassword")
+	form.Set("confirm_password", "brandnewpassword")
+
+	w := env.post("/user/okuser/password", form, cookies)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+	assert.NotEqual(
+		t, originalHash, env.storedHash(t, "okuser"),
+		"an under-limit password change should still apply",
+	)
+}

internal/session/session.go

@@ -10,6 +10,7 @@ import (
 	"log/slog"
 	"maps"
 	"net/http"
+	"time"
 
 	"github.com/gorilla/sessions"
 	"go.uber.org/fx"
@@ -32,6 +33,18 @@ const (
 	// status.
 	AuthenticatedKey = "authenticated"
 
+	// CreatedAtKey is the session key holding the Unix timestamp at
+	// which the session was authenticated. It anchors the ABSOLUTE
+	// expiry clock and is written exactly once, by SetUser. Nothing
+	// refreshes it: an absolute deadline that moved with activity
+	// would not be a cap at all.
+	CreatedAtKey = "created_at"
+
+	// LastSeenKey is the session key holding the Unix timestamp of
+	// the most recent authenticated request. It anchors the IDLE
+	// expiry clock and is pushed forward by Touch.
+	LastSeenKey = "last_seen"
+
 	// sessionKeyLength is the required length in bytes for the
 	// session authentication key.
 	sessionKeyLength = 32
@@ -41,6 +54,19 @@ const (
 
 	// secondsPerDay is the number of seconds in a day.
 	secondsPerDay = 86400
+
+	// sessionAbsoluteMaxAge is the hard upper bound on how long a
+	// session may live, measured from CreatedAtKey. Activity never
+	// extends it, so even a continuously used session ends here and
+	// the user has to authenticate again.
+	sessionAbsoluteMaxAge = sessionMaxAgeDays * secondsPerDay * time.Second
+
+	// idleRefreshDivisor rate-limits idle-deadline refreshes. Touch
+	// only rewrites LastSeenKey once the stored value is older than
+	// idleTimeout/idleRefreshDivisor, so an active session is
+	// re-saved at most this many times per idle window instead of
+	// once per request. See Touch for the tradeoff this buys.
+	idleRefreshDivisor = 10
 )
 
 // ErrSessionKeyLength is returned when the decoded session key
@@ -62,6 +88,16 @@ type Session struct {
 	key    []byte // raw 32-byte auth key, also used for CSRF cookie signing
 	log    *slog.Logger
 	config *config.Config
+
+	// idleTimeout is the sliding inactivity window. A session that
+	// sees no authenticated request within this window expires,
+	// independently of the absolute cap. Non-positive disables idle
+	// expiry and leaves sessionAbsoluteMaxAge as the only bound.
+	idleTimeout time.Duration
+
+	// now reads the current time. Injected so expiry can be tested
+	// without sleeping.
+	now func() time.Time
 }
 
 // New creates a new session manager. The cookie store is
@@ -73,8 +109,10 @@ func New(
 	params Params,
 ) (*Session, error) {
 	s := &Session{
-		log:    params.Logger.Get(),
-		config: params.Config,
+		log:         params.Logger.Get(),
+		config:      params.Config,
+		idleTimeout: params.Config.SessionIdleTimeout,
+		now:         time.Now,
 	}
 
 	lc.Append(fx.Hook{
@@ -149,29 +187,98 @@ func (s *Session) Save(
 	return sess.Save(r, w)
 }
 
-// SetUser sets the user information in the session.
+// SetUser sets the user information in the session. It starts both
+// expiry clocks: CreatedAtKey (absolute, never refreshed again) and
+// LastSeenKey (idle, refreshed by Touch).
 func (s *Session) SetUser(
 	sess *sessions.Session,
 	userID, username string,
 ) {
+	now := s.now().Unix()
+
 	sess.Values[UserIDKey] = userID
 	sess.Values[UsernameKey] = username
 	sess.Values[AuthenticatedKey] = true
+	sess.Values[CreatedAtKey] = now
+	sess.Values[LastSeenKey] = now
 }
 
-// ClearUser removes user information from the session.
+// ClearUser removes user information from the session, including
+// both expiry timestamps.
 func (s *Session) ClearUser(sess *sessions.Session) {
 	delete(sess.Values, UserIDKey)
 	delete(sess.Values, UsernameKey)
 	delete(sess.Values, AuthenticatedKey)
+	delete(sess.Values, CreatedAtKey)
+	delete(sess.Values, LastSeenKey)
 }
 
-// IsAuthenticated checks if the session has an authenticated
-// user.
+// sessionTime reads a Unix-second timestamp stored under key.
+func sessionTime(
+	sess *sessions.Session,
+	key string,
+) (time.Time, bool) {
+	secs, ok := sess.Values[key].(int64)
+	if !ok {
+		return time.Time{}, false
+	}
+
+	return time.Unix(secs, 0), true
+}
+
+// IsAuthenticated checks if the session has an authenticated user
+// whose session has not passed either expiry deadline. Every
+// authentication decision goes through here, so neither clock can
+// be bypassed by a caller that forgets to check it.
 func (s *Session) IsAuthenticated(sess *sessions.Session) bool {
 	auth, ok := sess.Values[AuthenticatedKey].(bool)
+	if !ok || !auth {
+		return false
+	}
 
-	return ok && auth
+	return !s.expired(sess)
+}
+
+// Touch records authenticated activity by pushing the IDLE deadline
+// forward. It writes LastSeenKey only; CreatedAtKey is left alone so
+// the absolute cap keeps counting down even for a user who never
+// stops clicking.
+//
+// Callers must only invoke Touch for a request that authenticated
+// with this session. Refreshing on an unauthenticated request would
+// let anyone holding a stolen or abandoned cookie keep the session
+// alive by polling a public endpoint. Touch enforces that itself by
+// returning false for any session that is not currently
+// authenticated and unexpired.
+//
+// To avoid re-encrypting and re-emitting the session cookie on every
+// single request, the timestamp is advanced only once it is older
+// than idleTimeout/idleRefreshDivisor. The tradeoff is that
+// LastSeenKey lags real activity by up to that much, so a session
+// can expire slightly early relative to the user's true last
+// request -- never late.
+//
+// Touch reports whether it changed the session; only then does the
+// caller need to save it.
+func (s *Session) Touch(sess *sessions.Session) bool {
+	if s.idleTimeout <= 0 {
+		return false
+	}
+
+	if !s.IsAuthenticated(sess) {
+		return false
+	}
+
+	now := s.now()
+
+	lastSeen, ok := sessionTime(sess, LastSeenKey)
+	if ok && now.Sub(lastSeen) < s.idleTimeout/idleRefreshDivisor {
+		return false
+	}
+
+	sess.Values[LastSeenKey] = now.Unix()
+
+	return true
 }
 
 // GetUserID retrieves the user ID from the session.
@@ -253,3 +360,41 @@ func (s *Session) Regenerate(
 
 	return newSess, nil
 }
+
+// expired reports whether the session has passed either of its two
+// independent deadlines. They are deliberately kept apart:
+//
+//   - the ABSOLUTE deadline is CreatedAtKey + sessionAbsoluteMaxAge.
+//     It is fixed at login and no amount of activity moves it.
+//   - the IDLE deadline is LastSeenKey + idleTimeout. Activity moves
+//     it forward via Touch.
+//
+// Whichever comes first ends the session.
+//
+// A session that claims to be authenticated but carries no
+// timestamps predates this check; it is treated as expired so the
+// user re-authenticates rather than being granted an unbounded
+// session.
+func (s *Session) expired(sess *sessions.Session) bool {
+	now := s.now()
+
+	createdAt, ok := sessionTime(sess, CreatedAtKey)
+	if !ok {
+		return true
+	}
+
+	if !now.Before(createdAt.Add(sessionAbsoluteMaxAge)) {
+		return true
+	}
+
+	if s.idleTimeout <= 0 {
+		return false
+	}
+
+	lastSeen, ok := sessionTime(sess, LastSeenKey)
+	if !ok {
+		return true
+	}
+
+	return !now.Before(lastSeen.Add(s.idleTimeout))
+}

internal/session/session_test.go

@@ -7,6 +7,7 @@ import (
 	"net/http/httptest"
 	"os"
 	"testing"
+	"time"
 
 	"github.com/gorilla/sessions"
 	"github.com/stretchr/testify/assert"
@@ -17,11 +18,47 @@ import (
 
 const testKeySize = 32
 
-// testSession creates a Session with a real cookie store for
-// testing.
+// testIdleTimeout is the idle window used by the expiry tests.
+const testIdleTimeout = time.Hour
+
+// testAbsoluteMaxAge restates the documented absolute session cap
+// independently of the implementation constant.
+const testAbsoluteMaxAge = 7 * 24 * time.Hour
+
+// fakeClock is a manually advanced clock, so expiry can be tested
+// without sleeping.
+type fakeClock struct {
+	t time.Time
+}
+
+func (c *fakeClock) Now() time.Time {
+	return c.t
+}
+
+func (c *fakeClock) Advance(d time.Duration) {
+	c.t = c.t.Add(d)
+}
+
+// testSession creates a Session with a real cookie store and the
+// real clock.
 func testSession(t *testing.T) *session.Session {
 	t.Helper()
 
+	s, _ := testSessionWithClock(t, testIdleTimeout, nil)
+
+	return s
+}
+
+// testSessionWithClock creates a Session with a real cookie store,
+// the given idle timeout, and a manually advanced clock. Passing a
+// nil clock uses the real one.
+func testSessionWithClock(
+	t *testing.T,
+	idleTimeout time.Duration,
+	clock *fakeClock,
+) (*session.Session, *fakeClock) {
+	t.Helper()
+
 	key := make([]byte, testKeySize)
 
 	for i := range key {
@@ -38,7 +75,8 @@ func testSession(t *testing.T) *session.Session {
 	}
 
 	cfg := &config.Config{
-		Environment: config.EnvironmentDev,
+		Environment:        config.EnvironmentDev,
+		SessionIdleTimeout: idleTimeout,
 	}
 
 	log := slog.New(slog.NewTextHandler(
@@ -46,7 +84,46 @@ func testSession(t *testing.T) *session.Session {
 		&slog.HandlerOptions{Level: slog.LevelDebug},
 	))
 
-	return session.NewForTest(store, cfg, log, key)
+	var now func() time.Time
+
+	if clock != nil {
+		now = clock.Now
+	}
+
+	return session.NewForTest(store, cfg, log, key, now), clock
+}
+
+// newFakeClock returns a clock started at a fixed instant.
+func newFakeClock() *fakeClock {
+	return &fakeClock{
+		t: time.Date(
+			2026, time.January, 2, 3, 4, 5, 0, time.UTC,
+		),
+	}
+}
+
+// authenticatedSession returns a fresh session that has just been
+// logged in, along with its manager and clock.
+func authenticatedSession(
+	t *testing.T,
+	idleTimeout time.Duration,
+) (*session.Session, *sessions.Session, *fakeClock) {
+	t.Helper()
+
+	s, clock := testSessionWithClock(
+		t, idleTimeout, newFakeClock(),
+	)
+
+	req := httptest.NewRequestWithContext(
+		context.Background(), http.MethodGet, "/", nil)
+
+	sess, err := s.Get(req)
+	require.NoError(t, err)
+
+	s.SetUser(sess, "user-123", "alice")
+	require.True(t, s.IsAuthenticated(sess))
+
+	return s, sess, clock
 }
 
 // --- Get and Save Tests ---
@@ -430,6 +507,263 @@ func TestSessionConstants(t *testing.T) {
 	assert.Equal(t, "user_id", session.UserIDKey)
 	assert.Equal(t, "username", session.UsernameKey)
 	assert.Equal(t, "authenticated", session.AuthenticatedKey)
+	assert.Equal(t, "created_at", session.CreatedAtKey)
+	assert.Equal(t, "last_seen", session.LastSeenKey)
+}
+
+// --- Expiry Tests ---
+
+func TestSetUser_StartsBothClocks(t *testing.T) {
+	t.Parallel()
+
+	_, sess, clock := authenticatedSession(t, testIdleTimeout)
+
+	assert.Equal(
+		t, clock.Now().Unix(), sess.Values[session.CreatedAtKey],
+		"SetUser should anchor the absolute clock",
+	)
+	assert.Equal(
+		t, clock.Now().Unix(), sess.Values[session.LastSeenKey],
+		"SetUser should anchor the idle clock",
+	)
+}
+
+func TestIsAuthenticated_WithinIdleWindow(t *testing.T) {
+	t.Parallel()
+
+	s, sess, clock := authenticatedSession(t, testIdleTimeout)
+
+	clock.Advance(testIdleTimeout - time.Second)
+
+	assert.True(
+		t, s.IsAuthenticated(sess),
+		"session should still be valid just inside the idle window",
+	)
+}
+
+func TestIsAuthenticated_IdleExpired(t *testing.T) {
+	t.Parallel()
+
+	s, sess, clock := authenticatedSession(t, testIdleTimeout)
+
+	clock.Advance(testIdleTimeout)
+
+	assert.False(
+		t, s.IsAuthenticated(sess),
+		"session should expire once the idle window lapses",
+	)
+}
+
+// TestTouch_DoesNotExtendAbsoluteCap is the regression test for the
+// refresh-the-wrong-clock bug: a session that is used continuously
+// must survive well past the idle window and still die at the
+// absolute cap.
+func TestTouch_DoesNotExtendAbsoluteCap(t *testing.T) {
+	t.Parallel()
+
+	s, sess, clock := authenticatedSession(t, testIdleTimeout)
+
+	createdAt := sess.Values[session.CreatedAtKey]
+
+	// Stay active: a request every half idle window, right up to
+	// the absolute cap.
+	step := testIdleTimeout / 2
+	steps := int(testAbsoluteMaxAge/step) - 1
+
+	for i := range steps {
+		clock.Advance(step)
+		s.Touch(sess)
+
+		require.True(
+			t, s.IsAuthenticated(sess),
+			"active session should survive the idle window "+
+				"(step %d of %d)", i+1, steps,
+		)
+	}
+
+	// One more step of activity takes the session to exactly the
+	// absolute cap, measured from login. Nothing that happened in
+	// the loop may have moved that deadline.
+	clock.Advance(step)
+	s.Touch(sess)
+
+	assert.False(
+		t, s.IsAuthenticated(sess),
+		"activity must not extend the absolute cap",
+	)
+	assert.Equal(
+		t, createdAt, sess.Values[session.CreatedAtKey],
+		"Touch must never rewrite the absolute-clock anchor",
+	)
+}
+
+func TestTouch_RefreshesIdleDeadline(t *testing.T) {
+	t.Parallel()
+
+	s, sess, clock := authenticatedSession(t, testIdleTimeout)
+
+	// Halfway through the window, activity happens.
+	clock.Advance(testIdleTimeout / 2)
+	assert.True(
+		t, s.Touch(sess),
+		"Touch should refresh once past the lazy-refresh threshold",
+	)
+
+	// Past the original deadline, but inside the refreshed one.
+	clock.Advance(testIdleTimeout - time.Second)
+	assert.True(
+		t, s.IsAuthenticated(sess),
+		"refreshed session should outlive the original deadline",
+	)
+
+	// And it still expires an idle window after that activity.
+	clock.Advance(time.Second)
+	assert.False(
+		t, s.IsAuthenticated(sess),
+		"refreshed session should expire one window after activity",
+	)
+}
+
+func TestTouch_LazyBelowRefreshThreshold(t *testing.T) {
+	t.Parallel()
+
+	s, sess, clock := authenticatedSession(t, testIdleTimeout)
+
+	before := sess.Values[session.LastSeenKey]
+
+	// A request arriving almost immediately is not worth a cookie
+	// rewrite.
+	clock.Advance(time.Second)
+
+	assert.False(
+		t, s.Touch(sess),
+		"Touch should not rewrite the session below the threshold",
+	)
+	assert.Equal(
+		t, before, sess.Values[session.LastSeenKey],
+		"last-seen should be unchanged below the threshold",
+	)
+}
+
+func TestTouch_UnauthenticatedSessionIsNotRefreshed(t *testing.T) {
+	t.Parallel()
+
+	s, clock := testSessionWithClock(
+		t, testIdleTimeout, newFakeClock(),
+	)
+
+	req := httptest.NewRequestWithContext(
+		context.Background(), http.MethodGet, "/", nil)
+
+	sess, err := s.Get(req)
+	require.NoError(t, err)
+
+	clock.Advance(testIdleTimeout / 2)
+
+	assert.False(
+		t, s.Touch(sess),
+		"an unauthenticated session must not be refreshed",
+	)
+
+	_, hasLastSeen := sess.Values[session.LastSeenKey]
+	assert.False(
+		t, hasLastSeen,
+		"Touch must not stamp an unauthenticated session",
+	)
+}
+
+func TestTouch_IdleExpiredSessionIsNotRevived(t *testing.T) {
+	t.Parallel()
+
+	s, sess, clock := authenticatedSession(t, testIdleTimeout)
+
+	clock.Advance(testIdleTimeout)
+	require.False(t, s.IsAuthenticated(sess))
+
+	assert.False(
+		t, s.Touch(sess),
+		"an already expired session must not be refreshed",
+	)
+	assert.False(
+		t, s.IsAuthenticated(sess),
+		"Touch must not revive an expired session",
+	)
+}
+
+func TestIsAuthenticated_MissingTimestamps(t *testing.T) {
+	t.Parallel()
+
+	s, _ := testSessionWithClock(
+		t, testIdleTimeout, newFakeClock(),
+	)
+
+	req := httptest.NewRequestWithContext(
+		context.Background(), http.MethodGet, "/", nil)
+
+	sess, err := s.Get(req)
+	require.NoError(t, err)
+
+	// A session from before idle expiry existed: authenticated,
+	// but with no timestamps. Fail closed.
+	sess.Values[session.AuthenticatedKey] = true
+
+	assert.False(
+		t, s.IsAuthenticated(sess),
+		"a session with no timestamps should be rejected",
+	)
+}
+
+func TestIsAuthenticated_MissingLastSeen(t *testing.T) {
+	t.Parallel()
+
+	s, sess, _ := authenticatedSession(t, testIdleTimeout)
+
+	delete(sess.Values, session.LastSeenKey)
+
+	assert.False(
+		t, s.IsAuthenticated(sess),
+		"a session with no idle anchor should be rejected",
+	)
+}
+
+func TestIdleTimeoutDisabled_AbsoluteCapStillApplies(t *testing.T) {
+	t.Parallel()
+
+	s, sess, clock := authenticatedSession(t, 0)
+
+	// Idle expiry is off, so an untouched session survives an
+	// arbitrary idle stretch.
+	clock.Advance(testAbsoluteMaxAge - time.Second)
+	assert.True(
+		t, s.IsAuthenticated(sess),
+		"idle expiry should be disabled by a non-positive timeout",
+	)
+
+	assert.False(
+		t, s.Touch(sess),
+		"Touch should be a no-op when idle expiry is disabled",
+	)
+
+	// The absolute cap still ends it.
+	clock.Advance(time.Second)
+	assert.False(
+		t, s.IsAuthenticated(sess),
+		"the absolute cap must still apply with idle expiry off",
+	)
+}
+
+func TestClearUser_RemovesTimestamps(t *testing.T) {
+	t.Parallel()
+
+	s, sess, _ := authenticatedSession(t, testIdleTimeout)
+
+	s.ClearUser(sess)
+
+	_, hasCreatedAt := sess.Values[session.CreatedAtKey]
+	assert.False(t, hasCreatedAt, "CreatedAtKey should be removed")
+
+	_, hasLastSeen := sess.Values[session.LastSeenKey]
+	assert.False(t, hasLastSeen, "LastSeenKey should be removed")
 }
 
 // --- Edge Cases ---

internal/session/testing.go

@@ -2,6 +2,7 @@ package session
 
 import (
 	"log/slog"
+	"time"
 
 	"github.com/gorilla/sessions"
 	"sneak.berlin/go/webhooker/internal/config"
@@ -12,16 +13,28 @@ import (
 // middleware and handler tests to use real session functionality. The key
 // parameter is the raw 32-byte authentication key used for session encryption
 // and CSRF cookie signing.
+//
+// The idle timeout is taken from cfg.SessionIdleTimeout, exactly as in
+// production. The now parameter supplies the clock used for expiry
+// checks so tests can advance time without sleeping; pass nil for the
+// real clock.
 func NewForTest(
 	store *sessions.CookieStore,
 	cfg *config.Config,
 	log *slog.Logger,
 	key []byte,
+	now func() time.Time,
 ) *Session {
+	if now == nil {
+		now = time.Now
+	}
+
 	return &Session{
-		store:  store,
-		key:    key,
-		config: cfg,
-		log:    log,
+		store:       store,
+		key:         key,
+		config:      cfg,
+		log:         log,
+		idleTimeout: cfg.SessionIdleTimeout,
+		now:         now,
 	}
 }

static/js/app.js

@@ -1,2 +1,60 @@
 // Webhooker client-side JavaScript
 console.log("Webhooker loaded");
+
+// Copy-to-clipboard, as progressive enhancement.
+//
+// Markup renders each copy button with the `hidden` attribute and a
+// `data-copy-target` pointing at the id of the element holding the
+// text. This script reveals a button only once it has both a resolvable
+// target and a usable Clipboard API, so a browser without either shows
+// no button at all and the text stays selectable.
+(function () {
+    "use strict";
+
+    const revertDelayMs = 2000;
+
+    function flash(button, message) {
+        const original = button.getAttribute("data-copy-label");
+        button.textContent = message;
+        window.setTimeout(function () {
+            button.textContent = original;
+        }, revertDelayMs);
+    }
+
+    function wire(button) {
+        const target = document.getElementById(
+            button.getAttribute("data-copy-target")
+        );
+        if (!target) {
+            return;
+        }
+
+        button.setAttribute("data-copy-label", button.textContent);
+        button.addEventListener("click", function () {
+            navigator.clipboard.writeText(target.textContent.trim()).then(
+                function () {
+                    flash(button, "Copied");
+                },
+                function () {
+                    flash(button, "Copy failed");
+                }
+            );
+        });
+        button.removeAttribute("hidden");
+    }
+
+    function init() {
+        if (!navigator.clipboard || !navigator.clipboard.writeText) {
+            return;
+        }
+
+        const buttons = document.querySelectorAll("[data-copy-target]");
+        buttons.forEach(wire);
+    }
+
+    if (document.readyState === "loading") {
+        document.addEventListener("DOMContentLoaded", init);
+    } else {
+        init();
+    }
+})();

templates/navbar.html

@@ -16,7 +16,7 @@
         <!-- Desktop navigation -->
         <div class="hidden md:flex items-center gap-4">
             {{if .User}}
-            <a href="/sources" class="btn-text">Sources</a>
+            <a href="/sources" class="btn-text">Webhooks</a>
             <a href="/user/{{.User.Username}}" class="btn-text">
                 <svg class="w-5 h-5 mr-1" fill="currentColor" viewBox="0 0 16 16">
                     <path d="M11 6a3 3 0 1 1-6 0 3 3 0 0 1 6 0z"/>
@@ -38,7 +38,7 @@
     <div x-show="open" x-cloak x-transition class="md:hidden mt-4 pt-4 border-t border-gray-200">
         <div class="flex flex-col gap-2">
             {{if .User}}
-            <a href="/sources" class="btn-text w-full text-left">Sources</a>
+            <a href="/sources" class="btn-text w-full text-left">Webhooks</a>
             <a href="/user/{{.User.Username}}" class="btn-text w-full text-left">Profile</a>
             <form method="POST" action="/pages/logout">
                 <input type="hidden" name="csrf_token" value="{{.CSRFToken}}">

templates/profile.html

@@ -34,24 +34,18 @@
 
         <hr class="border-gray-200 mb-6">
 
-        <div class="grid grid-cols-1 md:grid-cols-2 gap-8">
-            <div>
-                <h3 class="text-lg font-medium text-gray-900 mb-3">Account Information</h3>
-                <dl class="space-y-3">
-                    <div class="flex">
-                        <dt class="w-32 text-sm font-medium text-gray-500">Username</dt>
-                        <dd class="text-sm text-gray-900">{{.User.Username}}</dd>
-                    </div>
-                    <div class="flex">
-                        <dt class="w-32 text-sm font-medium text-gray-500">Account Type</dt>
-                        <dd class="text-sm text-gray-900">Standard User</dd>
-                    </div>
-                </dl>
-            </div>
-            <div>
-                <h3 class="text-lg font-medium text-gray-900 mb-3">Settings</h3>
-                <p class="text-sm text-gray-500">Profile settings and preferences will be available here.</p>
-            </div>
+        <div>
+            <h3 class="text-lg font-medium text-gray-900 mb-3">Account Information</h3>
+            <dl class="space-y-3">
+                <div class="flex">
+                    <dt class="w-32 text-sm font-medium text-gray-500">Username</dt>
+                    <dd class="text-sm text-gray-900">{{.User.Username}}</dd>
+                </div>
+                <div class="flex">
+                    <dt class="w-32 text-sm font-medium text-gray-500">Account Type</dt>
+                    <dd class="text-sm text-gray-900">Standard User</dd>
+                </div>
+            </dl>
         </div>
     </div>
 

templates/source_detail.html

@@ -69,7 +69,12 @@
                             </form>
                         </div>
                     </div>
-                    <code class="text-xs text-gray-500 break-all block mt-1">{{$.BaseURL}}/webhook/{{.Path}}</code>
+                    <div class="flex items-start gap-2 mt-1">
+                        <code id="entrypoint-url-{{.ID}}" class="text-xs text-gray-500 break-all block flex-1">{{$.BaseURL}}/webhook/{{.Path}}</code>
+                        <!-- Hidden until app.js reveals it; without the
+                             script the URL above stays selectable. -->
+                        <button type="button" hidden data-copy-target="entrypoint-url-{{.ID}}" class="text-xs text-gray-500 hover:text-primary-600">Copy</button>
+                    </div>
                 </div>
                 {{else}}
                 <div class="p-4 text-sm text-gray-500">No entrypoints configured.</div>
@@ -145,8 +150,11 @@
                             </form>
                         </div>
                     </div>
-                    {{if .Config}}
-                    <code class="text-xs text-gray-500 break-all block mt-1">{{.Config}}</code>
+                    {{range .Config}}
+                    <div class="text-xs text-gray-500 break-all mt-1">
+                        <span class="font-medium text-gray-700">{{.Label}}:</span>
+                        <span>{{.Value}}</span>
+                    </div>
                     {{end}}
                 </div>
                 {{else}}
@@ -181,7 +189,7 @@
 
     <!-- Info -->
     <div class="mt-4 text-sm text-gray-400">
-        <p>Retention: {{.Webhook.RetentionDays}} days &middot; Created: {{.Webhook.CreatedAt.Format "2006-01-02 15:04:05 UTC"}}</p>
+        <p>Retention: {{.Webhook.RetentionLabel}} &middot; Created: {{.Webhook.CreatedAt.Format "2006-01-02 15:04:05 UTC"}}</p>
     </div>
 </div>
 {{end}}

templates/source_edit.html

@@ -28,7 +28,8 @@
 
             <div class="form-group">
                 <label for="retention_days" class="label">Retention (days)</label>
-                <input type="number" id="retention_days" name="retention_days" value="{{.Webhook.RetentionDays}}" min="1" max="365" class="input">
+                <input type="number" id="retention_days" name="retention_days" value="{{.Webhook.RetentionDays}}" min="0" class="input">
+                <p class="text-xs text-gray-500 mt-1">Currently {{.Webhook.RetentionLabel}}.{{if .Webhook.RetainsForever}} No events are deleted while retention is set to forever.{{else}} A periodic cleanup permanently deletes events older than this, along with their delivery records.{{end}} Enter 0 to retain events forever; leave blank to keep the current setting.</p>
             </div>
 
             <div class="flex gap-3">

templates/sources_list.html

@@ -1,6 +1,6 @@
 {{template "base" .}}
 
-{{define "title"}}Sources - Webhooker{{end}}
+{{define "title"}}Webhooks - Webhooker{{end}}
 
 {{define "content"}}
 <div class="max-w-6xl mx-auto px-6 py-8">
@@ -25,7 +25,7 @@
                     <p class="text-sm text-gray-500 mt-1">{{.Description}}</p>
                     {{end}}
                 </div>
-                <span class="badge-info">{{.RetentionDays}}d retention</span>
+                <span class="badge-info">Retention: {{.RetentionLabel}}</span>
             </div>
             <div class="flex gap-6 mt-4 text-sm text-gray-500">
                 <span>{{.EntrypointCount}} entrypoint{{if ne .EntrypointCount 1}}s{{end}}</span>

templates/sources_new.html

@@ -18,18 +18,18 @@
             <input type="hidden" name="csrf_token" value="{{.CSRFToken}}">
             <div class="form-group">
                 <label for="name" class="label">Name</label>
-                <input type="text" id="name" name="name" required autofocus placeholder="My Webhook" class="input">
+                <input type="text" id="name" name="name" value="{{.Name}}" required autofocus placeholder="My Webhook" class="input">
             </div>
 
             <div class="form-group">
                 <label for="description" class="label">Description</label>
-                <textarea id="description" name="description" rows="3" placeholder="Optional description" class="input"></textarea>
+                <textarea id="description" name="description" rows="3" placeholder="Optional description" class="input">{{.Description}}</textarea>
             </div>
 
             <div class="form-group">
                 <label for="retention_days" class="label">Retention (days)</label>
-                <input type="number" id="retention_days" name="retention_days" value="30" min="1" max="365" class="input">
-                <p class="text-xs text-gray-500 mt-1">How long to keep event data.</p>
+                <input type="number" id="retention_days" name="retention_days" value="{{.DefaultRetentionDays}}" min="0" class="input">
+                <p class="text-xs text-gray-500 mt-1">A periodic cleanup permanently deletes events older than this, along with their delivery records. Enter 0 to retain events forever; leave blank to use the default of {{.DefaultRetentionDays}} days.</p>
             </div>
 
             <div class="flex gap-3">