Terminally fail retrying deliveries with a non-retry target type (closes #82)

Restart recovery and the 60s retry sweep both looked an orphaned
`retrying` delivery's target up in the registry and silently returned
when it did not implement `rescheduler`. If a target's type was edited
from a retry type (`http`/`slack`) to a fire-and-forget type
(`database`/`log`) or an unknown one while a delivery was still
retrying, that delivery stayed `retrying` forever.

Both sites now hand the delivery to one shared helper,
`failUnretryableRetry`, which records a `DeliveryResult` naming the
current target type as the reason and marks the delivery `failed`. It
logs at warn, not error: this is operator-caused state, not a system
fault.

Re-dispatching under the new type was rejected as it would perform a
delivery the operator never asked for; the event itself stays in the
per-webhook event database, so manual redelivery can recover it
deliberately.

Fire-and-forget targets never set status `retrying` under normal
operation, so this path stays unreachable for them in practice.

README.md

@@ -89,27 +89,10 @@ 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          | `""`     |
 
-#### 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.
-
-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
 persists across restarts — no manual key management is needed.
@@ -653,6 +636,18 @@ 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

TODO.md

@@ -10,28 +10,28 @@
 
 # Status
 
-pre-1.0. No git tags exist. main (4f5ecb1) is a working webhook proxy
+pre-1.0. No git tags exist. main (afe88c6) is a working webhook proxy
 with auth, CSRF/SSRF protections, login rate limiting, Slack target,
-policy compliance (#6), pinned lint tooling (#55), a per-webhook event
-retention reaper (#63), 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.
+policy compliance (#6), and pinned lint tooling (#55). 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
 
-Manual event redelivery from the web UI (replay is a core promised
-capability in the README rationale).
+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.
 
 # Completed Steps
 
-- 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)
+- 2026-08-09 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)
 - 2026-08-07 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
@@ -60,6 +60,8 @@ capability in the README rationale).
 
 # 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

internal/config/config.go

@@ -7,6 +7,7 @@ import (
 	"log/slog"
 	"os"
 	"strconv"
+	"strings"
 	"time"
 
 	"go.uber.org/fx"
@@ -30,24 +31,12 @@ const (
 	// defaultRetentionSweepInterval is how often the retention
 	// reaper deletes events older than each webhook's RetentionDays.
 	defaultRetentionSweepInterval = time.Hour
-
-	// maxPort is the highest valid TCP port number. The lower
-	// bound (at least 1) is enforced by envPositiveInt.
-	maxPort = 65535
 )
 
 // 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")
-
 //nolint:revive // ConfigParams is a standard fx naming convention.
 type ConfigParams struct {
 	fx.In
@@ -92,81 +81,27 @@ func envString(key string) string {
 }
 
 // envBool returns the value of the named environment variable
-// 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
+// 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"
 	}
 
-	b, err := strconv.ParseBool(v)
-	if err != nil {
-		return false, fmt.Errorf(
-			"invalid boolean for %s: %q: %w", key, v, err,
-		)
-	}
-
-	return b, nil
+	return defaultValue
 }
 
-// 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
+// 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
+		}
 	}
 
-	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
+	return defaultValue
 }
 
 // envDuration returns the value of the named environment variable
@@ -193,52 +128,32 @@ func envDuration(
 	return d, nil
 }
 
-// resolveEnvironment reads WEBHOOKER_ENVIRONMENT, defaulting to
-// dev, and rejects unrecognised values.
-func resolveEnvironment() (string, error) {
+// 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()
+
+	// Determine environment from WEBHOOKER_ENVIRONMENT env var,
+	// default to dev
 	environment := os.Getenv("WEBHOOKER_ENVIRONMENT")
 	if environment == "" {
 		environment = EnvironmentDev
 	}
 
+	// Validate environment
 	if environment != EnvironmentDev &&
 		environment != EnvironmentProd {
-		return "", fmt.Errorf(
+		return nil, fmt.Errorf(
 			"%w: WEBHOOKER_ENVIRONMENT must be '%s' or '%s', got '%s'",
 			ErrInvalidEnvironment,
 			EnvironmentDev, EnvironmentProd, environment,
 		)
 	}
 
-	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
-	}
-
+	// Parse the retention sweep interval; a set-but-unparseable value
+	// is a hard error so fx aborts startup rather than silently using
+	// the default.
 	retentionSweepInterval, err := envDuration(
 		"RETENTION_SWEEP_INTERVAL",
 		defaultRetentionSweepInterval,
@@ -247,36 +162,21 @@ func loadFromEnv() (*Config, error) {
 		return nil, err
 	}
 
-	return &Config{
+	// Load configuration values from environment variables
+	s := &Config{
 		DataDir:                envString("DATA_DIR"),
-		Debug:                  debug,
-		MaintenanceMode:        maintenanceMode,
+		Debug:                  envBool("DEBUG", false),
+		MaintenanceMode:        envBool("MAINTENANCE_MODE", false),
 		Environment:            environment,
 		MetricsUsername:        envString("METRICS_USERNAME"),
 		MetricsPassword:        envString("METRICS_PASSWORD"),
-		Port:                   port,
+		Port:                   envInt("PORT", defaultPort),
 		SentryDSN:              envString("SENTRY_DSN"),
 		RetentionSweepInterval: retentionSweepInterval,
-	}, 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
+		log:                    log,
+		params:                 &params,
 	}
 
-	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

internal/config/env_test.go

@@ -1,409 +0,0 @@
-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

@@ -1,20 +0,0 @@
-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/delivery/engine.go

@@ -453,8 +453,9 @@ 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 +476,10 @@ func (e *Engine) recoverSingleRetry(
 
 	rs, ok := e.targets[target.Type].(rescheduler)
 	if !ok {
+		e.failUnretryableRetry(
+			webhookDB, webhookID, d, &target,
+		)
+
 		return
 	}
 
@@ -649,8 +654,8 @@ 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 +675,10 @@ func (e *Engine) sweepSingleRetry(
 
 	rs, ok := e.targets[target.Type].(rescheduler)
 	if !ok {
+		e.failUnretryableRetry(
+			webhookDB, webhookID, d, &target,
+		)
+
 		return
 	}
 
@@ -710,6 +719,59 @@ 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

@@ -748,6 +748,193 @@ 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/export_test.go

@@ -188,6 +188,13 @@ 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)