docs: update README schema section to match actual database schema

Update the Schema section and related references throughout README.md to accurately reflect the current 001_initial.sql migration: - Rename 'users' table to 'sessions' with new columns: uuid, password_hash, signing_key, away_message - Add new 'clients' table (uuid, session_id FK, token, created_at, last_seen) - Add topic_set_by and topic_set_at columns to 'channels' table - Update channel_members FK from user_id to session_id - Add params column to messages table - Update client_queues FK from user_id to client_id - Update Queue Architecture diagram labels and surrounding text - Update In-Memory Broker description to use client_id terminology - Update Multi-Client Model MVP note to reflect sessions/clients split
2026-03-17 04:55:41 -07:00
10 changed files with 93 additions and 1495 deletions
--- a/19
+++ b/19
@@ -1,4 +1,4 @@
-.PHONY: all build lint fmt fmt-check test check clean run debug docker hooks ensure-web-dist
+.PHONY: all build lint fmt fmt-check test check clean run debug docker hooks

 BINARY := neoircd
 VERSION := $(shell git describe --tags --always --dirty 2>/dev/null || echo "dev")
@@ -7,21 +7,10 @@ LDFLAGS := -X main.Version=$(VERSION) -X main.Buildarch=$(BUILDARCH)

 all: check build

-# ensure-web-dist creates placeholder files so //go:embed dist/* in
-# web/embed.go resolves without a full Node.js build.  The real SPA is
-# built by the web-builder Docker stage; these placeholders let
-# "make test" and "make build" work outside Docker.
-ensure-web-dist:
-	@if [ ! -d web/dist ]; then \
-		mkdir -p web/dist && \
-		touch web/dist/index.html web/dist/style.css web/dist/app.js && \
-		echo "==> Created placeholder web/dist/ for go:embed"; \
-	fi
-
-build: ensure-web-dist
+build:
 	go build -ldflags "$(LDFLAGS)" -o bin/$(BINARY) ./cmd/neoircd

-lint: ensure-web-dist
+lint:
 	golangci-lint run --config .golangci.yml ./...

 fmt:
@@ -31,7 +20,7 @@ fmt:
 fmt-check:
 	@test -z "$$(gofmt -l .)" || (echo "Files not formatted:" && gofmt -l . && exit 1)

-test: ensure-web-dist
+test:
 	go test -timeout 30s -v -race -cover ./...

 # check runs all validation without making changes
--- a/README.md
+++ b/README.md
@@ -301,8 +301,8 @@ The server implements HTTP long-polling for real-time message delivery:
   - The client disconnects (connection closed, no response needed)

 **Implementation detail:** The server maintains an in-memory broker with
-per-user notification channels. When a message is enqueued for a user, the
-broker closes all waiting channels for that user, waking up any blocked
+per-client notification channels. When a message is enqueued for a client, the
+broker closes all waiting channels for that client, waking up any blocked
 long-poll handlers. This is O(1) notification — no polling loops, no database
 scanning.

@@ -460,28 +460,28 @@ The entire read/write loop for a client is two endpoints. Everything else
              │              │              │
    ┌─────────▼──┐  ┌───────▼────┐  ┌──────▼─────┐
    │client_queue│  │client_queue│  │client_queue│
-    │ user_id=1  │  │ user_id=2  │  │ user_id=3  │
+    │ client_id=1│  │ client_id=2│  │ client_id=3│
    │ msg_id=N   │  │ msg_id=N   │  │ msg_id=N   │
    └────────────┘  └────────────┘  └────────────┘
         alice           bob             carol

-Each message is stored ONCE. One queue entry per recipient.
+Each message is stored ONCE. One queue entry per recipient client.
 ```

-The `client_queues` table contains `(user_id, message_id)` pairs. When a
+The `client_queues` table contains `(client_id, message_id)` pairs. When a
 client polls with `GET /messages?after=<queue_id>`, the server queries for
-queue entries with `id > after` for that user, joins against the messages
+queue entries with `id > after` for that client, joins against the messages
 table, and returns the results. The `queue_id` (auto-incrementing primary
 key of `client_queues`) serves as a monotonically increasing cursor.

 ### In-Memory Broker

 The server maintains an in-memory notification broker to avoid database
-polling. The broker is a map of `user_id → []chan struct{}`. When a message
-is enqueued for a user:
+polling. The broker is a map of `client_id → []chan struct{}`. When a message
+is enqueued for a client:

-1. The handler calls `broker.Notify(userID)`
-2. The broker closes all waiting channels for that user
+1. The handler calls `broker.Notify(clientID)`
+2. The broker closes all waiting channels for that client
 3. Any goroutines blocked in `select` on those channels wake up
 4. The woken handler queries the database for new queue entries
 5. Messages are returned to the client
@@ -523,7 +523,7 @@ the same JSON envelope:
 | `params`  | array of strings    | Sometimes | Sometimes | Additional IRC-style positional parameters. Used by commands like `MODE`, `KICK`, and numeric replies like `353` (NAMES). |
 | `body`    | array or object     | Usually   | Usually   | Structured message body. For text messages: array of strings (one per line). For structured data (e.g., `PUBKEY`): JSON object. **Never a raw string.** |
 | `ts`      | string (ISO 8601)   | Ignored   | Always    | Server-assigned timestamp in RFC 3339 / ISO 8601 format with nanosecond precision. Example: `"2026-02-10T20:00:00.000000000Z"`. Always UTC. |
-| `meta`    | object              | Optional  | If present | Extensible metadata. Used for cryptographic signatures (`meta.sig`, `meta.alg`), hashcash proof-of-work (`meta.hashcash`), content hashes, or any client-defined key/value pairs. Server relays `meta` verbatim except for `hashcash` which is validated on channels with `+H` mode. |
+| `meta`    | object              | Optional  | If present | Extensible metadata. Used for cryptographic signatures (`meta.sig`, `meta.alg`), content hashes, or any client-defined key/value pairs. Server relays `meta` verbatim — it does not interpret or validate it. |

 **Important invariants:**

@@ -1013,13 +1013,12 @@ carries IRC-style parameters (e.g., channel name, target nick).
 Inspired by IRC, simplified:

 | Mode | Name         | Meaning |
-|------|----------------|---------|
+|------|--------------|---------|
 | `+i` | Invite-only  | Only invited users can join |
 | `+m` | Moderated    | Only voiced (`+v`) users and operators (`+o`) can send |
 | `+s` | Secret       | Channel hidden from LIST response |
 | `+t` | Topic lock   | Only operators can change the topic |
 | `+n` | No external  | Only channel members can send messages to the channel |
-| `+H` | Hashcash       | Requires proof-of-work for PRIVMSG (parameter: bits, e.g. `+H 20`) |

 **User channel modes (set per-user per-channel):**

@@ -1030,56 +1029,6 @@ Inspired by IRC, simplified:

 **Status:** Channel modes are defined but not yet enforced. The `modes` column
 exists in the channels table but the server does not check modes on actions.
-Exception: `+H` (hashcash) is fully enforced — see below.
-
-### Per-Channel Hashcash (Anti-Spam)
-
-Channels can require hashcash proof-of-work for every `PRIVMSG`. This is an
-anti-spam mechanism: channel operators set a difficulty level, and clients must
-compute a proof-of-work stamp bound to the specific channel and message before
-sending.
-
-**Setting the requirement:**
-
-```
-MODE #channel +H <bits>    — require <bits> leading zero bits (1-40)
-MODE #channel -H           — disable hashcash requirement
-```
-
-**Stamp format:** `1:bits:YYMMDD:channel:bodyhash:counter`
-
- `bits` — difficulty (leading zero bits in SHA-256 hash of the stamp)
- `YYMMDD` — current date (prevents old token reuse)
- `channel` — channel name (prevents cross-channel reuse)
- `bodyhash` — hex-encoded SHA-256 of the message body (binds stamp to message)
- `counter` — hex nonce
-
-**Sending a message to a hashcash-protected channel:**
-
-Include the hashcash stamp in the `meta` field:
-
-```json
-{
-  "command": "PRIVMSG",
-  "to": "#general",
-  "body": ["hello world"],
-  "meta": {
-    "hashcash": "1:20:260317:#general:a1b2c3...bodyhash:1f4a"
-  }
-}
-```
-
-**Server validation:** The server checks that the stamp is well-formed, meets
-the required difficulty, is bound to the correct channel and message body, has a
-recent date, and has not been previously used. Spent stamps are cached for 1
-year to prevent replay attacks.
-
-**Error responses:** If the channel requires hashcash and the stamp is missing,
-invalid, or replayed, the server returns `ERR_CANNOTSENDTOCHAN (404)` with a
-descriptive reason.
-
-**Client minting:** The CLI provides `MintChannelHashcash(bits, channel, body)`
-to compute stamps. Higher bit counts take exponentially longer to compute.

 ---

@@ -1988,7 +1937,7 @@ The database schema is managed via embedded SQL migration files in

 #### `sessions`
 | Column          | Type     | Description |
-|----------------|----------|-------------|
+|-----------------|----------|-------------|
 | `id`            | INTEGER  | Primary key (auto-increment) |
 | `uuid`          | TEXT     | Unique session UUID |
 | `nick`          | TEXT     | Unique nick |
@@ -1998,9 +1947,11 @@ The database schema is managed via embedded SQL migration files in
 | `created_at`    | DATETIME | Session creation time |
 | `last_seen`     | DATETIME | Last API request time |

+Index on `(uuid)`.
+
 #### `clients`
 | Column       | Type     | Description |
-|-------------|----------|-------------|
+|--------------|----------|-------------|
 | `id`         | INTEGER  | Primary key (auto-increment) |
 | `uuid`       | TEXT     | Unique client UUID |
 | `session_id` | INTEGER  | FK → sessions.id (cascade delete) |
@@ -2008,24 +1959,28 @@ The database schema is managed via embedded SQL migration files in
 | `created_at` | DATETIME | Client creation time |
 | `last_seen`  | DATETIME | Last API request time |

+Indexes on `(token)` and `(session_id)`.
+
 #### `channels`
 | Column        | Type     | Description |
-|-------------|----------|-------------|
+|---------------|----------|-------------|
 | `id`          | INTEGER  | Primary key (auto-increment) |
 | `name`        | TEXT     | Unique channel name (e.g., `#general`) |
 | `topic`       | TEXT     | Channel topic (default empty) |
+| `topic_set_by`| TEXT     | Nick of the user who set the topic (default empty) |
+| `topic_set_at`| DATETIME | When the topic was last set |
 | `created_at`  | DATETIME | Channel creation time |
 | `updated_at`  | DATETIME | Last modification time |

 #### `channel_members`
 | Column       | Type     | Description |
-|-------------|----------|-------------|
+|--------------|----------|-------------|
 | `id`         | INTEGER  | Primary key (auto-increment) |
-| `channel_id`| INTEGER  | FK → channels.id |
-| `user_id`   | INTEGER  | FK → users.id |
+| `channel_id` | INTEGER  | FK → channels.id (cascade delete) |
+| `session_id` | INTEGER  | FK → sessions.id (cascade delete) |
 | `joined_at`  | DATETIME | When the user joined |

-Unique constraint on `(channel_id, user_id)`.
+Unique constraint on `(channel_id, session_id)`.

 #### `messages`
 | Column      | Type     | Description |
@@ -2035,6 +1990,7 @@ Unique constraint on `(channel_id, user_id)`.
 | `command`   | TEXT     | IRC command (`PRIVMSG`, `JOIN`, etc.) |
 | `msg_from`  | TEXT     | Sender nick |
 | `msg_to`    | TEXT     | Target (`#channel` or nick) |
+| `params`    | TEXT     | JSON-encoded IRC-style positional parameters |
 | `body`      | TEXT     | JSON-encoded body (array or object) |
 | `meta`      | TEXT     | JSON-encoded metadata |
 | `created_at`| DATETIME | Server timestamp |
@@ -2045,11 +2001,11 @@ Indexes on `(msg_to, id)` and `(created_at)`.
 | Column      | Type     | Description |
 |-------------|----------|-------------|
 | `id`        | INTEGER  | Primary key (auto-increment). Used as the poll cursor. |
-| `user_id`   | INTEGER  | FK → users.id |
-| `message_id`| INTEGER  | FK → messages.id |
+| `client_id` | INTEGER  | FK → clients.id (cascade delete) |
+| `message_id`| INTEGER  | FK → messages.id (cascade delete) |
 | `created_at`| DATETIME | When the entry was queued |

-Unique constraint on `(user_id, message_id)`. Index on `(user_id, id)`.
+Unique constraint on `(client_id, message_id)`. Index on `(client_id, id)`.

 The `client_queues.id` is the monotonically increasing cursor used by
 `GET /messages?after=<id>`. This is more reliable than timestamps (no clock
--- a/internal/cli/api/hashcash.go
+++ b/internal/cli/api/hashcash.go
@@ -7,8 +7,6 @@ import (
 	"fmt"
 	"math/big"
 	"time"
-
-	"git.eeqj.de/sneak/neoirc/internal/hashcash"
 )

 const (
@@ -39,23 +37,6 @@ func MintHashcash(bits int, resource string) string {
 	}
 }

-// MintChannelHashcash computes a hashcash stamp bound to
-// a specific channel and message body. The stamp format
-// is 1:bits:YYMMDD:channel:bodyhash:counter where
-// bodyhash is the hex-encoded SHA-256 of the message
-// body bytes. Delegates to the internal/hashcash package.
-func MintChannelHashcash(
-	bits int,
-	channel string,
-	body []byte,
-) string {
-	bodyHash := hashcash.BodyHash(body)
-
-	return hashcash.MintChannelStamp(
-		bits, channel, bodyHash,
-	)
-}
-
 // hasLeadingZeroBits checks if hash has at least numBits
 // leading zero bits.
 func hasLeadingZeroBits(
--- a/internal/db/queries.go
+++ b/internal/db/queries.go
@@ -1305,110 +1305,3 @@ func (database *Database) GetQueueEntryCount(

 	return count, nil
 }
-
-// GetChannelHashcashBits returns the hashcash difficulty
-// requirement for a channel. Returns 0 if not set.
-func (database *Database) GetChannelHashcashBits(
-	ctx context.Context,
-	channelID int64,
-) (int, error) {
-	var bits int
-
-	err := database.conn.QueryRowContext(
-		ctx,
-		"SELECT hashcash_bits FROM channels WHERE id = ?",
-		channelID,
-	).Scan(&bits)
-	if err != nil {
-		return 0, fmt.Errorf(
-			"get channel hashcash bits: %w", err,
-		)
-	}
-
-	return bits, nil
-}
-
-// SetChannelHashcashBits sets the hashcash difficulty
-// requirement for a channel. A value of 0 disables the
-// requirement.
-func (database *Database) SetChannelHashcashBits(
-	ctx context.Context,
-	channelID int64,
-	bits int,
-) error {
-	_, err := database.conn.ExecContext(ctx,
-		`UPDATE channels
-		 SET hashcash_bits = ?, updated_at = ?
-		 WHERE id = ?`,
-		bits, time.Now(), channelID)
-	if err != nil {
-		return fmt.Errorf(
-			"set channel hashcash bits: %w", err,
-		)
-	}
-
-	return nil
-}
-
-// RecordSpentHashcash stores a spent hashcash stamp hash
-// for replay prevention.
-func (database *Database) RecordSpentHashcash(
-	ctx context.Context,
-	stampHash string,
-) error {
-	_, err := database.conn.ExecContext(ctx,
-		`INSERT OR IGNORE INTO spent_hashcash
-		 (stamp_hash, created_at)
-		 VALUES (?, ?)`,
-		stampHash, time.Now())
-	if err != nil {
-		return fmt.Errorf(
-			"record spent hashcash: %w", err,
-		)
-	}
-
-	return nil
-}
-
-// IsHashcashSpent checks whether a hashcash stamp hash
-// has already been used.
-func (database *Database) IsHashcashSpent(
-	ctx context.Context,
-	stampHash string,
-) (bool, error) {
-	var count int
-
-	err := database.conn.QueryRowContext(ctx,
-		`SELECT COUNT(*) FROM spent_hashcash
-		 WHERE stamp_hash = ?`,
-		stampHash,
-	).Scan(&count)
-	if err != nil {
-		return false, fmt.Errorf(
-			"check spent hashcash: %w", err,
-		)
-	}
-
-	return count > 0, nil
-}
-
-// PruneSpentHashcash deletes spent hashcash tokens older
-// than the cutoff and returns the number of rows removed.
-func (database *Database) PruneSpentHashcash(
-	ctx context.Context,
-	cutoff time.Time,
-) (int64, error) {
-	res, err := database.conn.ExecContext(ctx,
-		"DELETE FROM spent_hashcash WHERE created_at < ?",
-		cutoff,
-	)
-	if err != nil {
-		return 0, fmt.Errorf(
-			"prune spent hashcash: %w", err,
-		)
-	}
-
-	deleted, _ := res.RowsAffected()
-
-	return deleted, nil
-}
--- a/internal/db/schema/001_initial.sql
+++ b/internal/db/schema/001_initial.sql
@@ -33,7 +33,6 @@ CREATE TABLE IF NOT EXISTS channels (
    topic TEXT NOT NULL DEFAULT '',
    topic_set_by TEXT NOT NULL DEFAULT '',
    topic_set_at DATETIME,
-    hashcash_bits INTEGER NOT NULL DEFAULT 0,
    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
    updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
 );
@@ -62,14 +61,6 @@ CREATE TABLE IF NOT EXISTS messages (
 CREATE INDEX IF NOT EXISTS idx_messages_to_id ON messages(msg_to, id);
 CREATE INDEX IF NOT EXISTS idx_messages_created ON messages(created_at);

-- Spent hashcash tokens for replay prevention (1-year TTL)
-CREATE TABLE IF NOT EXISTS spent_hashcash (
-    id INTEGER PRIMARY KEY AUTOINCREMENT,
-    stamp_hash TEXT NOT NULL UNIQUE,
-    created_at DATETIME DEFAULT CURRENT_TIMESTAMP
-);
-CREATE INDEX IF NOT EXISTS idx_spent_hashcash_created ON spent_hashcash(created_at);
-
 -- Per-client message queues for fan-out delivery
 CREATE TABLE IF NOT EXISTS client_queues (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
--- a/internal/handlers/api.go
+++ b/internal/handlers/api.go
@@ -3,7 +3,6 @@ package handlers
 import (
 	"context"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"net/http"
 	"regexp"
@@ -12,16 +11,10 @@ import (
 	"time"

 	"git.eeqj.de/sneak/neoirc/internal/db"
-	"git.eeqj.de/sneak/neoirc/internal/hashcash"
 	"git.eeqj.de/sneak/neoirc/pkg/irc"
 	"github.com/go-chi/chi/v5"
 )

-var (
-	errHashcashRequired = errors.New("hashcash required")
-	errHashcashReused   = errors.New("hashcash reused")
-)
-
 var validNickRe = regexp.MustCompile(
 	`^[a-zA-Z_][a-zA-Z0-9_\-\[\]\\^{}|` + "`" + `]{0,31}$`,
 )
@@ -95,11 +88,10 @@ func (hdlr *Handlers) fanOut(
 	request *http.Request,
 	command, from, target string,
 	body json.RawMessage,
-	meta json.RawMessage,
 	sessionIDs []int64,
 ) (string, error) {
 	dbID, msgUUID, err := hdlr.params.Database.InsertMessage(
-		request.Context(), command, from, target, nil, body, meta,
+		request.Context(), command, from, target, nil, body, nil,
 	)
 	if err != nil {
 		return "", fmt.Errorf("insert message: %w", err)
@@ -125,11 +117,10 @@ func (hdlr *Handlers) fanOutSilent(
 	request *http.Request,
 	command, from, target string,
 	body json.RawMessage,
-	meta json.RawMessage,
 	sessionIDs []int64,
 ) error {
 	_, err := hdlr.fanOut(
-		request, command, from, target, body, meta, sessionIDs,
+		request, command, from, target, body, sessionIDs,
 	)

 	return err
@@ -303,7 +294,7 @@ func (hdlr *Handlers) deliverWelcome(
 		[]string{
 			"CHANTYPES=#",
 			"NICKLEN=32",
-			"CHANMODES=,,H," + "imnst",
+			"CHANMODES=,,," + "imnst",
 			"NETWORK=neoirc",
 			"CASEMAPPING=ascii",
 		},
@@ -834,7 +825,7 @@ func (hdlr *Handlers) HandleSendCommand() http.HandlerFunc {
 			writer, request,
 			sessionID, clientID, nick,
 			payload.Command, payload.To,
-			payload.Body, payload.Meta, bodyLines,
+			payload.Body, bodyLines,
 		)
 	}
 }
@@ -845,7 +836,6 @@ func (hdlr *Handlers) dispatchCommand(
 	sessionID, clientID int64,
 	nick, command, target string,
 	body json.RawMessage,
-	meta json.RawMessage,
 	bodyLines func() []string,
 ) {
 	switch command {
@@ -858,7 +848,7 @@ func (hdlr *Handlers) dispatchCommand(
 		hdlr.handlePrivmsg(
 			writer, request,
 			sessionID, clientID, nick,
-			command, target, body, meta, bodyLines,
+			command, target, body, bodyLines,
 		)
 	case irc.CmdJoin:
 		hdlr.handleJoin(
@@ -959,7 +949,6 @@ func (hdlr *Handlers) handlePrivmsg(
 	sessionID, clientID int64,
 	nick, command, target string,
 	body json.RawMessage,
-	meta json.RawMessage,
 	bodyLines func() []string,
 ) {
 	if target == "" {
@@ -997,7 +986,7 @@ func (hdlr *Handlers) handlePrivmsg(
 		hdlr.handleChannelMsg(
 			writer, request,
 			sessionID, clientID, nick,
-			command, target, body, meta,
+			command, target, body,
 		)

 		return
@@ -1006,7 +995,7 @@ func (hdlr *Handlers) handlePrivmsg(
 	hdlr.handleDirectMsg(
 		writer, request,
 		sessionID, clientID, nick,
-		command, target, body, meta,
+		command, target, body,
 	)
 }

@@ -1037,7 +1026,6 @@ func (hdlr *Handlers) handleChannelMsg(
 	sessionID, clientID int64,
 	nick, command, target string,
 	body json.RawMessage,
-	meta json.RawMessage,
 ) {
 	chID, err := hdlr.params.Database.GetChannelByName(
 		request.Context(), target,
@@ -1078,180 +1066,16 @@ func (hdlr *Handlers) handleChannelMsg(
 		return
 	}

-	hashcashErr := hdlr.validateChannelHashcash(
-		request, clientID, sessionID,
-		writer, nick, target, body, meta, chID,
-	)
-	if hashcashErr != nil {
-		return
-	}
-
 	hdlr.sendChannelMsg(
-		writer, request, command, nick, target,
-		body, meta, chID,
+		writer, request, command, nick, target, body, chID,
 	)
 }

-// validateChannelHashcash checks whether the channel
-// requires hashcash proof-of-work for messages and
-// validates the stamp from the message meta field.
-// Returns nil on success or if the channel has no
-// hashcash requirement. On failure, it sends the
-// appropriate IRC error and returns a non-nil error.
-func (hdlr *Handlers) validateChannelHashcash(
-	request *http.Request,
-	clientID, sessionID int64,
-	writer http.ResponseWriter,
-	nick, target string,
-	body json.RawMessage,
-	meta json.RawMessage,
-	chID int64,
-) error {
-	ctx := request.Context()
-
-	bits, bitsErr := hdlr.params.Database.GetChannelHashcashBits(
-		ctx, chID,
-	)
-	if bitsErr != nil {
-		hdlr.log.Error(
-			"get channel hashcash bits", "error", bitsErr,
-		)
-		hdlr.respondError(
-			writer, request,
-			"internal error",
-			http.StatusInternalServerError,
-		)
-
-		return fmt.Errorf("channel hashcash bits: %w", bitsErr)
-	}
-
-	if bits <= 0 {
-		return nil
-	}
-
-	stamp := hdlr.extractHashcashFromMeta(meta)
-	if stamp == "" {
-		hdlr.respondIRCError(
-			writer, request, clientID, sessionID,
-			irc.ErrCannotSendToChan, nick, []string{target},
-			"Channel requires hashcash proof-of-work",
-		)
-
-		return errHashcashRequired
-	}
-
-	return hdlr.verifyChannelStamp(
-		request, writer,
-		clientID, sessionID,
-		nick, target, body, stamp, bits,
-	)
-}
-
-// verifyChannelStamp validates a channel hashcash stamp
-// and checks for replay attacks.
-func (hdlr *Handlers) verifyChannelStamp(
-	request *http.Request,
-	writer http.ResponseWriter,
-	clientID, sessionID int64,
-	nick, target string,
-	body json.RawMessage,
-	stamp string,
-	bits int,
-) error {
-	ctx := request.Context()
-	bodyHashStr := hashcash.BodyHash(body)
-
-	valErr := hdlr.channelHashcash.ValidateStamp(
-		stamp, bits, target, bodyHashStr,
-	)
-	if valErr != nil {
-		hdlr.respondIRCError(
-			writer, request, clientID, sessionID,
-			irc.ErrCannotSendToChan, nick, []string{target},
-			"Invalid hashcash: "+valErr.Error(),
-		)
-
-		return fmt.Errorf("channel hashcash: %w", valErr)
-	}
-
-	stampKey := hashcash.StampHash(stamp)
-
-	spent, spentErr := hdlr.params.Database.IsHashcashSpent(
-		ctx, stampKey,
-	)
-	if spentErr != nil {
-		hdlr.log.Error(
-			"check spent hashcash", "error", spentErr,
-		)
-		hdlr.respondError(
-			writer, request,
-			"internal error",
-			http.StatusInternalServerError,
-		)
-
-		return fmt.Errorf("check spent hashcash: %w", spentErr)
-	}
-
-	if spent {
-		hdlr.respondIRCError(
-			writer, request, clientID, sessionID,
-			irc.ErrCannotSendToChan, nick, []string{target},
-			"Hashcash stamp already used",
-		)
-
-		return errHashcashReused
-	}
-
-	recordErr := hdlr.params.Database.RecordSpentHashcash(
-		ctx, stampKey,
-	)
-	if recordErr != nil {
-		hdlr.log.Error(
-			"record spent hashcash", "error", recordErr,
-		)
-	}
-
-	return nil
-}
-
-// extractHashcashFromMeta parses the meta JSON and
-// returns the hashcash stamp string, or empty string
-// if not present.
-func (hdlr *Handlers) extractHashcashFromMeta(
-	meta json.RawMessage,
-) string {
-	if len(meta) == 0 {
-		return ""
-	}
-
-	var metaMap map[string]json.RawMessage
-
-	err := json.Unmarshal(meta, &metaMap)
-	if err != nil {
-		return ""
-	}
-
-	raw, ok := metaMap["hashcash"]
-	if !ok {
-		return ""
-	}
-
-	var stamp string
-
-	err = json.Unmarshal(raw, &stamp)
-	if err != nil {
-		return ""
-	}
-
-	return stamp
-}
-
 func (hdlr *Handlers) sendChannelMsg(
 	writer http.ResponseWriter,
 	request *http.Request,
 	command, nick, target string,
 	body json.RawMessage,
-	meta json.RawMessage,
 	chID int64,
 ) {
 	memberIDs, err := hdlr.params.Database.GetChannelMemberIDs(
@@ -1271,7 +1095,7 @@ func (hdlr *Handlers) sendChannelMsg(
 	}

 	msgUUID, err := hdlr.fanOut(
-		request, command, nick, target, body, meta, memberIDs,
+		request, command, nick, target, body, memberIDs,
 	)
 	if err != nil {
 		hdlr.log.Error("send message failed", "error", err)
@@ -1295,7 +1119,6 @@ func (hdlr *Handlers) handleDirectMsg(
 	sessionID, clientID int64,
 	nick, command, target string,
 	body json.RawMessage,
-	meta json.RawMessage,
 ) {
 	targetSID, err := hdlr.params.Database.GetSessionByNick(
 		request.Context(), target,
@@ -1320,7 +1143,7 @@ func (hdlr *Handlers) handleDirectMsg(
 	}

 	msgUUID, err := hdlr.fanOut(
-		request, command, nick, target, body, meta, recipients,
+		request, command, nick, target, body, recipients,
 	)
 	if err != nil {
 		hdlr.log.Error("send dm failed", "error", err)
@@ -1431,7 +1254,7 @@ func (hdlr *Handlers) executeJoin(
 	)

 	_ = hdlr.fanOutSilent(
-		request, irc.CmdJoin, nick, channel, nil, nil, memberIDs,
+		request, irc.CmdJoin, nick, channel, nil, memberIDs,
 	)

 	hdlr.deliverJoinNumerics(
@@ -1601,7 +1424,7 @@ func (hdlr *Handlers) handlePart(
 	)

 	_ = hdlr.fanOutSilent(
-		request, irc.CmdPart, nick, channel, body, nil, memberIDs,
+		request, irc.CmdPart, nick, channel, body, memberIDs,
 	)

 	err = hdlr.params.Database.PartChannel(
@@ -1881,7 +1704,7 @@ func (hdlr *Handlers) executeTopic(
 	)

 	_ = hdlr.fanOutSilent(
-		request, irc.CmdTopic, nick, channel, body, nil, memberIDs,
+		request, irc.CmdTopic, nick, channel, body, memberIDs,
 	)

 	hdlr.enqueueNumeric(
@@ -2044,10 +1867,11 @@ func (hdlr *Handlers) handleMode(
 		return
 	}

+	_ = bodyLines
+
 	hdlr.handleChannelMode(
 		writer, request,
 		sessionID, clientID, nick, channel,
-		bodyLines,
 	)
 }

@@ -2056,7 +1880,6 @@ func (hdlr *Handlers) handleChannelMode(
 	request *http.Request,
 	sessionID, clientID int64,
 	nick, channel string,
-	bodyLines func() []string,
 ) {
 	ctx := request.Context()

@@ -2073,47 +1896,10 @@ func (hdlr *Handlers) handleChannelMode(
 		return
 	}

-	lines := bodyLines()
-	if len(lines) > 0 {
-		hdlr.applyChannelMode(
-			writer, request,
-			sessionID, clientID, nick,
-			channel, chID, lines,
-		)
-
-		return
-	}
-
-	hdlr.queryChannelMode(
-		writer, request,
-		sessionID, clientID, nick, channel, chID,
-	)
-}
-
-// queryChannelMode sends RPL_CHANNELMODEIS and
-// RPL_CREATIONTIME for a channel. Includes +H if
-// the channel has a hashcash requirement.
-func (hdlr *Handlers) queryChannelMode(
-	writer http.ResponseWriter,
-	request *http.Request,
-	sessionID, clientID int64,
-	nick, channel string,
-	chID int64,
-) {
-	ctx := request.Context()
-
-	modeStr := "+n"
-
-	bits, bitsErr := hdlr.params.Database.
-		GetChannelHashcashBits(ctx, chID)
-	if bitsErr == nil && bits > 0 {
-		modeStr = fmt.Sprintf("+nH %d", bits)
-	}
-
 	// 324 RPL_CHANNELMODEIS
 	hdlr.enqueueNumeric(
 		ctx, clientID, irc.RplChannelModeIs, nick,
-		[]string{channel, modeStr}, "",
+		[]string{channel, "+n"}, "",
 	)

 	// 329 RPL_CREATIONTIME
@@ -2138,156 +1924,6 @@ func (hdlr *Handlers) queryChannelMode(
 		http.StatusOK)
 }

-// applyChannelMode handles setting channel modes.
-// Currently supports +H/-H for hashcash bits.
-func (hdlr *Handlers) applyChannelMode(
-	writer http.ResponseWriter,
-	request *http.Request,
-	sessionID, clientID int64,
-	nick, channel string,
-	chID int64,
-	modeArgs []string,
-) {
-	ctx := request.Context()
-	modeStr := modeArgs[0]
-
-	switch modeStr {
-	case "+H":
-		hdlr.setHashcashMode(
-			writer, request,
-			sessionID, clientID, nick,
-			channel, chID, modeArgs,
-		)
-	case "-H":
-		hdlr.clearHashcashMode(
-			writer, request,
-			sessionID, clientID, nick,
-			channel, chID,
-		)
-	default:
-		// Unknown or unsupported mode change.
-		hdlr.enqueueNumeric(
-			ctx, clientID, irc.ErrUnknownMode, nick,
-			[]string{modeStr},
-			"is unknown mode char to me",
-		)
-		hdlr.broker.Notify(sessionID)
-		hdlr.respondJSON(writer, request,
-			map[string]string{"status": "error"},
-			http.StatusOK)
-	}
-}
-
-const (
-	// minHashcashBits is the minimum allowed hashcash
-	// difficulty for channels.
-	minHashcashBits = 1
-	// maxHashcashBits is the maximum allowed hashcash
-	// difficulty for channels.
-	maxHashcashBits = 40
-)
-
-// setHashcashMode handles MODE #channel +H <bits>.
-func (hdlr *Handlers) setHashcashMode(
-	writer http.ResponseWriter,
-	request *http.Request,
-	sessionID, clientID int64,
-	nick, channel string,
-	chID int64,
-	modeArgs []string,
-) {
-	ctx := request.Context()
-
-	if len(modeArgs) < 2 { //nolint:mnd // +H requires a bits arg
-		hdlr.respondIRCError(
-			writer, request, clientID, sessionID,
-			irc.ErrNeedMoreParams, nick, []string{irc.CmdMode},
-			"Not enough parameters (+H requires bits)",
-		)
-
-		return
-	}
-
-	bits, err := strconv.Atoi(modeArgs[1])
-	if err != nil || bits < minHashcashBits ||
-		bits > maxHashcashBits {
-		hdlr.respondIRCError(
-			writer, request, clientID, sessionID,
-			irc.ErrUnknownMode, nick, []string{"+H"},
-			fmt.Sprintf(
-				"Invalid hashcash bits (must be %d-%d)",
-				minHashcashBits, maxHashcashBits,
-			),
-		)
-
-		return
-	}
-
-	err = hdlr.params.Database.SetChannelHashcashBits(
-		ctx, chID, bits,
-	)
-	if err != nil {
-		hdlr.log.Error(
-			"set channel hashcash bits", "error", err,
-		)
-		hdlr.respondError(
-			writer, request,
-			"internal error",
-			http.StatusInternalServerError,
-		)
-
-		return
-	}
-
-	hdlr.enqueueNumeric(
-		ctx, clientID, irc.RplChannelModeIs, nick,
-		[]string{
-			channel,
-			fmt.Sprintf("+H %d", bits),
-		}, "",
-	)
-	hdlr.broker.Notify(sessionID)
-	hdlr.respondJSON(writer, request,
-		map[string]string{"status": "ok"},
-		http.StatusOK)
-}
-
-// clearHashcashMode handles MODE #channel -H.
-func (hdlr *Handlers) clearHashcashMode(
-	writer http.ResponseWriter,
-	request *http.Request,
-	sessionID, clientID int64,
-	nick, channel string,
-	chID int64,
-) {
-	ctx := request.Context()
-
-	err := hdlr.params.Database.SetChannelHashcashBits(
-		ctx, chID, 0,
-	)
-	if err != nil {
-		hdlr.log.Error(
-			"clear channel hashcash bits", "error", err,
-		)
-		hdlr.respondError(
-			writer, request,
-			"internal error",
-			http.StatusInternalServerError,
-		)
-
-		return
-	}
-
-	hdlr.enqueueNumeric(
-		ctx, clientID, irc.RplChannelModeIs, nick,
-		[]string{channel, "+n"}, "",
-	)
-	hdlr.broker.Notify(sessionID)
-	hdlr.respondJSON(writer, request,
-		map[string]string{"status": "ok"},
-		http.StatusOK)
-}
-
 // handleNames sends NAMES reply for a channel.
 func (hdlr *Handlers) handleNames(
 	writer http.ResponseWriter,
--- a/internal/handlers/api_test.go
+++ b/internal/handlers/api_test.go
@@ -22,7 +22,6 @@ import (
 	"git.eeqj.de/sneak/neoirc/internal/db"
 	"git.eeqj.de/sneak/neoirc/internal/globals"
 	"git.eeqj.de/sneak/neoirc/internal/handlers"
-	"git.eeqj.de/sneak/neoirc/internal/hashcash"
 	"git.eeqj.de/sneak/neoirc/internal/healthcheck"
 	"git.eeqj.de/sneak/neoirc/internal/logger"
 	"git.eeqj.de/sneak/neoirc/internal/middleware"
@@ -2158,397 +2157,3 @@ func TestNickBroadcastToChannels(t *testing.T) {
 		)
 	}
 }
-
-// --- Channel Hashcash Tests ---
-
-const (
-	metaKey     = "meta"
-	modeCmd     = "MODE"
-	hashcashKey = "hashcash"
-)
-
-func mintTestChannelHashcash(
-	tb testing.TB,
-	bits int,
-	channel string,
-	body json.RawMessage,
-) string {
-	tb.Helper()
-
-	bodyHash := hashcash.BodyHash(body)
-
-	return hashcash.MintChannelStamp(bits, channel, bodyHash)
-}
-
-func TestChannelHashcashSetMode(t *testing.T) {
-	tserver := newTestServer(t)
-	token := tserver.createSession("hcmode_user")
-
-	tserver.sendCommand(token, map[string]any{
-		commandKey: joinCmd, toKey: "#hctest",
-	})
-
-	_, lastID := tserver.pollMessages(token, 0)
-
-	// Set hashcash bits to 2 via MODE +H.
-	status, _ := tserver.sendCommand(
-		token,
-		map[string]any{
-			commandKey: modeCmd,
-			toKey:      "#hctest",
-			bodyKey:    []string{"+H", "2"},
-		},
-	)
-	if status != http.StatusOK {
-		t.Fatalf("expected 200, got %d", status)
-	}
-
-	msgs, _ := tserver.pollMessages(token, lastID)
-
-	// Should get RPL_CHANNELMODEIS (324) confirming +H.
-	if !findNumeric(msgs, "324") {
-		t.Fatalf(
-			"expected RPL_CHANNELMODEIS (324), got %v",
-			msgs,
-		)
-	}
-}
-
-func TestChannelHashcashQueryMode(t *testing.T) {
-	tserver := newTestServer(t)
-	token := tserver.createSession("hcquery_user")
-
-	tserver.sendCommand(token, map[string]any{
-		commandKey: joinCmd, toKey: "#hcquery",
-	})
-
-	// Set hashcash bits.
-	tserver.sendCommand(token, map[string]any{
-		commandKey: modeCmd,
-		toKey:      "#hcquery",
-		bodyKey:    []string{"+H", "5"},
-	})
-
-	_, lastID := tserver.pollMessages(token, 0)
-
-	// Query mode — should show +nH.
-	tserver.sendCommand(token, map[string]any{
-		commandKey: modeCmd,
-		toKey:      "#hcquery",
-	})
-
-	msgs, _ := tserver.pollMessages(token, lastID)
-
-	found := false
-
-	for _, msg := range msgs {
-		code, ok := msg["code"].(float64)
-		if ok && int(code) == 324 {
-			found = true
-		}
-	}
-
-	if !found {
-		t.Fatalf(
-			"expected RPL_CHANNELMODEIS (324), got %v",
-			msgs,
-		)
-	}
-}
-
-func TestChannelHashcashClearMode(t *testing.T) {
-	tserver := newTestServer(t)
-	token := tserver.createSession("hcclear_user")
-
-	tserver.sendCommand(token, map[string]any{
-		commandKey: joinCmd, toKey: "#hcclear",
-	})
-
-	// Set hashcash bits.
-	tserver.sendCommand(token, map[string]any{
-		commandKey: modeCmd,
-		toKey:      "#hcclear",
-		bodyKey:    []string{"+H", "5"},
-	})
-
-	// Clear hashcash bits.
-	status, _ := tserver.sendCommand(token, map[string]any{
-		commandKey: modeCmd,
-		toKey:      "#hcclear",
-		bodyKey:    []string{"-H"},
-	})
-	if status != http.StatusOK {
-		t.Fatalf("expected 200, got %d", status)
-	}
-
-	// Now message should succeed without hashcash.
-	status, result := tserver.sendCommand(
-		token,
-		map[string]any{
-			commandKey: privmsgCmd,
-			toKey:      "#hcclear",
-			bodyKey:    []string{"test message"},
-		},
-	)
-	if status != http.StatusOK {
-		t.Fatalf(
-			"expected 200, got %d: %v", status, result,
-		)
-	}
-}
-
-func TestChannelHashcashRejectNoStamp(t *testing.T) {
-	tserver := newTestServer(t)
-	token := tserver.createSession("hcreject_user")
-
-	tserver.sendCommand(token, map[string]any{
-		commandKey: joinCmd, toKey: "#hcreject",
-	})
-
-	// Set hashcash requirement.
-	tserver.sendCommand(token, map[string]any{
-		commandKey: modeCmd,
-		toKey:      "#hcreject",
-		bodyKey:    []string{"+H", "2"},
-	})
-
-	_, lastID := tserver.pollMessages(token, 0)
-
-	// Send message without hashcash — should fail.
-	status, _ := tserver.sendCommand(
-		token,
-		map[string]any{
-			commandKey: privmsgCmd,
-			toKey:      "#hcreject",
-			bodyKey:    []string{"spam message"},
-		},
-	)
-	if status != http.StatusOK {
-		t.Fatalf("expected 200, got %d", status)
-	}
-
-	msgs, _ := tserver.pollMessages(token, lastID)
-
-	// Should get ERR_CANNOTSENDTOCHAN (404).
-	if !findNumeric(msgs, "404") {
-		t.Fatalf(
-			"expected ERR_CANNOTSENDTOCHAN (404), got %v",
-			msgs,
-		)
-	}
-}
-
-func TestChannelHashcashAcceptValidStamp(t *testing.T) {
-	tserver := newTestServer(t)
-	token := tserver.createSession("hcaccept_user")
-
-	tserver.sendCommand(token, map[string]any{
-		commandKey: joinCmd, toKey: "#hcaccept",
-	})
-
-	// Set hashcash requirement (2 bits = fast to mint).
-	tserver.sendCommand(token, map[string]any{
-		commandKey: modeCmd,
-		toKey:      "#hcaccept",
-		bodyKey:    []string{"+H", "2"},
-	})
-
-	_, lastID := tserver.pollMessages(token, 0)
-
-	// Mint a valid hashcash stamp.
-	msgBody, marshalErr := json.Marshal(
-		[]string{"hello world"},
-	)
-	if marshalErr != nil {
-		t.Fatal(marshalErr)
-	}
-
-	stamp := mintTestChannelHashcash(
-		t, 2, "#hcaccept", msgBody,
-	)
-
-	// Send message with valid hashcash.
-	status, result := tserver.sendCommand(
-		token,
-		map[string]any{
-			commandKey: privmsgCmd,
-			toKey:      "#hcaccept",
-			bodyKey:    []string{"hello world"},
-			metaKey: map[string]any{
-				hashcashKey: stamp,
-			},
-		},
-	)
-	if status != http.StatusOK {
-		t.Fatalf(
-			"expected 200, got %d: %v", status, result,
-		)
-	}
-
-	if result["id"] == nil || result["id"] == "" {
-		t.Fatal("expected message id for valid hashcash")
-	}
-
-	// Verify the message was delivered.
-	msgs, _ := tserver.pollMessages(token, lastID)
-	if !findMessage(msgs, privmsgCmd, "hcaccept_user") {
-		t.Fatalf(
-			"message not received: %v", msgs,
-		)
-	}
-}
-
-func TestChannelHashcashRejectReplayedStamp(t *testing.T) {
-	tserver := newTestServer(t)
-	token := tserver.createSession("hcreplay_user")
-
-	tserver.sendCommand(token, map[string]any{
-		commandKey: joinCmd, toKey: "#hcreplay",
-	})
-
-	// Set hashcash requirement.
-	tserver.sendCommand(token, map[string]any{
-		commandKey: modeCmd,
-		toKey:      "#hcreplay",
-		bodyKey:    []string{"+H", "2"},
-	})
-
-	_, _ = tserver.pollMessages(token, 0)
-
-	// Mint and send once — should succeed.
-	msgBody, marshalErr := json.Marshal(
-		[]string{"unique msg"},
-	)
-	if marshalErr != nil {
-		t.Fatal(marshalErr)
-	}
-
-	stamp := mintTestChannelHashcash(
-		t, 2, "#hcreplay", msgBody,
-	)
-
-	status, _ := tserver.sendCommand(
-		token,
-		map[string]any{
-			commandKey: privmsgCmd,
-			toKey:      "#hcreplay",
-			bodyKey:    []string{"unique msg"},
-			metaKey: map[string]any{
-				hashcashKey: stamp,
-			},
-		},
-	)
-	if status != http.StatusOK {
-		t.Fatalf("expected 200, got %d", status)
-	}
-
-	_, lastID := tserver.pollMessages(token, 0)
-
-	// Replay the same stamp — should fail.
-	status, _ = tserver.sendCommand(
-		token,
-		map[string]any{
-			commandKey: privmsgCmd,
-			toKey:      "#hcreplay",
-			bodyKey:    []string{"unique msg"},
-			metaKey: map[string]any{
-				hashcashKey: stamp,
-			},
-		},
-	)
-	if status != http.StatusOK {
-		t.Fatalf("expected 200, got %d", status)
-	}
-
-	msgs, _ := tserver.pollMessages(token, lastID)
-
-	// Should get ERR_CANNOTSENDTOCHAN (404).
-	if !findNumeric(msgs, "404") {
-		t.Fatalf(
-			"expected replay rejection (404), got %v",
-			msgs,
-		)
-	}
-}
-
-func TestChannelHashcashNoRequirementWorks(t *testing.T) {
-	tserver := newTestServer(t)
-	token := tserver.createSession("hcnone_user")
-
-	tserver.sendCommand(token, map[string]any{
-		commandKey: joinCmd, toKey: "#nohashcash",
-	})
-
-	// No hashcash set — message should work.
-	status, result := tserver.sendCommand(
-		token,
-		map[string]any{
-			commandKey: privmsgCmd,
-			toKey:      "#nohashcash",
-			bodyKey:    []string{"free message"},
-		},
-	)
-	if status != http.StatusOK {
-		t.Fatalf(
-			"expected 200, got %d: %v", status, result,
-		)
-	}
-
-	if result["id"] == nil || result["id"] == "" {
-		t.Fatal("expected message id")
-	}
-}
-
-func TestChannelHashcashInvalidBitsRange(t *testing.T) {
-	tserver := newTestServer(t)
-	token := tserver.createSession("hcbits_user")
-
-	tserver.sendCommand(token, map[string]any{
-		commandKey: joinCmd, toKey: "#hcbits",
-	})
-
-	_, lastID := tserver.pollMessages(token, 0)
-
-	// Try to set bits to 0 — should fail.
-	tserver.sendCommand(token, map[string]any{
-		commandKey: modeCmd,
-		toKey:      "#hcbits",
-		bodyKey:    []string{"+H", "0"},
-	})
-
-	msgs, _ := tserver.pollMessages(token, lastID)
-
-	if !findNumeric(msgs, "472") {
-		t.Fatalf(
-			"expected ERR_UNKNOWNMODE (472), got %v",
-			msgs,
-		)
-	}
-}
-
-func TestChannelHashcashMissingBitsArg(t *testing.T) {
-	tserver := newTestServer(t)
-	token := tserver.createSession("hcnoarg_user")
-
-	tserver.sendCommand(token, map[string]any{
-		commandKey: joinCmd, toKey: "#hcnoarg",
-	})
-
-	_, lastID := tserver.pollMessages(token, 0)
-
-	// Try to set +H without bits argument.
-	tserver.sendCommand(token, map[string]any{
-		commandKey: modeCmd,
-		toKey:      "#hcnoarg",
-		bodyKey:    []string{"+H"},
-	})
-
-	msgs, _ := tserver.pollMessages(token, lastID)
-
-	if !findNumeric(msgs, "461") {
-		t.Fatalf(
-			"expected ERR_NEEDMOREPARAMS (461), got %v",
-			msgs,
-		)
-	}
-}
--- a/internal/handlers/handlers.go
+++ b/internal/handlers/handlers.go
@@ -36,11 +36,6 @@ type Params struct {

 const defaultIdleTimeout = 30 * 24 * time.Hour

-// spentHashcashTTL is how long spent hashcash tokens are
-// retained for replay prevention. Per issue requirements,
-// this is 1 year.
-const spentHashcashTTL = 365 * 24 * time.Hour
-
 // Handlers manages HTTP request handling.
 type Handlers struct {
 	params        *Params
@@ -48,7 +43,6 @@ type Handlers struct {
 	hc            *healthcheck.Healthcheck
 	broker        *broker.Broker
 	hashcashVal   *hashcash.Validator
-	channelHashcash *hashcash.ChannelValidator
 	stats         *stats.Tracker
 	cancelCleanup context.CancelFunc
 }
@@ -69,7 +63,6 @@ func New(
 		hc:          params.Healthcheck,
 		broker:      broker.New(),
 		hashcashVal: hashcash.NewValidator(resource),
-		channelHashcash: hashcash.NewChannelValidator(),
 		stats:       params.Stats,
 	}

@@ -292,20 +285,4 @@ func (hdlr *Handlers) pruneQueuesAndMessages(
 			)
 		}
 	}
-
-	// Prune spent hashcash tokens older than 1 year.
-	hashcashCutoff := time.Now().Add(-spentHashcashTTL)
-
-	pruned, err := hdlr.params.Database.
-		PruneSpentHashcash(ctx, hashcashCutoff)
-	if err != nil {
-		hdlr.log.Error(
-			"spent hashcash pruning failed", "error", err,
-		)
-	} else if pruned > 0 {
-		hdlr.log.Info(
-			"pruned spent hashcash tokens",
-			"deleted", pruned,
-		)
-	}
 }
--- a/internal/hashcash/channel.go
+++ b/internal/hashcash/channel.go
@@ -1,186 +0,0 @@
-package hashcash
-
-import (
-	"crypto/sha256"
-	"encoding/hex"
-	"errors"
-	"fmt"
-	"strconv"
-	"strings"
-	"time"
-)
-
-var (
-	errBodyHashMismatch = errors.New(
-		"body hash mismatch",
-	)
-	errBodyHashMissing = errors.New(
-		"body hash missing",
-	)
-)
-
-// ChannelValidator checks hashcash stamps for
-// per-channel PRIVMSG validation. It verifies that
-// stamps are bound to a specific channel and message
-// body. Replay prevention is handled externally via
-// the database spent_hashcash table for persistence
-// across server restarts (1-year TTL).
-type ChannelValidator struct{}
-
-// NewChannelValidator creates a ChannelValidator.
-func NewChannelValidator() *ChannelValidator {
-	return &ChannelValidator{}
-}
-
-// BodyHash computes the hex-encoded SHA-256 hash of a
-// message body for use in hashcash stamp validation.
-func BodyHash(body []byte) string {
-	hash := sha256.Sum256(body)
-
-	return hex.EncodeToString(hash[:])
-}
-
-// ValidateStamp checks a channel hashcash stamp. It
-// verifies the stamp format, difficulty, date, channel
-// binding, body hash binding, and proof-of-work. Replay
-// detection is NOT performed here — callers must check
-// the spent_hashcash table separately.
-//
-// Stamp format: 1:bits:YYMMDD:channel:bodyhash:counter.
-func (cv *ChannelValidator) ValidateStamp(
-	stamp string,
-	requiredBits int,
-	channel string,
-	bodyHash string,
-) error {
-	if requiredBits <= 0 {
-		return nil
-	}
-
-	parts := strings.Split(stamp, ":")
-	if len(parts) != stampFields {
-		return fmt.Errorf(
-			"%w: expected %d, got %d",
-			errInvalidFields, stampFields, len(parts),
-		)
-	}
-
-	version := parts[0]
-	bitsStr := parts[1]
-	dateStr := parts[2]
-	resource := parts[3]
-	stampBodyHash := parts[4]
-
-	headerErr := validateChannelHeader(
-		version, bitsStr, resource,
-		requiredBits, channel,
-	)
-	if headerErr != nil {
-		return headerErr
-	}
-
-	stampTime, parseErr := parseStampDate(dateStr)
-	if parseErr != nil {
-		return parseErr
-	}
-
-	timeErr := validateTime(stampTime)
-	if timeErr != nil {
-		return timeErr
-	}
-
-	bodyErr := validateBodyHash(
-		stampBodyHash, bodyHash,
-	)
-	if bodyErr != nil {
-		return bodyErr
-	}
-
-	return validateProof(stamp, requiredBits)
-}
-
-// StampHash returns a deterministic hash of a stamp
-// string for use as a spent-token key.
-func StampHash(stamp string) string {
-	hash := sha256.Sum256([]byte(stamp))
-
-	return hex.EncodeToString(hash[:])
-}
-
-func validateChannelHeader(
-	version, bitsStr, resource string,
-	requiredBits int,
-	channel string,
-) error {
-	if version != stampVersion {
-		return fmt.Errorf(
-			"%w: %s", errBadVersion, version,
-		)
-	}
-
-	claimedBits, err := strconv.Atoi(bitsStr)
-	if err != nil || claimedBits < requiredBits {
-		return fmt.Errorf(
-			"%w: need %d bits",
-			errInsufficientBits, requiredBits,
-		)
-	}
-
-	if resource != channel {
-		return fmt.Errorf(
-			"%w: got %q, want %q",
-			errWrongResource, resource, channel,
-		)
-	}
-
-	return nil
-}
-
-func validateBodyHash(
-	stampBodyHash, expectedBodyHash string,
-) error {
-	if stampBodyHash == "" {
-		return errBodyHashMissing
-	}
-
-	if stampBodyHash != expectedBodyHash {
-		return fmt.Errorf(
-			"%w: got %q, want %q",
-			errBodyHashMismatch,
-			stampBodyHash, expectedBodyHash,
-		)
-	}
-
-	return nil
-}
-
-// MintChannelStamp computes a channel hashcash stamp
-// with the given difficulty, channel name, and body hash.
-// This is intended for clients to generate stamps before
-// sending PRIVMSG to hashcash-protected channels.
-//
-// Stamp format: 1:bits:YYMMDD:channel:bodyhash:counter.
-func MintChannelStamp(
-	bits int,
-	channel string,
-	bodyHash string,
-) string {
-	date := time.Now().UTC().Format(dateFormatShort)
-	prefix := fmt.Sprintf(
-		"1:%d:%s:%s:%s:",
-		bits, date, channel, bodyHash,
-	)
-
-	counter := uint64(0)
-
-	for {
-		stamp := prefix + strconv.FormatUint(counter, 16)
-		hash := sha256.Sum256([]byte(stamp))
-
-		if hasLeadingZeroBits(hash[:], bits) {
-			return stamp
-		}
-
-		counter++
-	}
-}
--- a/internal/hashcash/channel_test.go
+++ b/internal/hashcash/channel_test.go
@@ -1,244 +0,0 @@
-package hashcash_test
-
-import (
-	"crypto/sha256"
-	"encoding/hex"
-	"testing"
-
-	"git.eeqj.de/sneak/neoirc/internal/hashcash"
-)
-
-const (
-	testChannel  = "#general"
-	testBodyText = `["hello world"]`
-)
-
-func testBodyHash() string {
-	hash := sha256.Sum256([]byte(testBodyText))
-
-	return hex.EncodeToString(hash[:])
-}
-
-func TestChannelValidateHappyPath(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-	bodyHash := testBodyHash()
-
-	stamp := hashcash.MintChannelStamp(
-		testBits, testChannel, bodyHash,
-	)
-
-	err := validator.ValidateStamp(
-		stamp, testBits, testChannel, bodyHash,
-	)
-	if err != nil {
-		t.Fatalf("valid channel stamp rejected: %v", err)
-	}
-}
-
-func TestChannelValidateWrongChannel(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-	bodyHash := testBodyHash()
-
-	stamp := hashcash.MintChannelStamp(
-		testBits, testChannel, bodyHash,
-	)
-
-	err := validator.ValidateStamp(
-		stamp, testBits, "#other", bodyHash,
-	)
-	if err == nil {
-		t.Fatal("expected channel mismatch error")
-	}
-}
-
-func TestChannelValidateWrongBodyHash(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-	bodyHash := testBodyHash()
-
-	stamp := hashcash.MintChannelStamp(
-		testBits, testChannel, bodyHash,
-	)
-
-	wrongHash := sha256.Sum256([]byte("different body"))
-	wrongBodyHash := hex.EncodeToString(wrongHash[:])
-
-	err := validator.ValidateStamp(
-		stamp, testBits, testChannel, wrongBodyHash,
-	)
-	if err == nil {
-		t.Fatal("expected body hash mismatch error")
-	}
-}
-
-func TestChannelValidateInsufficientBits(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-	bodyHash := testBodyHash()
-
-	// Mint with 2 bits but require 4.
-	stamp := hashcash.MintChannelStamp(
-		testBits, testChannel, bodyHash,
-	)
-
-	err := validator.ValidateStamp(
-		stamp, 4, testChannel, bodyHash,
-	)
-	if err == nil {
-		t.Fatal("expected insufficient bits error")
-	}
-}
-
-func TestChannelValidateZeroBitsSkips(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-
-	err := validator.ValidateStamp(
-		"garbage", 0, "#ch", "abc",
-	)
-	if err != nil {
-		t.Fatalf("zero bits should skip: %v", err)
-	}
-}
-
-func TestChannelValidateBadFormat(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-
-	err := validator.ValidateStamp(
-		"not:valid", testBits, testChannel, "abc",
-	)
-	if err == nil {
-		t.Fatal("expected bad format error")
-	}
-}
-
-func TestChannelValidateBadVersion(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-	bodyHash := testBodyHash()
-
-	stamp := "2:2:260317:#general:" + bodyHash + ":counter"
-
-	err := validator.ValidateStamp(
-		stamp, testBits, testChannel, bodyHash,
-	)
-	if err == nil {
-		t.Fatal("expected bad version error")
-	}
-}
-
-func TestChannelValidateExpiredStamp(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-	bodyHash := testBodyHash()
-
-	// Mint with a very old date by manually constructing.
-	stamp := mintStampWithDate(
-		t, testBits, testChannel, "200101",
-	)
-
-	err := validator.ValidateStamp(
-		stamp, testBits, testChannel, bodyHash,
-	)
-	if err == nil {
-		t.Fatal("expected expired stamp error")
-	}
-}
-
-func TestChannelValidateMissingBodyHash(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-	bodyHash := testBodyHash()
-
-	// Construct a stamp with empty body hash field.
-	stamp := mintStampWithDate(
-		t, testBits, testChannel, todayDate(),
-	)
-
-	// This uses the session-style stamp which has empty
-	// ext field — body hash is missing.
-	err := validator.ValidateStamp(
-		stamp, testBits, testChannel, bodyHash,
-	)
-	if err == nil {
-		t.Fatal("expected missing body hash error")
-	}
-}
-
-func TestBodyHash(t *testing.T) {
-	t.Parallel()
-
-	body := []byte(`["hello world"]`)
-	bodyHash := hashcash.BodyHash(body)
-
-	if len(bodyHash) != 64 {
-		t.Fatalf(
-			"expected 64-char hex hash, got %d",
-			len(bodyHash),
-		)
-	}
-
-	// Same input should produce same hash.
-	bodyHash2 := hashcash.BodyHash(body)
-	if bodyHash != bodyHash2 {
-		t.Fatal("body hash not deterministic")
-	}
-
-	// Different input should produce different hash.
-	bodyHash3 := hashcash.BodyHash([]byte("different"))
-	if bodyHash == bodyHash3 {
-		t.Fatal("different inputs produced same hash")
-	}
-}
-
-func TestStampHash(t *testing.T) {
-	t.Parallel()
-
-	hash1 := hashcash.StampHash("stamp1")
-	hash2 := hashcash.StampHash("stamp2")
-
-	if hash1 == hash2 {
-		t.Fatal("different stamps produced same hash")
-	}
-
-	// Same input should be deterministic.
-	hash1b := hashcash.StampHash("stamp1")
-	if hash1 != hash1b {
-		t.Fatal("stamp hash not deterministic")
-	}
-}
-
-func TestMintChannelStamp(t *testing.T) {
-	t.Parallel()
-
-	bodyHash := testBodyHash()
-	stamp := hashcash.MintChannelStamp(
-		testBits, testChannel, bodyHash,
-	)
-
-	if stamp == "" {
-		t.Fatal("expected non-empty stamp")
-	}
-
-	// Validate the minted stamp.
-	validator := hashcash.NewChannelValidator()
-
-	err := validator.ValidateStamp(
-		stamp, testBits, testChannel, bodyHash,
-	)
-	if err != nil {
-		t.Fatalf("minted stamp failed validation: %v", err)
-	}
-}