feat(tools): fabric-send-message + fabric-channel-list + fabric-message-history

Plugin previously had no way for an agent to send text into a specific
channel proactively — outbound went only through the channel-reply
path (responds to the channel that woke the agent). discussion-complete
internally called client.postMessage but only for the close-time
summary, no general-purpose surface.

Three new tools (+ declare existing fabric-canvas / fabric-channel that
were registered but missing from contracts.tools so agents couldn't
see them per the openclaw plugin contract):

  * fabric-send-message {guildNodeId, channelId, content}
      → {ok, messageId, seq}
    Author = calling agent. Use for ARD broadcasts, follow-ups in a
    different channel, etc.

  * fabric-channel-list {guildNodeId, nameFilter?, xType?, includeClosed?}
      → {ok, count, channels[]}
    Backend filters to public + member channels; nameFilter is client-
    side case-insensitive substring; xType / includeClosed apply post-
    fetch. Returns id/name/xType/lastSeq so callers can pipe into the
    other tools.

  * fabric-message-history {guildNodeId, channelId, seqFrom?, seqTo?, limit?}
      → {ok, page, messages[]}
    Tail-by-default: omit seqFrom/seqTo and the tool fetches the
    channel head from listChannels then asks for [head-limit+1, head].
    Limit default 20, max 200. Backend rejects non-participants.

Plus 3 supporting client methods (listChannels, listMessages — both
GET via existing req helper).

contracts.tools updated to declare these 5 (3 new + 2 previously-
silent ones). Verified earlier in sim restart logs: openclaw warned
'plugin tool is undeclared (fabric): fabric-canvas / fabric-channel'
so agents couldn't use them despite registerTool firing.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

dist/fabric/src/inbound.js

@@ -14,6 +14,14 @@ export class FabricInbound {
     accounts;
     sockets = [];
     seen = new Set();
+    // Timers that periodically re-sync channel membership per (agent, guild).
+    // Without this, the agent's socket.io subscriptions are a snapshot taken
+    // at connect time — any channel the agent joins later (e.g. a fresh DM
+    // created by another user) is unreachable until the gateway restarts.
+    channelSyncTimers = [];
+    // Resync cadence. Backend doesn't push a `channel.joined` event, so we
+    // poll. 60s keeps the lag bounded without hammering the backend.
+    static CHANNEL_SYNC_INTERVAL_MS = 60_000;
     // Guild access tokens are short-lived (~15 min). The socket survives via
     // socket.io reconnect, but the token captured at connect time goes stale,
     // so HTTP calls (attachment download, posting the reply) start 401ing.
@@ -75,6 +83,9 @@ export class FabricInbound {
         }
     }
     stop() {
+        for (const t of this.channelSyncTimers)
+            clearInterval(t);
+        this.channelSyncTimers = [];
         for (const s of this.sockets)
             s.disconnect();
         this.sockets = [];
@@ -90,19 +101,83 @@ export class FabricInbound {
                 auth: { token: tok },
                 autoConnect: false,
             });
-            const joinAll = async () => {
+            // Tracked socket.io rooms for this (agent, guild). The initial fetch
+            // on `connect` seeds it; the periodic resync diffs against it so we
+            // only emit `join_channel` for genuinely new channels (and
+            // `leave_channel` for ones the agent is no longer in).
+            const joined = new Set();
+            const syncChannels = async (kind) => {
+                let freshTok;
                 try {
-                    const res = await fetch(`${g.endpoint}/api/channels?guildId=${encodeURIComponent(g.nodeId)}`, { headers: { authorization: `Bearer ${tok}` } });
-                    const channels = res.ok ? (await res.json()) : [];
-                    for (const c of channels)
-                        socket.emit('join_channel', { channelId: c.id });
-                    this.log.info(`fabric: agent ${agentId} joined ${channels.length} channel(s) on ${g.nodeId}`);
+                    freshTok = await this.freshGuildToken(agentId, g.nodeId, session);
                 }
                 catch {
-                    /* best effort */
+                    freshTok = tok;
+                }
+                const authTok = freshTok ?? tok;
+                try {
+                    const res = await fetch(`${g.endpoint}/api/channels?guildId=${encodeURIComponent(g.nodeId)}`, { headers: { authorization: `Bearer ${authTok}` } });
+                    if (!res.ok)
+                        return;
+                    const channels = (await res.json());
+                    const current = new Set(channels.map((c) => c.id));
+                    let added = 0;
+                    let removed = 0;
+                    for (const id of current) {
+                        if (!joined.has(id)) {
+                            socket.emit('join_channel', { channelId: id });
+                            joined.add(id);
+                            added++;
+                        }
+                    }
+                    for (const id of [...joined]) {
+                        if (!current.has(id)) {
+                            socket.emit('leave_channel', { channelId: id });
+                            joined.delete(id);
+                            removed++;
+                        }
+                    }
+                    if (kind === 'initial') {
+                        this.log.info(`fabric: agent ${agentId} joined ${current.size} channel(s) on ${g.nodeId}`);
+                    }
+                    else if (added > 0 || removed > 0) {
+                        this.log.info(`fabric: agent ${agentId} channel resync on ${g.nodeId}: +${added} -${removed} (now ${joined.size})`);
+                    }
+                }
+                catch {
+                    /* best effort — next tick will retry */
                 }
             };
-            socket.on('connect', () => void joinAll());
+            socket.on('connect', () => {
+                // On every (re)connect the server forgets prior subscriptions, so
+                // reset our local view and seed from a fresh fetch.
+                joined.clear();
+                void syncChannels('initial');
+            });
+            // Push-based membership events from the backend (companion to
+            // Fabric.Backend.Guild's RealtimeGateway.emitToUser). When the
+            // server tells us this user was added to / removed from a
+            // channel, we sub/unsub the socket.io room immediately — no
+            // 60s wait for the polling resync. Polling remains as a safety
+            // net for missed events.
+            socket.on('channel.joined', (evt) => {
+                const id = evt?.channelId;
+                if (!id || joined.has(id))
+                    return;
+                socket.emit('join_channel', { channelId: id });
+                joined.add(id);
+                this.log.info(`fabric: agent ${agentId} channel.joined push on ${g.nodeId}: ${id} (now ${joined.size})`);
+            });
+            socket.on('channel.left', (evt) => {
+                const id = evt?.channelId;
+                if (!id || !joined.has(id))
+                    return;
+                socket.emit('leave_channel', { channelId: id });
+                joined.delete(id);
+                this.log.info(`fabric: agent ${agentId} channel.left push on ${g.nodeId}: ${id} (now ${joined.size})`);
+            });
+            const syncTimer = setInterval(() => void syncChannels('resync'), FabricInbound.CHANNEL_SYNC_INTERVAL_MS);
+            this.channelSyncTimers.push(syncTimer);
             socket.on('message.created', (m) => {
                 const channelId = m.channelId ?? '';
                 if (!channelId)

openclaw.plugin.json

@@ -14,7 +14,12 @@
       "create-work-channel",
       "create-report-channel",
       "create-discussion-channel",
-      "discussion-complete"
+      "discussion-complete",
+      "fabric-canvas",
+      "fabric-channel",
+      "fabric-send-message",
+      "fabric-channel-list",
+      "fabric-message-history"
     ]
   },
   "configSchema": {

src/fabric-client.ts

@@ -190,6 +190,76 @@ export class FabricClient {
   removeCanvas(endpoint: string, token: string, channelId: string): Promise<unknown> {
     return this.req('DELETE', this.canvasUrl(endpoint, channelId), token);
   }
+
+  // ---- channel discovery + message read (used by the agent-facing
+  // fabric-channel-list / fabric-message-history tools) ----
+
+  /**
+   * List channels in a guild visible to the calling user. Backend
+   * filters to public + channels the user is a member of.
+   */
+  listChannels(
+    guildEndpoint: string,
+    guildToken: string,
+    guildNodeId: string,
+  ): Promise<Array<{
+    id: string;
+    guildId: string;
+    name: string;
+    xType: string;
+    kind: string;
+    isPublic: boolean;
+    closed: boolean;
+    lastSeq: number;
+    createdAt: string;
+  }>> {
+    return this.req(
+      'GET',
+      `${guildEndpoint}/api/channels?guildId=${encodeURIComponent(guildNodeId)}`,
+      guildToken,
+    );
+  }
+
+  /**
+   * Page through a channel's message history by `seq`.
+   *
+   * Backend defaults: 50 / call, max 200. The `seq` field starts at 1
+   * per channel; pass `seqFrom=channel.lastSeq - N + 1` to get the
+   * tail. Page metadata in the response describes what to ask next.
+   */
+  listMessages(
+    guildEndpoint: string,
+    guildToken: string,
+    channelId: string,
+    opts: { seqFrom?: number; seqTo?: number; limit?: number } = {},
+  ): Promise<{
+    items: Array<{
+      messageId: string;
+      seq: number;
+      content: string;
+      authorUserId: string;
+      createdAt: string;
+      editedAt: string | null;
+      deletedAt: string | null;
+      isDeleted: boolean;
+    }>;
+    page: {
+      seqFrom: number;
+      seqTo: number;
+      limit: number;
+      returned: number;
+      hasMore: boolean;
+      nextExpectedSeq: number;
+      highestCommittedSeq: number;
+    };
+  }> {
+    const qs = new URLSearchParams();
+    if (opts.seqFrom !== undefined) qs.set('seq_from', String(opts.seqFrom));
+    if (opts.seqTo !== undefined) qs.set('seq_to', String(opts.seqTo));
+    if (opts.limit !== undefined) qs.set('limit', String(opts.limit));
+    const url = `${guildEndpoint}/api/channels/${channelId}/messages` + (qs.toString() ? `?${qs}` : '');
+    return this.req('GET', url, guildToken);
+  }
 }
 
 export type CanvasFormat = 'md' | 'html' | 'text';

src/inbound.ts

@@ -52,6 +52,14 @@ type FabricMessage = {
 export class FabricInbound {
   private sockets: Socket[] = [];
   private seen = new Set<string>();
+  // Timers that periodically re-sync channel membership per (agent, guild).
+  // Without this, the agent's socket.io subscriptions are a snapshot taken
+  // at connect time — any channel the agent joins later (e.g. a fresh DM
+  // created by another user) is unreachable until the gateway restarts.
+  private channelSyncTimers: NodeJS.Timeout[] = [];
+  // Resync cadence. Backend doesn't push a `channel.joined` event, so we
+  // poll. 60s keeps the lag bounded without hammering the backend.
+  private static readonly CHANNEL_SYNC_INTERVAL_MS = 60_000;
   // Guild access tokens are short-lived (~15 min). The socket survives via
   // socket.io reconnect, but the token captured at connect time goes stale,
   // so HTTP calls (attachment download, posting the reply) start 401ing.
@@ -59,6 +67,136 @@ export class FabricInbound {
   private tokenCache = new Map<string, { session: FabricSession; at: number }>();
   private static readonly TOKEN_TTL_MS = 8 * 60 * 1000;
 
+  // Per-channel serial work queue. Every inbound socket message for a
+  // channel awaits the previous task for that same channel, so model
+  // turns never interleave. Map key = channelId; value is the tail of
+  // the chain (an in-flight promise the next task awaits).
+  //
+  // Why per-channel and not per-agent: a single agent may sit in
+  // several triage / general channels; we want each channel to flow at
+  // its own speed but the SAME channel's traffic to be strictly serial.
+  // For dm and discuss the queue also serialises but those traditionally
+  // had at-most-one-in-flight anyway via the turn engine.
+  private channelChains = new Map<string, Promise<void>>();
+
+  // Agent.status snapshot cache (5s TTL) — keeps the HF /calendar/
+  // agent/status round-trip off the hot path for back-to-back triage
+  // messages. Short TTL because status flips are rare-but-meaningful.
+  private agentStatusCache = new Map<string, { onCall: boolean; at: number }>();
+  private static readonly AGENT_STATUS_TTL_MS = 5_000;
+
+  // Triage messages that arrived while the on-duty agent wasn't on_call
+  // — sit here until either (a) the agent becomes on_call and the next
+  // triage arrival drains them, or (b) the gateway restarts (lost; ok
+  // because the underlying Fabric messages are persisted and re-fetched
+  // on agent reconnect's history sweep).
+  private pendingTriageGated: Array<{
+    agentId: string;
+    g: { nodeId: string; endpoint: string };
+    channelId: string;
+    m: FabricMessage;
+    session: FabricSession;
+  }> = [];
+
+  // Schedule `task` to run after every previous task on the same
+  // channel has completed. Returns the promise so callers can await
+  // their own result if they need to; the chain itself is fire-and-
+  // forget from the socket.on handler.
+  private enqueueChannelTask(channelId: string, task: () => Promise<void>): Promise<void> {
+    const prev = this.channelChains.get(channelId) ?? Promise.resolve();
+    const next = prev.then(task).catch((err) => {
+      this.log.warn(`fabric: per-channel task failed channel=${channelId}: ${String(err)}`);
+    });
+    this.channelChains.set(channelId, next);
+    // Best-effort cleanup so the Map doesn't grow without bound for
+    // long-running gateways: drop the entry when the chain settles, but
+    // only if it's still the latest reference (newer enqueue may have
+    // overwritten it in the meantime).
+    void next.finally(() => {
+      if (this.channelChains.get(channelId) === next) {
+        this.channelChains.delete(channelId);
+      }
+    });
+    return next;
+  }
+
+  // Hit HF backend to check whether `agentId` is currently on_call.
+  // Cached for 5s. Failures (network, 404, etc.) are treated as "not
+  // on_call" — triage stays gated rather than risking a confused wake.
+  private async checkAgentOnCall(agentId: string): Promise<boolean> {
+    const cached = this.agentStatusCache.get(agentId);
+    if (cached && Date.now() - cached.at < FabricInbound.AGENT_STATUS_TTL_MS) {
+      return cached.onCall;
+    }
+    const base = (process.env.HF_API_BASE_URL ?? '').trim() || 'https://monitor.hangman-lab.top';
+    // CLAW_IDENTIFIER resolution priority:
+    //   1. HF_CLAW_IDENTIFIER env (operator override)
+    //   2. openclaw config `plugins.harbor-forge.identifier` (what the HF
+    //      plugin itself uses — keeps the two in sync without an extra
+    //      env per service unit)
+    //   3. os.hostname() last-resort fallback (often wrong: e.g. sim
+    //      container hostname is `server.t2` but HF agent row has
+    //      `claw_identifier=sim-t2`; matching is mandatory for the HF
+    //      backend's _require_agent() check)
+    let claw = (process.env.HF_CLAW_IDENTIFIER ?? '').trim();
+    if (!claw) {
+      try {
+        // openclaw config shape (verified in sim):
+        //   { plugins: { entries: { 'harbor-forge': { config: { identifier } } } } }
+        const cfg = this.cfg as {
+          plugins?: { entries?: Record<string, { config?: { identifier?: string } }> };
+        };
+        const fromCfg = cfg?.plugins?.entries?.['harbor-forge']?.config?.identifier;
+        if (fromCfg && typeof fromCfg === 'string' && fromCfg.trim()) {
+          claw = fromCfg.trim();
+        }
+      } catch {
+        /* fall through to hostname */
+      }
+    }
+    if (!claw) {
+      claw = (await import('os')).hostname();
+    }
+    let onCall = false;
+    try {
+      const url = `${base.replace(/\/$/, '')}/calendar/agent/status?agent_id=${encodeURIComponent(agentId)}`;
+      const res = await fetch(url, {
+        headers: { 'X-Agent-ID': agentId, 'X-Claw-Identifier': claw },
+      });
+      if (res.ok) {
+        const data = (await res.json()) as { status?: string };
+        onCall = (data.status ?? '').toLowerCase() === 'on_call';
+      }
+    } catch (err) {
+      this.log.warn(`fabric: HF status check failed agent=${agentId}: ${String(err)}`);
+    }
+    this.agentStatusCache.set(agentId, { onCall, at: Date.now() });
+    return onCall;
+  }
+
+  // FIFO drain of all triage-gated messages for `agentId` (called when
+  // we just learned they're on_call). Each drained message is dispatched
+  // through its own channel chain so per-channel serial order is kept.
+  private async drainGatedFor(agentId: string): Promise<void> {
+    const keep: typeof this.pendingTriageGated = [];
+    const drain: typeof this.pendingTriageGated = [];
+    for (const item of this.pendingTriageGated) {
+      if (item.agentId === agentId) drain.push(item);
+      else keep.push(item);
+    }
+    if (drain.length === 0) return;
+    this.pendingTriageGated = keep;
+    for (const item of drain) {
+      this.log.info(
+        `fabric: triage drain agent=${item.agentId} channel=${item.channelId} msg=${item.m.messageId}`,
+      );
+      // Re-enqueue via the per-channel chain so ordering is preserved.
+      this.enqueueChannelTask(item.channelId, async () => {
+        await this.dispatch(item.agentId, item.g, item.channelId, item.m, item.session);
+      });
+    }
+  }
+
   // Return a fresh guild access token for the agent, re-authenticating with
   // the agent's Fabric API key when the cached session is stale. Falls back
   // to the connect-time session token if re-login fails.
@@ -119,6 +257,8 @@ export class FabricInbound {
   }
 
   stop(): void {
+    for (const t of this.channelSyncTimers) clearInterval(t);
+    this.channelSyncTimers = [];
     for (const s of this.sockets) s.disconnect();
     this.sockets = [];
   }
@@ -133,20 +273,87 @@ export class FabricInbound {
         auth: { token: tok },
         autoConnect: false,
       });
-      const joinAll = async () => {
+      // Tracked socket.io rooms for this (agent, guild). The initial fetch
+      // on `connect` seeds it; the periodic resync diffs against it so we
+      // only emit `join_channel` for genuinely new channels (and
+      // `leave_channel` for ones the agent is no longer in).
+      const joined = new Set<string>();
+      const syncChannels = async (kind: 'initial' | 'resync') => {
+        let freshTok: string | undefined;
+        try {
+          freshTok = await this.freshGuildToken(agentId, g.nodeId, session);
+        } catch {
+          freshTok = tok;
+        }
+        const authTok = freshTok ?? tok;
         try {
           const res = await fetch(
             `${g.endpoint}/api/channels?guildId=${encodeURIComponent(g.nodeId)}`,
-            { headers: { authorization: `Bearer ${tok}` } },
+            { headers: { authorization: `Bearer ${authTok}` } },
           );
-          const channels = res.ok ? ((await res.json()) as Array<{ id: string }>) : [];
-          for (const c of channels) socket.emit('join_channel', { channelId: c.id });
-          this.log.info(`fabric: agent ${agentId} joined ${channels.length} channel(s) on ${g.nodeId}`);
+          if (!res.ok) return;
+          const channels = (await res.json()) as Array<{ id: string }>;
+          const current = new Set(channels.map((c) => c.id));
+          let added = 0;
+          let removed = 0;
+          for (const id of current) {
+            if (!joined.has(id)) {
+              socket.emit('join_channel', { channelId: id });
+              joined.add(id);
+              added++;
+            }
+          }
+          for (const id of [...joined]) {
+            if (!current.has(id)) {
+              socket.emit('leave_channel', { channelId: id });
+              joined.delete(id);
+              removed++;
+            }
+          }
+          if (kind === 'initial') {
+            this.log.info(
+              `fabric: agent ${agentId} joined ${current.size} channel(s) on ${g.nodeId}`,
+            );
+          } else if (added > 0 || removed > 0) {
+            this.log.info(
+              `fabric: agent ${agentId} channel resync on ${g.nodeId}: +${added} -${removed} (now ${joined.size})`,
+            );
+          }
         } catch {
-          /* best effort */
+          /* best effort — next tick will retry */
         }
       };
-      socket.on('connect', () => void joinAll());
+      socket.on('connect', () => {
+        // On every (re)connect the server forgets prior subscriptions, so
+        // reset our local view and seed from a fresh fetch.
+        joined.clear();
+        void syncChannels('initial');
+      });
+      // Push-based membership events from the backend (companion to
+      // Fabric.Backend.Guild's RealtimeGateway.emitToUser). When the
+      // server tells us this user was added to / removed from a
+      // channel, we sub/unsub the socket.io room immediately — no
+      // 60s wait for the polling resync. Polling remains as a safety
+      // net for missed events.
+      socket.on('channel.joined', (evt: { channelId?: string }) => {
+        const id = evt?.channelId;
+        if (!id || joined.has(id)) return;
+        socket.emit('join_channel', { channelId: id });
+        joined.add(id);
+        this.log.info(`fabric: agent ${agentId} channel.joined push on ${g.nodeId}: ${id} (now ${joined.size})`);
+      });
+      socket.on('channel.left', (evt: { channelId?: string }) => {
+        const id = evt?.channelId;
+        if (!id || !joined.has(id)) return;
+        socket.emit('leave_channel', { channelId: id });
+        joined.delete(id);
+        this.log.info(`fabric: agent ${agentId} channel.left push on ${g.nodeId}: ${id} (now ${joined.size})`);
+      });
+      const syncTimer = setInterval(
+        () => void syncChannels('resync'),
+        FabricInbound.CHANNEL_SYNC_INTERVAL_MS,
+      );
+      this.channelSyncTimers.push(syncTimer);
       socket.on('message.created', (m: FabricMessage) => {
         const channelId = m.channelId ?? '';
         if (!channelId) return;
@@ -155,7 +362,33 @@ export class FabricInbound {
         if (this.seen.has(key)) return;
         this.seen.add(key);
         if (this.seen.size > 5000) this.seen.clear();
-        void this.dispatch(agentId, g, channelId, m, session);
+        // Per-channel serial queue. Prevents concurrent model turns for
+        // the same channel — important for triage where a second wake
+        // arriving mid-reply would interleave with the in-flight one.
+        this.enqueueChannelTask(channelId, async () => {
+          // Triage on_call gate: if the on-duty agent isn't currently
+          // on_call per HF, don't dispatch yet — just sit on the
+          // per-channel queue. Subsequent triage messages will recheck;
+          // when the agent becomes on_call, the next arrival drains.
+          //
+          // Also handles: triage + wake=true must verify status before
+          // committing to a model turn. Non-triage and triage observer
+          // (wake=false) skip the gate.
+          if (m.xType === 'triage' && m.wakeup === true) {
+            const onCall = await this.checkAgentOnCall(agentId);
+            if (!onCall) {
+              this.log.info(
+                `fabric: triage wake gated (agent=${agentId} not on_call) — re-queue msg=${m.messageId}`,
+              );
+              this.pendingTriageGated.push({ agentId, g, channelId, m, session });
+              return;
+            }
+            // Drain any previously-gated messages (FIFO) before this one,
+            // now that we know the agent is on_call.
+            await this.drainGatedFor(agentId);
+          }
+          await this.dispatch(agentId, g, channelId, m, session);
+        });
       });
       socket.connect();
       this.sockets.push(socket);
@@ -260,6 +493,19 @@ export class FabricInbound {
       // any message that isn't the agent's own (already filtered above) is
       // always delivered to the model.
       if (m.xType !== 'dm' && m.wakeup !== true) {
+        // Triage exception: non-wake messages (admin observer) MUST NOT
+        // enter the agent's session at all. The next time the agent
+        // wakes for a triage message, their context should contain only
+        // their own past wakeups + their own outgoing messages — never
+        // the observer-only chatter from other agents. For non-triage
+        // channels keep the legacy "record-as-history" so a later wake
+        // sees the full channel conversation.
+        if (m.xType === 'triage') {
+          this.log.info(
+            `fabric: triage observer skip agent=${agentId} channel=${channelId} msg=${m.messageId}`,
+          );
+          return;
+        }
         const ctxPayload = core.channel.reply.finalizeInboundContext(baseCtx);
         await core.channel.session.recordInboundSession({
           storePath,

src/tools.ts

@@ -243,4 +243,173 @@ export function registerFabricTools(
       }
     },
   }));
+
+  // -----------------------------------------------------------------
+  // fabric-send-message: post a message into a specific channel.
+  //
+  // Unlike a normal channel reply (which goes back to whatever channel
+  // woke the agent), this lets the agent proactively initiate text into
+  // any channel they are a member of — e.g. ARD broadcasting daily
+  // workload to #agents-room, or triage agent following up on an
+  // already-routed task by commenting in #updates.
+  // -----------------------------------------------------------------
+  api.registerTool((ctx: Ctx) => ({
+    name: 'fabric-send-message',
+    description:
+      'Send a text message into a specific Fabric channel. Author is the calling agent. ' +
+      'Requires guildNodeId + channelId + content. Returns {ok, messageId, seq}.',
+    parameters: {
+      type: 'object',
+      additionalProperties: false,
+      required: ['guildNodeId', 'channelId', 'content'],
+      properties: {
+        guildNodeId: { type: 'string' },
+        channelId: { type: 'string' },
+        content: { type: 'string', description: 'Message body (markdown supported by the renderer).' },
+      },
+    },
+    execute: async (p: { guildNodeId: string; channelId: string; content: string }) => {
+      const agentId = ctx.agentId;
+      if (!agentId) return { ok: false, error: 'no agent context' };
+      const { session, guild, token } = await ctxGuild(agentId, p.guildNodeId);
+      const res = (await client.postMessage(
+        guild.endpoint,
+        token,
+        p.channelId,
+        p.content,
+        session.user.id,
+      )) as { messageId?: string; seq?: number };
+      return { ok: true, messageId: res.messageId, seq: res.seq };
+    },
+  }));
+
+  // -----------------------------------------------------------------
+  // fabric-channel-list: enumerate channels the calling agent can see
+  // in a given guild. Backend filters to public channels + channels the
+  // agent is a member of. Returns id / name / xType per channel so the
+  // agent can pick a channelId for fabric-send-message etc.
+  // -----------------------------------------------------------------
+  api.registerTool((ctx: Ctx) => ({
+    name: 'fabric-channel-list',
+    description:
+      'List channels visible to the calling agent in a guild. Optional ' +
+      'nameFilter does a case-insensitive substring match client-side. ' +
+      'Use this to find a channelId before fabric-send-message / fabric-message-history.',
+    parameters: {
+      type: 'object',
+      additionalProperties: false,
+      required: ['guildNodeId'],
+      properties: {
+        guildNodeId: { type: 'string' },
+        nameFilter: { type: 'string', description: 'optional substring match on channel name (case-insensitive)' },
+        xType: {
+          type: 'string',
+          enum: ['general', 'work', 'report', 'discuss', 'triage', 'custom', 'dm'],
+          description: 'optional filter by x_type',
+        },
+        includeClosed: { type: 'boolean', description: 'default false — closed channels filtered out' },
+      },
+    },
+    execute: async (p: {
+      guildNodeId: string;
+      nameFilter?: string;
+      xType?: string;
+      includeClosed?: boolean;
+    }) => {
+      const agentId = ctx.agentId;
+      if (!agentId) return { ok: false, error: 'no agent context' };
+      const { guild, token } = await ctxGuild(agentId, p.guildNodeId);
+      const all = await client.listChannels(guild.endpoint, token, p.guildNodeId);
+      const needle = (p.nameFilter ?? '').toLowerCase();
+      const filtered = all.filter((c) => {
+        if (!p.includeClosed && c.closed) return false;
+        if (p.xType && c.xType !== p.xType) return false;
+        if (needle && !c.name.toLowerCase().includes(needle)) return false;
+        return true;
+      });
+      return {
+        ok: true,
+        count: filtered.length,
+        channels: filtered.map((c) => ({
+          id: c.id,
+          name: c.name,
+          xType: c.xType,
+          isPublic: c.isPublic,
+          closed: c.closed,
+          lastSeq: c.lastSeq,
+        })),
+      };
+    },
+  }));
+
+  // -----------------------------------------------------------------
+  // fabric-message-history: read a channel's recent message history by
+  // `seq`. Tail-by-default: when `seqFrom`/`seqTo` are omitted, returns
+  // the last `limit` messages (limit defaults to 20, max 200).
+  //
+  // Use cases: catch-up on a channel that was muted while the agent was
+  // gated; verify a previous message went through; lookup recent
+  // duplicates before opening a new task in triage.
+  // -----------------------------------------------------------------
+  api.registerTool((ctx: Ctx) => ({
+    name: 'fabric-message-history',
+    description:
+      "Read a channel's recent message history. Omit seqFrom/seqTo to " +
+      'tail (last `limit` messages, default 20, max 200). Backend ' +
+      'requires the calling agent to be a channel participant.',
+    parameters: {
+      type: 'object',
+      additionalProperties: false,
+      required: ['guildNodeId', 'channelId'],
+      properties: {
+        guildNodeId: { type: 'string' },
+        channelId: { type: 'string' },
+        seqFrom: { type: 'integer', minimum: 1, description: 'inclusive lower bound; default = tail' },
+        seqTo: { type: 'integer', minimum: 1, description: 'inclusive upper bound; default = channel head' },
+        limit: { type: 'integer', minimum: 1, maximum: 200, description: 'default 20' },
+      },
+    },
+    execute: async (p: {
+      guildNodeId: string;
+      channelId: string;
+      seqFrom?: number;
+      seqTo?: number;
+      limit?: number;
+    }) => {
+      const agentId = ctx.agentId;
+      if (!agentId) return { ok: false, error: 'no agent context' };
+      const { guild, token } = await ctxGuild(agentId, p.guildNodeId);
+      const limit = p.limit ?? 20;
+
+      // Tail mode: discover channel head via channel listing, then ask
+      // for [head-limit+1, head]. Avoids needing the agent to know seq.
+      let seqFrom = p.seqFrom;
+      let seqTo = p.seqTo;
+      if (seqFrom === undefined && seqTo === undefined) {
+        const channels = await client.listChannels(guild.endpoint, token, p.guildNodeId);
+        const ch = channels.find((c) => c.id === p.channelId);
+        const head = ch?.lastSeq ?? 0;
+        seqFrom = Math.max(1, head - limit + 1);
+        seqTo = head;
+      }
+
+      const res = await client.listMessages(guild.endpoint, token, p.channelId, {
+        seqFrom,
+        seqTo,
+        limit,
+      });
+      return {
+        ok: true,
+        page: res.page,
+        messages: res.items.map((m) => ({
+          messageId: m.messageId,
+          seq: m.seq,
+          authorUserId: m.authorUserId,
+          content: m.content,
+          createdAt: m.createdAt,
+          isDeleted: m.isDeleted,
+        })),
+      };
+    },
+  }));
 }