feat(discord): two-way Discord bridge with a thread per tab

Alerts for permission prompts, questions, idle and errors post into a per-tab thread; a reply from an allowlisted user is typed into that tab. Thread creation, thread cleanup on tab delete and pinging are configurable. POST /api/sessions/:id/discord-notify lets a CLI ask for the user. Setup is in docs/discord-bridge.md.

src/web/routes/discord-routes.ts

@@ -0,0 +1,132 @@
+/**
+ * @fileoverview Discord bridge settings and the deliberate-post route (src/discord-bridge.ts).
+ *
+ * GET  /api/discord                    the config WITHOUT its token, plus gateway state and last result
+ * PUT  /api/discord                    change any field; an empty `token` clears it
+ * POST /api/discord/test               post one test message to the parent channel
+ * POST /api/sessions/:id/discord-notify  a CLI asks for the user (physical step, blocker, timed-out watch)
+ *
+ * The bot token is a bearer secret, so it is stored in its own 0600 file and never returned. In
+ * multi-user mode the three settings routes are admin only: the server receives every session's
+ * events. `discord-notify` follows the session's own ownership rules instead.
+ */
+
+import type { FastifyInstance, FastifyReply, FastifyRequest } from 'fastify';
+import { ApiErrorCode, createErrorResponse, getErrorMessage, type ApiResponse } from '../../types.js';
+import { findSessionOrFail, isAdmin, parseBody } from '../route-helpers.js';
+import type { SessionPort } from '../ports/session-port.js';
+import { isMultiUserMode } from '../../config/multiuser.js';
+import { DiscordNotifySchema, DiscordUpdateSchema } from '../schemas.js';
+import {
+  discordConfigProblem,
+  maskToken,
+  readDiscordConfig,
+  writeDiscordConfig,
+  type DiscordBridge,
+  type DiscordConfig,
+  type DiscordGatewayState,
+  type DiscordResult,
+} from '../../discord-bridge.js';
+
+export interface DiscordRouteDeps {
+  bridge: DiscordBridge;
+  configDir: string;
+  ctx: SessionPort;
+  hostTitle: () => string;
+}
+
+export type DiscordStatus = Omit<DiscordConfig, 'token'> & {
+  hasToken: boolean;
+  tokenMasked: string;
+  gateway: DiscordGatewayState;
+  gatewayError: string | null;
+  lastResult: DiscordResult | null;
+};
+
+export function registerDiscordRoutes(app: FastifyInstance, deps: DiscordRouteDeps): void {
+  const denied = (req: FastifyRequest, reply: FastifyReply): ApiResponse<never> | null => {
+    if (isMultiUserMode() && !isAdmin(req)) {
+      reply.code(403);
+      return createErrorResponse(ApiErrorCode.FORBIDDEN, 'Admin only in multi-user mode');
+    }
+    return null;
+  };
+
+  const status = async (): Promise<DiscordStatus> => {
+    const { token, ...rest } = await readDiscordConfig(deps.configDir);
+    return {
+      ...rest,
+      hasToken: token !== '',
+      tokenMasked: maskToken(token),
+      gateway: deps.bridge.gatewayState,
+      gatewayError: deps.bridge.gatewayError,
+      lastResult: deps.bridge.lastResult,
+    };
+  };
+
+  app.get('/api/discord', async (req, reply): Promise<ApiResponse<DiscordStatus>> => {
+    const no = denied(req, reply);
+    if (no) return no;
+    return { success: true, data: await status() };
+  });
+
+  app.put('/api/discord', async (req, reply): Promise<ApiResponse<DiscordStatus>> => {
+    const no = denied(req, reply);
+    if (no) return no;
+    const patch = parseBody(DiscordUpdateSchema, req.body, 'Invalid Discord settings');
+    const current = await readDiscordConfig(deps.configDir);
+    const next: DiscordConfig = {
+      ...current,
+      ...patch,
+      token: patch.token !== undefined ? patch.token.trim() : current.token,
+    };
+    const problem = discordConfigProblem(next);
+    if (problem) {
+      reply.code(400);
+      return createErrorResponse(ApiErrorCode.INVALID_INPUT, problem);
+    }
+    try {
+      await writeDiscordConfig(deps.configDir, next);
+      await deps.bridge.reload();
+    } catch (err) {
+      reply.code(500);
+      return createErrorResponse(ApiErrorCode.OPERATION_FAILED, getErrorMessage(err));
+    }
+    return { success: true, data: await status() };
+  });
+
+  app.post('/api/discord/test', async (req, reply): Promise<ApiResponse<DiscordResult>> => {
+    const no = denied(req, reply);
+    if (no) return no;
+    const cfg = await readDiscordConfig(deps.configDir);
+    if (!cfg.token || !cfg.parentChannelId) {
+      reply.code(400);
+      return createErrorResponse(ApiErrorCode.INVALID_INPUT, 'Save the bot token and parent channel ID first');
+    }
+    // 200 even when delivery failed: the request to Codeman worked, `data.ok` says whether Discord did.
+    return { success: true, data: await deps.bridge.sendTest(cfg, deps.hostTitle()) };
+  });
+
+  app.post('/api/sessions/:id/discord-notify', async (req, reply): Promise<ApiResponse<DiscordResult | null>> => {
+    const { id } = req.params as { id: string };
+    const { message, urgent } = parseBody(DiscordNotifySchema, req.body, 'Invalid Discord message');
+    const session = findSessionOrFail(deps.ctx, id, req);
+    const result = await deps.bridge.notify(
+      {
+        event: 'session:discord-notify',
+        title: urgent ? 'Needs you now' : 'Message from the CLI',
+        body: message,
+        urgency: urgent ? 'critical' : 'warning',
+        sessionId: session.id,
+        sessionName: session.name,
+        host: deps.hostTitle(),
+      },
+      urgent === true
+    );
+    if (result === null) {
+      reply.code(409);
+      return createErrorResponse(ApiErrorCode.CONFLICT, 'The Discord bridge is not enabled');
+    }
+    return { success: true, data: result };
+  });
+}

src/web/routes/index.ts

@@ -35,6 +35,7 @@ export { registerTabLayoutRoutes } from './tab-layout-routes.js';
 export { registerMcpSyncRoutes } from './mcp-sync-routes.js';
 export { registerConfigBackupRoutes, runConfigBackup } from './config-backup-routes.js';
 export { registerWebhookRoutes } from './webhook-routes.js';
+export { registerDiscordRoutes } from './discord-routes.js';
 export { registerDoctorRoutes } from './doctor-routes.js';
 export {
   registerCustomModelRoutes,