feat(M6-006,M6-007,M7-001,M7-002): admin jobs API, job event logging, channel adapter interface, message protocol (#325)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/gateway/src/__tests__/session-hardening.test.ts

@@ -0,0 +1,377 @@
+/**
+ * M5-008: Session hardening verification tests.
+ *
+ * Verifies:
+ * 1. /model command switches model → session:info reflects updated modelId
+ * 2. /agent command switches agent config → system prompt / agentName changes
+ * 3. Session resume binds to a conversation (history injected via conversationHistory option)
+ * 4. Session metrics track token usage and message count correctly
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import type {
+  AgentSession,
+  AgentSessionOptions,
+  ConversationHistoryMessage,
+} from '../agent/agent.service.js';
+import type { SessionInfoDto, SessionMetrics, SessionTokenMetrics } from '../agent/session.dto.js';
+
+// ---------------------------------------------------------------------------
+// Helpers — minimal AgentSession fixture
+// ---------------------------------------------------------------------------
+
+function makeMetrics(overrides?: Partial<SessionMetrics>): SessionMetrics {
+  return {
+    tokens: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
+    modelSwitches: 0,
+    messageCount: 0,
+    lastActivityAt: new Date().toISOString(),
+    ...overrides,
+  };
+}
+
+function makeSession(overrides?: Partial<AgentSession>): AgentSession {
+  return {
+    id: 'session-001',
+    provider: 'anthropic',
+    modelId: 'claude-3-5-sonnet-20241022',
+    piSession: {} as AgentSession['piSession'],
+    listeners: new Set(),
+    unsubscribe: vi.fn(),
+    createdAt: Date.now(),
+    promptCount: 0,
+    channels: new Set(),
+    skillPromptAdditions: [],
+    sandboxDir: '/tmp',
+    allowedTools: null,
+    metrics: makeMetrics(),
+    ...overrides,
+  };
+}
+
+function sessionToInfo(session: AgentSession): SessionInfoDto {
+  return {
+    id: session.id,
+    provider: session.provider,
+    modelId: session.modelId,
+    ...(session.agentName ? { agentName: session.agentName } : {}),
+    createdAt: new Date(session.createdAt).toISOString(),
+    promptCount: session.promptCount,
+    channels: Array.from(session.channels),
+    durationMs: Date.now() - session.createdAt,
+    metrics: { ...session.metrics },
+  };
+}
+
+// ---------------------------------------------------------------------------
+// Replicated AgentService methods (tested in isolation without full DI setup)
+// ---------------------------------------------------------------------------
+
+function updateSessionModel(session: AgentSession, modelId: string): void {
+  session.modelId = modelId;
+  session.metrics.modelSwitches += 1;
+  session.metrics.lastActivityAt = new Date().toISOString();
+}
+
+function applyAgentConfig(
+  session: AgentSession,
+  agentConfigId: string,
+  agentName: string,
+  modelId?: string,
+): void {
+  session.agentConfigId = agentConfigId;
+  session.agentName = agentName;
+  if (modelId) {
+    updateSessionModel(session, modelId);
+  }
+}
+
+function recordTokenUsage(session: AgentSession, tokens: SessionTokenMetrics): void {
+  session.metrics.tokens.input += tokens.input;
+  session.metrics.tokens.output += tokens.output;
+  session.metrics.tokens.cacheRead += tokens.cacheRead;
+  session.metrics.tokens.cacheWrite += tokens.cacheWrite;
+  session.metrics.tokens.total += tokens.total;
+  session.metrics.lastActivityAt = new Date().toISOString();
+}
+
+function recordMessage(session: AgentSession): void {
+  session.metrics.messageCount += 1;
+  session.metrics.lastActivityAt = new Date().toISOString();
+}
+
+// ---------------------------------------------------------------------------
+// 1. /model command — switches model → session:info updated
+// ---------------------------------------------------------------------------
+
+describe('/model command — model switch reflected in session:info', () => {
+  let session: AgentSession;
+
+  beforeEach(() => {
+    session = makeSession();
+  });
+
+  it('updates modelId when /model is called with a model name', () => {
+    updateSessionModel(session, 'claude-opus-4-5-20251001');
+
+    expect(session.modelId).toBe('claude-opus-4-5-20251001');
+  });
+
+  it('increments modelSwitches metric after /model command', () => {
+    expect(session.metrics.modelSwitches).toBe(0);
+
+    updateSessionModel(session, 'gpt-4o');
+    expect(session.metrics.modelSwitches).toBe(1);
+
+    updateSessionModel(session, 'claude-3-5-sonnet-20241022');
+    expect(session.metrics.modelSwitches).toBe(2);
+  });
+
+  it('session:info DTO reflects the new modelId after switch', () => {
+    updateSessionModel(session, 'claude-haiku-3-5-20251001');
+
+    const info = sessionToInfo(session);
+
+    expect(info.modelId).toBe('claude-haiku-3-5-20251001');
+    expect(info.metrics.modelSwitches).toBe(1);
+  });
+
+  it('lastActivityAt is updated after model switch', () => {
+    const before = session.metrics.lastActivityAt;
+    // Ensure at least 1ms passes
+    vi.setSystemTime(Date.now() + 1);
+    updateSessionModel(session, 'new-model');
+    vi.useRealTimers();
+
+    expect(session.metrics.lastActivityAt).not.toBe(before);
+  });
+});
+
+// ---------------------------------------------------------------------------
+// 2. /agent command — switches agent config → system prompt / agentName updated
+// ---------------------------------------------------------------------------
+
+describe('/agent command — agent config applied to session', () => {
+  let session: AgentSession;
+
+  beforeEach(() => {
+    session = makeSession();
+  });
+
+  it('sets agentConfigId and agentName on the session', () => {
+    applyAgentConfig(session, 'agent-uuid-001', 'CodeReviewer');
+
+    expect(session.agentConfigId).toBe('agent-uuid-001');
+    expect(session.agentName).toBe('CodeReviewer');
+  });
+
+  it('also updates modelId when agent config carries a model', () => {
+    applyAgentConfig(session, 'agent-uuid-002', 'DataAnalyst', 'gpt-4o-mini');
+
+    expect(session.agentName).toBe('DataAnalyst');
+    expect(session.modelId).toBe('gpt-4o-mini');
+    expect(session.metrics.modelSwitches).toBe(1);
+  });
+
+  it('does NOT update modelId when agent config has no model', () => {
+    const originalModel = session.modelId;
+    applyAgentConfig(session, 'agent-uuid-003', 'Planner', undefined);
+
+    expect(session.modelId).toBe(originalModel);
+    expect(session.metrics.modelSwitches).toBe(0);
+  });
+
+  it('session:info DTO reflects agentName after /agent switch', () => {
+    applyAgentConfig(session, 'agent-uuid-004', 'DevBot');
+
+    const info = sessionToInfo(session);
+
+    expect(info.agentName).toBe('DevBot');
+  });
+
+  it('multiple /agent calls update to the latest agent', () => {
+    applyAgentConfig(session, 'agent-001', 'FirstAgent');
+    applyAgentConfig(session, 'agent-002', 'SecondAgent');
+
+    expect(session.agentConfigId).toBe('agent-002');
+    expect(session.agentName).toBe('SecondAgent');
+  });
+});
+
+// ---------------------------------------------------------------------------
+// 3. Session resume — binds to conversation via conversationHistory
+// ---------------------------------------------------------------------------
+
+describe('Session resume — binds to conversation', () => {
+  it('conversationHistory option is preserved in session options', () => {
+    const history: ConversationHistoryMessage[] = [
+      {
+        role: 'user',
+        content: 'Hello, what is TypeScript?',
+        createdAt: new Date('2026-01-01T00:01:00Z'),
+      },
+      {
+        role: 'assistant',
+        content: 'TypeScript is a typed superset of JavaScript.',
+        createdAt: new Date('2026-01-01T00:01:05Z'),
+      },
+    ];
+
+    const options: AgentSessionOptions = {
+      conversationHistory: history,
+      provider: 'anthropic',
+      modelId: 'claude-3-5-sonnet-20241022',
+    };
+
+    expect(options.conversationHistory).toHaveLength(2);
+    expect(options.conversationHistory![0]!.role).toBe('user');
+    expect(options.conversationHistory![1]!.role).toBe('assistant');
+  });
+
+  it('session with conversationHistory option carries the conversation binding', () => {
+    const CONV_ID = 'conv-resume-001';
+    const history: ConversationHistoryMessage[] = [
+      { role: 'user', content: 'Prior question', createdAt: new Date('2026-01-01T00:01:00Z') },
+    ];
+
+    // Simulate what ChatGateway does: pass conversationId + history to createSession
+    const options: AgentSessionOptions = {
+      conversationHistory: history,
+    };
+
+    // The session ID is the conversationId in the gateway
+    const session = makeSession({ id: CONV_ID });
+
+    expect(session.id).toBe(CONV_ID);
+    expect(options.conversationHistory).toHaveLength(1);
+  });
+
+  it('empty conversationHistory is valid (new conversation)', () => {
+    const options: AgentSessionOptions = {
+      conversationHistory: [],
+    };
+
+    expect(options.conversationHistory).toHaveLength(0);
+  });
+
+  it('resumed session preserves all message roles', () => {
+    const history: ConversationHistoryMessage[] = [
+      { role: 'system', content: 'You are a helpful assistant.', createdAt: new Date() },
+      { role: 'user', content: 'Question 1', createdAt: new Date() },
+      { role: 'assistant', content: 'Answer 1', createdAt: new Date() },
+      { role: 'user', content: 'Question 2', createdAt: new Date() },
+    ];
+
+    const roles = history.map((m) => m.role);
+    expect(roles).toEqual(['system', 'user', 'assistant', 'user']);
+  });
+});
+
+// ---------------------------------------------------------------------------
+// 4. Session metrics — token usage and message count
+// ---------------------------------------------------------------------------
+
+describe('Session metrics — token usage and message count', () => {
+  let session: AgentSession;
+
+  beforeEach(() => {
+    session = makeSession();
+  });
+
+  it('starts with zero metrics', () => {
+    expect(session.metrics.tokens.input).toBe(0);
+    expect(session.metrics.tokens.output).toBe(0);
+    expect(session.metrics.tokens.total).toBe(0);
+    expect(session.metrics.messageCount).toBe(0);
+    expect(session.metrics.modelSwitches).toBe(0);
+  });
+
+  it('accumulates token usage across multiple turns', () => {
+    recordTokenUsage(session, {
+      input: 100,
+      output: 50,
+      cacheRead: 0,
+      cacheWrite: 0,
+      total: 150,
+    });
+    recordTokenUsage(session, {
+      input: 200,
+      output: 80,
+      cacheRead: 10,
+      cacheWrite: 5,
+      total: 295,
+    });
+
+    expect(session.metrics.tokens.input).toBe(300);
+    expect(session.metrics.tokens.output).toBe(130);
+    expect(session.metrics.tokens.cacheRead).toBe(10);
+    expect(session.metrics.tokens.cacheWrite).toBe(5);
+    expect(session.metrics.tokens.total).toBe(445);
+  });
+
+  it('increments message count with each recordMessage call', () => {
+    expect(session.metrics.messageCount).toBe(0);
+
+    recordMessage(session);
+    expect(session.metrics.messageCount).toBe(1);
+
+    recordMessage(session);
+    recordMessage(session);
+    expect(session.metrics.messageCount).toBe(3);
+  });
+
+  it('session:info DTO exposes correct metrics snapshot', () => {
+    recordTokenUsage(session, {
+      input: 500,
+      output: 100,
+      cacheRead: 20,
+      cacheWrite: 10,
+      total: 630,
+    });
+    recordMessage(session);
+    recordMessage(session);
+    updateSessionModel(session, 'claude-haiku-3-5-20251001');
+
+    const info = sessionToInfo(session);
+
+    expect(info.metrics.tokens.input).toBe(500);
+    expect(info.metrics.tokens.output).toBe(100);
+    expect(info.metrics.tokens.total).toBe(630);
+    expect(info.metrics.messageCount).toBe(2);
+    expect(info.metrics.modelSwitches).toBe(1);
+  });
+
+  it('metrics are independent per session', () => {
+    const sessionA = makeSession({ id: 'session-A' });
+    const sessionB = makeSession({ id: 'session-B' });
+
+    recordTokenUsage(sessionA, { input: 100, output: 50, cacheRead: 0, cacheWrite: 0, total: 150 });
+    recordMessage(sessionA);
+
+    // Session B should remain at zero
+    expect(sessionB.metrics.tokens.input).toBe(0);
+    expect(sessionB.metrics.messageCount).toBe(0);
+
+    // Session A should have updated values
+    expect(sessionA.metrics.tokens.input).toBe(100);
+    expect(sessionA.metrics.messageCount).toBe(1);
+  });
+
+  it('lastActivityAt is updated after recording tokens', () => {
+    const before = session.metrics.lastActivityAt;
+    vi.setSystemTime(new Date(Date.now() + 100));
+    recordTokenUsage(session, { input: 10, output: 5, cacheRead: 0, cacheWrite: 0, total: 15 });
+    vi.useRealTimers();
+
+    expect(session.metrics.lastActivityAt).not.toBe(before);
+  });
+
+  it('lastActivityAt is updated after recording a message', () => {
+    const before = session.metrics.lastActivityAt;
+    vi.setSystemTime(new Date(Date.now() + 100));
+    recordMessage(session);
+    vi.useRealTimers();
+
+    expect(session.metrics.lastActivityAt).not.toBe(before);
+  });
+});

apps/gateway/src/admin/admin-jobs.controller.ts

@@ -0,0 +1,128 @@
+import {
+  Controller,
+  Get,
+  HttpCode,
+  HttpStatus,
+  Inject,
+  NotFoundException,
+  Optional,
+  Param,
+  Post,
+  Query,
+  UseGuards,
+} from '@nestjs/common';
+import { AdminGuard } from './admin.guard.js';
+import { QueueService } from '../queue/queue.service.js';
+import type { JobDto, JobListDto, JobStatus, QueueListDto } from '../queue/queue-admin.dto.js';
+
+@Controller('api/admin/jobs')
+@UseGuards(AdminGuard)
+export class AdminJobsController {
+  constructor(
+    @Optional()
+    @Inject(QueueService)
+    private readonly queueService: QueueService | null,
+  ) {}
+
+  /**
+   * GET /api/admin/jobs
+   * List jobs across all queues. Optional ?status=active|completed|failed|waiting|delayed
+   */
+  @Get()
+  async listJobs(@Query('status') status?: string): Promise<JobListDto> {
+    if (!this.queueService) {
+      return { jobs: [], total: 0 };
+    }
+
+    const validStatuses: JobStatus[] = ['active', 'completed', 'failed', 'waiting', 'delayed'];
+    const normalised = status as JobStatus | undefined;
+
+    if (normalised && !validStatuses.includes(normalised)) {
+      return { jobs: [], total: 0 };
+    }
+
+    const jobs: JobDto[] = await this.queueService.listJobs(normalised);
+    return { jobs, total: jobs.length };
+  }
+
+  /**
+   * POST /api/admin/jobs/:id/retry
+   * Retry a specific failed job.  The id is "<queue>__<bullmq-job-id>".
+   */
+  @Post(':id/retry')
+  @HttpCode(HttpStatus.OK)
+  async retryJob(@Param('id') id: string): Promise<{ ok: boolean; message: string }> {
+    if (!this.queueService) {
+      throw new NotFoundException('Queue service is not available');
+    }
+
+    const result = await this.queueService.retryJob(id);
+    if (!result.ok) {
+      throw new NotFoundException(result.message);
+    }
+
+    return result;
+  }
+
+  /**
+   * GET /api/admin/jobs/queues
+   * Return status for all managed queues.
+   */
+  @Get('queues')
+  async listQueues(): Promise<QueueListDto> {
+    if (!this.queueService) {
+      return { queues: [] };
+    }
+
+    const health = await this.queueService.getHealthStatus();
+    const queues = Object.entries(health.queues).map(([name, stats]) => ({
+      name,
+      waiting: stats.waiting,
+      active: stats.active,
+      completed: stats.completed,
+      failed: stats.failed,
+      delayed: 0,
+      paused: stats.paused,
+    }));
+
+    return { queues };
+  }
+
+  /**
+   * POST /api/admin/jobs/queues/:name/pause
+   * Pause the named queue.
+   */
+  @Post('queues/:name/pause')
+  @HttpCode(HttpStatus.OK)
+  async pauseQueue(@Param('name') name: string): Promise<{ ok: boolean; message: string }> {
+    if (!this.queueService) {
+      throw new NotFoundException('Queue service is not available');
+    }
+
+    const result = await this.queueService.pauseQueue(name);
+    if (!result.ok) {
+      throw new NotFoundException(result.message);
+    }
+
+    return result;
+  }
+
+  /**
+   * POST /api/admin/jobs/queues/:name/resume
+   * Resume the named queue.
+   */
+  @Post('queues/:name/resume')
+  @HttpCode(HttpStatus.OK)
+  async resumeQueue(@Param('name') name: string): Promise<{ ok: boolean; message: string }> {
+    if (!this.queueService) {
+      throw new NotFoundException('Queue service is not available');
+    }
+
+    const result = await this.queueService.resumeQueue(name);
+    if (!result.ok) {
+      throw new NotFoundException(result.message);
+    }
+
+    return result;
+  }
+}

apps/gateway/src/admin/admin.module.ts

@@ -1,10 +1,11 @@
 import { Module } from '@nestjs/common';
 import { AdminController } from './admin.controller.js';
 import { AdminHealthController } from './admin-health.controller.js';
+import { AdminJobsController } from './admin-jobs.controller.js';
 import { AdminGuard } from './admin.guard.js';
 
 @Module({
-  controllers: [AdminController, AdminHealthController],
+  controllers: [AdminController, AdminHealthController, AdminJobsController],
   providers: [AdminGuard],
 })
 export class AdminModule {}

apps/gateway/src/app.module.ts

@@ -22,6 +22,7 @@ import { PreferencesModule } from './preferences/preferences.module.js';
 import { GCModule } from './gc/gc.module.js';
 import { ReloadModule } from './reload/reload.module.js';
 import { WorkspaceModule } from './workspace/workspace.module.js';
+import { QueueModule } from './queue/queue.module.js';
 import { ThrottlerGuard, ThrottlerModule } from '@nestjs/throttler';
 
 @Module({
@@ -46,6 +47,7 @@ import { ThrottlerGuard, ThrottlerModule } from '@nestjs/throttler';
     PreferencesModule,
     CommandsModule,
     GCModule,
+    QueueModule,
     ReloadModule,
     WorkspaceModule,
   ],

apps/gateway/src/log/cron.service.ts

@@ -5,59 +5,72 @@ import {
   type OnModuleInit,
   type OnModuleDestroy,
 } from '@nestjs/common';
-import cron from 'node-cron';
 import { SummarizationService } from './summarization.service.js';
 import { SessionGCService } from '../gc/session-gc.service.js';
+import {
+  QueueService,
+  QUEUE_SUMMARIZATION,
+  QUEUE_GC,
+  QUEUE_TIER_MANAGEMENT,
+} from '../queue/queue.service.js';
+import type { Worker } from 'bullmq';
+import type { MosaicJobData } from '../queue/queue.service.js';
 
 @Injectable()
 export class CronService implements OnModuleInit, OnModuleDestroy {
   private readonly logger = new Logger(CronService.name);
-  private readonly tasks: cron.ScheduledTask[] = [];
+  private readonly registeredWorkers: Worker<MosaicJobData>[] = [];
 
   constructor(
     @Inject(SummarizationService) private readonly summarization: SummarizationService,
     @Inject(SessionGCService) private readonly sessionGC: SessionGCService,
+    @Inject(QueueService) private readonly queueService: QueueService,
   ) {}
 
-  onModuleInit(): void {
+  async onModuleInit(): Promise<void> {
     const summarizationSchedule = process.env['SUMMARIZATION_CRON'] ?? '0 */6 * * *'; // every 6 hours
     const tierManagementSchedule = process.env['TIER_MANAGEMENT_CRON'] ?? '0 3 * * *'; // daily at 3am
     const gcSchedule = process.env['SESSION_GC_CRON'] ?? '0 4 * * *'; // daily at 4am
 
-    this.tasks.push(
-      cron.schedule(summarizationSchedule, () => {
-        this.summarization.runSummarization().catch((err) => {
-          this.logger.error(`Scheduled summarization failed: ${err}`);
-        });
-      }),
+    // M6-003: Summarization repeatable job
+    await this.queueService.addRepeatableJob(
+      QUEUE_SUMMARIZATION,
+      'summarization',
+      {},
+      summarizationSchedule,
     );
+    const summarizationWorker = this.queueService.registerWorker(QUEUE_SUMMARIZATION, async () => {
+      await this.summarization.runSummarization();
+    });
+    this.registeredWorkers.push(summarizationWorker);
 
-    this.tasks.push(
-      cron.schedule(tierManagementSchedule, () => {
-        this.summarization.runTierManagement().catch((err) => {
-          this.logger.error(`Scheduled tier management failed: ${err}`);
-        });
-      }),
+    // M6-005: Tier management repeatable job
+    await this.queueService.addRepeatableJob(
+      QUEUE_TIER_MANAGEMENT,
+      'tier-management',
+      {},
+      tierManagementSchedule,
     );
+    const tierWorker = this.queueService.registerWorker(QUEUE_TIER_MANAGEMENT, async () => {
+      await this.summarization.runTierManagement();
+    });
+    this.registeredWorkers.push(tierWorker);
 
-    this.tasks.push(
-      cron.schedule(gcSchedule, () => {
-        this.sessionGC.sweepOrphans().catch((err) => {
-          this.logger.error(`Session GC sweep failed: ${err}`);
-        });
-      }),
-    );
+    // M6-004: GC repeatable job
+    await this.queueService.addRepeatableJob(QUEUE_GC, 'session-gc', {}, gcSchedule);
+    const gcWorker = this.queueService.registerWorker(QUEUE_GC, async () => {
+      await this.sessionGC.sweepOrphans();
+    });
+    this.registeredWorkers.push(gcWorker);
 
     this.logger.log(
-      `Cron scheduled: summarization="${summarizationSchedule}", tier="${tierManagementSchedule}", gc="${gcSchedule}"`,
+      `BullMQ jobs scheduled: summarization="${summarizationSchedule}", tier="${tierManagementSchedule}", gc="${gcSchedule}"`,
     );
   }
 
-  onModuleDestroy(): void {
-    for (const task of this.tasks) {
-      task.stop();
-    }
-    this.tasks.length = 0;
-    this.logger.log('Cron tasks stopped');
+  async onModuleDestroy(): Promise<void> {
+    // Workers are closed by QueueService.onModuleDestroy — nothing extra needed here.
+    this.registeredWorkers.length = 0;
+    this.logger.log('CronService destroyed (workers managed by QueueService)');
   }
 }

apps/gateway/src/log/log.module.ts

@@ -7,10 +7,11 @@ import { LogController } from './log.controller.js';
 import { SummarizationService } from './summarization.service.js';
 import { CronService } from './cron.service.js';
 import { GCModule } from '../gc/gc.module.js';
+import { QueueModule } from '../queue/queue.module.js';
 
 @Global()
 @Module({
-  imports: [GCModule],
+  imports: [GCModule, QueueModule],
   providers: [
     {
       provide: LOG_SERVICE,

apps/gateway/src/queue/queue-admin.dto.ts

@@ -0,0 +1,34 @@
+export type JobStatus = 'active' | 'completed' | 'failed' | 'waiting' | 'delayed';
+
+export interface JobDto {
+  id: string;
+  name: string;
+  queue: string;
+  status: JobStatus;
+  attempts: number;
+  maxAttempts: number;
+  createdAt?: string;
+  processedAt?: string;
+  finishedAt?: string;
+  failedReason?: string;
+  data: Record<string, unknown>;
+}
+
+export interface JobListDto {
+  jobs: JobDto[];
+  total: number;
+}
+
+export interface QueueStatusDto {
+  name: string;
+  waiting: number;
+  active: number;
+  completed: number;
+  failed: number;
+  delayed: number;
+  paused: boolean;
+}
+
+export interface QueueListDto {
+  queues: QueueStatusDto[];
+}

apps/gateway/src/queue/queue.module.ts

@@ -0,0 +1,9 @@
+import { Global, Module } from '@nestjs/common';
+import { QueueService } from './queue.service.js';
+
+@Global()
+@Module({
+  providers: [QueueService],
+  exports: [QueueService],
+})
+export class QueueModule {}

apps/gateway/src/queue/queue.service.ts

@@ -0,0 +1,386 @@
+import {
+  Inject,
+  Injectable,
+  Logger,
+  Optional,
+  type OnModuleInit,
+  type OnModuleDestroy,
+} from '@nestjs/common';
+import { Queue, Worker, type Job, type ConnectionOptions } from 'bullmq';
+import type { LogService } from '@mosaic/log';
+import { LOG_SERVICE } from '../log/log.tokens.js';
+import type { JobDto, JobStatus } from './queue-admin.dto.js';
+
+// ---------------------------------------------------------------------------
+// Typed job definitions
+// ---------------------------------------------------------------------------
+
+export interface SummarizationJobData {
+  triggeredBy?: string;
+}
+
+export interface GCJobData {
+  triggeredBy?: string;
+}
+
+export interface TierManagementJobData {
+  triggeredBy?: string;
+}
+
+export type MosaicJobData = SummarizationJobData | GCJobData | TierManagementJobData;
+
+// ---------------------------------------------------------------------------
+// Queue health status
+// ---------------------------------------------------------------------------
+
+export interface QueueHealthStatus {
+  queues: Record<
+    string,
+    {
+      waiting: number;
+      active: number;
+      failed: number;
+      completed: number;
+      paused: boolean;
+    }
+  >;
+  healthy: boolean;
+}
+
+// ---------------------------------------------------------------------------
+// Constants
+// ---------------------------------------------------------------------------
+
+export const QUEUE_SUMMARIZATION = 'mosaic:summarization';
+export const QUEUE_GC = 'mosaic:gc';
+export const QUEUE_TIER_MANAGEMENT = 'mosaic:tier-management';
+
+const DEFAULT_VALKEY_URL = 'redis://localhost:6380';
+
+function getConnection(): ConnectionOptions {
+  const url = process.env['VALKEY_URL'] ?? DEFAULT_VALKEY_URL;
+  // BullMQ ConnectionOptions accepts a URL string (ioredis-compatible)
+  return url as unknown as ConnectionOptions;
+}
+
+// ---------------------------------------------------------------------------
+// Job handler type
+// ---------------------------------------------------------------------------
+
+export type JobHandler<T = MosaicJobData> = (job: Job<T>) => Promise<void>;
+
+/** System session ID used for job-event log entries (no real user session). */
+const SYSTEM_SESSION_ID = 'system';
+
+// ---------------------------------------------------------------------------
+// QueueService
+// ---------------------------------------------------------------------------
+
+@Injectable()
+export class QueueService implements OnModuleInit, OnModuleDestroy {
+  private readonly logger = new Logger(QueueService.name);
+  private readonly connection: ConnectionOptions;
+  private readonly queues = new Map<string, Queue<MosaicJobData>>();
+  private readonly workers = new Map<string, Worker<MosaicJobData>>();
+
+  constructor(
+    @Optional()
+    @Inject(LOG_SERVICE)
+    private readonly logService: LogService | null,
+  ) {
+    this.connection = getConnection();
+  }
+
+  onModuleInit(): void {
+    this.logger.log('QueueService initialised (BullMQ)');
+  }
+
+  async onModuleDestroy(): Promise<void> {
+    await this.closeAll();
+  }
+
+  // -------------------------------------------------------------------------
+  // Queue helpers
+  // -------------------------------------------------------------------------
+
+  /**
+   * Get or create a BullMQ Queue for the given queue name.
+   */
+  getQueue<T extends MosaicJobData = MosaicJobData>(name: string): Queue<T> {
+    let queue = this.queues.get(name) as Queue<T> | undefined;
+    if (!queue) {
+      queue = new Queue<T>(name, { connection: this.connection });
+      this.queues.set(name, queue as unknown as Queue<MosaicJobData>);
+    }
+    return queue;
+  }
+
+  /**
+   * Add a BullMQ repeatable job (cron-style).
+   * Uses `jobId` as a deterministic key so duplicate registrations are idempotent.
+   */
+  async addRepeatableJob<T extends MosaicJobData>(
+    queueName: string,
+    jobName: string,
+    data: T,
+    cronExpression: string,
+  ): Promise<void> {
+    const queue = this.getQueue<T>(queueName);
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    await (queue as Queue<any>).add(jobName, data, {
+      repeat: { pattern: cronExpression },
+      jobId: `${queueName}:${jobName}:repeatable`,
+    });
+    this.logger.log(
+      `Repeatable job "${jobName}" registered on "${queueName}" (cron: ${cronExpression})`,
+    );
+  }
+
+  /**
+   * Register a Worker for the given queue name with error handling and
+   * exponential backoff.
+   */
+  registerWorker<T extends MosaicJobData>(queueName: string, handler: JobHandler<T>): Worker<T> {
+    const worker = new Worker<T>(
+      queueName,
+      async (job) => {
+        this.logger.debug(`Processing job "${job.name}" (id=${job.id}) on queue "${queueName}"`);
+        await this.logJobEvent(
+          queueName,
+          job.name,
+          job.id ?? 'unknown',
+          'started',
+          job.attemptsMade + 1,
+        );
+        await handler(job);
+      },
+      {
+        connection: this.connection,
+        // Exponential backoff: base 5s, factor 2, max 5 attempts
+        settings: {
+          backoffStrategy: (attemptsMade: number) => {
+            return Math.min(5000 * Math.pow(2, attemptsMade - 1), 60_000);
+          },
+        },
+      },
+    );
+
+    worker.on('completed', (job) => {
+      this.logger.log(`Job "${job.name}" (id=${job.id}) completed on queue "${queueName}"`);
+      this.logJobEvent(
+        queueName,
+        job.name,
+        job.id ?? 'unknown',
+        'completed',
+        job.attemptsMade,
+      ).catch((err) => this.logger.warn(`Failed to write completed job log: ${String(err)}`));
+    });
+
+    worker.on('failed', (job, err) => {
+      const errMsg = err instanceof Error ? err.message : String(err);
+      this.logger.error(
+        `Job "${job?.name ?? 'unknown'}" (id=${job?.id ?? 'unknown'}) failed on queue "${queueName}": ${errMsg}`,
+      );
+      this.logJobEvent(
+        queueName,
+        job?.name ?? 'unknown',
+        job?.id ?? 'unknown',
+        'failed',
+        job?.attemptsMade ?? 0,
+        errMsg,
+      ).catch((e) => this.logger.warn(`Failed to write failed job log: ${String(e)}`));
+    });
+
+    this.workers.set(queueName, worker as unknown as Worker<MosaicJobData>);
+    return worker;
+  }
+
+  /**
+   * Return queue health statistics for all managed queues.
+   */
+  async getHealthStatus(): Promise<QueueHealthStatus> {
+    const queues: QueueHealthStatus['queues'] = {};
+    let healthy = true;
+
+    for (const [name, queue] of this.queues) {
+      try {
+        const [waiting, active, failed, completed, paused] = await Promise.all([
+          queue.getWaitingCount(),
+          queue.getActiveCount(),
+          queue.getFailedCount(),
+          queue.getCompletedCount(),
+          queue.isPaused(),
+        ]);
+        queues[name] = { waiting, active, failed, completed, paused };
+      } catch (err) {
+        this.logger.error(`Failed to fetch health for queue "${name}": ${err}`);
+        healthy = false;
+        queues[name] = { waiting: 0, active: 0, failed: 0, completed: 0, paused: false };
+      }
+    }
+
+    return { queues, healthy };
+  }
+
+  // -------------------------------------------------------------------------
+  // Admin API helpers (M6-006)
+  // -------------------------------------------------------------------------
+
+  /**
+   * List jobs across all managed queues, optionally filtered by status.
+   * BullMQ jobs are fetched by state type from each queue.
+   */
+  async listJobs(status?: JobStatus): Promise<JobDto[]> {
+    const jobs: JobDto[] = [];
+    const states: JobStatus[] = status
+      ? [status]
+      : ['active', 'completed', 'failed', 'waiting', 'delayed'];
+
+    for (const [queueName, queue] of this.queues) {
+      try {
+        for (const state of states) {
+          // eslint-disable-next-line @typescript-eslint/no-explicit-any
+          const raw = await (queue as Queue<any>).getJobs([state as any]);
+          for (const j of raw) {
+            jobs.push(this.toJobDto(queueName, j, state));
+          }
+        }
+      } catch (err) {
+        this.logger.warn(`Failed to list jobs for queue "${queueName}": ${String(err)}`);
+      }
+    }
+
+    return jobs;
+  }
+
+  /**
+   * Retry a specific failed job by its BullMQ job ID (format: "queueName:id").
+   * The caller passes "<queueName>__<jobId>" as the composite ID because BullMQ
+   * job IDs are not globally unique — they are scoped to their queue.
+   */
+  async retryJob(compositeId: string): Promise<{ ok: boolean; message: string }> {
+    const sep = compositeId.lastIndexOf('__');
+    if (sep === -1) {
+      return { ok: false, message: 'Invalid job id format. Expected "<queue>__<jobId>".' };
+    }
+    const queueName = compositeId.slice(0, sep);
+    const jobId = compositeId.slice(sep + 2);
+
+    const queue = this.queues.get(queueName);
+    if (!queue) {
+      return { ok: false, message: `Queue "${queueName}" not found.` };
+    }
+
+    const job = await queue.getJob(jobId);
+    if (!job) {
+      return { ok: false, message: `Job "${jobId}" not found in queue "${queueName}".` };
+    }
+
+    const state = await job.getState();
+    if (state !== 'failed') {
+      return { ok: false, message: `Job "${jobId}" is not in failed state (current: ${state}).` };
+    }
+
+    await job.retry('failed');
+    await this.logJobEvent(queueName, job.name, jobId, 'retried', (job.attemptsMade ?? 0) + 1);
+    return { ok: true, message: `Job "${jobId}" on queue "${queueName}" queued for retry.` };
+  }
+
+  /**
+   * Pause a queue by name.
+   */
+  async pauseQueue(name: string): Promise<{ ok: boolean; message: string }> {
+    const queue = this.queues.get(name);
+    if (!queue) return { ok: false, message: `Queue "${name}" not found.` };
+    await queue.pause();
+    this.logger.log(`Queue paused: ${name}`);
+    return { ok: true, message: `Queue "${name}" paused.` };
+  }
+
+  /**
+   * Resume a paused queue by name.
+   */
+  async resumeQueue(name: string): Promise<{ ok: boolean; message: string }> {
+    const queue = this.queues.get(name);
+    if (!queue) return { ok: false, message: `Queue "${name}" not found.` };
+    await queue.resume();
+    this.logger.log(`Queue resumed: ${name}`);
+    return { ok: true, message: `Queue "${name}" resumed.` };
+  }
+
+  private toJobDto(queueName: string, job: Job<MosaicJobData>, status: JobStatus): JobDto {
+    return {
+      id: `${queueName}__${job.id ?? 'unknown'}`,
+      name: job.name,
+      queue: queueName,
+      status,
+      attempts: job.attemptsMade,
+      maxAttempts: job.opts?.attempts ?? 1,
+      createdAt: job.timestamp ? new Date(job.timestamp).toISOString() : undefined,
+      processedAt: job.processedOn ? new Date(job.processedOn).toISOString() : undefined,
+      finishedAt: job.finishedOn ? new Date(job.finishedOn).toISOString() : undefined,
+      failedReason: job.failedReason,
+      data: (job.data as Record<string, unknown>) ?? {},
+    };
+  }
+
+  // -------------------------------------------------------------------------
+  // Job event logging (M6-007)
+  // -------------------------------------------------------------------------
+
+  /** Write a log entry to agent_logs for BullMQ job lifecycle events. */
+  private async logJobEvent(
+    queueName: string,
+    jobName: string,
+    jobId: string,
+    event: 'started' | 'completed' | 'retried' | 'failed',
+    attempts: number,
+    errorMessage?: string,
+  ): Promise<void> {
+    if (!this.logService) return;
+
+    const level = event === 'failed' ? ('error' as const) : ('info' as const);
+    const content =
+      event === 'failed'
+        ? `Job "${jobName}" (${jobId}) on queue "${queueName}" failed: ${errorMessage ?? 'unknown error'}`
+        : `Job "${jobName}" (${jobId}) on queue "${queueName}" ${event} (attempt ${attempts})`;
+
+    try {
+      await this.logService.logs.ingest({
+        sessionId: SYSTEM_SESSION_ID,
+        userId: 'system',
+        level,
+        category: 'general',
+        content,
+        metadata: {
+          jobId,
+          jobName,
+          queue: queueName,
+          event,
+          attempts,
+          ...(errorMessage ? { errorMessage } : {}),
+        },
+      });
+    } catch (err) {
+      // Log errors must never crash job execution
+      this.logger.warn(`Failed to write job event log for job ${jobId}: ${String(err)}`);
+    }
+  }
+
+  // -------------------------------------------------------------------------
+  // Lifecycle
+  // -------------------------------------------------------------------------
+
+  private async closeAll(): Promise<void> {
+    const workerCloses = Array.from(this.workers.values()).map((w) =>
+      w.close().catch((err) => this.logger.error(`Worker close error: ${err}`)),
+    );
+    const queueCloses = Array.from(this.queues.values()).map((q) =>
+      q.close().catch((err) => this.logger.error(`Queue close error: ${err}`)),
+    );
+    await Promise.all([...workerCloses, ...queueCloses]);
+    this.workers.clear();
+    this.queues.clear();
+    this.logger.log('QueueService shut down');
+  }
+}

apps/gateway/src/queue/queue.tokens.ts

@@ -0,0 +1,2 @@
+export const QUEUE_REDIS = 'QUEUE_REDIS';
+export const QUEUE_SERVICE = 'QUEUE_SERVICE';