feat(P4-004): summarization pipeline — LLM + cron scheduling

Add SummarizationService that reads hot agent logs (>24h), groups by
session, calls a cheap LLM (gpt-4o-mini default, configurable via
SUMMARIZATION_MODEL) to extract key insights, stores them with
embeddings in the insights table, and transitions processed logs to
warm tier. Add CronService with node-cron for scheduled execution
(summarization every 6h, tier management daily at 3am). Tier
management promotes warm→cold (30d) and purges cold logs (90d).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/gateway/package.json

@@ -36,6 +36,7 @@
     "@sinclair/typebox": "^0.34.48",
     "better-auth": "^1.5.5",
     "fastify": "^5.0.0",
+    "node-cron": "^4.2.1",
     "reflect-metadata": "^0.2.0",
     "rxjs": "^7.8.0",
     "socket.io": "^4.8.0",
@@ -43,6 +44,7 @@
   },
   "devDependencies": {
     "@types/node": "^22.0.0",
+    "@types/node-cron": "^3.0.11",
     "@types/uuid": "^10.0.0",
     "tsx": "^4.0.0",
     "typescript": "^5.8.0",

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

@@ -0,0 +1,44 @@
+import { Injectable, Logger, type OnModuleInit, type OnModuleDestroy } from '@nestjs/common';
+import cron from 'node-cron';
+import { SummarizationService } from './summarization.service.js';
+
+@Injectable()
+export class CronService implements OnModuleInit, OnModuleDestroy {
+  private readonly logger = new Logger(CronService.name);
+  private readonly tasks: cron.ScheduledTask[] = [];
+
+  constructor(private readonly summarization: SummarizationService) {}
+
+  onModuleInit(): void {
+    const summarizationSchedule = process.env['SUMMARIZATION_CRON'] ?? '0 */6 * * *'; // every 6 hours
+    const tierManagementSchedule = process.env['TIER_MANAGEMENT_CRON'] ?? '0 3 * * *'; // daily at 3am
+
+    this.tasks.push(
+      cron.schedule(summarizationSchedule, () => {
+        this.summarization.runSummarization().catch((err) => {
+          this.logger.error(`Scheduled summarization failed: ${err}`);
+        });
+      }),
+    );
+
+    this.tasks.push(
+      cron.schedule(tierManagementSchedule, () => {
+        this.summarization.runTierManagement().catch((err) => {
+          this.logger.error(`Scheduled tier management failed: ${err}`);
+        });
+      }),
+    );
+
+    this.logger.log(
+      `Cron scheduled: summarization="${summarizationSchedule}", tier="${tierManagementSchedule}"`,
+    );
+  }
+
+  onModuleDestroy(): void {
+    for (const task of this.tasks) {
+      task.stop();
+    }
+    this.tasks.length = 0;
+    this.logger.log('Cron tasks stopped');
+  }
+}

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

@@ -4,6 +4,8 @@ import type { Db } from '@mosaic/db';
 import { DB } from '../database/database.module.js';
 import { LOG_SERVICE } from './log.tokens.js';
 import { LogController } from './log.controller.js';
+import { SummarizationService } from './summarization.service.js';
+import { CronService } from './cron.service.js';
 
 @Global()
 @Module({
@@ -13,8 +15,10 @@ import { LogController } from './log.controller.js';
       useFactory: (db: Db): LogService => createLogService(db),
       inject: [DB],
     },
+    SummarizationService,
+    CronService,
   ],
   controllers: [LogController],
-  exports: [LOG_SERVICE],
+  exports: [LOG_SERVICE, SummarizationService],
 })
 export class LogModule {}

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

@@ -0,0 +1,178 @@
+import { Inject, Injectable, Logger } from '@nestjs/common';
+import type { LogService } from '@mosaic/log';
+import type { Memory } from '@mosaic/memory';
+import { LOG_SERVICE } from './log.tokens.js';
+import { MEMORY } from '../memory/memory.tokens.js';
+import { EmbeddingService } from '../memory/embedding.service.js';
+import type { Db } from '@mosaic/db';
+import { sql, summarizationJobs } from '@mosaic/db';
+import { DB } from '../database/database.module.js';
+
+const SUMMARIZATION_PROMPT = `You are a knowledge extraction assistant. Given the following agent interaction logs, extract the key decisions, learnings, and patterns. Output a concise summary (2-4 sentences) that captures the most important information for future reference. Focus on actionable insights, not raw events.
+
+Logs:
+{logs}
+
+Summary:`;
+
+interface ChatCompletion {
+  choices: Array<{ message: { content: string } }>;
+}
+
+@Injectable()
+export class SummarizationService {
+  private readonly logger = new Logger(SummarizationService.name);
+  private readonly apiKey: string | undefined;
+  private readonly baseUrl: string;
+  private readonly model: string;
+
+  constructor(
+    @Inject(LOG_SERVICE) private readonly logService: LogService,
+    @Inject(MEMORY) private readonly memory: Memory,
+    private readonly embeddings: EmbeddingService,
+    @Inject(DB) private readonly db: Db,
+  ) {
+    this.apiKey = process.env['OPENAI_API_KEY'];
+    this.baseUrl = process.env['SUMMARIZATION_API_URL'] ?? 'https://api.openai.com/v1';
+    this.model = process.env['SUMMARIZATION_MODEL'] ?? 'gpt-4o-mini';
+  }
+
+  /**
+   * Run one summarization cycle:
+   * 1. Find hot logs older than 24h with decision/learning/tool_use categories
+   * 2. Group by session
+   * 3. Summarize each group via cheap LLM
+   * 4. Store as insights with embeddings
+   * 5. Transition processed logs to warm tier
+   */
+  async runSummarization(): Promise<{ logsProcessed: number; insightsCreated: number }> {
+    const cutoff = new Date(Date.now() - 24 * 60 * 60 * 1000); // 24h ago
+
+    // Create job record
+    const [job] = await this.db
+      .insert(summarizationJobs)
+      .values({ status: 'running', startedAt: new Date() })
+      .returning();
+
+    try {
+      const logs = await this.logService.logs.getLogsForSummarization(cutoff, 200);
+      if (logs.length === 0) {
+        await this.db
+          .update(summarizationJobs)
+          .set({ status: 'completed', completedAt: new Date() })
+          .where(sql`id = ${job!.id}`);
+        return { logsProcessed: 0, insightsCreated: 0 };
+      }
+
+      // Group logs by session
+      const bySession = new Map<string, typeof logs>();
+      for (const log of logs) {
+        const group = bySession.get(log.sessionId) ?? [];
+        group.push(log);
+        bySession.set(log.sessionId, group);
+      }
+
+      let insightsCreated = 0;
+
+      for (const [sessionId, sessionLogs] of bySession) {
+        const userId = sessionLogs[0]?.userId;
+        if (!userId) continue;
+
+        const logsText = sessionLogs.map((l) => `[${l.category}] ${l.content}`).join('\n');
+
+        const summary = await this.summarize(logsText);
+        if (!summary) continue;
+
+        const embedding = this.embeddings.available
+          ? await this.embeddings.embed(summary)
+          : undefined;
+
+        await this.memory.insights.create({
+          userId,
+          content: summary,
+          embedding: embedding ?? null,
+          source: 'summarization',
+          category: 'learning',
+          metadata: { sessionId, logCount: sessionLogs.length },
+        });
+        insightsCreated++;
+      }
+
+      // Transition processed logs to warm
+      await this.logService.logs.promoteToWarm(cutoff);
+
+      await this.db
+        .update(summarizationJobs)
+        .set({
+          status: 'completed',
+          logsProcessed: logs.length,
+          insightsCreated,
+          completedAt: new Date(),
+        })
+        .where(sql`id = ${job!.id}`);
+
+      this.logger.log(`Summarization complete: ${logs.length} logs → ${insightsCreated} insights`);
+      return { logsProcessed: logs.length, insightsCreated };
+    } catch (error) {
+      const message = error instanceof Error ? error.message : String(error);
+      await this.db
+        .update(summarizationJobs)
+        .set({ status: 'failed', errorMessage: message, completedAt: new Date() })
+        .where(sql`id = ${job!.id}`);
+      this.logger.error(`Summarization failed: ${message}`);
+      throw error;
+    }
+  }
+
+  /**
+   * Run tier management:
+   * - Warm logs older than 30 days → cold
+   * - Cold logs older than 90 days → purged
+   * - Decay old insight relevance scores
+   */
+  async runTierManagement(): Promise<void> {
+    const warmCutoff = new Date(Date.now() - 30 * 24 * 60 * 60 * 1000);
+    const coldCutoff = new Date(Date.now() - 90 * 24 * 60 * 60 * 1000);
+    const decayCutoff = new Date(Date.now() - 14 * 24 * 60 * 60 * 1000);
+
+    const promoted = await this.logService.logs.promoteToCold(warmCutoff);
+    const purged = await this.logService.logs.purge(coldCutoff);
+    const decayed = await this.memory.insights.decayOldInsights(decayCutoff);
+
+    this.logger.log(
+      `Tier management: ${promoted} logs→cold, ${purged} purged, ${decayed} insights decayed`,
+    );
+  }
+
+  private async summarize(logsText: string): Promise<string | null> {
+    if (!this.apiKey) {
+      this.logger.warn('No API key configured — skipping summarization');
+      return null;
+    }
+
+    const prompt = SUMMARIZATION_PROMPT.replace('{logs}', logsText);
+
+    const response = await fetch(`${this.baseUrl}/chat/completions`, {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+        Authorization: `Bearer ${this.apiKey}`,
+      },
+      body: JSON.stringify({
+        model: this.model,
+        messages: [{ role: 'user', content: prompt }],
+        max_tokens: 300,
+        temperature: 0.3,
+      }),
+    });
+
+    if (!response.ok) {
+      const body = await response.text();
+      this.logger.error(`Summarization API error: ${response.status} ${body}`);
+      return null;
+    }
+
+    const json = (await response.json()) as ChatCompletion;
+    return json.choices[0]?.message.content ?? null;
+  }
+}

docs/TASKS.md

@@ -40,7 +40,7 @@
 | P4-001 | in-progress | Phase 4   | @mosaic/memory — preference + insight stores                  | —   | #34   |
 | P4-002 | in-progress | Phase 4   | Semantic search — pgvector embeddings + search API            | —   | #35   |
 | P4-003 | in-progress | Phase 4   | @mosaic/log — log ingest, parsing, tiered storage             | —   | #36   |
-| P4-004 | not-started | Phase 4   | Summarization pipeline — Haiku-tier LLM + cron                | —   | #37   |
+| P4-004 | in-progress | Phase 4   | Summarization pipeline — Haiku-tier LLM + cron                | —   | #37   |
 | P4-005 | not-started | Phase 4   | Memory integration — inject into agent sessions               | —   | #38   |
 | P4-006 | not-started | Phase 4   | Skill management — catalog, install, config                   | —   | #39   |
 | P4-007 | not-started | Phase 4   | Verify Phase 4 — memory + log pipeline working                | —   | #40   |

pnpm-lock.yaml

@@ -113,6 +113,9 @@ importers:
       fastify:
         specifier: ^5.0.0
         version: 5.8.2
+      node-cron:
+        specifier: ^4.2.1
+        version: 4.2.1
       reflect-metadata:
         specifier: ^0.2.0
         version: 0.2.2
@@ -129,6 +132,9 @@ importers:
       '@types/node':
         specifier: ^22.0.0
         version: 22.19.15
+      '@types/node-cron':
+        specifier: ^3.0.11
+        version: 3.0.11
       '@types/uuid':
         specifier: ^10.0.0
         version: 10.0.0
@@ -2747,6 +2753,9 @@ packages:
   '@types/mysql@2.15.27':
     resolution: {integrity: sha512-YfWiV16IY0OeBfBCk8+hXKmdTKrKlwKN1MNKAPBu5JYxLwBEZl7QzeEpGnlZb3VMGJrrGmB84gXiH+ofs/TezA==}
 
+  '@types/node-cron@3.0.11':
+    resolution: {integrity: sha512-0ikrnug3/IyneSHqCBeslAhlK2aBfYek1fGo4bP4QnZPmiqSGRK+Oy7ZMisLWkesffJvQ1cqAcBnJC+8+nxIAg==}
+
   '@types/node@22.19.15':
     resolution: {integrity: sha512-F0R/h2+dsy5wJAUe3tAU6oqa2qbWY5TpNfL/RGmo1y38hiyO1w3x2jPtt76wmuaJI4DQnOBu21cNXQ2STIUUWg==}
 
@@ -4174,6 +4183,10 @@ packages:
       sass:
         optional: true
 
+  node-cron@4.2.1:
+    resolution: {integrity: sha512-lgimEHPE/QDgFlywTd8yTR61ptugX3Qer29efeyWw2rv259HtGBNn1vZVmp8lB9uo9wC0t/AT4iGqXxia+CJFg==}
+    engines: {node: '>=6.0.0'}
+
   node-domexception@1.0.0:
     resolution: {integrity: sha512-/jKZoMpw0F8GRwl4/eLROPA3cfcXtLApP0QzLmUT/HuPCZWyB7IY9ZrMeKw2O/nFIqPQB3PVM9aYm0F312AXDQ==}
     engines: {node: '>=10.5.0'}
@@ -7548,6 +7561,8 @@ snapshots:
     dependencies:
       '@types/node': 22.19.15
 
+  '@types/node-cron@3.0.11': {}
+
   '@types/node@22.19.15':
     dependencies:
       undici-types: 6.21.0
@@ -9001,6 +9016,8 @@ snapshots:
       - '@babel/core'
       - babel-plugin-macros
 
+  node-cron@4.2.1: {}
+
   node-domexception@1.0.0: {}
 
   node-fetch@3.3.2: