feat(Phase 4): Memory & Intelligence — memory, log, summarization, skills (#91)

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

apps/gateway/package.json

@@ -18,6 +18,8 @@
     "@mosaic/brain": "workspace:^",
     "@mosaic/coord": "workspace:^",
     "@mosaic/db": "workspace:^",
+    "@mosaic/log": "workspace:^",
+    "@mosaic/memory": "workspace:^",
     "@mosaic/types": "workspace:^",
     "@nestjs/common": "^11.0.0",
     "@nestjs/core": "^11.0.0",
@@ -34,6 +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",
@@ -41,6 +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/agent/agent.service.ts

@@ -7,11 +7,15 @@ import {
   type ToolDefinition,
 } from '@mariozechner/pi-coding-agent';
 import type { Brain } from '@mosaic/brain';
+import type { Memory } from '@mosaic/memory';
 import { BRAIN } from '../brain/brain.tokens.js';
+import { MEMORY } from '../memory/memory.tokens.js';
+import { EmbeddingService } from '../memory/embedding.service.js';
 import { CoordService } from '../coord/coord.service.js';
 import { ProviderService } from './provider.service.js';
 import { createBrainTools } from './tools/brain-tools.js';
 import { createCoordTools } from './tools/coord-tools.js';
+import { createMemoryTools } from './tools/memory-tools.js';
 import type { SessionInfoDto } from './session.dto.js';
 
 export interface AgentSessionOptions {
@@ -42,9 +46,15 @@ export class AgentService implements OnModuleDestroy {
   constructor(
     @Inject(ProviderService) private readonly providerService: ProviderService,
     @Inject(BRAIN) private readonly brain: Brain,
+    @Inject(MEMORY) private readonly memory: Memory,
+    @Inject(EmbeddingService) private readonly embeddingService: EmbeddingService,
     @Inject(CoordService) private readonly coordService: CoordService,
   ) {
-    this.customTools = [...createBrainTools(brain), ...createCoordTools(coordService)];
+    this.customTools = [
+      ...createBrainTools(brain),
+      ...createCoordTools(coordService),
+      ...createMemoryTools(memory, embeddingService.available ? embeddingService : null),
+    ];
     this.logger.log(`Registered ${this.customTools.length} custom tools`);
   }
 

apps/gateway/src/agent/tools/memory-tools.ts

@@ -0,0 +1,158 @@
+import { Type } from '@sinclair/typebox';
+import type { ToolDefinition } from '@mariozechner/pi-coding-agent';
+import type { Memory } from '@mosaic/memory';
+import type { EmbeddingProvider } from '@mosaic/memory';
+
+export function createMemoryTools(
+  memory: Memory,
+  embeddingProvider: EmbeddingProvider | null,
+): ToolDefinition[] {
+  const searchMemory: ToolDefinition = {
+    name: 'memory_search',
+    label: 'Search Memory',
+    description:
+      'Search across stored insights and knowledge using natural language. Returns semantically similar results.',
+    parameters: Type.Object({
+      userId: Type.String({ description: 'User ID to search memory for' }),
+      query: Type.String({ description: 'Natural language search query' }),
+      limit: Type.Optional(Type.Number({ description: 'Max results (default 5)' })),
+    }),
+    async execute(_toolCallId, params) {
+      const { userId, query, limit } = params as {
+        userId: string;
+        query: string;
+        limit?: number;
+      };
+
+      if (!embeddingProvider) {
+        return {
+          content: [
+            {
+              type: 'text' as const,
+              text: 'Semantic search unavailable — no embedding provider configured',
+            },
+          ],
+          details: undefined,
+        };
+      }
+
+      const embedding = await embeddingProvider.embed(query);
+      const results = await memory.insights.searchByEmbedding(userId, embedding, limit ?? 5);
+      return {
+        content: [{ type: 'text' as const, text: JSON.stringify(results, null, 2) }],
+        details: undefined,
+      };
+    },
+  };
+
+  const getPreferences: ToolDefinition = {
+    name: 'memory_get_preferences',
+    label: 'Get User Preferences',
+    description: 'Retrieve stored preferences for a user.',
+    parameters: Type.Object({
+      userId: Type.String({ description: 'User ID' }),
+      category: Type.Optional(
+        Type.String({
+          description: 'Filter by category: communication, coding, workflow, appearance, general',
+        }),
+      ),
+    }),
+    async execute(_toolCallId, params) {
+      const { userId, category } = params as { userId: string; category?: string };
+      type Cat = 'communication' | 'coding' | 'workflow' | 'appearance' | 'general';
+      const prefs = category
+        ? await memory.preferences.findByUserAndCategory(userId, category as Cat)
+        : await memory.preferences.findByUser(userId);
+      return {
+        content: [{ type: 'text' as const, text: JSON.stringify(prefs, null, 2) }],
+        details: undefined,
+      };
+    },
+  };
+
+  const savePreference: ToolDefinition = {
+    name: 'memory_save_preference',
+    label: 'Save User Preference',
+    description:
+      'Store a learned user preference (e.g., "prefers tables over paragraphs", "timezone: America/Chicago").',
+    parameters: Type.Object({
+      userId: Type.String({ description: 'User ID' }),
+      key: Type.String({ description: 'Preference key' }),
+      value: Type.String({ description: 'Preference value (JSON string)' }),
+      category: Type.Optional(
+        Type.String({
+          description: 'Category: communication, coding, workflow, appearance, general',
+        }),
+      ),
+    }),
+    async execute(_toolCallId, params) {
+      const { userId, key, value, category } = params as {
+        userId: string;
+        key: string;
+        value: string;
+        category?: string;
+      };
+      type Cat = 'communication' | 'coding' | 'workflow' | 'appearance' | 'general';
+      let parsedValue: unknown;
+      try {
+        parsedValue = JSON.parse(value);
+      } catch {
+        parsedValue = value;
+      }
+      const pref = await memory.preferences.upsert({
+        userId,
+        key,
+        value: parsedValue,
+        category: (category as Cat) ?? 'general',
+        source: 'agent',
+      });
+      return {
+        content: [{ type: 'text' as const, text: JSON.stringify(pref, null, 2) }],
+        details: undefined,
+      };
+    },
+  };
+
+  const saveInsight: ToolDefinition = {
+    name: 'memory_save_insight',
+    label: 'Save Insight',
+    description:
+      'Store a learned insight, decision, or knowledge extracted from the current interaction.',
+    parameters: Type.Object({
+      userId: Type.String({ description: 'User ID' }),
+      content: Type.String({ description: 'The insight or knowledge to store' }),
+      category: Type.Optional(
+        Type.String({
+          description: 'Category: decision, learning, preference, fact, pattern, general',
+        }),
+      ),
+    }),
+    async execute(_toolCallId, params) {
+      const { userId, content, category } = params as {
+        userId: string;
+        content: string;
+        category?: string;
+      };
+      type Cat = 'decision' | 'learning' | 'preference' | 'fact' | 'pattern' | 'general';
+
+      let embedding: number[] | null = null;
+      if (embeddingProvider) {
+        embedding = await embeddingProvider.embed(content);
+      }
+
+      const insight = await memory.insights.create({
+        userId,
+        content,
+        embedding,
+        source: 'agent',
+        category: (category as Cat) ?? 'learning',
+      });
+      return {
+        content: [{ type: 'text' as const, text: JSON.stringify(insight, null, 2) }],
+        details: undefined,
+      };
+    },
+  };
+
+  return [searchMemory, getPreferences, savePreference, saveInsight];
+}

apps/gateway/src/app.module.ts

@@ -10,6 +10,9 @@ import { ProjectsModule } from './projects/projects.module.js';
 import { MissionsModule } from './missions/missions.module.js';
 import { TasksModule } from './tasks/tasks.module.js';
 import { CoordModule } from './coord/coord.module.js';
+import { MemoryModule } from './memory/memory.module.js';
+import { LogModule } from './log/log.module.js';
+import { SkillsModule } from './skills/skills.module.js';
 
 @Module({
   imports: [
@@ -23,6 +26,9 @@ import { CoordModule } from './coord/coord.module.js';
     MissionsModule,
     TasksModule,
     CoordModule,
+    MemoryModule,
+    LogModule,
+    SkillsModule,
   ],
   controllers: [HealthController],
 })

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.controller.ts

@@ -0,0 +1,62 @@
+import { Body, Controller, Get, Inject, Param, Post, Query, UseGuards } from '@nestjs/common';
+import type { LogService } from '@mosaic/log';
+import { LOG_SERVICE } from './log.tokens.js';
+import { AuthGuard } from '../auth/auth.guard.js';
+import type { IngestLogDto, QueryLogsDto } from './log.dto.js';
+
+@Controller('api/logs')
+@UseGuards(AuthGuard)
+export class LogController {
+  constructor(@Inject(LOG_SERVICE) private readonly logService: LogService) {}
+
+  @Post()
+  async ingest(@Query('userId') userId: string, @Body() dto: IngestLogDto) {
+    return this.logService.logs.ingest({
+      sessionId: dto.sessionId,
+      userId,
+      level: dto.level,
+      category: dto.category,
+      content: dto.content,
+      metadata: dto.metadata,
+    });
+  }
+
+  @Post('batch')
+  async ingestBatch(@Query('userId') userId: string, @Body() dtos: IngestLogDto[]) {
+    const entries = dtos.map((dto) => ({
+      sessionId: dto.sessionId,
+      userId,
+      level: dto.level as 'debug' | 'info' | 'warn' | 'error' | undefined,
+      category: dto.category as
+        | 'decision'
+        | 'tool_use'
+        | 'learning'
+        | 'error'
+        | 'general'
+        | undefined,
+      content: dto.content,
+      metadata: dto.metadata,
+    }));
+    return this.logService.logs.ingestBatch(entries);
+  }
+
+  @Get()
+  async query(@Query('userId') userId: string, @Query() params: QueryLogsDto) {
+    return this.logService.logs.query({
+      userId,
+      sessionId: params.sessionId,
+      level: params.level,
+      category: params.category,
+      tier: params.tier,
+      since: params.since ? new Date(params.since) : undefined,
+      until: params.until ? new Date(params.until) : undefined,
+      limit: params.limit ? Number(params.limit) : undefined,
+      offset: params.offset ? Number(params.offset) : undefined,
+    });
+  }
+
+  @Get(':id')
+  async findOne(@Param('id') id: string) {
+    return this.logService.logs.findById(id);
+  }
+}

apps/gateway/src/log/log.dto.ts

@@ -0,0 +1,18 @@
+export interface IngestLogDto {
+  sessionId: string;
+  level?: 'debug' | 'info' | 'warn' | 'error';
+  category?: 'decision' | 'tool_use' | 'learning' | 'error' | 'general';
+  content: string;
+  metadata?: Record<string, unknown>;
+}
+
+export interface QueryLogsDto {
+  sessionId?: string;
+  level?: 'debug' | 'info' | 'warn' | 'error';
+  category?: 'decision' | 'tool_use' | 'learning' | 'error' | 'general';
+  tier?: 'hot' | 'warm' | 'cold';
+  since?: string;
+  until?: string;
+  limit?: string;
+  offset?: string;
+}

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

@@ -0,0 +1,24 @@
+import { Global, Module } from '@nestjs/common';
+import { createLogService, type LogService } from '@mosaic/log';
+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({
+  providers: [
+    {
+      provide: LOG_SERVICE,
+      useFactory: (db: Db): LogService => createLogService(db),
+      inject: [DB],
+    },
+    SummarizationService,
+    CronService,
+  ],
+  controllers: [LogController],
+  exports: [LOG_SERVICE, SummarizationService],
+})
+export class LogModule {}

apps/gateway/src/log/log.tokens.ts

@@ -0,0 +1 @@
+export const LOG_SERVICE = 'LOG_SERVICE';

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;
+  }
+}

apps/gateway/src/memory/embedding.service.ts

@@ -0,0 +1,69 @@
+import { Injectable, Logger } from '@nestjs/common';
+import type { EmbeddingProvider } from '@mosaic/memory';
+
+const DEFAULT_MODEL = 'text-embedding-3-small';
+const DEFAULT_DIMENSIONS = 1536;
+
+interface EmbeddingResponse {
+  data: Array<{ embedding: number[]; index: number }>;
+  model: string;
+  usage: { prompt_tokens: number; total_tokens: number };
+}
+
+/**
+ * Generates embeddings via the OpenAI-compatible embeddings API.
+ * Supports OpenAI, Azure OpenAI, and any provider with a compatible endpoint.
+ */
+@Injectable()
+export class EmbeddingService implements EmbeddingProvider {
+  private readonly logger = new Logger(EmbeddingService.name);
+  private readonly apiKey: string | undefined;
+  private readonly baseUrl: string;
+  private readonly model: string;
+
+  readonly dimensions = DEFAULT_DIMENSIONS;
+
+  constructor() {
+    this.apiKey = process.env['OPENAI_API_KEY'];
+    this.baseUrl = process.env['EMBEDDING_API_URL'] ?? 'https://api.openai.com/v1';
+    this.model = process.env['EMBEDDING_MODEL'] ?? DEFAULT_MODEL;
+  }
+
+  get available(): boolean {
+    return !!this.apiKey;
+  }
+
+  async embed(text: string): Promise<number[]> {
+    const results = await this.embedBatch([text]);
+    return results[0]!;
+  }
+
+  async embedBatch(texts: string[]): Promise<number[][]> {
+    if (!this.apiKey) {
+      this.logger.warn('No OPENAI_API_KEY configured — returning zero vectors');
+      return texts.map(() => new Array<number>(this.dimensions).fill(0));
+    }
+
+    const response = await fetch(`${this.baseUrl}/embeddings`, {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+        Authorization: `Bearer ${this.apiKey}`,
+      },
+      body: JSON.stringify({
+        model: this.model,
+        input: texts,
+        dimensions: this.dimensions,
+      }),
+    });
+
+    if (!response.ok) {
+      const body = await response.text();
+      this.logger.error(`Embedding API error: ${response.status} ${body}`);
+      throw new Error(`Embedding API returned ${response.status}`);
+    }
+
+    const json = (await response.json()) as EmbeddingResponse;
+    return json.data.sort((a, b) => a.index - b.index).map((d) => d.embedding);
+  }
+}

apps/gateway/src/memory/memory.controller.ts

@@ -0,0 +1,126 @@
+import {
+  Body,
+  Controller,
+  Delete,
+  Get,
+  HttpCode,
+  HttpStatus,
+  Inject,
+  NotFoundException,
+  Param,
+  Post,
+  Query,
+  UseGuards,
+} from '@nestjs/common';
+import type { Memory } from '@mosaic/memory';
+import { MEMORY } from './memory.tokens.js';
+import { AuthGuard } from '../auth/auth.guard.js';
+import { EmbeddingService } from './embedding.service.js';
+import type { UpsertPreferenceDto, CreateInsightDto, SearchMemoryDto } from './memory.dto.js';
+
+@Controller('api/memory')
+@UseGuards(AuthGuard)
+export class MemoryController {
+  constructor(
+    @Inject(MEMORY) private readonly memory: Memory,
+    private readonly embeddings: EmbeddingService,
+  ) {}
+
+  // ─── Preferences ────────────────────────────────────────────────────
+
+  @Get('preferences')
+  async listPreferences(@Query('userId') userId: string, @Query('category') category?: string) {
+    if (category) {
+      return this.memory.preferences.findByUserAndCategory(
+        userId,
+        category as Parameters<typeof this.memory.preferences.findByUserAndCategory>[1],
+      );
+    }
+    return this.memory.preferences.findByUser(userId);
+  }
+
+  @Get('preferences/:key')
+  async getPreference(@Query('userId') userId: string, @Param('key') key: string) {
+    const pref = await this.memory.preferences.findByUserAndKey(userId, key);
+    if (!pref) throw new NotFoundException('Preference not found');
+    return pref;
+  }
+
+  @Post('preferences')
+  async upsertPreference(@Query('userId') userId: string, @Body() dto: UpsertPreferenceDto) {
+    return this.memory.preferences.upsert({
+      userId,
+      key: dto.key,
+      value: dto.value,
+      category: dto.category,
+      source: dto.source,
+    });
+  }
+
+  @Delete('preferences/:key')
+  @HttpCode(HttpStatus.NO_CONTENT)
+  async removePreference(@Query('userId') userId: string, @Param('key') key: string) {
+    const deleted = await this.memory.preferences.remove(userId, key);
+    if (!deleted) throw new NotFoundException('Preference not found');
+  }
+
+  // ─── Insights ───────────────────────────────────────────────────────
+
+  @Get('insights')
+  async listInsights(@Query('userId') userId: string, @Query('limit') limit?: string) {
+    return this.memory.insights.findByUser(userId, limit ? Number(limit) : undefined);
+  }
+
+  @Get('insights/:id')
+  async getInsight(@Param('id') id: string) {
+    const insight = await this.memory.insights.findById(id);
+    if (!insight) throw new NotFoundException('Insight not found');
+    return insight;
+  }
+
+  @Post('insights')
+  async createInsight(@Query('userId') userId: string, @Body() dto: CreateInsightDto) {
+    const embedding = this.embeddings.available
+      ? await this.embeddings.embed(dto.content)
+      : undefined;
+
+    return this.memory.insights.create({
+      userId,
+      content: dto.content,
+      source: dto.source,
+      category: dto.category,
+      metadata: dto.metadata,
+      embedding: embedding ?? null,
+    });
+  }
+
+  @Delete('insights/:id')
+  @HttpCode(HttpStatus.NO_CONTENT)
+  async removeInsight(@Param('id') id: string) {
+    const deleted = await this.memory.insights.remove(id);
+    if (!deleted) throw new NotFoundException('Insight not found');
+  }
+
+  // ─── Search ─────────────────────────────────────────────────────────
+
+  @Post('search')
+  async searchMemory(@Query('userId') userId: string, @Body() dto: SearchMemoryDto) {
+    if (!this.embeddings.available) {
+      return {
+        query: dto.query,
+        results: [],
+        message: 'Semantic search requires OPENAI_API_KEY for embeddings',
+      };
+    }
+
+    const queryEmbedding = await this.embeddings.embed(dto.query);
+    const results = await this.memory.insights.searchByEmbedding(
+      userId,
+      queryEmbedding,
+      dto.limit ?? 10,
+      dto.maxDistance ?? 0.8,
+    );
+
+    return { query: dto.query, results };
+  }
+}

apps/gateway/src/memory/memory.dto.ts

@@ -0,0 +1,19 @@
+export interface UpsertPreferenceDto {
+  key: string;
+  value: unknown;
+  category?: 'communication' | 'coding' | 'workflow' | 'appearance' | 'general';
+  source?: string;
+}
+
+export interface CreateInsightDto {
+  content: string;
+  source?: 'agent' | 'user' | 'summarization' | 'system';
+  category?: 'decision' | 'learning' | 'preference' | 'fact' | 'pattern' | 'general';
+  metadata?: Record<string, unknown>;
+}
+
+export interface SearchMemoryDto {
+  query: string;
+  limit?: number;
+  maxDistance?: number;
+}

apps/gateway/src/memory/memory.module.ts

@@ -0,0 +1,22 @@
+import { Global, Module } from '@nestjs/common';
+import { createMemory, type Memory } from '@mosaic/memory';
+import type { Db } from '@mosaic/db';
+import { DB } from '../database/database.module.js';
+import { MEMORY } from './memory.tokens.js';
+import { MemoryController } from './memory.controller.js';
+import { EmbeddingService } from './embedding.service.js';
+
+@Global()
+@Module({
+  providers: [
+    {
+      provide: MEMORY,
+      useFactory: (db: Db): Memory => createMemory(db),
+      inject: [DB],
+    },
+    EmbeddingService,
+  ],
+  controllers: [MemoryController],
+  exports: [MEMORY, EmbeddingService],
+})
+export class MemoryModule {}

apps/gateway/src/memory/memory.tokens.ts

@@ -0,0 +1 @@
+export const MEMORY = 'MEMORY';

apps/gateway/src/skills/skills.controller.ts

@@ -0,0 +1,67 @@
+import {
+  Body,
+  Controller,
+  Delete,
+  Get,
+  HttpCode,
+  HttpStatus,
+  NotFoundException,
+  Param,
+  Patch,
+  Post,
+  UseGuards,
+} from '@nestjs/common';
+import { SkillsService } from './skills.service.js';
+import { AuthGuard } from '../auth/auth.guard.js';
+import type { CreateSkillDto, UpdateSkillDto } from './skills.dto.js';
+
+@Controller('api/skills')
+@UseGuards(AuthGuard)
+export class SkillsController {
+  constructor(private readonly skills: SkillsService) {}
+
+  @Get()
+  async list() {
+    return this.skills.findAll();
+  }
+
+  @Get(':id')
+  async findOne(@Param('id') id: string) {
+    const skill = await this.skills.findById(id);
+    if (!skill) throw new NotFoundException('Skill not found');
+    return skill;
+  }
+
+  @Post()
+  async create(@Body() dto: CreateSkillDto) {
+    return this.skills.create({
+      name: dto.name,
+      description: dto.description,
+      version: dto.version,
+      source: dto.source,
+      config: dto.config,
+      enabled: dto.enabled,
+    });
+  }
+
+  @Patch(':id')
+  async update(@Param('id') id: string, @Body() dto: UpdateSkillDto) {
+    const skill = await this.skills.update(id, dto);
+    if (!skill) throw new NotFoundException('Skill not found');
+    return skill;
+  }
+
+  @Patch(':id/toggle')
+  async toggle(@Param('id') id: string, @Body() body: { enabled: boolean }) {
+    const skill = await this.skills.toggle(id, body.enabled);
+    if (!skill) throw new NotFoundException('Skill not found');
+    return skill;
+  }
+
+  @Delete(':id')
+  @HttpCode(HttpStatus.NO_CONTENT)
+  async remove(@Param('id') id: string) {
+    const deleted = await this.skills.remove(id);
+    if (!deleted) throw new NotFoundException('Skill not found');
+  }
+}

apps/gateway/src/skills/skills.dto.ts

@@ -0,0 +1,15 @@
+export interface CreateSkillDto {
+  name: string;
+  description?: string;
+  version?: string;
+  source?: 'builtin' | 'community' | 'custom';
+  config?: Record<string, unknown>;
+  enabled?: boolean;
+}
+
+export interface UpdateSkillDto {
+  description?: string;
+  version?: string;
+  config?: Record<string, unknown>;
+  enabled?: boolean;
+}

apps/gateway/src/skills/skills.module.ts

@@ -0,0 +1,10 @@
+import { Module } from '@nestjs/common';
+import { SkillsService } from './skills.service.js';
+import { SkillsController } from './skills.controller.js';
+
+@Module({
+  providers: [SkillsService],
+  controllers: [SkillsController],
+  exports: [SkillsService],
+})
+export class SkillsModule {}

apps/gateway/src/skills/skills.service.ts

@@ -0,0 +1,52 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { eq, type Db, skills } from '@mosaic/db';
+import { DB } from '../database/database.module.js';
+
+type Skill = typeof skills.$inferSelect;
+type NewSkill = typeof skills.$inferInsert;
+
+@Injectable()
+export class SkillsService {
+  constructor(@Inject(DB) private readonly db: Db) {}
+
+  async findAll(): Promise<Skill[]> {
+    return this.db.select().from(skills);
+  }
+
+  async findEnabled(): Promise<Skill[]> {
+    return this.db.select().from(skills).where(eq(skills.enabled, true));
+  }
+
+  async findById(id: string): Promise<Skill | undefined> {
+    const rows = await this.db.select().from(skills).where(eq(skills.id, id));
+    return rows[0];
+  }
+
+  async findByName(name: string): Promise<Skill | undefined> {
+    const rows = await this.db.select().from(skills).where(eq(skills.name, name));
+    return rows[0];
+  }
+
+  async create(data: NewSkill): Promise<Skill> {
+    const rows = await this.db.insert(skills).values(data).returning();
+    return rows[0]!;
+  }
+
+  async update(id: string, data: Partial<NewSkill>): Promise<Skill | undefined> {
+    const rows = await this.db
+      .update(skills)
+      .set({ ...data, updatedAt: new Date() })
+      .where(eq(skills.id, id))
+      .returning();
+    return rows[0];
+  }
+
+  async remove(id: string): Promise<boolean> {
+    const rows = await this.db.delete(skills).where(eq(skills.id, id)).returning();
+    return rows.length > 0;
+  }
+
+  async toggle(id: string, enabled: boolean): Promise<Skill | undefined> {
+    return this.update(id, { enabled });
+  }
+}