feat(config): add MosaicConfig schema + loader with tier auto-detection

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

packages/config/src/index.ts

@@ -0,0 +1,7 @@
+export type { MosaicConfig, StorageTier, MemoryConfigRef } from './mosaic-config.js';
+export {
+  DEFAULT_LOCAL_CONFIG,
+  DEFAULT_TEAM_CONFIG,
+  loadConfig,
+  validateConfig,
+} from './mosaic-config.js';

packages/config/src/mosaic-config.ts

@@ -0,0 +1,140 @@
+import { readFileSync, existsSync } from 'node:fs';
+import { resolve } from 'node:path';
+import type { StorageConfig } from '@mosaic/storage';
+import type { QueueAdapterConfig as QueueConfig } from '@mosaic/queue';
+
+/* ------------------------------------------------------------------ */
+/*  Types                                                              */
+/* ------------------------------------------------------------------ */
+
+export type StorageTier = 'local' | 'team';
+
+export interface MemoryConfigRef {
+  type: 'pgvector' | 'sqlite-vec' | 'keyword';
+}
+
+export interface MosaicConfig {
+  tier: StorageTier;
+  storage: StorageConfig;
+  queue: QueueConfig;
+  memory: MemoryConfigRef;
+}
+
+/* ------------------------------------------------------------------ */
+/*  Defaults                                                           */
+/* ------------------------------------------------------------------ */
+
+export const DEFAULT_LOCAL_CONFIG: MosaicConfig = {
+  tier: 'local',
+  storage: { type: 'sqlite', path: '.mosaic/data.db' },
+  queue: { type: 'local', dataDir: '.mosaic/queue' },
+  memory: { type: 'keyword' },
+};
+
+export const DEFAULT_TEAM_CONFIG: MosaicConfig = {
+  tier: 'team',
+  storage: { type: 'postgres', url: 'postgresql://mosaic:mosaic@localhost:5432/mosaic' },
+  queue: { type: 'bullmq' },
+  memory: { type: 'pgvector' },
+};
+
+/* ------------------------------------------------------------------ */
+/*  Validation                                                         */
+/* ------------------------------------------------------------------ */
+
+const VALID_TIERS = new Set<string>(['local', 'team']);
+const VALID_STORAGE_TYPES = new Set<string>(['postgres', 'sqlite', 'files']);
+const VALID_QUEUE_TYPES = new Set<string>(['bullmq', 'local']);
+const VALID_MEMORY_TYPES = new Set<string>(['pgvector', 'sqlite-vec', 'keyword']);
+
+export function validateConfig(raw: unknown): MosaicConfig {
+  if (typeof raw !== 'object' || raw === null) {
+    throw new Error('MosaicConfig must be a non-null object');
+  }
+
+  const obj = raw as Record<string, unknown>;
+
+  // tier
+  const tier = obj['tier'];
+  if (typeof tier !== 'string' || !VALID_TIERS.has(tier)) {
+    throw new Error(`Invalid tier "${String(tier)}" — expected "local" or "team"`);
+  }
+
+  // storage
+  const storage = obj['storage'];
+  if (typeof storage !== 'object' || storage === null) {
+    throw new Error('config.storage must be a non-null object');
+  }
+  const storageType = (storage as Record<string, unknown>)['type'];
+  if (typeof storageType !== 'string' || !VALID_STORAGE_TYPES.has(storageType)) {
+    throw new Error(`Invalid storage.type "${String(storageType)}"`);
+  }
+
+  // queue
+  const queue = obj['queue'];
+  if (typeof queue !== 'object' || queue === null) {
+    throw new Error('config.queue must be a non-null object');
+  }
+  const queueType = (queue as Record<string, unknown>)['type'];
+  if (typeof queueType !== 'string' || !VALID_QUEUE_TYPES.has(queueType)) {
+    throw new Error(`Invalid queue.type "${String(queueType)}"`);
+  }
+
+  // memory
+  const memory = obj['memory'];
+  if (typeof memory !== 'object' || memory === null) {
+    throw new Error('config.memory must be a non-null object');
+  }
+  const memoryType = (memory as Record<string, unknown>)['type'];
+  if (typeof memoryType !== 'string' || !VALID_MEMORY_TYPES.has(memoryType)) {
+    throw new Error(`Invalid memory.type "${String(memoryType)}"`);
+  }
+
+  return {
+    tier: tier as StorageTier,
+    storage: storage as StorageConfig,
+    queue: queue as QueueConfig,
+    memory: memory as MemoryConfigRef,
+  };
+}
+
+/* ------------------------------------------------------------------ */
+/*  Loader                                                             */
+/* ------------------------------------------------------------------ */
+
+function detectFromEnv(): MosaicConfig {
+  if (process.env['DATABASE_URL']) {
+    return {
+      ...DEFAULT_TEAM_CONFIG,
+      storage: {
+        type: 'postgres',
+        url: process.env['DATABASE_URL'],
+      },
+      queue: {
+        type: 'bullmq',
+        url: process.env['VALKEY_URL'],
+      },
+    };
+  }
+  return DEFAULT_LOCAL_CONFIG;
+}
+
+export function loadConfig(configPath?: string): MosaicConfig {
+  // 1. Explicit path or default location
+  const paths = configPath
+    ? [resolve(configPath)]
+    : [
+        resolve(process.cwd(), 'mosaic.config.json'),
+        resolve(process.cwd(), '../../mosaic.config.json'), // monorepo root when cwd is apps/gateway
+      ];
+
+  for (const p of paths) {
+    if (existsSync(p)) {
+      const raw: unknown = JSON.parse(readFileSync(p, 'utf-8'));
+      return validateConfig(raw);
+    }
+  }
+
+  // 2. Fall back to env-var detection
+  return detectFromEnv();
+}