feat: add @objectstack/service-ai — unified AI capability service plugin

- Expand IAIService contract with streamChat, tool calling, conversation management
- Create packages/services/service-ai with LLM adapter layer, ToolRegistry,
  InMemoryConversationService, REST/SSE routes, kernel plugin
- Add 52 comprehensive tests covering all components
- Update changeset config, CHANGELOG.md, ROADMAP.md

Agent-Logs-Url: https://github.com/objectstack-ai/spec/sessions/c48a190a-19bb-45fd-8caa-0b6b9e1f7c49

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

.changeset/config.json

@@ -37,6 +37,7 @@
       "@objectstack/service-job",
       "@objectstack/service-queue",
       "@objectstack/service-realtime",
+      "@objectstack/service-ai",
       "@objectstack/service-storage",
       "@objectstack/docs",
       "create-objectstack",

CHANGELOG.md

@@ -7,6 +7,23 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+- **`@objectstack/service-ai` — Unified AI capability service plugin** — New kernel plugin
+  providing standardized AI service integration:
+  - Registers as kernel `'ai'` service conforming to `IAIService` contract
+  - LLM adapter layer with provider abstraction (`LLMAdapter` interface) and built-in
+    `MemoryLLMAdapter` for testing/development
+  - `ToolRegistry` for metadata/business tool registration and execution
+  - `InMemoryConversationService` implementing `IAIConversationService` for multi-turn
+    conversation management with message persistence
+  - REST/SSE route self-registration (`/api/v1/ai/chat`, `/api/v1/ai/chat/stream`,
+    `/api/v1/ai/complete`, `/api/v1/ai/models`, `/api/v1/ai/conversations`)
+  - Plugin lifecycle hooks (`ai:ready`, `ai:routes`) for extensibility
+- **Expanded `IAIService` contract** — Added streaming (`streamChat`), tool calling protocol
+  (`AIToolDefinition`, `AIToolCall`, `AIToolResult`, `AIMessageWithTools`,
+  `AIRequestOptionsWithTools`, `AIStreamEvent`), and conversation management
+  (`IAIConversationService`, `AIConversation`) to `packages/spec/src/contracts/ai-service.ts`
+
 ### Documentation
 - **Unified API query syntax documentation with Spec canonical format** — Rewrote
   `content/docs/protocol/objectql/query-syntax.mdx` and

ROADMAP.md

@@ -534,13 +534,13 @@ Objects now declare `namespace: 'sys'` and a short `name` (e.g., `name: 'user'`)
 | `IAutomationService` | **P2** | `@objectstack/service-automation` | ✅ Plugin-based DAG flow engine + HTTP API + Client SDK (67 tests) |
 | `IWorkflowService` | **P2** | `@objectstack/service-workflow` | State machine + approval processes |
 | `IGraphQLService` | **P2** | `@objectstack/service-graphql` | Auto-generated GraphQL from objects |
-| `IAIService` | **P2** | `@objectstack/service-ai` | LLM integration (OpenAI/Anthropic/local) |
+| `IAIService` | **P2** | `@objectstack/service-ai` | ✅ LLM adapter layer, ToolRegistry, conversation management, REST/SSE routes, streaming (52 tests) |
 | `IAnalyticsService` | **P3** | `@objectstack/service-analytics` | ✅ Multi-driver analytics with strategy pattern (NativeSQL/ObjectQL/InMemory), CubeRegistry, generateSql (34 tests) |
 
 - [x] `service-automation` — Implement `IAutomationService` with plugin-based DAG flow engine (CRUD/Logic/HTTP nodes, fault edges, parallel branches, cycle detection, safe eval, timeout, versioning), HTTP API CRUD (9 routes), Client SDK (10 methods), execution history with step-level logging
 - [ ] `service-workflow` — Implement `IWorkflowService` with state machine runtime
 - [ ] `service-graphql` — Implement `IGraphQLService` with auto-schema generation
-- [ ] `service-ai` — Implement `IAIService` with multi-provider LLM routing
+- [x] `service-ai` — Implement `IAIService` with LLM adapter layer, ToolRegistry, InMemoryConversationService, REST/SSE routes (/api/v1/ai/*), streaming support (streamChat), kernel plugin (52 tests)
 - [x] `service-analytics` — Implement full `IAnalyticsService` with multi-driver strategy pattern (NativeSQLStrategy P1, ObjectQLStrategy P2, InMemoryStrategy P3), CubeRegistry with auto-inference from object schemas, generateSql dry-run, kernel plugin lifecycle
 
 ---
@@ -583,7 +583,7 @@ Objects now declare `namespace: 'sys'` and a short `name` (e.g., `name: 'user'`)
   - [x] **Phase A+: Dual Transport** (v3.2) — Remote-only mode via `@libsql/client` (libsql://, https://), auto-detection of transport mode, pre-configured client injection, full CRUD/schema/bulk/transaction support in remote mode
   - [ ] **Phase B: Edge & Sync** (v3.2) — Embedded replica sync, WASM build for Cloudflare/Deno, offline write queue
   - [x] **Phase C: Multi-Tenancy** (v3.3) — Database-per-tenant router with TTL cache, concurrency dedup, lifecycle callbacks
-  - [ ] **Phase D: Advanced** (v4.0) — Vector search + `IAIService`, FTS5 + `ISearchService`, ~~better-auth adapter~~ (✅ done in plugin-auth)
+  - [ ] **Phase D: Advanced** (v4.0) — Vector search + `IAIService` (✅ `service-ai` base implemented), FTS5 + `ISearchService`, ~~better-auth adapter~~ (✅ done in plugin-auth)
 - [ ] Driver benchmark suite comparing performance across all drivers
 
 ### 6.2 Multi-Tenancy
@@ -643,15 +643,15 @@ Objects now declare `namespace: 'sys'` and a short `name` (e.g., `name: 'user'`)
 
 ### 7.1 Core AI Services
 
-- [ ] `service-ai` — Multi-provider LLM service (OpenAI, Anthropic, Gemini, local models)
+- [x] `service-ai` — Multi-provider LLM service with adapter pattern, streaming, tool registry, conversation management, REST/SSE routes
 - [ ] NLQ (Natural Language Query) runtime — translate natural language to ObjectQL
 - [ ] Embedding service for vector search and RAG
 
 ### 7.2 Agent Framework
 
 - [ ] Agent runtime — execute AI agents defined in spec schemas
-- [ ] Tool registry — connect agents to ObjectQL operations, APIs, and workflows
-- [ ] Conversation management — persistent chat with context windows
+- [x] Tool registry — connect agents to ObjectQL operations, APIs, and workflows (initial implementation in `service-ai`)
+- [x] Conversation management — persistent chat with context windows (initial implementation in `service-ai`)
 
 ### 7.3 RAG Pipeline
 
@@ -869,7 +869,7 @@ Final polish and advanced features.
 | 15 | Feed Service | `IFeedService` | ✅ | `@objectstack/service-feed` | In-memory feed/chatter (comments, reactions, subscriptions) |
 | 16 | Search Service | `ISearchService` | ❌ | `@objectstack/service-search` (planned) | Spec only |
 | 17 | Notification Service | `INotificationService` | ❌ | `@objectstack/service-notification` (planned) | Spec only |
-| 18 | AI Service | `IAIService` | ❌ | `@objectstack/service-ai` (planned) | Spec only |
+| 18 | AI Service | `IAIService` | ✅ | `@objectstack/service-ai` | LLM adapter layer, ToolRegistry, conversation management, REST/SSE routes (52 tests) |
 | 19 | Automation Service | `IAutomationService` | ✅ | `@objectstack/service-automation` | DAG engine + HTTP API CRUD + Client SDK + typed returns (67 tests) |
 | 20 | Workflow Service | `IWorkflowService` | ❌ | `@objectstack/service-workflow` (planned) | Spec only |
 | 21 | GraphQL Service | `IGraphQLService` | ❌ | `@objectstack/service-graphql` (planned) | Spec only |

packages/services/service-ai/CHANGELOG.md

@@ -0,0 +1,12 @@
+# @objectstack/service-ai
+
+## 3.3.1
+
+### Patch Changes
+
+- Initial release of AI Service plugin
+  - LLM adapter layer with provider abstraction (memory adapter included)
+  - Conversation management service with in-memory persistence
+  - Tool registry for metadata/business tool registration
+  - REST/SSE route self-registration (`/api/v1/ai/*`)
+  - Kernel plugin registering as `'ai'` service conforming to `IAIService` contract

packages/services/service-ai/package.json

@@ -0,0 +1,29 @@
+{
+  "name": "@objectstack/service-ai",
+  "version": "3.3.1",
+  "license": "Apache-2.0",
+  "description": "AI Service for ObjectStack — implements IAIService with LLM adapter layer, conversation management, tool registry, and REST/SSE routes",
+  "type": "module",
+  "main": "dist/index.js",
+  "types": "dist/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./dist/index.d.ts",
+      "import": "./dist/index.js",
+      "require": "./dist/index.cjs"
+    }
+  },
+  "scripts": {
+    "build": "tsup --config ../../../tsup.config.ts",
+    "test": "vitest run"
+  },
+  "dependencies": {
+    "@objectstack/core": "workspace:*",
+    "@objectstack/spec": "workspace:*"
+  },
+  "devDependencies": {
+    "@types/node": "^25.5.0",
+    "typescript": "^6.0.2",
+    "vitest": "^4.1.2"
+  }
+}