ChatKit Botbuilder

Overview

Create production-grade chatbots using the OpenAI ChatKit framework. This skill enables building chatbots that:

• Integrate AI Agents: Use OpenAI Agents SDK for intelligent conversation handling
• Execute Tools: Connect MCP (Model Context Protocol) tools for real-world task execution
• Support Custom Backends: Build FastAPI backends with full protocol support
• Ensure User Isolation: Implement multi-user systems with JWT authentication
• Real-Time Synchronization: Enable live UI updates when chatbot performs actions
• Flexible Deployment: Deploy to web, mobile, or desktop applications

This skill provides the complete architecture pattern for ChatKit integration, from frontend configuration to backend server implementation.

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When to Use This Skill

Use this skill when you need to:

1. Build a task management chatbot - Create conversational interfaces for task creation, updates, completion
2. Integrate AI into existing apps - Add ChatKit to dashboards, web apps, or platforms
3. Create specialized AI assistants - Build domain-specific chatbots with custom tool integrations
4. Implement multi-user chatbots - Create systems where each user has isolated conversations and data
5. Add real-time capabilities - Build chatbots that trigger actual application changes
6. Deploy AI conversations - Create chatbots that interact with your database and APIs

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Architecture Overview

High-Level Flow

User Message
    ↓
ChatKit Frontend (React/Next.js)
    ↓ [JWT Token in Authorization Header]
    ↓
FastAPI Backend (ChatKit Server)
    ↓ [Extract user_id from JWT]
    ↓
OpenAI Agent (Agents SDK)
    ↓ [Needs tool execution]
    ↓
MCP Tools (Custom Tool Functions)
    ↓ [Creates/Updates/Lists data]
    ↓
Database (User-Isolated Data)
    ↓
Response → ChatKit → Frontend → User

Key Components

1. Frontend (Next.js + ChatKit SDK)

   • ChatKit UI component with conversation history
   • JWT token management in localStorage
   • Custom fetch wrapper with Bearer token authentication
   • Real-time auto-refresh to sync with backend changes

2. Backend (FastAPI + ChatKit Server)

   • ChatKit protocol endpoint handling requests
   • MyChatKitServer class extending ChatKitServer
   • User isolation through JWT middleware
   • Tool wrapper functions for automatic user_id injection

3. Agent (OpenAI Agents SDK)

   • Task management agent with instructions
   • Tool registration and execution
   • Session management

4. Tools (MCP + Custom Functions)

   • Wrapped functions injecting user_id automatically
   • Database operations with user isolation
   • Consistent error handling

5. Database

   • SQLModel ORM models
   • Per-user task filtering
   • Conversation persistence

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Quick Start Workflow

Phase 1: Backend Setup (FastAPI)

1. Create ChatKit Server Class

from chatkit.server import ChatKitServer
from chatkit.store import Store

class MyChatKitServer(ChatKitServer):
    def __init__(self):
        store = CustomChatKitStore()
        super().__init__(store=store)

    async def respond(self, thread, input, context):
        """Process user message and stream AI response"""
        user_id = getattr(context, 'user_id', None)
        # Create agent with wrapped tools
        # Stream response using official pattern

2. Create MCP Tool Wrappers

# Extract user_id from context and inject into tool calls
def add_task_wrapper(title: str, description: str = None):
    return mcp_add_task(user_id=user_id, title=title, description=description)

def list_tasks_wrapper(status: str = "all"):
    return mcp_list_tasks(user_id=user_id, status=status)

3. Create FastAPI Endpoint

@router.post("/api/v1/chatkit")
async def chatkit_protocol_endpoint(request: Request):
    user_id = request.state.user_id  # From JWT middleware
    context = create_context_object(user_id=user_id)
    result = await chatkit_server.process(body, context)
    return StreamingResponse(result, media_type="text/event-stream")

4. Configure JWT Middleware

class JWTAuthMiddleware(BaseHTTPMiddleware):
    async def dispatch(self, request, call_next):
        # Extract JWT token from Authorization header
        # Decode and set request.state.user_id
        # All endpoints have access to authenticated user_id

Phase 2: Frontend Setup (Next.js + React)

1. Configure ChatKit SDK

const chatKitConfig: UseChatKitOptions = {
  api: {
    url: `${API_BASE_URL}/api/v1/chatkit`,
    domainKey: 'your-domain-key',
    fetch: authenticatedFetch, // Custom fetch with JWT
  },
  theme: 'light',
  header: { enabled: true, title: { text: 'AI Chat' } },
  history: { enabled: true },
}

2. Create Authenticated Fetch Wrapper

async function authenticatedFetch(input, options) {
  const token = localStorage.getItem('access_token')
  const headers = {
    ...options?.headers,
    'Authorization': `Bearer ${token}`,
  }
  return fetch(input, { ...options, headers })
}

3. Integrate ChatKit Widget

import { ChatKitWidget } from '@openai/chatkit-react'

export default function Dashboard() {
  return (
    <div className="flex gap-4">
      {/* Your app content */}
      {showChat && (
        <ChatKitWidget {...chatKitConfig} />
      )}
    </div>
  )
}

4. Add Auto-Refresh for Real-Time Sync

useEffect(() => {
  if (!showChatKit) return

  // Refresh immediately when chat opens
  fetchTasks()

  // Refresh every 1 second for real-time updates
  const interval = setInterval(() => {
    fetchTasks()
  }, 1000)

  return () => clearInterval(interval)
}, [showChatKit])

Phase 3: Tool Implementation (MCP)

1. Create MCP Tools with User Isolation

def add_task(user_id: str, title: str, description: Optional[str] = None):
    """Create task - receives user_id from wrapper"""
    task = Task(
        id=str(uuid.uuid4()),
        user_id=user_id,  # Critical: ensure user isolation
        title=title,
        description=description,
        completed=False,
        created_at=datetime.utcnow(),
    )
    with Session(engine) as session:
        session.add(task)
        session.commit()

2. Register MCP Tools

mcp_server = MCPServer()
mcp_server.register_tool("add_task", add_task)
mcp_server.register_tool("list_tasks", list_tasks)
mcp_server.register_tool("delete_task", delete_task)
# ... more tools

---

Core Patterns & Best Practices

1. User Isolation Strategy

Three-Level Guarantee:

1. Middleware Level - JWT validation ensures only authenticated users
2. Tool Level - Wrapper functions automatically inject user_id
3. Database Level - All queries filtered by user_id

# Middleware extracts user_id from token
request.state.user_id = payload.get("user_id")

# Tool wrapper captures and injects it
def add_task_wrapper(title):
    return mcp_add_task(user_id=user_id, ...)

# Database enforces it
WHERE user_id = ? AND task_id = ?

2. Message Flow with User Context

User sends: "Create a task called 'Buy milk'"
    ↓
ChatKit Protocol: POST /api/v1/chatkit
    Header: Authorization: Bearer <JWT>
    Body: { "type": "message", "text": "Create..." }
    ↓
JWT Middleware:
    Extracts user_id from token → request.state.user_id
    ↓
ChatKit Server (MyChatKitServer.respond):
    Gets user_id from context
    Creates wrapper functions capturing user_id
    Passes wrappers to Agent
    ↓
OpenAI Agent:
    Receives message: "Create a task..."
    Selects tool: add_task_wrapper
    Calls: add_task_wrapper(title="Buy milk")
    ↓
Wrapper Function:
    Calls: mcp_add_task(user_id="user-123", title="Buy milk")
    ↓
MCP Tool:
    Creates task with correct user_id
    Returns: {"task_id": "...", "title": "Buy milk"}
    ↓
Agent Response:
    "I've created 'Buy milk' task ✓"
    ↓
ChatKit Frontend:
    Displays response
    Auto-refreshes task list → Sees new task

3. Streaming Response Pattern

# Official ChatKit pattern using Runner.run_streamed
result = Runner.run_streamed(
    task_agent.agent,
    agent_input,
    context=agent_context,
)

# Stream events using official stream_agent_response
async for event in stream_agent_response(agent_context, result):
    yield event

4. Thread and Item Management

# Add user message to thread
await self.store.add_thread_item(thread.id, input, context)

# Load conversation history
items_page = await self.store.load_thread_items(
    thread.id,
    after=None,
    limit=30,
    order="desc",
    context=context,
)

# Convert to agent input
agent_input = await simple_to_agent_input(items)

---

Integration Patterns

Pattern 1: Task Management Chatbot (Basic)

What it does:

• Users create tasks by talking to ChatKit
• ChatKit shows task list in sidebar
• Auto-refresh keeps task list in sync

Files to reference:

• TaskPilotAI Backend Architecture
• Frontend Integration Pattern

Pattern 2: Multi-App ChatKit Deployment

What it does:

• Deploy ChatKit to multiple applications
• Share the same backend and database
• Each app has isolated user contexts

Key setup:

• Use environment variables for API_BASE_URL
• Configure domain key per application
• Implement per-app authentication

Pattern 3: Real-Time Collaboration

What it does:

• Multiple users chat with the same chatbot instance
• Auto-refresh keeps everyone's data in sync
• User isolation prevents cross-user data leaks

Implementation:

• WebSocket connections for true real-time (optional advanced)
• Polling with auto-refresh for simplicity
• Database transactions for data consistency

---

Common Issues & Solutions

Issue 1: Tasks Created in ChatKit Don't Appear in Dashboard

Root Cause: user_id not passed to MCP tools

Solution: Use wrapper functions that capture and inject user_id

def add_task_wrapper(title):
    return mcp_add_task(user_id=user_id, title=title)

Issue 2: One User Sees Another User's Tasks

Root Cause: Missing user_id filter in database queries

Solution: Always filter by user_id at the tool level

stmt = select(Task).where(
    Task.user_id == user_id,
    Task.completed == False
)

Issue 3: ChatKit API Endpoint Not Found

Root Cause: Router not included in FastAPI app

Solution: Include router in main.py

from routes import chatkit
app.include_router(chatkit.router)

Issue 4: Chat Widget Not Showing Messages

Root Cause: Custom fetch not adding JWT token

Solution: Ensure authenticatedFetch adds Bearer token

const token = localStorage.getItem('access_token')
headers['Authorization'] = `Bearer ${token}`

---

Advanced Topics

Real-Time Updates (WebSocket)

For true real-time (not polling):

• Implement WebSocket endpoint alongside HTTP endpoint
• Broadcast updates to all connected clients
• Maintain connection state with user context

Custom Tool Schemas

Structure tool responses for ChatKit widgets:

return {
    "tasks": task_list,
    "total": len(task_list),
    "pending": pending_count,
    "message": "You have 5 tasks",
    "widget": {
        "type": "card",
        "items": formatted_items,
    }
}

Session Persistence

Store conversation history in database:

• Link conversations to users
• Retrieve chat history for context
• Allow resuming conversations

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Resources

This skill includes comprehensive resources for building ChatKit chatbots:

references/

Backend Architecture: Complete FastAPI ChatKit server implementation details and patterns

Frontend Integration: Next.js ChatKit widget configuration and authentication

MCP Tools Guide: Creating wrapped tool functions with automatic user_id injection

User Isolation: Three-level user isolation strategy and verification checklist

scripts/

chatkit_server_template.py - FastAPI ChatKit server boilerplate with all required methods

mcp_wrapper_generator.py - Script to auto-generate MCP tool wrappers

frontend_config_generator.ts - TypeScript config generator for ChatKit frontend setup

assets/

chatkit-nextjs-template/ - Complete Next.js project with ChatKit integrated

fastapi-backend-template/ - Complete FastAPI backend with ChatKit server implementation

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Verification Checklist

When building a ChatKit chatbot, verify:

• JWT middleware extracts user_id from token
• ChatKit endpoint receives user_id in context
• Tool wrappers capture and inject user_id
• Database queries filter by user_id
• Frontend authenticatedFetch includes Bearer token
• ChatKit configuration points to correct backend endpoint
• Auto-refresh periodically fetches updated data
• One user cannot see another user's data
• Chatbot can successfully call MCP tools
• Tool responses appear in ChatKit conversation
• Real-time sync works between chatbot and dashboard

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Next Steps

1. For a new project: Copy the template from assets/fastapi-backend-template/ and assets/chatkit-nextjs-template/
2. For existing app: Follow the "Integration Patterns" section and reference the architecture guides
3. For advanced features: Read the "Advanced Topics" section and extend as needed
4. For troubleshooting: Check "Common Issues & Solutions" and verify the checklist