# How to integrate Bart MCP with Pydantic AI ```json { "title": "How to integrate Bart MCP with Pydantic AI", "toolkit": "Bart", "toolkit_slug": "bart", "framework": "Pydantic AI", "framework_slug": "pydantic-ai", "url": "https://composio.dev/toolkits/bart/framework/pydantic-ai", "markdown_url": "https://composio.dev/toolkits/bart/framework/pydantic-ai.md", "updated_at": "2026-05-12T10:02:26.975Z" } ``` ## Introduction This guide walks you through connecting Bart to Pydantic AI using the Composio tool router. By the end, you'll have a working Bart agent that can find next departures from embarcadero station, get real-time trip updates for richmond line, check current bart service advisories and alerts through natural language commands. This guide will help you understand how to give your Pydantic AI agent real control over a Bart account through Composio's Bart MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved. ## Also integrate Bart with - [OpenAI Agents SDK](https://composio.dev/toolkits/bart/framework/open-ai-agents-sdk) - [Claude Agent SDK](https://composio.dev/toolkits/bart/framework/claude-agents-sdk) - [Claude Code](https://composio.dev/toolkits/bart/framework/claude-code) - [Claude Cowork](https://composio.dev/toolkits/bart/framework/claude-cowork) - [Codex](https://composio.dev/toolkits/bart/framework/codex) - [OpenClaw](https://composio.dev/toolkits/bart/framework/openclaw) - [Hermes](https://composio.dev/toolkits/bart/framework/hermes-agent) - [CLI](https://composio.dev/toolkits/bart/framework/cli) - [Google ADK](https://composio.dev/toolkits/bart/framework/google-adk) - [LangChain](https://composio.dev/toolkits/bart/framework/langchain) - [Vercel AI SDK](https://composio.dev/toolkits/bart/framework/ai-sdk) - [Mastra AI](https://composio.dev/toolkits/bart/framework/mastra-ai) - [LlamaIndex](https://composio.dev/toolkits/bart/framework/llama-index) - [CrewAI](https://composio.dev/toolkits/bart/framework/crew-ai) ## TL;DR Here's what you'll learn: - How to set up your Composio API key and User ID - How to create a Composio Tool Router session for Bart - How to attach an MCP Server to a Pydantic AI agent - How to stream responses and maintain chat history - How to build a simple REPL-style chat interface to test your Bart workflows ## What is Pydantic AI? Pydantic AI is a Python framework for building AI agents with strong typing and validation. It leverages Pydantic's data validation capabilities to create robust, type-safe AI applications. Key features include: - Type Safety: Built on Pydantic for automatic data validation - MCP Support: Native support for Model Context Protocol servers - Streaming: Built-in support for streaming responses - Async First: Designed for async/await patterns ## What is the Bart MCP server, and what's possible with it? The Bart MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to BART's public transit data. It provides structured and secure access to real-time schedules, route information, station details, and service advisories, so your agent can plan trips, fetch live updates, check advisories, and explore routes for you. - Trip planning with live schedules: Instantly retrieve train arrival or departure times and help users plan journeys between any BART stations based on the latest schedule data. - Live service advisories and alerts: Keep travelers informed by fetching up-to-date system-wide or station-specific service advisories, ensuring users know about delays or disruptions before they travel. - Route and station discovery: Access detailed information about BART routes and stations, including amenities and configuration, so your agent can answer travel questions or recommend stations. - Real-time trip and schedule updates: Get the latest trip updates and schedule changes in real time, allowing users to adapt plans quickly if there are changes or issues along their route. - Access to static and GTFS feeds: Download the latest BART GTFS (General Transit Feed Specification) data for offline schedule planning, analysis, or integration with third-party transit tools. ## Supported Tools | Tool slug | Name | Description | |---|---|---| | `BART_BART_GET_API_VERSION` | Get BART API Version | Get the current version of the BART API. This action retrieves version information for the BART (Bay Area Rapid Transit) API, including the current API version number, copyright information, and license details. This is useful for verifying API compatibility and ensuring you're working with the expected API version. The BART API is currently at version 3.10 and supports both XML and JSON output formats. Use this action to confirm which version of the API you're interfacing with and to access licensing information. | | `BART_GET_ELEVATOR_STATUS` | Get Elevator Status | Tool to fetch current elevator status across all BART stations. Use when you need real-time elevator availability information for accessibility planning or route guidance. | | `BART_GET_ESTIMATED_DEPARTURES` | Get Estimated Departures | Tool to get real-time estimated departure times for a specified BART station. Returns live train departure predictions including minutes until departure, platform assignments, train lengths, line colors, bicycle accommodation, and delay information. Use this when you need current departure times for planning trips or checking train status. | | `BART_GET_FARE` | Get BART Fare | Get fare information between two BART stations including Clipper and cash prices. Returns multiple fare types (Clipper, cash, senior/disabled, youth, Clipper START) with their respective prices. Use this when you need to find out how much a BART trip costs between two stations. | | `BART_GET_GTFS_ALERTS` | Get GTFS-RT Service Alerts | Tool to fetch GTFS-RT service alerts in protobuf format for integration with GTFS static feed. Use when you need real-time service advisories, disruptions, or alert information. | | `BART_GET_GTFS_RT_TRIP_UPDATES` | Get GTFS-RT Trip Updates | Tool to fetch real-time trip updates in GTFS-Realtime format. Use when you need the latest live trip information as raw protobuf. | | `BART_GET_GTFS_STATIC_SCHEDULE_FEED` | Download GTFS Static Schedule Feed | Downloads the BART static GTFS (General Transit Feed Specification) schedule feed as a ZIP archive. The GTFS feed contains comprehensive transit data including stations, routes, trip schedules, fares, and service calendars in standardized CSV format. Use this to access complete BART schedule information for route planning, analysis, or integration with transit applications. | | `BART_BART_GET_ROUTE_INFO` | Get Route Info | Tool to fetch detailed information about a specific BART route. Use when you know the route number (1–12) or need all routes configuration. Call after confirming the route ID. | | `BART_GET_ROUTE_SCHEDULE` | Get Route Schedule | Tool to get detailed schedule information for a specific BART route showing all trains and their stops. Use when you need to see the complete schedule for a route including departure times, station stops, bike policies, and passenger load indicators. Call this after determining the specific route number (1-12). | | `BART_GET_SCHEDULE_ARRIVE` | Get BART Schedule Arrive | Tool to retrieve schedule information based on a specified arrival time. Use when planning trips arriving by a given time. | | `BART_GET_SCHEDULE_DEPART` | Get BART Schedule Depart | Get BART train schedules departing from an origin station to a destination station at a specified time. Returns multiple trip options with departure/arrival times, fares (Clipper, cash, senior/disabled, youth), transfer details, train information, and platform numbers. Use this when you need to plan BART trips with specific departure times or when users ask about train schedules between two stations. | | `BART_GET_SERVICE_ADVISORIES` | Get Service Advisories | Tool to fetch current BART service advisories. Use when you need up-to-date system-wide or station-level alerts before presenting or planning transit routes. | | `BART_GET_STATION_ACCESS` | Get Station Access | Get comprehensive station access information including parking, transit, bike facilities, and lockers. Returns detailed access information for a specific BART station including: entering/exiting instructions, parking availability and lot capacity, bike parking and bike station details, locker availability, car-sharing options, nearby destinations, and connected transit services. Use this when you need to help users understand how to access a BART station or what facilities are available. | | `BART_GET_STATION_INFO` | Get Station Info | Get detailed information for a specific BART station by its abbreviation code. Returns comprehensive station details including: name, location (address, city, county, coordinates), routes serving the station (northbound/southbound), platform information, nearby amenities (food, shopping, attractions), and general station description. Use this when you need detailed information about a specific BART station and you already have its 4-letter abbreviation code (e.g., 'EMBR' for Embarcadero, 'MONT' for Montgomery Street, '12TH' for 12th Street Oakland). | | `BART_BART_GET_STATIONS` | Get BART Stations | Get a list of all BART stations with their complete information. This action retrieves information about all BART (Bay Area Rapid Transit) stations including station names, abbreviation codes, geographic coordinates (latitude/longitude), and full addresses. This is useful for finding station locations, getting station codes for other API calls, or building station lookup tools. | | `BART_GET_STATION_SCHEDULE` | Get Station Schedule | Get detailed scheduled departure information for a specific BART station. Returns all trains departing from the station including route line, destination, departure time, bike allowance, crowding level, and platform number. Use this when you need to see all departures from a specific station. | | `BART_GET_TRAIN_COUNT` | Get Train Count | Tool to fetch current count of trains active in the BART system. Use when you need real-time information about how many trains are currently operating. | | `BART_LIST_ROUTES` | List BART Routes | Tool to get a list of all current BART routes/lines with basic information. Use when you need to see all available routes, their colors, directions, or route numbers. | ## Supported Triggers None listed. ## Creating MCP Server - Stand-alone vs Composio SDK The Bart MCP server is an implementation of the Model Context Protocol that connects your AI agent to Bart. It provides structured and secure access so your agent can perform Bart operations on your behalf through a secure, permission-based interface. With Composio's managed implementation, you don't have to create your own developer app. For production, if you're building an end product, we recommend using your own credentials. The managed server helps you prototype fast and go from 0-1 faster. ## Step-by-step Guide ### 1. Prerequisites Before starting, make sure you have: - Python 3.9 or higher - A Composio account with an active API key - Basic familiarity with Python and async programming ### 1. Getting API Keys for OpenAI and Composio OpenAI API Key - Go to the [OpenAI dashboard](https://platform.openai.com/settings/organization/api-keys) and create an API key. You'll need credits to use the models, or you can connect to another model provider. - Keep the API key safe. Composio API Key - Log in to the [Composio dashboard](https://dashboard.composio.dev?utm_source=toolkits&utm_medium=framework_docs). - Navigate to your API settings and generate a new API key. - Store this key securely as you'll need it for authentication. ### 2. Install dependencies Install the required libraries. What's happening: - composio connects your agent to external SaaS tools like Bart - pydantic-ai lets you create structured AI agents with tool support - python-dotenv loads your environment variables securely from a .env file ```bash pip install composio pydantic-ai python-dotenv ``` ### 3. Set up environment variables Create a .env file in your project root. What's happening: - COMPOSIO_API_KEY authenticates your agent to Composio's API - USER_ID associates your session with your account for secure tool access - OPENAI_API_KEY to access OpenAI LLMs ```bash COMPOSIO_API_KEY=your_composio_api_key_here USER_ID=your_user_id_here OPENAI_API_KEY=your_openai_api_key ``` ### 4. Import dependencies What's happening: - We load environment variables and import required modules - Composio manages connections to Bart - MCPServerStreamableHTTP connects to the Bart MCP server endpoint - Agent from Pydantic AI lets you define and run the AI assistant ```python import asyncio import os from dotenv import load_dotenv from composio import Composio from pydantic_ai import Agent from pydantic_ai.mcp import MCPServerStreamableHTTP load_dotenv() ``` ### 5. Create a Tool Router Session What's happening: - We're creating a Tool Router session that gives your agent access to Bart tools - The create method takes the user ID and specifies which toolkits should be available - The returned session.mcp.url is the MCP server URL that your agent will use ```python async def main(): api_key = os.getenv("COMPOSIO_API_KEY") user_id = os.getenv("USER_ID") if not api_key or not user_id: raise RuntimeError("Set COMPOSIO_API_KEY and USER_ID in your environment") # Create a Composio Tool Router session for Bart composio = Composio(api_key=api_key) session = composio.create( user_id=user_id, toolkits=["bart"], ) url = session.mcp.url if not url: raise ValueError("Composio session did not return an MCP URL") ``` ### 6. Initialize the Pydantic AI Agent What's happening: - The MCP client connects to the Bart endpoint - The agent uses GPT-5 to interpret user commands and perform Bart operations - The instructions field defines the agent's role and behavior ```python # Attach the MCP server to a Pydantic AI Agent bart_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY}) agent = Agent( "openai:gpt-5", toolsets=[bart_mcp], instructions=( "You are a Bart assistant. Use Bart tools to help users " "with their requests. Ask clarifying questions when needed." ), ) ``` ### 7. Build the chat interface What's happening: - The agent reads input from the terminal and streams its response - Bart API calls happen automatically under the hood - The model keeps conversation history to maintain context across turns ```python # Simple REPL with message history history = [] print("Chat started! Type 'exit' or 'quit' to end.\n") print("Try asking the agent to help you with Bart.\n") while True: user_input = input("You: ").strip() if user_input.lower() in {"exit", "quit", "bye"}: print("\nGoodbye!") break if not user_input: continue print("\nAgent is thinking...\n", flush=True) async with agent.run_stream(user_input, message_history=history) as stream_result: collected_text = "" async for chunk in stream_result.stream_output(): text_piece = None if isinstance(chunk, str): text_piece = chunk elif hasattr(chunk, "delta") and isinstance(chunk.delta, str): text_piece = chunk.delta elif hasattr(chunk, "text"): text_piece = chunk.text if text_piece: collected_text += text_piece result = stream_result print(f"Agent: {collected_text}\n") history = result.all_messages() ``` ### 8. Run the application What's happening: - The asyncio loop launches the agent and keeps it running until you exit ```python if __name__ == "__main__": asyncio.run(main()) ``` ## Complete Code ```python import asyncio import os from dotenv import load_dotenv from composio import Composio from pydantic_ai import Agent from pydantic_ai.mcp import MCPServerStreamableHTTP load_dotenv() async def main(): api_key = os.getenv("COMPOSIO_API_KEY") user_id = os.getenv("USER_ID") if not api_key or not user_id: raise RuntimeError("Set COMPOSIO_API_KEY and USER_ID in your environment") # Create a Composio Tool Router session for Bart composio = Composio(api_key=api_key) session = composio.create( user_id=user_id, toolkits=["bart"], ) url = session.mcp.url if not url: raise ValueError("Composio session did not return an MCP URL") # Attach the MCP server to a Pydantic AI Agent bart_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY}) agent = Agent( "openai:gpt-5", toolsets=[bart_mcp], instructions=( "You are a Bart assistant. Use Bart tools to help users " "with their requests. Ask clarifying questions when needed." ), ) # Simple REPL with message history history = [] print("Chat started! Type 'exit' or 'quit' to end.\n") print("Try asking the agent to help you with Bart.\n") while True: user_input = input("You: ").strip() if user_input.lower() in {"exit", "quit", "bye"}: print("\nGoodbye!") break if not user_input: continue print("\nAgent is thinking...\n", flush=True) async with agent.run_stream(user_input, message_history=history) as stream_result: collected_text = "" async for chunk in stream_result.stream_output(): text_piece = None if isinstance(chunk, str): text_piece = chunk elif hasattr(chunk, "delta") and isinstance(chunk.delta, str): text_piece = chunk.delta elif hasattr(chunk, "text"): text_piece = chunk.text if text_piece: collected_text += text_piece result = stream_result print(f"Agent: {collected_text}\n") history = result.all_messages() if __name__ == "__main__": asyncio.run(main()) ``` ## Conclusion You've built a Pydantic AI agent that can interact with Bart through Composio's Tool Router. With this setup, your agent can perform real Bart actions through natural language. You can extend this further by: - Adding other toolkits like Gmail, HubSpot, or Salesforce - Building a web-based chat interface around this agent - Using multiple MCP endpoints to enable cross-app workflows (for example, Gmail + Bart for workflow automation) This architecture makes your AI agent "agent-native", able to securely use APIs in a unified, composable way without custom integrations. ## How to build Bart MCP Agent with another framework - [OpenAI Agents SDK](https://composio.dev/toolkits/bart/framework/open-ai-agents-sdk) - [Claude Agent SDK](https://composio.dev/toolkits/bart/framework/claude-agents-sdk) - [Claude Code](https://composio.dev/toolkits/bart/framework/claude-code) - [Claude Cowork](https://composio.dev/toolkits/bart/framework/claude-cowork) - [Codex](https://composio.dev/toolkits/bart/framework/codex) - [OpenClaw](https://composio.dev/toolkits/bart/framework/openclaw) - [Hermes](https://composio.dev/toolkits/bart/framework/hermes-agent) - [CLI](https://composio.dev/toolkits/bart/framework/cli) - [Google ADK](https://composio.dev/toolkits/bart/framework/google-adk) - [LangChain](https://composio.dev/toolkits/bart/framework/langchain) - [Vercel AI SDK](https://composio.dev/toolkits/bart/framework/ai-sdk) - [Mastra AI](https://composio.dev/toolkits/bart/framework/mastra-ai) - [LlamaIndex](https://composio.dev/toolkits/bart/framework/llama-index) - [CrewAI](https://composio.dev/toolkits/bart/framework/crew-ai) ## Related Toolkits - [Google Calendar](https://composio.dev/toolkits/googlecalendar) - Google Calendar is a time management service for scheduling meetings, events, and reminders. It streamlines personal and team organization with integrated notifications and sharing options. - [Apaleo](https://composio.dev/toolkits/apaleo) - Apaleo is a cloud-based property management platform for hospitality businesses. It centralizes reservations, billing, and daily operations for smoother hotel management. - [Appointo](https://composio.dev/toolkits/appointo) - Appointo is an appointment booking platform for Shopify stores. It lets businesses add online scheduling to their websites with zero coding. - [Bookingmood](https://composio.dev/toolkits/bookingmood) - Bookingmood is commission-free booking software for rental businesses. It lets you manage reservations and sync bookings directly on your website. - [Booqable](https://composio.dev/toolkits/booqable) - Booqable is a rental software platform for managing inventory, bookings, and reservations. It helps businesses streamline rentals and keep track of every item with ease. - [Cal](https://composio.dev/toolkits/cal) - Cal is a meeting scheduling platform that offers shareable booking links and real-time calendar syncing. It streamlines the process of finding mutual availability to make scheduling effortless. - [Calendarhero](https://composio.dev/toolkits/calendarhero) - Calendarhero is a powerful scheduling platform that streamlines your calendar management across multiple services. It helps you efficiently schedule, reschedule, and organize meetings without the back-and-forth. - [Calendly](https://composio.dev/toolkits/calendly) - Calendly is an appointment scheduling tool that automates meeting invitations, availability checks, and reminders. It helps individuals and teams avoid endless email back-and-forth when booking meetings. - [Etermin](https://composio.dev/toolkits/etermin) - eTermin is an online appointment scheduling platform for businesses to manage bookings. It streamlines client appointments, saving time and reducing scheduling conflicts. - [Evenium](https://composio.dev/toolkits/evenium) - Evenium is an all-in-one platform for managing professional events, from planning to analysis. It helps teams simplify event logistics, boost engagement, and track every detail in one place. - [Eventee](https://composio.dev/toolkits/eventee) - Eventee is a user-friendly event management platform for mobile and web. It boosts attendee engagement for in-person, virtual, and hybrid events. - [Eventzilla](https://composio.dev/toolkits/eventzilla) - Eventzilla is an event management platform for creating, promoting, and running events. It streamlines ticketing, registration, and attendee coordination for organizers. - [Humanitix](https://composio.dev/toolkits/humanitix) - Humanitix is a not-for-profit ticketing platform that donates 100% of profits to charity. It empowers event organizers to make social impact with every ticket sold. - [Lodgify](https://composio.dev/toolkits/lodgify) - Lodgify is an all-in-one vacation rental software for property managers and owners. It centralizes bookings, guest messaging, and channel synchronization in one dashboard. - [Planyo Online Booking](https://composio.dev/toolkits/planyo_online_booking) - Planyo Online Booking is a flexible reservation system for managing bookings by day, hour, or event. It streamlines scheduling for any business needing reservations. - [Scheduleonce](https://composio.dev/toolkits/scheduleonce) - Scheduleonce is a scheduling platform for capturing, qualifying, and engaging with inbound leads. It streamlines appointment booking and follow-ups for faster lead conversion. - [Supersaas](https://composio.dev/toolkits/supersaas) - Supersaas is a flexible appointment scheduling platform for businesses and individuals. It streamlines bookings, reminders, and calendar management in one place. - [Sympla](https://composio.dev/toolkits/sympla) - Sympla is a platform for managing in-person and online events, ticket sales, and registrations. It streamlines event setup, attendee tracking, and digital content delivery. - [Gmail](https://composio.dev/toolkits/gmail) - Gmail is Google's email service with powerful spam protection, search, and G Suite integration. It keeps your inbox organized and makes communication fast and reliable. - [Google Drive](https://composio.dev/toolkits/googledrive) - Google Drive is a cloud storage platform for uploading, sharing, and collaborating on files. It's perfect for keeping your documents accessible and organized across devices. ## Frequently Asked Questions ### What are the differences in Tool Router MCP and Bart MCP? With a standalone Bart MCP server, the agents and LLMs can only access a fixed set of Bart tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Bart and many other apps based on the task at hand, all through a single MCP endpoint. ### Can I use Tool Router MCP with Pydantic AI? Yes, you can. Pydantic AI fully supports MCP integration. You get structured tool calling, message history handling, and model orchestration while Tool Router takes care of discovering and serving the right Bart tools. ### Can I manage the permissions and scopes for Bart while using Tool Router? Yes, absolutely. You can configure which Bart scopes and actions are allowed when connecting your account to Composio. You can also bring your own OAuth credentials or API configuration so you keep full control over what the agent can do. ### How safe is my data with Composio Tool Router? All sensitive data such as tokens, keys, and configuration is fully encrypted at rest and in transit. Composio is SOC 2 Type 2 compliant and follows strict security practices so your Bart data and credentials are handled as safely as possible. --- [See all toolkits](https://composio.dev/toolkits) · [Composio docs](https://docs.composio.dev/llms.txt)