# How to integrate Writer MCP with Pydantic AI ```json { "title": "How to integrate Writer MCP with Pydantic AI", "toolkit": "Writer", "toolkit_slug": "writer", "framework": "Pydantic AI", "framework_slug": "pydantic-ai", "url": "https://composio.dev/toolkits/writer/framework/pydantic-ai", "markdown_url": "https://composio.dev/toolkits/writer/framework/pydantic-ai.md", "updated_at": "2026-05-12T10:30:46.134Z" } ``` ## Introduction This guide walks you through connecting Writer to Pydantic AI using the Composio tool router. By the end, you'll have a working Writer agent that can summarize key findings from uploaded medical notes, generate chat responses using enterprise llm, list all knowledge graphs in your workspace through natural language commands. This guide will help you understand how to give your Pydantic AI agent real control over a Writer account through Composio's Writer MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved. ## Also integrate Writer with - [OpenAI Agents SDK](https://composio.dev/toolkits/writer/framework/open-ai-agents-sdk) - [Claude Agent SDK](https://composio.dev/toolkits/writer/framework/claude-agents-sdk) - [Claude Code](https://composio.dev/toolkits/writer/framework/claude-code) - [Claude Cowork](https://composio.dev/toolkits/writer/framework/claude-cowork) - [Codex](https://composio.dev/toolkits/writer/framework/codex) - [OpenClaw](https://composio.dev/toolkits/writer/framework/openclaw) - [Hermes](https://composio.dev/toolkits/writer/framework/hermes-agent) - [CLI](https://composio.dev/toolkits/writer/framework/cli) - [Google ADK](https://composio.dev/toolkits/writer/framework/google-adk) - [LangChain](https://composio.dev/toolkits/writer/framework/langchain) - [Vercel AI SDK](https://composio.dev/toolkits/writer/framework/ai-sdk) - [Mastra AI](https://composio.dev/toolkits/writer/framework/mastra-ai) - [LlamaIndex](https://composio.dev/toolkits/writer/framework/llama-index) - [CrewAI](https://composio.dev/toolkits/writer/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 Writer - 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 Writer 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 Writer MCP server, and what's possible with it? The Writer MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Writer account. It provides structured and secure access to your Writer AI platform, so your agent can perform actions like querying knowledge graphs, generating chat completions, extracting medical concepts, managing files, and orchestrating enterprise AI workflows on your behalf. - Conversational AI and content generation: Use your agent to generate chat-based completions and natural language responses using Writer's advanced LLMs. - Enterprise knowledge graph management: Create, retrieve, list, or delete knowledge graphs to organize and access structured knowledge within your organization. - Automated data extraction from clinical text: Extract medical entities and standardized codes (like SNOMED CT) from unstructured clinical or healthcare text for downstream analysis. - Application and model discovery: List available no-code agent applications and LLM models to streamline how your agent selects tools for specific tasks. - File management and inspection: Retrieve and review uploaded files, filter by attributes, and manage your enterprise content for further AI-driven actions. ## Supported Tools | Tool slug | Name | Description | |---|---|---| | `WRITER_ADD_FILE_TO_GRAPH` | Add File to Knowledge Graph | Tool to add a file to a knowledge graph for indexing and retrieval. Use when you need to add an uploaded file to an existing knowledge graph for RAG applications. | | `WRITER_ANALYZE_IMAGES` | Analyze Images | Tool to analyze images using Writer's vision capabilities. Use when you need image understanding, text extraction from images, or visual question answering. Images must be uploaded via POST /v1/files before analysis. | | `WRITER_ASK_QUESTION_TO_KNOWLEDGE_GRAPH` | Ask Question to Knowledge Graph | Tool to send a question to the knowledge graph and retrieve the answer. Use after defining your question and optional context. | | `WRITER_CHAT_COMPLETION` | Chat Completion | Tool to generate chat-based completions. Use when you need conversational AI responses; call after assembling system and user messages. | | `WRITER_CREATE_KNOWLEDGE_GRAPH` | Create Knowledge Graph | Tool to create a new knowledge graph. Use when you need to create an empty graph that files can be added to. | | `WRITER_DELETE_FILE` | Delete File | Tool to delete a file by its ID. Use when you need to permanently remove a file from Writer with no recovery option available. | | `WRITER_DELETE_GRAPH` | Delete Graph | Tool to delete a knowledge graph by its ID. Use when you need to remove a graph after confirming its identifier. | | `WRITER_DETECT_AI_CONTENT` | Detect AI Content | Tool to detect whether content was generated by AI. Returns a classification label and confidence score indicating the likelihood of AI-generated content. Use when you need to verify content authenticity or identify AI-written text. | | `WRITER_DOWNLOAD_FILE` | Download File | Tool to download the binary content of a file. Use when you need to retrieve file data from the Writer platform. The response contains the file in its original format. | | `WRITER_GET_FILE` | Get File | Tool to retrieve detailed information about a specific file by its ID. Use when you need to check a file's metadata, processing status, or associated knowledge graphs. | | `WRITER_LIST_APPLICATIONS` | List Applications | Tool to list all no-code agent applications. Use when you need to retrieve all registered applications. | | `WRITER_LIST_FILES` | List Files | Tool to list all uploaded files. Use when you need to retrieve a paginated set of user files, optionally filtered by status, graph, or type. Use after uploading files to inspect available files. | | `WRITER_LIST_GRAPHS` | List Knowledge Graphs | Tool to retrieve a list of knowledge graphs. Use when you need an overview of existing graphs. | | `WRITER_LIST_MODELS` | List Models | Tool to list all available language models. Use when you need to discover which models can be used for completions. | | `WRITER_MEDICAL_COMPREHEND` | Medical Text Comprehension | Tool to extract medical entities and concepts from unstructured clinical text. Use when you need to label medical text with standardized codes such as SNOMED CT. | | `WRITER_PARSE_PDF` | Parse PDF | Tool to parse and extract text content from a previously uploaded PDF file. Use when you need to convert PDF documents to text or markdown format for further processing. | | `WRITER_REMOVE_FILE_FROM_GRAPH` | Remove File From Graph | Tool to remove a file from a Knowledge Graph. Use when you need to unlink a specific file from a graph by providing both graph and file identifiers. | | `WRITER_RETRIEVE_GRAPH` | Retrieve Knowledge Graph | Tool to retrieve a knowledge graph by its ID. Use when you need details of an existing graph. | | `WRITER_TEXT_GENERATION` | Text Generation | Tool to generate text based on a given prompt. Use when you need model-driven completions after crafting a prompt. | | `WRITER_TRANSLATE_TEXT` | Translate Text | Tool to translate text from one language to another with support for formality, length control, and profanity masking. Use when you need to convert text between different languages. | | `WRITER_UPDATE_GRAPH` | Update Knowledge Graph | Tool to update an existing knowledge graph. Use after confirming the graph_id. Specify at least one of name or description to modify. | | `WRITER_UPLOAD_FILE` | Upload File | Tool to upload a file to Writer. Use when you need to add files for Knowledge Graphs, PDF parsing, or other file-based operations. Files can be associated with Knowledge Graphs for RAG applications. | | `WRITER_WEB_SEARCH` | Web Search | Tool to perform a web search. Use when you need relevant web page results for a given query. | ## Supported Triggers None listed. ## Creating MCP Server - Stand-alone vs Composio SDK The Writer MCP server is an implementation of the Model Context Protocol that connects your AI agent to Writer. It provides structured and secure access so your agent can perform Writer 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 Writer - 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 Writer - MCPServerStreamableHTTP connects to the Writer 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 Writer 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 Writer composio = Composio(api_key=api_key) session = composio.create( user_id=user_id, toolkits=["writer"], ) 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 Writer endpoint - The agent uses GPT-5 to interpret user commands and perform Writer operations - The instructions field defines the agent's role and behavior ```python # Attach the MCP server to a Pydantic AI Agent writer_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY}) agent = Agent( "openai:gpt-5", toolsets=[writer_mcp], instructions=( "You are a Writer assistant. Use Writer 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 - Writer 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 Writer.\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 Writer composio = Composio(api_key=api_key) session = composio.create( user_id=user_id, toolkits=["writer"], ) 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 writer_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY}) agent = Agent( "openai:gpt-5", toolsets=[writer_mcp], instructions=( "You are a Writer assistant. Use Writer 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 Writer.\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 Writer through Composio's Tool Router. With this setup, your agent can perform real Writer 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 + Writer 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 Writer MCP Agent with another framework - [OpenAI Agents SDK](https://composio.dev/toolkits/writer/framework/open-ai-agents-sdk) - [Claude Agent SDK](https://composio.dev/toolkits/writer/framework/claude-agents-sdk) - [Claude Code](https://composio.dev/toolkits/writer/framework/claude-code) - [Claude Cowork](https://composio.dev/toolkits/writer/framework/claude-cowork) - [Codex](https://composio.dev/toolkits/writer/framework/codex) - [OpenClaw](https://composio.dev/toolkits/writer/framework/openclaw) - [Hermes](https://composio.dev/toolkits/writer/framework/hermes-agent) - [CLI](https://composio.dev/toolkits/writer/framework/cli) - [Google ADK](https://composio.dev/toolkits/writer/framework/google-adk) - [LangChain](https://composio.dev/toolkits/writer/framework/langchain) - [Vercel AI SDK](https://composio.dev/toolkits/writer/framework/ai-sdk) - [Mastra AI](https://composio.dev/toolkits/writer/framework/mastra-ai) - [LlamaIndex](https://composio.dev/toolkits/writer/framework/llama-index) - [CrewAI](https://composio.dev/toolkits/writer/framework/crew-ai) ## Related Toolkits - [Composio](https://composio.dev/toolkits/composio) - Composio is an integration platform that connects AI agents with hundreds of business tools. It streamlines authentication and lets you trigger actions across services—no custom code needed. - [Composio search](https://composio.dev/toolkits/composio_search) - Composio search is a unified web search toolkit spanning travel, e-commerce, news, financial markets, images, and more. It lets you and your apps tap into up-to-date web data from a single, easy-to-integrate service. - [Perplexityai](https://composio.dev/toolkits/perplexityai) - Perplexityai delivers natural, conversational AI models for generating human-like text. Instantly get context-aware, high-quality responses for chat, search, or complex workflows. - [Browser tool](https://composio.dev/toolkits/browser_tool) - Browser tool is a virtual browser integration that lets AI agents interact with the web programmatically. It enables automated browsing, scraping, and action-taking from any AI workflow. - [Ai ml api](https://composio.dev/toolkits/ai_ml_api) - Ai ml api is a suite of AI/ML models for natural language and image tasks. It provides fast, scalable access to advanced AI capabilities for your apps and workflows. - [Aivoov](https://composio.dev/toolkits/aivoov) - Aivoov is an AI-powered text-to-speech platform offering 1,000+ voices in over 150 languages. Instantly turn written content into natural, human-like audio for any application. - [All images ai](https://composio.dev/toolkits/all_images_ai) - All-Images.ai is an AI-powered image generation and management platform. It helps you create, search, and organize images effortlessly with advanced AI capabilities. - [Anthropic administrator](https://composio.dev/toolkits/anthropic_administrator) - Anthropic administrator is an API for managing Anthropic organizational resources like members, workspaces, and API keys. It helps you automate admin tasks and streamline resource management across your Anthropic organization. - [Api labz](https://composio.dev/toolkits/api_labz) - Api labz is a platform offering a suite of AI-driven APIs and workflow tools. It helps developers automate tasks and build smarter, more efficient applications. - [Apipie ai](https://composio.dev/toolkits/apipie_ai) - Apipie ai is an AI model aggregator offering a single API for accessing top AI models from multiple providers. It helps developers build cost-efficient, latency-optimized AI solutions without juggling multiple integrations. - [Astica ai](https://composio.dev/toolkits/astica_ai) - Astica ai provides APIs for computer vision, NLP, and voice synthesis. Integrate advanced AI features into your app with a single API key. - [Bigml](https://composio.dev/toolkits/bigml) - BigML is a machine learning platform that lets you build, train, and deploy predictive models from your data. Its intuitive interface and robust API make machine learning accessible and efficient. - [Botbaba](https://composio.dev/toolkits/botbaba) - Botbaba is a platform for building, managing, and deploying conversational AI chatbots across messaging channels. It streamlines chatbot automation, making it easier to integrate AI into customer interactions. - [Botpress](https://composio.dev/toolkits/botpress) - Botpress is an open-source platform for building, deploying, and managing chatbots. It helps teams automate conversations and deliver rich, interactive messaging experiences. - [Chatbotkit](https://composio.dev/toolkits/chatbotkit) - Chatbotkit is a platform for building and managing AI-powered chatbots using robust APIs and SDKs. It lets you easily add conversational AI to your apps for better user engagement. - [Cody](https://composio.dev/toolkits/cody) - Cody is an AI assistant built for businesses, trained on your company's knowledge and data. It delivers instant answers and insights, tailored for your team. - [Context7 MCP](https://composio.dev/toolkits/context7_mcp) - Context7 MCP delivers live, version-specific code docs and examples right from the source. It helps developers and AI agents instantly retrieve authoritative programming info—no more out-of-date docs. - [Customgpt](https://composio.dev/toolkits/customgpt) - CustomGPT.ai lets you build and deploy chatbots tailored to your own data and business needs. Get precise and context-aware AI conversations without writing code. - [Datarobot](https://composio.dev/toolkits/datarobot) - Datarobot is a machine learning platform that automates model development, deployment, and monitoring. It empowers organizations to quickly gain predictive insights from large datasets. - [Deepgram](https://composio.dev/toolkits/deepgram) - Deepgram is an AI-powered speech recognition platform for accurate audio transcription and understanding. It enables fast, scalable speech-to-text with advanced audio intelligence features. ## Frequently Asked Questions ### What are the differences in Tool Router MCP and Writer MCP? With a standalone Writer MCP server, the agents and LLMs can only access a fixed set of Writer tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Writer 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 Writer tools. ### Can I manage the permissions and scopes for Writer while using Tool Router? Yes, absolutely. You can configure which Writer 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 Writer data and credentials are handled as safely as possible. --- [See all toolkits](https://composio.dev/toolkits) · [Composio docs](https://docs.composio.dev/llms.txt)