# How to integrate Fixer io MCP with Pydantic AI ```json { "title": "How to integrate Fixer io MCP with Pydantic AI", "toolkit": "Fixer io", "toolkit_slug": "fixer_io", "framework": "Pydantic AI", "framework_slug": "pydantic-ai", "url": "https://composio.dev/toolkits/fixer_io/framework/pydantic-ai", "markdown_url": "https://composio.dev/toolkits/fixer_io/framework/pydantic-ai.md", "updated_at": "2026-05-06T08:12:00.600Z" } ``` ## Introduction This guide walks you through connecting Fixer io to Pydantic AI using the Composio tool router. By the end, you'll have a working Fixer io agent that can convert 150 usd to eur today, show exchange rate trends for gbp last month, list all supported currency codes and names through natural language commands. This guide will help you understand how to give your Pydantic AI agent real control over a Fixer io account through Composio's Fixer io MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved. ## Also integrate Fixer io with - [OpenAI Agents SDK](https://composio.dev/toolkits/fixer_io/framework/open-ai-agents-sdk) - [Claude Agent SDK](https://composio.dev/toolkits/fixer_io/framework/claude-agents-sdk) - [Claude Code](https://composio.dev/toolkits/fixer_io/framework/claude-code) - [Claude Cowork](https://composio.dev/toolkits/fixer_io/framework/claude-cowork) - [Codex](https://composio.dev/toolkits/fixer_io/framework/codex) - [OpenClaw](https://composio.dev/toolkits/fixer_io/framework/openclaw) - [Hermes](https://composio.dev/toolkits/fixer_io/framework/hermes-agent) - [CLI](https://composio.dev/toolkits/fixer_io/framework/cli) - [Google ADK](https://composio.dev/toolkits/fixer_io/framework/google-adk) - [LangChain](https://composio.dev/toolkits/fixer_io/framework/langchain) - [Vercel AI SDK](https://composio.dev/toolkits/fixer_io/framework/ai-sdk) - [Mastra AI](https://composio.dev/toolkits/fixer_io/framework/mastra-ai) - [LlamaIndex](https://composio.dev/toolkits/fixer_io/framework/llama-index) - [CrewAI](https://composio.dev/toolkits/fixer_io/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 Fixer io - 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 Fixer io 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 Fixer io MCP server, and what's possible with it? The Fixer io MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Fixer io account. It provides structured and secure access to global currency exchange data, so your agent can perform actions like converting currencies, fetching historical rates, tracking exchange fluctuations, and listing supported symbols on your behalf. - Real-time currency conversion: Instantly convert amounts between currencies using up-to-date or historical exchange rates with a single prompt. - Fetch latest and historical rates: Let your agent retrieve the most recent exchange rates or get historical rates for any supported date to power financial analysis. - Analyze currency fluctuations: Ask your agent to track and summarize day-to-day currency changes between two dates to monitor trends or volatility. - Retrieve supported currency symbols: Quickly list all available currency codes and their full names to support app interfaces or custom workflows. - Get exchange rate time series: Easily pull daily exchange rates over a custom period (up to 365 days) for detailed trend analysis or reporting. ## Supported Tools | Tool slug | Name | Description | |---|---|---| | `FIXER_IO_CONVERT_CURRENCY` | Convert Currency | Tool to convert an amount from one currency to another. Use when you need current or historical exchange rates. Specify `date` for historical rates. | | `FIXER_IO_GET_FLUCTUATION` | Get Currency Fluctuations | Tool to fetch exchange rate fluctuations between two dates. Use when you need day-to-day currency rate changes. | | `FIXER_IO_GET_HISTORICAL_RATES` | Get Historical Rates | Tool to fetch historical exchange rates for a specific date. Use when you need past currency rates. | | `FIXER_IO_GET_LATEST_RATES` | Get Latest Rates | Tool to retrieve the most recent exchange rates. Use when you need current currency conversion rates for all or specified currencies. | | `FIXER_IO_GET_SUPPORTED_SYMBOLS` | Get Supported Symbols | Tool to retrieve the list of all available currency symbols and their corresponding names. Use when you need to fetch and display supported currency codes. | | `FIXER_IO_GET_TIME_SERIES` | Get Time Series | Tool to retrieve daily exchange rates for a specified period. Use when you need historical FX rates between two dates (max 365 days). | ## Supported Triggers None listed. ## Creating MCP Server - Stand-alone vs Composio SDK The Fixer io MCP server is an implementation of the Model Context Protocol that connects your AI agent to Fixer io. It provides structured and secure access so your agent can perform Fixer io 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 Fixer io - 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 Fixer io - MCPServerStreamableHTTP connects to the Fixer io 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 Fixer io 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 Fixer io composio = Composio(api_key=api_key) session = composio.create( user_id=user_id, toolkits=["fixer_io"], ) 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 Fixer io endpoint - The agent uses GPT-5 to interpret user commands and perform Fixer io operations - The instructions field defines the agent's role and behavior ```python # Attach the MCP server to a Pydantic AI Agent fixer_io_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY}) agent = Agent( "openai:gpt-5", toolsets=[fixer_io_mcp], instructions=( "You are a Fixer io assistant. Use Fixer io 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 - Fixer io 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 Fixer io.\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 Fixer io composio = Composio(api_key=api_key) session = composio.create( user_id=user_id, toolkits=["fixer_io"], ) 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 fixer_io_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY}) agent = Agent( "openai:gpt-5", toolsets=[fixer_io_mcp], instructions=( "You are a Fixer io assistant. Use Fixer io 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 Fixer io.\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 Fixer io through Composio's Tool Router. With this setup, your agent can perform real Fixer io 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 + Fixer io 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 Fixer io MCP Agent with another framework - [OpenAI Agents SDK](https://composio.dev/toolkits/fixer_io/framework/open-ai-agents-sdk) - [Claude Agent SDK](https://composio.dev/toolkits/fixer_io/framework/claude-agents-sdk) - [Claude Code](https://composio.dev/toolkits/fixer_io/framework/claude-code) - [Claude Cowork](https://composio.dev/toolkits/fixer_io/framework/claude-cowork) - [Codex](https://composio.dev/toolkits/fixer_io/framework/codex) - [OpenClaw](https://composio.dev/toolkits/fixer_io/framework/openclaw) - [Hermes](https://composio.dev/toolkits/fixer_io/framework/hermes-agent) - [CLI](https://composio.dev/toolkits/fixer_io/framework/cli) - [Google ADK](https://composio.dev/toolkits/fixer_io/framework/google-adk) - [LangChain](https://composio.dev/toolkits/fixer_io/framework/langchain) - [Vercel AI SDK](https://composio.dev/toolkits/fixer_io/framework/ai-sdk) - [Mastra AI](https://composio.dev/toolkits/fixer_io/framework/mastra-ai) - [LlamaIndex](https://composio.dev/toolkits/fixer_io/framework/llama-index) - [CrewAI](https://composio.dev/toolkits/fixer_io/framework/crew-ai) ## Related Toolkits - [Stripe](https://composio.dev/toolkits/stripe) - Stripe is a global online payments platform offering APIs for managing payments, customers, and subscriptions. Trusted by businesses for secure, efficient, and scalable payment processing worldwide. - [Alpha vantage](https://composio.dev/toolkits/alpha_vantage) - Alpha Vantage is a financial data platform offering real-time and historical stock market APIs. Get instant, reliable access to equities, forex, and technical analysis data for smarter trading decisions. - [Altoviz](https://composio.dev/toolkits/altoviz) - Altoviz is a cloud-based billing and invoicing platform for businesses. It streamlines online payments, expense tracking, and customizable invoice management. - [Benzinga](https://composio.dev/toolkits/benzinga) - Benzinga provides real-time financial news and data APIs for market coverage. It helps you track breaking news and actionable market insights instantly. - [Brex](https://composio.dev/toolkits/brex) - Brex provides corporate credit cards and spend management tailored for startups and tech businesses. It helps optimize company cash flow, streamline accounting, and accelerate business growth. - [Chaser](https://composio.dev/toolkits/chaser) - Chaser is accounts receivable automation software that sends invoice reminders and helps businesses get paid faster. It streamlines the collections process to save time and improve cash flow. - [Clientary](https://composio.dev/toolkits/clientary) - Clientary is a platform for managing clients, invoices, projects, proposals, and more. It streamlines client work and saves you serious admin time. - [Coinbase](https://composio.dev/toolkits/coinbase) - Coinbase is a platform for buying, selling, and storing cryptocurrency. It makes exchanging and managing crypto simple and secure for everyone. - [Coinranking](https://composio.dev/toolkits/coinranking) - Coinranking is a comprehensive cryptocurrency market data platform offering access to real-time coin prices, market caps, and historical data. Get accurate, up-to-date stats for thousands of digital assets in one place. - [Coupa](https://composio.dev/toolkits/coupa) - Coupa is a business spend management platform for procurement, invoicing, and expenses. It helps organizations streamline purchasing, control costs, and gain complete visibility over financial operations. - [CurrencyScoop](https://composio.dev/toolkits/currencyscoop) - CurrencyScoop is a developer-friendly API for real-time and historical currency exchange rates. Easily access fiat and crypto data for smart, up-to-date financial applications. - [Daffy](https://composio.dev/toolkits/daffy) - Daffy is a modern charitable giving platform with a donor-advised fund. Easily set aside funds, grow them tax-free, and donate to over 1.7 million U.S. charities. - [Eagle doc](https://composio.dev/toolkits/eagle_doc) - Eagle doc is an AI-powered OCR API for invoices and receipts. It delivers fast, reliable, and accurate document data extraction for seamless automation. - [Elorus](https://composio.dev/toolkits/elorus) - Elorus is an online invoicing and time-tracking software for freelancers and small businesses. Easily manage finances, bill clients, and track work in one place. - [Eodhd apis](https://composio.dev/toolkits/eodhd_apis) - Eodhd apis delivers comprehensive financial data, including live and historical stock prices, via robust APIs. Easily access reliable, up-to-date market insights to power your apps, dashboards, and analytics. - [Fidel api](https://composio.dev/toolkits/fidel_api) - Fidel api is a secure platform for linking payment cards to web and mobile apps. It enables real-time card transaction monitoring and event-based automation for businesses. - [Finage](https://composio.dev/toolkits/finage) - Finage is a secure API platform delivering real-time and historical financial data for stocks, forex, crypto, indices, and commodities. It empowers developers and businesses to access, analyze, and act on market data instantly. - [Finmei](https://composio.dev/toolkits/finmei) - Finmei is an invoicing tool that simplifies billing, invoice management, and expense tracking. Ideal for automating and organizing your business finances in one place. - [Fixer](https://composio.dev/toolkits/fixer) - Fixer is a currency data API offering real-time and historical exchange rates for 170 currencies. Instantly access accurate, up-to-date forex data for your applications and workflows. - [Flutterwave](https://composio.dev/toolkits/flutterwave) - Flutterwave is a global payments platform enabling businesses to accept and send payments across Africa and beyond. Its robust APIs simplify cross-border transactions and financial operations. ## Frequently Asked Questions ### What are the differences in Tool Router MCP and Fixer io MCP? With a standalone Fixer io MCP server, the agents and LLMs can only access a fixed set of Fixer io tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Fixer io 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 Fixer io tools. ### Can I manage the permissions and scopes for Fixer io while using Tool Router? Yes, absolutely. You can configure which Fixer io 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 Fixer io data and credentials are handled as safely as possible. --- [See all toolkits](https://composio.dev/toolkits) ยท [Composio docs](https://docs.composio.dev/llms.txt)