# How to integrate Reply io MCP with Pydantic AI ```json { "title": "How to integrate Reply io MCP with Pydantic AI", "toolkit": "Reply io", "toolkit_slug": "reply_io", "framework": "Pydantic AI", "framework_slug": "pydantic-ai", "url": "https://composio.dev/toolkits/reply_io/framework/pydantic-ai", "markdown_url": "https://composio.dev/toolkits/reply_io/framework/pydantic-ai.md", "updated_at": "2026-05-12T10:23:56.407Z" } ``` ## Introduction This guide walks you through connecting Reply io to Pydantic AI using the Composio tool router. By the end, you'll have a working Reply io agent that can list all active campaigns this week, show contacts added to sales lists, delete a campaign by campaign id through natural language commands. This guide will help you understand how to give your Pydantic AI agent real control over a Reply io account through Composio's Reply io MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved. ## Also integrate Reply io with - [OpenAI Agents SDK](https://composio.dev/toolkits/reply_io/framework/open-ai-agents-sdk) - [Claude Agent SDK](https://composio.dev/toolkits/reply_io/framework/claude-agents-sdk) - [Claude Code](https://composio.dev/toolkits/reply_io/framework/claude-code) - [Claude Cowork](https://composio.dev/toolkits/reply_io/framework/claude-cowork) - [Codex](https://composio.dev/toolkits/reply_io/framework/codex) - [OpenClaw](https://composio.dev/toolkits/reply_io/framework/openclaw) - [Hermes](https://composio.dev/toolkits/reply_io/framework/hermes-agent) - [CLI](https://composio.dev/toolkits/reply_io/framework/cli) - [Google ADK](https://composio.dev/toolkits/reply_io/framework/google-adk) - [LangChain](https://composio.dev/toolkits/reply_io/framework/langchain) - [Vercel AI SDK](https://composio.dev/toolkits/reply_io/framework/ai-sdk) - [Mastra AI](https://composio.dev/toolkits/reply_io/framework/mastra-ai) - [LlamaIndex](https://composio.dev/toolkits/reply_io/framework/llama-index) - [CrewAI](https://composio.dev/toolkits/reply_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 Reply 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 Reply 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 Reply io MCP server, and what's possible with it? The Reply 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 Reply io account. It provides structured and secure access to your sales engagement platform, so your agent can manage campaigns, handle contacts, organize sequences, and automate routine sales operations on your behalf. - Campaign and sequence management: Effortlessly list, browse, and delete campaigns or sequences to keep your outreach organized and up to date. - Contact and list organization: Let your agent fetch, review, and organize your Reply io contacts and contact lists for targeted sales actions. - Email account administration: Retrieve all connected email accounts or remove outdated ones, making sure your sales tools stay streamlined. - User and access control: Easily remove users or generate unique identifiers for tasks, maintaining security and clarity in your team’s workflow. - Automated data retrieval: Quickly pull up paginated lists of campaigns, sequences, email accounts, or contact lists to inform your sales strategies and next steps. ## Supported Tools | Tool slug | Name | Description | |---|---|---| | `REPLY_IO_ADD_CONTACT_TO_SEQUENCE` | Add Contact to Sequence | Move an existing contact to a sequence in Reply.io. Use this action to enroll contacts in email sequences for automated outreach campaigns. This action allows you to specify where in the sequence to start, whether to remove the contact from their current sequence, and when to begin processing. | | `REPLY_IO_ARCHIVE_SEQUENCE` | Archive Sequence | Tool to archive a sequence. Use when you need to archive an existing sequence without permanently deleting it. | | `REPLY_IO_CLEAR_CONTACT_STATUS` | Clear Contact Status | Tool to clear statuses from contacts. Use when you need to remove specific or all clearable statuses from contacts. | | `REPLY_IO_CONNECT_EXCHANGE_ACCOUNT` | Connect Exchange Account via OAuth | Tool to initiate OAuth connection for an Exchange email account. Use when you need to connect an Exchange account to Reply.io via OAuth flow. Returns the Microsoft OAuth consent page URL where the user should be redirected. | | `REPLY_IO_CONNECT_GMAIL_ACCOUNT` | Connect Gmail Account | Tool to initiate Gmail account connection via OAuth. Returns the OAuth authorization URL where the user should be redirected to grant permissions. | | `REPLY_IO_CREATE_CONTACT` | Create Contact | Tool to create a new contact in Reply.io. Use when adding contacts to your outreach database. | | `REPLY_IO_CREATE_SEQUENCE_STEP` | Create Sequence Step | Tool to add a new step to an existing sequence. Use when you need to build or modify sequence workflows with Email, Call, Task, SMS, WhatsApp, LinkedIn, Condition, or Zapier steps. | | `REPLY_IO_DELETE_CONTACT` | Delete Contact | Tool to delete a contact. Use after confirming the contact exists to remove it permanently. | | `REPLY_IO_DELETE_EMAIL_ACCOUNT` | Delete Email Account | Tool to delete a specific email account. Use when you need to remove an existing email account identified by its ID. | | `REPLY_IO_DELETE_SCHEDULE` | Delete Schedule | Tool to delete a schedule. Use after confirming the schedule exists to remove it permanently. | | `REPLY_IO_DELETE_SEQUENCE` | Delete Sequence | Tool to delete a sequence. Use after confirming the sequence exists to remove it permanently. | | `REPLY_IO_DELETE_USER` | Delete User | Tool to delete a user. Use after confirming the user exists to remove them permanently. | | `REPLY_IO_GENERATE_ULID` | Generate ULID | Generate ULID | | `REPLY_IO_GET_CONTACT_BY_ID` | Get Contact by ID | Tool to retrieve a contact by ID. Use when you have a contact ID and need detailed contact information. | | `REPLY_IO_GET_CONTACT_STATUS` | Get Contact Status | Tool to get contact status. Use when you need to retrieve all current statuses for a contact. | | `REPLY_IO_GET_CURRENT_USER` | Get Current User | Tool to get the current authenticated user's ID. Use when you need to verify API key validity or identify the current user. | | `REPLY_IO_GET_DISCONNECTED_EMAIL_ACCOUNTS` | Reply.io Get Disconnected Email Accounts | Tool to list email accounts that are currently disconnected due to authentication or connection errors. Use when you need to identify and troubleshoot problematic email accounts. | | `REPLY_IO_GET_SEQUENCE_BY_ID` | Get Sequence By ID | Tool to retrieve detailed information about a sequence by its ID. Use when you need to get comprehensive sequence details including settings, email accounts, and workflow steps. | | `REPLY_IO_GET_SEQUENCE_CONTACTS_EXTENDED` | Get Sequence Contacts Extended | Tool to retrieve all contacts enrolled in a sequence with additional details. Use when you need to see contact engagement status, current step, or completion timestamps within a sequence. | | `REPLY_IO_GET_SEQUENCE_STEP_BY_ID` | Get Sequence Step by ID | Tool to retrieve details of a specific sequence step. Use when you need to inspect step configuration including type, delays, execution mode, and type-specific settings. | | `REPLY_IO_LIST_CONTACTS_BASIC` | List Contacts Basic | Tool to list contacts. Use when verifying API access and gathering contact IDs. | | `REPLY_IO_LIST_EMAIL_ACCOUNTS` | Reply.io List Email Accounts | Tool to list all email accounts. Use when you need to retrieve email accounts page by page. | | `REPLY_IO_LIST_LISTS` | Reply.io List Lists | Tool to list all contact lists. Use when you need to retrieve all available lists in your Reply.io account. | | `REPLY_IO_LIST_SEQUENCES` | List Sequences | Tool to retrieve a paginated list of sequences. Use when you need to browse sequences with optional filtering by name. | | `REPLY_IO_LIST_SEQUENCE_STEPS` | List Sequence Steps | Tool to retrieve all steps in a sequence. Use when you need to get the complete list of steps configured for a specific sequence. | | `REPLY_IO_PAUSE_SEQUENCE` | Pause Sequence | Tool to pause a running sequence. Use when you need to temporarily stop a sequence from sending emails or executing steps. | | `REPLY_IO_REMOVE_CONTACT_FROM_SEQUENCE` | Remove Contact From Sequence | Tool to remove a contact from a sequence. Use when you need to stop a contact from receiving further steps in a specific sequence. | | `REPLY_IO_REMOVE_CONTACTS_FROM_SEQUENCE` | Bulk Remove Contacts from Sequence | Tool to bulk remove multiple contacts from a sequence at once. Use when you need to remove several contacts from a sequence efficiently in a single operation. | | `REPLY_IO_SEARCH_CONTACTS` | Search Contacts by Email | Tool to search contacts by email. Use when you need to find existing contact IDs for update tests. | | `REPLY_IO_SET_CONTACT_STATUS` | Set Contact Status | Tool to set the status of one or more contacts. Use when you need to update contact statuses in bulk. | | `REPLY_IO_START_SEQUENCE` | Start Sequence | Tool to start a sequence. Use when you need to activate a sequence that is in New or Paused status. | | `REPLY_IO_UPDATE_CONTACT` | Update Contact | Tool to update an existing contact's information. Use when you need to modify contact details. | | `REPLY_IO_UPDATE_EMAIL_ACCOUNT` | Update Email Account | Tool to update an existing email account with custom SMTP/IMAP settings. Use when you need to modify email account configuration such as sender name, signature, server settings, or daily limits. | ## Supported Triggers None listed. ## Creating MCP Server - Stand-alone vs Composio SDK The Reply io MCP server is an implementation of the Model Context Protocol that connects your AI agent to Reply io. It provides structured and secure access so your agent can perform Reply 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 Reply 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 Reply io - MCPServerStreamableHTTP connects to the Reply 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 Reply 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 Reply io composio = Composio(api_key=api_key) session = composio.create( user_id=user_id, toolkits=["reply_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 Reply io endpoint - The agent uses GPT-5 to interpret user commands and perform Reply io operations - The instructions field defines the agent's role and behavior ```python # Attach the MCP server to a Pydantic AI Agent reply_io_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY}) agent = Agent( "openai:gpt-5", toolsets=[reply_io_mcp], instructions=( "You are a Reply io assistant. Use Reply 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 - Reply 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 Reply 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 Reply io composio = Composio(api_key=api_key) session = composio.create( user_id=user_id, toolkits=["reply_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 reply_io_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY}) agent = Agent( "openai:gpt-5", toolsets=[reply_io_mcp], instructions=( "You are a Reply io assistant. Use Reply 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 Reply 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 Reply io through Composio's Tool Router. With this setup, your agent can perform real Reply 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 + Reply 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 Reply io MCP Agent with another framework - [OpenAI Agents SDK](https://composio.dev/toolkits/reply_io/framework/open-ai-agents-sdk) - [Claude Agent SDK](https://composio.dev/toolkits/reply_io/framework/claude-agents-sdk) - [Claude Code](https://composio.dev/toolkits/reply_io/framework/claude-code) - [Claude Cowork](https://composio.dev/toolkits/reply_io/framework/claude-cowork) - [Codex](https://composio.dev/toolkits/reply_io/framework/codex) - [OpenClaw](https://composio.dev/toolkits/reply_io/framework/openclaw) - [Hermes](https://composio.dev/toolkits/reply_io/framework/hermes-agent) - [CLI](https://composio.dev/toolkits/reply_io/framework/cli) - [Google ADK](https://composio.dev/toolkits/reply_io/framework/google-adk) - [LangChain](https://composio.dev/toolkits/reply_io/framework/langchain) - [Vercel AI SDK](https://composio.dev/toolkits/reply_io/framework/ai-sdk) - [Mastra AI](https://composio.dev/toolkits/reply_io/framework/mastra-ai) - [LlamaIndex](https://composio.dev/toolkits/reply_io/framework/llama-index) - [CrewAI](https://composio.dev/toolkits/reply_io/framework/crew-ai) ## Related Toolkits - [Aeroleads](https://composio.dev/toolkits/aeroleads) - Aeroleads is a B2B lead generation platform for finding business emails and phone numbers. Grow your sales pipeline faster with powerful prospecting tools. - [Autobound](https://composio.dev/toolkits/autobound) - Autobound is an AI-powered sales engagement platform that crafts hyper-personalized outreach and insights. It helps sales teams boost response rates and close more deals through tailored content and recommendations. - [Better proposals](https://composio.dev/toolkits/better_proposals) - Better Proposals is a web-based tool for crafting and sending professional proposals. It helps teams impress clients and close deals faster with slick, easy-to-use templates. - [Bidsketch](https://composio.dev/toolkits/bidsketch) - Bidsketch is a proposal software that helps businesses create professional proposals quickly and efficiently. It streamlines the proposal process, saving time while boosting client win rates. - [Bolna](https://composio.dev/toolkits/bolna) - Bolna is an AI platform for building conversational voice agents. It helps businesses automate support and streamline interactions through natural, voice-powered conversations. - [Botsonic](https://composio.dev/toolkits/botsonic) - Botsonic is a no-code AI chatbot builder for easily creating and deploying chatbots to your website. It empowers businesses to offer conversational experiences without writing code. - [Botstar](https://composio.dev/toolkits/botstar) - BotStar is a comprehensive chatbot platform for designing, developing, and training chatbots visually on Messenger and websites. It helps businesses automate conversations and customer interactions without coding. - [Callerapi](https://composio.dev/toolkits/callerapi) - CallerAPI is a white-label caller identification platform for branded caller ID and fraud prevention. It helps businesses boost customer trust while stopping spam, fraud, and robocalls. - [Callingly](https://composio.dev/toolkits/callingly) - Callingly is a lead response management platform that automates immediate call and text follow-ups with new leads. It helps sales teams boost response speed and close more deals by connecting seamlessly with CRMs and lead sources. - [Callpage](https://composio.dev/toolkits/callpage) - Callpage is a lead capture platform that lets businesses instantly connect with website visitors via callback. It boosts lead generation and increases your sales conversion rates. - [Clearout](https://composio.dev/toolkits/clearout) - Clearout is an AI-powered service for verifying, finding, and enriching email addresses. It boosts deliverability and helps you discover high-quality leads effortlessly. - [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. - [Convolo ai](https://composio.dev/toolkits/convolo_ai) - Convolo ai is an AI-powered communications platform for sales teams. It accelerates lead response and improves conversion rates by automating calls and integrating workflows. - [Delighted](https://composio.dev/toolkits/delighted) - Delighted is a customer feedback platform based on the Net Promoter System®. It helps you quickly gather, track, and act on customer sentiment. - [Emelia](https://composio.dev/toolkits/emelia) - Emelia is an all-in-one B2B prospecting platform for cold-email, LinkedIn outreach, and prospect research. It streamlines outbound campaigns so you can find, engage, and warm up leads faster. - [Findymail](https://composio.dev/toolkits/findymail) - Findymail is a B2B data provider offering verified email and phone contacts for sales prospecting. Enhance outreach with automated exports, email verification, and CRM enrichment. - [Freshdesk](https://composio.dev/toolkits/freshdesk) - Freshdesk is customer support software with ticketing and automation tools. It helps teams streamline helpdesk operations for faster, better customer support. - [Fullenrich](https://composio.dev/toolkits/fullenrich) - FullEnrich is a B2B contact enrichment platform that aggregates emails and phone numbers from 15+ data vendors. Instantly find and verify lead contact data to boost your outreach. - [Gatherup](https://composio.dev/toolkits/gatherup) - GatherUp is a customer feedback and online review management platform. It helps businesses boost their reputation by streamlining how they collect and manage customer feedback. - [Getprospect](https://composio.dev/toolkits/getprospect) - Getprospect is a business email discovery tool with LinkedIn integration. Use it to quickly find and verify professional email addresses. ## Frequently Asked Questions ### What are the differences in Tool Router MCP and Reply io MCP? With a standalone Reply io MCP server, the agents and LLMs can only access a fixed set of Reply io tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Reply 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 Reply io tools. ### Can I manage the permissions and scopes for Reply io while using Tool Router? Yes, absolutely. You can configure which Reply 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 Reply io data and credentials are handled as safely as possible. --- [See all toolkits](https://composio.dev/toolkits) · [Composio docs](https://docs.composio.dev/llms.txt)