# How to integrate Reply MCP with Mastra AI ```json { "title": "How to integrate Reply MCP with Mastra AI", "toolkit": "Reply", "toolkit_slug": "reply", "framework": "Mastra AI", "framework_slug": "mastra-ai", "url": "https://composio.dev/toolkits/reply/framework/mastra-ai", "markdown_url": "https://composio.dev/toolkits/reply/framework/mastra-ai.md", "updated_at": "2026-05-12T10:23:54.555Z" } ``` ## Introduction This guide walks you through connecting Reply to Mastra AI using the Composio tool router. By the end, you'll have a working Reply agent that can list all active email campaigns this week, get contacts in your 'leads q3' list, show all available email templates through natural language commands. This guide will help you understand how to give your Mastra AI agent real control over a Reply account through Composio's Reply MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved. ## Also integrate Reply with - [OpenAI Agents SDK](https://composio.dev/toolkits/reply/framework/open-ai-agents-sdk) - [Claude Agent SDK](https://composio.dev/toolkits/reply/framework/claude-agents-sdk) - [Claude Code](https://composio.dev/toolkits/reply/framework/claude-code) - [Claude Cowork](https://composio.dev/toolkits/reply/framework/claude-cowork) - [Codex](https://composio.dev/toolkits/reply/framework/codex) - [OpenClaw](https://composio.dev/toolkits/reply/framework/openclaw) - [Hermes](https://composio.dev/toolkits/reply/framework/hermes-agent) - [CLI](https://composio.dev/toolkits/reply/framework/cli) - [Google ADK](https://composio.dev/toolkits/reply/framework/google-adk) - [LangChain](https://composio.dev/toolkits/reply/framework/langchain) - [Vercel AI SDK](https://composio.dev/toolkits/reply/framework/ai-sdk) - [LlamaIndex](https://composio.dev/toolkits/reply/framework/llama-index) - [CrewAI](https://composio.dev/toolkits/reply/framework/crew-ai) ## TL;DR Here's what you'll learn: - Set up your environment so Mastra, OpenAI, and Composio work together - Create a Tool Router session in Composio that exposes Reply tools - Connect Mastra's MCP client to the Composio generated MCP URL - Fetch Reply tool definitions and attach them as a toolset - Build a Mastra agent that can reason, call tools, and return structured results - Run an interactive CLI where you can chat with your Reply agent ## What is Mastra AI? Mastra AI is a TypeScript framework for building AI agents with tool support. It provides a clean API for creating agents that can use external services through MCP. Key features include: - MCP Client: Built-in support for Model Context Protocol servers - Toolsets: Organize tools into logical groups - Step Callbacks: Monitor and debug agent execution - OpenAI Integration: Works with OpenAI models via @ai-sdk/openai ## What is the Reply MCP server, and what's possible with it? The Reply 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 create and manage lists, fetch campaign schedules, organize contacts, and monitor outreach performance for you. - Personal list creation and management: Easily instruct your agent to create, organize, or delete personal contact lists to streamline your outreach workflow. - Contact organization and retrieval: Have your agent fetch contacts within specific lists, helping you target and personalize campaigns more effectively. - Campaign and schedule insights: Ask your agent to retrieve all campaign schedules or see which campaigns a specific contact belongs to, giving you up-to-date visibility into your outreach pipeline. - Email account and template discovery: Let your agent pull a list of available email accounts or fetch your personal, team, and community templates for quick access while composing new campaigns. - Blacklist monitoring and management: Direct your agent to retrieve the full list of blacklisted domains and emails, so you can ensure compliance and maintain deliverability standards with ease. ## Supported Tools | Tool slug | Name | Description | |---|---|---| | `REPLY_CREATE_LIST` | Create Personal List | Tool to add a new personal list on the People page. Use when you need to organize contacts into a custom list. | | `REPLY_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_DELETE_LIST_BY_ID` | Delete List By ID | Tool to delete a list by its ID. Use when you need to remove a personal list you own. | | `REPLY_DELETE_SEQUENCE` | Delete Sequence | Tool to delete a sequence. Use after confirming the sequence exists to remove it permanently. | | `REPLY_DELETE_USER` | Delete User | Tool to delete a user. Use after confirming the user exists to remove them permanently. | | `REPLY_GENERATE_ULID` | Generate ULID | Generate ULID | | `REPLY_GET_ALL_LISTS` | Get All Lists | Tool to retrieve all available people lists. Use when you need to list all lists in your Reply account. | | `REPLY_GET_BLACKLIST_ALL` | Get full blacklist of domains and emails | Tool to retrieve the full list of blacklisted domains and emails. Use after confirming updates to the blacklist when you need a complete view. | | `REPLY_GET_CAMPAIGN_SCHEDULES_ALL` | Get all campaign schedules | Retrieves all campaign schedules from Reply.io, including the default schedule and any user-created schedules. Each schedule contains timezone settings, daily timing configurations (mainTimings), and follow-up timings. Use this to view available schedules before assigning one to a campaign or to audit existing schedule configurations. | | `REPLY_GET_CAMPAIGNS_FOR_CONTACT` | Get Campaigns For Contact | Tool to retrieve campaigns a contact belongs to by contact ID. Use when you need to list all sequences (campaigns) associated with a specific contact. | | `REPLY_GET_CONTACTS_IN_LIST_BY_ID` | Get Contacts in List by ID | Tool to retrieve contacts in a specific personal list. Use after obtaining the list ID when you need a paginated set of contacts for that list. | | `REPLY_GET_LIST_BY_ID` | Get List by ID | Tool to return a specific people list by its ID. Use after you know the list ID and need its details. | | `REPLY_GET_TEMPLATES_LIST` | Get templates list | Retrieves all email templates from Reply.io, including user-created, team-shared, organization-wide, and community templates. Use this to browse available templates before sending emails or creating campaigns. No parameters required - returns all accessible templates for the authenticated user. | | `REPLY_LIST_CAMPAIGNS` | List Campaigns | Tool to list all campaigns (sequences). Use when you need a paginated list of campaigns. | | `REPLY_LIST_CONTACTS_BASIC` | List Contacts Basic | Tool to list contacts. Use when verifying API access and gathering contact IDs. | | `REPLY_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_MARK_CONTACT_AS_FINISHED` | Mark Contact As Finished | Marks a contact (by email) or all contacts under a domain as finished in all Reply.io campaigns. Use this tool to stop outreach for contacts who have been successfully engaged or should no longer receive campaign messages. - When using 'email': The specific contact must exist and be enrolled in at least one campaign. - When using 'domain': Marks all contacts with that email domain as finished (succeeds even if no contacts match). Note: Provide exactly one of 'email' or 'domain', not both. | | `REPLY_MARK_CONTACT_AS_REPLIED` | Mark Contact as Replied | Tool to mark a contact as replied in all campaigns by email or domain. Use after confirming the contact has responded. | | `REPLY_MOVE_CONTACTS_TO_LISTS` | Move Contacts to Lists | Tool to move one or more contacts to specified lists. Use when reorganizing contacts across lists after verifying contact and list IDs. | | `REPLY_REMOVE_DOMAIN_FROM_BLACKLIST` | Remove Domain from Blacklist | Tool to remove the specified domain from the blacklist. Use when you need to allow sending to that domain again. | | `REPLY_SEARCH_CONTACTS` | Search Contacts by Email | Tool to search contacts by email. Use when you need to find existing contact IDs for update tests. | ## Supported Triggers None listed. ## Creating MCP Server - Stand-alone vs Composio SDK The Reply MCP server is an implementation of the Model Context Protocol that connects your AI agent to Reply. It provides structured and secure access so your agent can perform Reply 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: - Node.js 18 or higher - A Composio account with an active API key - An OpenAI API key - Basic familiarity with TypeScript ### 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 need credits or a connected billing setup to use the models. - Store the key somewhere safe. Composio API Key - Log in to the [Composio dashboard](https://dashboard.composio.dev?utm_source=toolkits&utm_medium=framework_docs). - Go to Settings and copy your API key. - This key lets your Mastra agent talk to Composio and reach Reply through MCP. ### 2. Install dependencies Install the required packages. What's happening: - @composio/core is the Composio SDK for creating MCP sessions - @mastra/core provides the Agent class - @mastra/mcp is Mastra's MCP client - @ai-sdk/openai is the model wrapper for OpenAI - dotenv loads environment variables from .env ```bash npm install @composio/core @mastra/core @mastra/mcp @ai-sdk/openai dotenv ``` ### 3. Set up environment variables Create a .env file in your project root. What's happening: - COMPOSIO_API_KEY authenticates your requests to Composio - COMPOSIO_USER_ID tells Composio which user this session belongs to - OPENAI_API_KEY lets the Mastra agent call OpenAI models ```bash COMPOSIO_API_KEY=your_composio_api_key_here COMPOSIO_USER_ID=your_user_id_here OPENAI_API_KEY=your_openai_api_key_here ``` ### 4. Import libraries and validate environment What's happening: - dotenv/config auto loads your .env so process.env.* is available - openai gives you a Mastra compatible model wrapper - Agent is the Mastra agent that will call tools and produce answers - MCPClient connects Mastra to your Composio MCP server - Composio is used to create a Tool Router session ```typescript import "dotenv/config"; import { openai } from "@ai-sdk/openai"; import { Agent } from "@mastra/core/agent"; import { MCPClient } from "@mastra/mcp"; import { Composio } from "@composio/core"; import * as readline from "readline"; import type { AiMessageType } from "@mastra/core/agent"; const openaiAPIKey = process.env.OPENAI_API_KEY; const composioAPIKey = process.env.COMPOSIO_API_KEY; const composioUserID = process.env.COMPOSIO_USER_ID; if (!openaiAPIKey) throw new Error("OPENAI_API_KEY is not set"); if (!composioAPIKey) throw new Error("COMPOSIO_API_KEY is not set"); if (!composioUserID) throw new Error("COMPOSIO_USER_ID is not set"); const composio = new Composio({ apiKey: composioAPIKey as string, }); ``` ### 5. Create a Tool Router session for Reply What's happening: - create spins up a short-lived MCP HTTP endpoint for this user - The toolkits array contains "reply" for Reply access - session.mcp.url is the MCP URL that Mastra's MCPClient will connect to ```typescript async function main() { const session = await composio.create( composioUserID as string, { toolkits: ["reply"], }, ); const composioMCPUrl = session.mcp.url; console.log("Reply MCP URL:", composioMCPUrl); ``` ### 6. Configure Mastra MCP client and fetch tools What's happening: - MCPClient takes an id for this client and a list of MCP servers - The headers property includes the x-api-key for authentication - getTools fetches the tool definitions exposed by the Reply toolkit ```typescript const mcpClient = new MCPClient({ id: composioUserID as string, servers: { nasdaq: { url: new URL(composioMCPUrl), requestInit: { headers: session.mcp.headers, }, }, }, timeout: 30_000, }); console.log("Fetching MCP tools from Composio..."); const composioTools = await mcpClient.getTools(); console.log("Number of tools:", Object.keys(composioTools).length); ``` ### 7. Create the Mastra agent What's happening: - Agent is the core Mastra agent - name is just an identifier for logging and debugging - instructions guide the agent to use tools instead of only answering in natural language - model uses openai("gpt-5") to configure the underlying LLM ```typescript const agent = new Agent({ name: "reply-mastra-agent", instructions: "You are an AI agent with Reply tools via Composio.", model: "openai/gpt-5", }); ``` ### 8. Set up interactive chat interface What's happening: - messages keeps the full conversation history in Mastra's expected format - agent.generate runs the agent with conversation history and Reply toolsets - maxSteps limits how many tool calls the agent can take in a single run - onStepFinish is a hook that prints intermediate steps for debugging ```typescript let messages: AiMessageType[] = []; console.log("Chat started! Type 'exit' or 'quit' to end.\n"); const rl = readline.createInterface({ input: process.stdin, output: process.stdout, prompt: "> ", }); rl.prompt(); rl.on("line", async (userInput: string) => { const trimmedInput = userInput.trim(); if (["exit", "quit", "bye"].includes(trimmedInput.toLowerCase())) { console.log("\nGoodbye!"); rl.close(); process.exit(0); } if (!trimmedInput) { rl.prompt(); return; } messages.push({ id: crypto.randomUUID(), role: "user", content: trimmedInput, }); console.log("\nAgent is thinking...\n"); try { const response = await agent.generate(messages, { toolsets: { reply: composioTools, }, maxSteps: 8, }); const { text } = response; if (text && text.trim().length > 0) { console.log(`Agent: ${text}\n`); messages.push({ id: crypto.randomUUID(), role: "assistant", content: text, }); } } catch (error) { console.error("\nError:", error); } rl.prompt(); }); rl.on("close", async () => { console.log("\nSession ended."); await mcpClient.disconnect(); process.exit(0); }); } main().catch((err) => { console.error("Fatal error:", err); process.exit(1); }); ``` ## Complete Code ```typescript import "dotenv/config"; import { openai } from "@ai-sdk/openai"; import { Agent } from "@mastra/core/agent"; import { MCPClient } from "@mastra/mcp"; import { Composio } from "@composio/core"; import * as readline from "readline"; import type { AiMessageType } from "@mastra/core/agent"; const openaiAPIKey = process.env.OPENAI_API_KEY; const composioAPIKey = process.env.COMPOSIO_API_KEY; const composioUserID = process.env.COMPOSIO_USER_ID; if (!openaiAPIKey) throw new Error("OPENAI_API_KEY is not set"); if (!composioAPIKey) throw new Error("COMPOSIO_API_KEY is not set"); if (!composioUserID) throw new Error("COMPOSIO_USER_ID is not set"); const composio = new Composio({ apiKey: composioAPIKey as string }); async function main() { const session = await composio.create(composioUserID as string, { toolkits: ["reply"], }); const composioMCPUrl = session.mcp.url; const mcpClient = new MCPClient({ id: composioUserID as string, servers: { reply: { url: new URL(composioMCPUrl), requestInit: { headers: session.mcp.headers, }, }, }, timeout: 30_000, }); const composioTools = await mcpClient.getTools(); const agent = new Agent({ name: "reply-mastra-agent", instructions: "You are an AI agent with Reply tools via Composio.", model: "openai/gpt-5", }); let messages: AiMessageType[] = []; const rl = readline.createInterface({ input: process.stdin, output: process.stdout, prompt: "> ", }); rl.prompt(); rl.on("line", async (input: string) => { const trimmed = input.trim(); if (["exit", "quit"].includes(trimmed.toLowerCase())) { rl.close(); return; } messages.push({ id: crypto.randomUUID(), role: "user", content: trimmed }); const { text } = await agent.generate(messages, { toolsets: { reply: composioTools }, maxSteps: 8, }); if (text) { console.log(`Agent: ${text}\n`); messages.push({ id: crypto.randomUUID(), role: "assistant", content: text }); } rl.prompt(); }); rl.on("close", async () => { await mcpClient.disconnect(); process.exit(0); }); } main(); ``` ## Conclusion You've built a Mastra AI agent that can interact with Reply through Composio's Tool Router. You can extend this further by: - Adding other toolkits like Gmail, Slack, or GitHub - Building a web-based chat interface around this agent - Using multiple MCP endpoints to enable cross-app workflows ## How to build Reply MCP Agent with another framework - [OpenAI Agents SDK](https://composio.dev/toolkits/reply/framework/open-ai-agents-sdk) - [Claude Agent SDK](https://composio.dev/toolkits/reply/framework/claude-agents-sdk) - [Claude Code](https://composio.dev/toolkits/reply/framework/claude-code) - [Claude Cowork](https://composio.dev/toolkits/reply/framework/claude-cowork) - [Codex](https://composio.dev/toolkits/reply/framework/codex) - [OpenClaw](https://composio.dev/toolkits/reply/framework/openclaw) - [Hermes](https://composio.dev/toolkits/reply/framework/hermes-agent) - [CLI](https://composio.dev/toolkits/reply/framework/cli) - [Google ADK](https://composio.dev/toolkits/reply/framework/google-adk) - [LangChain](https://composio.dev/toolkits/reply/framework/langchain) - [Vercel AI SDK](https://composio.dev/toolkits/reply/framework/ai-sdk) - [LlamaIndex](https://composio.dev/toolkits/reply/framework/llama-index) - [CrewAI](https://composio.dev/toolkits/reply/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 MCP? With a standalone Reply MCP server, the agents and LLMs can only access a fixed set of Reply tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Reply and many other apps based on the task at hand, all through a single MCP endpoint. ### Can I use Tool Router MCP with Mastra AI? Yes, you can. Mastra 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 tools. ### Can I manage the permissions and scopes for Reply while using Tool Router? Yes, absolutely. You can configure which Reply 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 data and credentials are handled as safely as possible. --- [See all toolkits](https://composio.dev/toolkits) · [Composio docs](https://docs.composio.dev/llms.txt)