# How to integrate Sendlane MCP with Mastra AI ```json { "title": "How to integrate Sendlane MCP with Mastra AI", "toolkit": "Sendlane", "toolkit_slug": "sendlane", "framework": "Mastra AI", "framework_slug": "mastra-ai", "url": "https://composio.dev/toolkits/sendlane/framework/mastra-ai", "markdown_url": "https://composio.dev/toolkits/sendlane/framework/mastra-ai.md", "updated_at": "2026-05-12T10:25:21.330Z" } ``` ## Introduction This guide walks you through connecting Sendlane to Mastra AI using the Composio tool router. By the end, you'll have a working Sendlane agent that can show all available sendlane custom fields, create a new email list for promotions, list custom fields with pagination details through natural language commands. This guide will help you understand how to give your Mastra AI agent real control over a Sendlane account through Composio's Sendlane MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved. ## Also integrate Sendlane with - [OpenAI Agents SDK](https://composio.dev/toolkits/sendlane/framework/open-ai-agents-sdk) - [Claude Agent SDK](https://composio.dev/toolkits/sendlane/framework/claude-agents-sdk) - [Claude Code](https://composio.dev/toolkits/sendlane/framework/claude-code) - [Claude Cowork](https://composio.dev/toolkits/sendlane/framework/claude-cowork) - [Codex](https://composio.dev/toolkits/sendlane/framework/codex) - [OpenClaw](https://composio.dev/toolkits/sendlane/framework/openclaw) - [Hermes](https://composio.dev/toolkits/sendlane/framework/hermes-agent) - [CLI](https://composio.dev/toolkits/sendlane/framework/cli) - [Google ADK](https://composio.dev/toolkits/sendlane/framework/google-adk) - [LangChain](https://composio.dev/toolkits/sendlane/framework/langchain) - [Vercel AI SDK](https://composio.dev/toolkits/sendlane/framework/ai-sdk) - [LlamaIndex](https://composio.dev/toolkits/sendlane/framework/llama-index) - [CrewAI](https://composio.dev/toolkits/sendlane/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 Sendlane tools - Connect Mastra's MCP client to the Composio generated MCP URL - Fetch Sendlane 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 Sendlane 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 Sendlane MCP server, and what's possible with it? The Sendlane MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Sendlane account. It provides structured and secure access to your Sendlane marketing automation tools, so your agent can perform actions like managing custom fields, creating new mailing lists, and streamlining campaign setup on your behalf. - Retrieve custom fields: Quickly fetch and review all custom fields in your Sendlane account to personalize your marketing and segmentation strategies. - Create new mailing lists: Direct your agent to set up brand new subscriber lists, making it easy to organize contacts before launching email or SMS campaigns. - Automate list management: Effortlessly build and maintain your audience lists through AI-driven workflows, minimizing manual effort and reducing errors. - Simplify campaign preparation: Ensure your agent can gather all required fields and lists before sending targeted email or SMS outreach, enabling smoother campaign launches. ## Supported Tools | Tool slug | Name | Description | |---|---|---| | `SENDLANE_GET_CAMPAIGNS` | Get Campaigns | Tool to retrieve a list of email campaigns. Use when you need to fetch all campaigns with optional pagination. | | `SENDLANE_GET_CUSTOM_FIELDS` | Get Custom Fields | Retrieve a list of all custom fields in your Sendlane account. Custom fields allow you to store additional contact information beyond the standard fields. Use this tool to discover available custom fields, their IDs, names, tags, and types before creating or updating contacts with custom field data. Supports optional pagination via page and per_page parameters. | | `SENDLANE_GET_LISTS` | Get Lists | Tool to retrieve all mailing lists. Use when you need to fetch or display all available contact lists with optional pagination. | | `SENDLANE_LIST_DELETE` | Delete List | Tool to delete a mailing list. Use when you need to remove an unwanted list after confirming its list_id. | | `SENDLANE_POST_LIST` | Create List | Tool to create a new list. Use when you need to add a brand-new mailing list before sending campaigns. | | `SENDLANE_TAG_CREATE` | Create Tag | Tool to create a new tag. Use when you need to segment subscribers using labels. | ## Supported Triggers None listed. ## Creating MCP Server - Stand-alone vs Composio SDK The Sendlane MCP server is an implementation of the Model Context Protocol that connects your AI agent to Sendlane. It provides structured and secure access so your agent can perform Sendlane 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 Sendlane 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 Sendlane What's happening: - create spins up a short-lived MCP HTTP endpoint for this user - The toolkits array contains "sendlane" for Sendlane 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: ["sendlane"], }, ); const composioMCPUrl = session.mcp.url; console.log("Sendlane 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 Sendlane 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: "sendlane-mastra-agent", instructions: "You are an AI agent with Sendlane 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 Sendlane 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: { sendlane: 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: ["sendlane"], }); const composioMCPUrl = session.mcp.url; const mcpClient = new MCPClient({ id: composioUserID as string, servers: { sendlane: { url: new URL(composioMCPUrl), requestInit: { headers: session.mcp.headers, }, }, }, timeout: 30_000, }); const composioTools = await mcpClient.getTools(); const agent = new Agent({ name: "sendlane-mastra-agent", instructions: "You are an AI agent with Sendlane 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: { sendlane: 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 Sendlane 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 Sendlane MCP Agent with another framework - [OpenAI Agents SDK](https://composio.dev/toolkits/sendlane/framework/open-ai-agents-sdk) - [Claude Agent SDK](https://composio.dev/toolkits/sendlane/framework/claude-agents-sdk) - [Claude Code](https://composio.dev/toolkits/sendlane/framework/claude-code) - [Claude Cowork](https://composio.dev/toolkits/sendlane/framework/claude-cowork) - [Codex](https://composio.dev/toolkits/sendlane/framework/codex) - [OpenClaw](https://composio.dev/toolkits/sendlane/framework/openclaw) - [Hermes](https://composio.dev/toolkits/sendlane/framework/hermes-agent) - [CLI](https://composio.dev/toolkits/sendlane/framework/cli) - [Google ADK](https://composio.dev/toolkits/sendlane/framework/google-adk) - [LangChain](https://composio.dev/toolkits/sendlane/framework/langchain) - [Vercel AI SDK](https://composio.dev/toolkits/sendlane/framework/ai-sdk) - [LlamaIndex](https://composio.dev/toolkits/sendlane/framework/llama-index) - [CrewAI](https://composio.dev/toolkits/sendlane/framework/crew-ai) ## Related Toolkits - [Reddit](https://composio.dev/toolkits/reddit) - Reddit is a social news platform with thriving user-driven communities (subreddits). It's the go-to place for discussion, content sharing, and viral marketing. - [Facebook](https://composio.dev/toolkits/facebook) - Facebook is a social media and advertising platform for businesses and creators. It helps you connect, share, and manage content across your public Facebook Pages. - [Linkedin](https://composio.dev/toolkits/linkedin) - LinkedIn is a professional networking platform for connecting, sharing content, and engaging with business opportunities. It's the go-to place for building your professional brand and unlocking new career connections. - [Active campaign](https://composio.dev/toolkits/active_campaign) - ActiveCampaign is a marketing automation and CRM platform for managing email campaigns, sales pipelines, and customer segmentation. It helps businesses engage customers and drive growth through smart automation and targeted outreach. - [ActiveTrail](https://composio.dev/toolkits/active_trail) - ActiveTrail is a user-friendly email marketing and automation platform. It helps you reach subscribers and automate campaigns with ease. - [Ahrefs](https://composio.dev/toolkits/ahrefs) - Ahrefs is an SEO and marketing platform for site audits, keyword research, and competitor insights. It helps you improve search rankings and drive organic traffic. - [Amcards](https://composio.dev/toolkits/amcards) - AMCards lets you create and mail personalized greeting cards online. Build stronger customer relationships with easy, automated card campaigns. - [Beamer](https://composio.dev/toolkits/beamer) - Beamer is a news and changelog platform for in-app announcements and feature updates. It helps companies boost user engagement by sharing news where users are most active. - [Benchmark email](https://composio.dev/toolkits/benchmark_email) - Benchmark Email is a platform for creating, sending, and tracking email campaigns. It's built to help you engage audiences and analyze results—all in one place. - [Bigmailer](https://composio.dev/toolkits/bigmailer) - BigMailer is an email marketing platform for managing multiple brands with white-labeling and automation. It helps teams streamline campaigns and simplify integration with Amazon SES. - [Brandfetch](https://composio.dev/toolkits/brandfetch) - Brandfetch is an API that delivers company logos, colors, and visual branding assets. It helps marketers and developers keep brand visuals consistent everywhere. - [Brevo](https://composio.dev/toolkits/brevo) - Brevo is an all-in-one email and SMS marketing platform for transactional messaging, automation, and CRM. It helps businesses engage customers and streamline communications through powerful campaign tools. - [Campayn](https://composio.dev/toolkits/campayn) - Campayn is an email marketing platform for creating, sending, and managing campaigns. It helps businesses engage contacts and grow audiences with easy-to-use tools. - [Cardly](https://composio.dev/toolkits/cardly) - Cardly is a platform for creating and sending personalized direct mail to customers. It helps businesses break through the digital clutter by getting real engagement via physical mailboxes. - [ClickSend](https://composio.dev/toolkits/clicksend) - ClickSend is a cloud-based SMS and email marketing platform for businesses. It streamlines communication by enabling quick message delivery and contact management. - [Crustdata](https://composio.dev/toolkits/crustdata) - CrustData is an AI-powered data intelligence platform for real-time company and people data. It helps B2B sales teams, AI SDRs, and investors react to live business signals. - [Curated](https://composio.dev/toolkits/curated) - Curated is a platform for collecting, curating, and publishing newsletters. It streamlines content aggregation and distribution for creators and teams. - [Customerio](https://composio.dev/toolkits/customerio) - Customer.io is a customer engagement platform for targeted messaging across email, SMS, and push. Easily automate, segment, and track communications with your audience. - [Cutt ly](https://composio.dev/toolkits/cutt_ly) - Cutt.ly is a URL shortening service for managing and analyzing links. Streamline your workflows with quick, trackable, and branded short URLs. - [Demio](https://composio.dev/toolkits/demio) - Demio is webinar software built for marketers, offering both live and automated sessions with interactive features. It helps teams engage audiences and optimize lead generation through detailed analytics. ## Frequently Asked Questions ### What are the differences in Tool Router MCP and Sendlane MCP? With a standalone Sendlane MCP server, the agents and LLMs can only access a fixed set of Sendlane tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Sendlane 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 Sendlane tools. ### Can I manage the permissions and scopes for Sendlane while using Tool Router? Yes, absolutely. You can configure which Sendlane 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 Sendlane data and credentials are handled as safely as possible. --- [See all toolkits](https://composio.dev/toolkits) · [Composio docs](https://docs.composio.dev/llms.txt)