# How to integrate Mailersend MCP with Claude Code

```json
{
  "title": "How to integrate Mailersend MCP with Claude Code",
  "toolkit": "Mailersend",
  "toolkit_slug": "mailersend",
  "framework": "Claude Code",
  "framework_slug": "claude-code",
  "url": "https://composio.dev/toolkits/mailersend/framework/claude-code",
  "markdown_url": "https://composio.dev/toolkits/mailersend/framework/claude-code.md",
  "updated_at": "2026-05-12T10:18:19.514Z"
}
```

## Introduction

Manage your Mailersend directly from Claude Code with zero worries about OAuth hassles, API-breaking issues, or reliability and security concerns.
You can do this in two different ways:
- Via [Composio Connect](https://dashboard.composio.dev/login?utm_source=toolkits&utm_medium=framework_template&utm_campaign=claude-code&utm_content=composio_connect&next=%2F~%2Forg%2Fconnect%2Fclients%2Fclaude-code) - Direct and easiest approach
- Via [Composio SDK](https://docs.composio.dev/docs?utm_source=toolkits&utm_medium=framework_template&utm_campaign=claude-code&utm_content=composio_sdk) - Programmatic approach with more control

## Also integrate Mailersend with

- [OpenAI Agents SDK](https://composio.dev/toolkits/mailersend/framework/open-ai-agents-sdk)
- [Claude Agent SDK](https://composio.dev/toolkits/mailersend/framework/claude-agents-sdk)
- [Claude Cowork](https://composio.dev/toolkits/mailersend/framework/claude-cowork)
- [Codex](https://composio.dev/toolkits/mailersend/framework/codex)
- [OpenClaw](https://composio.dev/toolkits/mailersend/framework/openclaw)
- [Hermes](https://composio.dev/toolkits/mailersend/framework/hermes-agent)
- [CLI](https://composio.dev/toolkits/mailersend/framework/cli)
- [Google ADK](https://composio.dev/toolkits/mailersend/framework/google-adk)
- [LangChain](https://composio.dev/toolkits/mailersend/framework/langchain)
- [Vercel AI SDK](https://composio.dev/toolkits/mailersend/framework/ai-sdk)
- [Mastra AI](https://composio.dev/toolkits/mailersend/framework/mastra-ai)
- [LlamaIndex](https://composio.dev/toolkits/mailersend/framework/llama-index)
- [CrewAI](https://composio.dev/toolkits/mailersend/framework/crew-ai)

## TL;DR

- Only one MCP URL to connect multiple apps with Claude Code with zero auth hassles.
- Programmatic tool calling allows LLMs to write its code in a remote workbench to handle complex tool chaining. Reduces to-and-fro with LLMs for frequent tool calling.
- Handling Large tool responses out of LLM context to minimize context rot.
- Dynamic just-in-time access to 20,000 tools across 1000+ other Apps for cross-app workflows. It loads the tools you need, so LLMs aren't overwhelmed by tools you don't need.

## Connect Mailersend to Claude Code

### Connecting Mailersend to Claude Code using Composio
1. Add the Composio MCP to Claude

```bash
claude mcp add --scope user --transport http composio https://connect.composio.dev/mcp
```

## What is Claude Code?

Claude Code is Anthropic's command line developer tool that lets you use Claude directly inside your terminal. Instead of switching between your editor, browser, and chat, you can stay in your project folder and ask Claude to help you build, debug, refactor, and understand code right where you're working.
Key features include:
- Terminal-Native Experience: Work with Claude directly in your command line without switching contexts
- MCP Support: Built-in support for Model Context Protocol servers to extend Claude's capabilities
- Project Context: Claude understands your project structure and can read, write, and modify files
- Interactive Development: Ask questions, debug code, and get help in real-time while coding
- Multi-Platform: Works on macOS, Linux, WSL, and Windows

## What is the Mailersend MCP server, and what's possible with it?

The Mailersend MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Mailersend account. It provides structured and secure access to your transactional email infrastructure, so your agent can perform actions like sending emails, managing domains, configuring webhooks, and monitoring API usage on your behalf.
- Seamless domain management: Register new sending domains, verify their status, and retrieve detailed configuration information to ensure reliable email delivery.
- Automated email and SMTP user setup: Quickly create SMTP users and API tokens as needed for secure and scalable application integration.
- Webhook configuration and event tracking: Set up and delete webhooks to monitor real-time email events such as sent, delivered, or opened messages, enabling proactive workflows and notifications.
- Recipient and quota insights: List recipients for specific domains and monitor your API usage to stay within account limits and optimize deliverability.
- Centralized resource discovery: Retrieve general API resources and overview endpoints to streamline Mailersend integration and administration directly from your agent.

## Supported Tools

| Tool slug | Name | Description |
|---|---|---|
| `MAILERSEND_CREATE_DOMAIN` | Create Sending Domain | Tool to add a new sending domain to MailerSend. Use when you need to register and configure a domain before sending emails. |
| `MAILERSEND_CREATE_SMTP_USER` | Create SMTP User | Tool to create a new SMTP user. Use after domain setup to obtain SMTP credentials. |
| `MAILERSEND_CREATE_TOKEN` | Create API Token | Creates a new API token with specified scopes (permissions) for a domain. The token allows programmatic access to MailerSend API endpoints based on granted scopes. WARNING: The token value is only displayed once upon creation and cannot be retrieved later. |
| `MAILERSEND_CREATE_WEBHOOK` | Create Webhook | Tool to create a new webhook for a MailerSend domain. Use after you have a domain ID and need to receive event notifications like sent, delivered, opened, etc. |
| `MAILERSEND_DELETE_WEBHOOK` | Delete Webhook | Tool to delete an existing webhook. Use when the webhook is no longer needed. Returns empty response on successful deletion (HTTP 204). |
| `MAILERSEND_GET_API_QUOTA` | Get API Quota | Tool to retrieve current API usage quota. Use when monitoring API rate limits to avoid exceeding allowed calls. |
| `MAILERSEND_GET_DOMAIN` | Get Domain | Tool to retrieve detailed information about a specific sending domain in MailerSend. Returns domain verification status (DKIM, SPF, MX, tracking), settings (click/open tracking, paused status), and metadata (creation/update timestamps). Use this when you need to check if a domain is properly verified and configured for sending emails, or to review domain-specific tracking settings. Note: For detailed DNS record values, use the Get Domain DNS Records action. |
| `MAILERSEND_GET_DOMAIN_RECIPIENTS` | List Domain Recipients | Tool to list recipients for a domain. Use after obtaining the domain ID to view recipients with optional pagination. |
| `MAILERSEND_GET_DOMAINS` | Get sending domains | Retrieve a paginated list of all sending domains configured in your MailerSend account. Use this to: - View all domains available for sending emails - Check domain verification and DNS status - Filter by verification status to find verified or unverified domains - Review domain settings like tracking and sending preferences Returns domain details including verification status, DNS configuration, and tracking settings. |
| `MAILERSEND_GET_GENERAL_RESOURCES` | Get general API resources | Tool to retrieve general API resources and information. Use when you need an overview of all MailerSend endpoints before constructing specific calls. |
| `MAILERSEND_GET_IDENTITIES` | List Sender Identities | Retrieves a paginated list of sender identities configured in your MailerSend account. Sender identities are the email addresses or domains authorized to send emails through MailerSend. Each identity includes verification status, reply-to configuration, domain association, and optional personal notes. Use this tool to discover available sender identities before sending emails or to verify which identities are ready for use. Returns: Paginated list of identity objects with metadata including verification status, domain details, and navigation links for pagination. |
| `MAILERSEND_GET_MESSAGES` | Get sent messages | Tool to retrieve a paginated list of sent messages. Use after sending emails to view message logs. |
| `MAILERSEND_GET_RECIPIENTS` | Get email recipients | Tool to retrieve a list of email recipients. Use when you need to list and filter recipients by list ID or search term. |
| `MAILERSEND_GET_SMS_ACTIVITY` | Get SMS Activity | Tool to retrieve SMS activity logs. Use when you need to fetch delivery status and logs of sent SMS messages. |
| `MAILERSEND_GET_SMS_INBOUNDS` | Get SMS Inbounds | Retrieve inbound SMS route configurations. Inbound routes define rules for forwarding incoming SMS messages to webhook URLs based on message content filters. Use this action when you need to: - List all configured SMS inbound routes - Filter routes by SMS number or enabled status - Review webhook forwarding configurations and filter rules |
| `MAILERSEND_GET_SMS_MESSAGES` | List SMS Messages | Retrieves a paginated list of SMS messages sent through the MailerSend API. Returns message details including sender, recipients, content, status, and timestamps. Use this to review sent SMS messages and track their delivery status. Note: For detailed activity tracking with filters (date ranges, status, phone numbers), use the SMS Activity endpoint instead. |
| `MAILERSEND_GET_SMS_NUMBERS` | Get SMS Numbers | Tool to retrieve a paginated list of SMS phone numbers. Use after purchasing numbers to fetch available SMS numbers. |
| `MAILERSEND_GET_SMS_RECIPIENTS` | Get SMS recipients | Tool to retrieve a list of SMS recipients. Use when you need to list and paginate SMS recipients, optionally filtering by SMS number ID and/or recipient status. |
| `MAILERSEND_GET_SMTP_USERS` | Get SMTP users | Tool to retrieve a list of SMTP users. Use when you need to list and paginate SMTP users. |
| `MAILERSEND_GET_TEMPLATES` | Get email templates | Retrieves a paginated list of email templates from your MailerSend account. Use this tool when you need to: - List all available email templates - Filter templates by domain ID - Browse templates with pagination - Check template details like name, type, and creation date Returns template metadata including IDs, names, types, and timestamps. For full template content, use a separate get single template endpoint. |
| `MAILERSEND_GET_TOKENS` | Get API Tokens | Retrieves a paginated list of API tokens associated with your MailerSend account. Returns token details including ID, name, status, creation date, and assigned scopes/permissions. Requires 'tokens_full' scope. |
| `MAILERSEND_GET_USERS` | Get users | Tool to retrieve a list of users associated with your account. Use after authenticating with a valid API token. |
| `MAILERSEND_GET_WEBHOOKS` | List webhooks | Tool to retrieve a list of webhooks. Use when you need to list and paginate all configured webhooks, optionally filtering by domain. |

## Supported Triggers

None listed.

## Creating MCP Server - Stand-alone vs Composio SDK

The Mailersend MCP server is an implementation of the Model Context Protocol that connects Claude Code (and other AI assistants like Claude and Cursor) directly to your Mailersend account. It provides structured and secure access so Claude can perform Mailersend operations on your behalf.
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:
- Claude Pro, Max, or API billing enabled Anthropic account
- Composio API Key
- A Mailersend account
- Basic knowledge of Python or TypeScript

### 1. Install Claude Code

To install Claude Code, use one of the following methods based on your operating system:
```bash
# macOS, Linux, WSL
curl -fsSL https://claude.ai/install.sh | bash

# Windows PowerShell
irm https://claude.ai/install.ps1 | iex

# Windows CMD
curl -fsSL https://claude.ai/install.cmd -o install.cmd && install.cmd && del install.cmd
```

### 2. Set up Claude Code

Open a terminal, go to your project folder, and start Claude Code:
- Claude Code will open in your terminal
- Follow the prompts to sign in with your Anthropic account
- Complete the authentication flow
- Once authenticated, you can start using Claude Code
```bash
cd your-project-folder
claude
```

### 3. Set up environment variables

Create a .env file in your project root with the following variables:
- COMPOSIO_API_KEY authenticates with Composio (get it from [Composio dashboard](https://dashboard.composio.dev/login?utm_source=toolkits&utm_medium=framework_template&utm_campaign=claude-code&utm_content=api_key&next=%2F~%2Forg%2Fconnect%2Fclients%2Fclaude-code))
- USER_ID identifies the user for session management (use any unique identifier)
```bash
COMPOSIO_API_KEY=your_composio_api_key_here
USER_ID=your_user_id_here
```

### 4. Install Composio library

No description provided.
```python
pip install composio-core python-dotenv
```

```typescript
npm install @composio/core dotenv
```

### 5. Generate Composio MCP URL

No description provided.
```python
import os
from composio import Composio
from dotenv import load_dotenv

load_dotenv()

COMPOSIO_API_KEY = os.getenv("COMPOSIO_API_KEY")
USER_ID = os.getenv("USER_ID")

composio_client = Composio(api_key=COMPOSIO_API_KEY)

composio_session = composio_client.create(
    user_id=USER_ID,
    toolkits=["mailersend"],
)

COMPOSIO_MCP_URL = composio_session.mcp.url

print(f"MCP URL: {COMPOSIO_MCP_URL}")
print(f"\nUse this command to add to Claude Code:")
print(f'claude mcp add --transport http mailersend-composio "{COMPOSIO_MCP_URL}" --headers "X-API-Key:{COMPOSIO_API_KEY}"')
```

```typescript
import 'dotenv/config';
import { Composio } from '@composio/core';

const { COMPOSIO_API_KEY, USER_ID } = process.env;

if (!COMPOSIO_API_KEY || !USER_ID) {
  throw new Error('COMPOSIO_API_KEY and USER_ID required in .env');
}

const composioClient = new Composio({ apiKey: COMPOSIO_API_KEY });

const composioSession = await composioClient.create(USER_ID, {
  toolkits: ['mailersend'],
});

const composioMcpUrl = composioSession?.mcp.url;

console.log(`MCP URL: ${composioMcpUrl}`);
console.log(`\nUse this command to add to Claude Code:`);
console.log(`claude mcp add --transport http mailersend-composio "${composioMcpUrl}" --headers "X-API-Key:${COMPOSIO_API_KEY}"`);
```

### 6. Run the script and copy the MCP URL

No description provided.
```python
python generate_mcp_url.py
```

```typescript
node --loader ts-node/esm generate_mcp_url.ts
# or if using tsx
tsx generate_mcp_url.ts
```

### 7. Add Mailersend MCP to Claude Code

In your terminal, add the MCP server using the command from the previous step. The command format is:
- claude mcp add registers a new MCP server with Claude Code
- --transport http specifies that this is an HTTP-based MCP server
- The server name (mailersend-composio) is how you'll reference it
- The URL points to your Composio Tool Router session
- --headers includes your Composio API key for authentication
After running the command, close the current Claude Code session and start a new one for the changes to take effect.
```bash
claude mcp add --transport http mailersend-composio "YOUR_MCP_URL_HERE" --headers "X-API-Key:YOUR_COMPOSIO_API_KEY"

# Then restart Claude Code
exit
claude
```

### 8. Verify the installation

Check that your Mailersend MCP server is properly configured.
- This command lists all MCP servers registered with Claude Code
- You should see your mailersend-composio entry in the list
- This confirms that Claude Code can now access Mailersend tools
If everything is wired up, you should see your mailersend-composio entry listed:
```bash
claude mcp list
```

### 9. Authenticate Mailersend

The first time you try to use Mailersend tools, you'll be prompted to authenticate.
- Claude Code will detect that you need to authenticate with Mailersend
- It will show you an authentication link
- Open the link in your browser (or copy/paste it)
- Complete the Mailersend authorization flow
- Return to the terminal and start using Mailersend through Claude Code
Once authenticated, you can ask Claude Code to perform Mailersend operations in natural language. For example:
- "Add a new sending domain for my app"
- "List all SMTP users for our domain"
- "Check current API quota usage"

## Complete Code

```python
import os
from composio import Composio
from dotenv import load_dotenv

load_dotenv()

COMPOSIO_API_KEY = os.getenv("COMPOSIO_API_KEY")
USER_ID = os.getenv("USER_ID")

composio_client = Composio(api_key=COMPOSIO_API_KEY)

composio_session = composio_client.create(
    user_id=USER_ID,
    toolkits=["mailersend"],
)

COMPOSIO_MCP_URL = composio_session.mcp.url

print(f"MCP URL: {COMPOSIO_MCP_URL}")
print(f"\nUse this command to add to Claude Code:")
print(f'claude mcp add --transport http mailersend-composio "{COMPOSIO_MCP_URL}" --headers "X-API-Key:{COMPOSIO_API_KEY}"')
```

```typescript
import 'dotenv/config';
import { Composio } from '@composio/core';

const { COMPOSIO_API_KEY, USER_ID } = process.env;

if (!COMPOSIO_API_KEY || !USER_ID) {
  throw new Error('COMPOSIO_API_KEY and USER_ID required in .env');
}

const composioClient = new Composio({ apiKey: COMPOSIO_API_KEY });

const composioSession = await composioClient.create(USER_ID, {
  toolkits: ['mailersend'],
});

const composioMcpUrl = composioSession?.mcp.url;

console.log(`MCP URL: ${composioMcpUrl}`);
console.log(`\nUse this command to add to Claude Code:`);
console.log(`claude mcp add --transport http mailersend-composio "${composioMcpUrl}" --headers "X-API-Key:${COMPOSIO_API_KEY}"`);
```

## Conclusion

You've successfully integrated Mailersend with Claude Code using Composio's MCP server. Now you can interact with Mailersend directly from your terminal using natural language commands.
Key features of this setup:
- Terminal-native experience without switching contexts
- Natural language commands for Mailersend operations
- Secure authentication through Composio's managed MCP
- Tool Router for dynamic tool discovery and execution
Next steps:
- Try asking Claude Code to perform various Mailersend operations
- Add more toolkits to your Tool Router session for multi-app workflows
- Integrate this setup into your development workflow for increased productivity
You can extend this by adding more toolkits, implementing custom workflows, or building automation scripts that leverage Claude Code's capabilities.

## How to build Mailersend MCP Agent with another framework

- [OpenAI Agents SDK](https://composio.dev/toolkits/mailersend/framework/open-ai-agents-sdk)
- [Claude Agent SDK](https://composio.dev/toolkits/mailersend/framework/claude-agents-sdk)
- [Claude Cowork](https://composio.dev/toolkits/mailersend/framework/claude-cowork)
- [Codex](https://composio.dev/toolkits/mailersend/framework/codex)
- [OpenClaw](https://composio.dev/toolkits/mailersend/framework/openclaw)
- [Hermes](https://composio.dev/toolkits/mailersend/framework/hermes-agent)
- [CLI](https://composio.dev/toolkits/mailersend/framework/cli)
- [Google ADK](https://composio.dev/toolkits/mailersend/framework/google-adk)
- [LangChain](https://composio.dev/toolkits/mailersend/framework/langchain)
- [Vercel AI SDK](https://composio.dev/toolkits/mailersend/framework/ai-sdk)
- [Mastra AI](https://composio.dev/toolkits/mailersend/framework/mastra-ai)
- [LlamaIndex](https://composio.dev/toolkits/mailersend/framework/llama-index)
- [CrewAI](https://composio.dev/toolkits/mailersend/framework/crew-ai)

## Related Toolkits

- [Gmail](https://composio.dev/toolkits/gmail) - Gmail is Google's email service with powerful spam protection, search, and G Suite integration. It keeps your inbox organized and makes communication fast and reliable.
- [Outlook](https://composio.dev/toolkits/outlook) - Outlook is Microsoft's email and calendaring platform for unified communications and scheduling. It helps users stay organized with powerful email, contacts, and calendar management.
- [Slack](https://composio.dev/toolkits/slack) - Slack is a channel-based messaging platform for teams and organizations. It helps people collaborate in real time, share files, and connect all their tools in one place.
- [Gong](https://composio.dev/toolkits/gong) - Gong is a platform for video meetings, call recording, and team collaboration. It helps teams capture conversations, analyze calls, and turn insights into action.
- [Microsoft teams](https://composio.dev/toolkits/microsoft_teams) - Microsoft Teams is a collaboration platform that combines chat, meetings, and file sharing within Microsoft 365. It keeps distributed teams connected and productive through seamless virtual communication.
- [Slackbot](https://composio.dev/toolkits/slackbot) - Slackbot is a conversational automation tool for Slack that handles reminders, notifications, and automated responses. It boosts team productivity by streamlining onboarding, answering FAQs, and managing timely alerts—all right inside Slack.
- [2chat](https://composio.dev/toolkits/_2chat) - 2chat is an API platform for WhatsApp and multichannel text messaging. It streamlines chat automation, group management, and real-time messaging for developers.
- [Agent mail](https://composio.dev/toolkits/agent_mail) - Agent mail provides AI agents with dedicated email inboxes for sending, receiving, and managing emails. It empowers agents to communicate autonomously with people, services, and other agents—no human intervention needed.
- [Basecamp](https://composio.dev/toolkits/basecamp) - Basecamp is a project management and team collaboration tool by 37signals. It helps teams organize tasks, share files, and communicate efficiently in one place.
- [Chatwork](https://composio.dev/toolkits/chatwork) - Chatwork is a team communication platform with group chats, file sharing, and task management. It helps businesses boost collaboration and streamline productivity.
- [Clickmeeting](https://composio.dev/toolkits/clickmeeting) - ClickMeeting is a cloud-based platform for running online meetings and webinars. It helps businesses and individuals host, manage, and engage virtual audiences with ease.
- [Confluence](https://composio.dev/toolkits/confluence) - Confluence is Atlassian's team collaboration and knowledge management platform. It helps your team organize, share, and update documents and project content in one secure workspace.
- [Dailybot](https://composio.dev/toolkits/dailybot) - DailyBot streamlines team collaboration with chat-based standups, reminders, and polls. It keeps work flowing smoothly in your favorite messaging platforms.
- [Dialmycalls](https://composio.dev/toolkits/dialmycalls) - Dialmycalls is a mass notification service for sending voice and text messages to contacts. It helps teams and organizations quickly broadcast urgent alerts and updates.
- [Dialpad](https://composio.dev/toolkits/dialpad) - Dialpad is a cloud-based business phone and contact center system for teams. It unifies voice, video, messaging, and meetings across your devices.
- [Discord](https://composio.dev/toolkits/discord) - Discord is a real-time messaging and VoIP platform for communities and teams. It lets users chat, share media, and collaborate across public and private channels.
- [Discordbot](https://composio.dev/toolkits/discordbot) - Discordbot is an automation tool for Discord servers that handles moderation, messaging, and user engagement. It helps communities run smoothly by automating routine and complex tasks.
- [Echtpost](https://composio.dev/toolkits/echtpost) - Echtpost is a secure digital communication platform for encrypted document and message exchange. It ensures confidential data stays private and protected during transmission.
- [Egnyte](https://composio.dev/toolkits/egnyte) - Egnyte is a cloud-based platform for secure file sharing, storage, and governance. It helps teams collaborate efficiently while maintaining data compliance and security.
- [Google Meet](https://composio.dev/toolkits/googlemeet) - Google Meet is a secure video conferencing platform for virtual meetings, chat, and screen sharing. It helps teams connect, collaborate, and communicate seamlessly from anywhere.

## Frequently Asked Questions

### What are the differences in Tool Router MCP and Mailersend MCP?

With a standalone Mailersend MCP server, the agents and LLMs can only access a fixed set of Mailersend tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Mailersend and many other apps based on the task at hand, all through a single MCP endpoint.

### Can I use Tool Router MCP with Claude Code?

Yes, you can. Claude Code 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 Mailersend tools.

### Can I manage the permissions and scopes for Mailersend while using Tool Router?

Yes, absolutely. You can configure which Mailersend 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 Mailersend data and credentials are handled as safely as possible.

---
[See all toolkits](https://composio.dev/toolkits) · [Composio docs](https://docs.composio.dev/llms.txt)