# Mailjet MCP Server and Claude

The [official Mailjet MCP server](https://github.com/mailgun/mailjet-mcp-server) runs locally on your computer and lets an MCP-compatible AI client, such as Claude Desktop, retrieve data from your Mailjet account.

MCP (Model Context Protocol) lets AI clients connect to external tools and data sources. For the complete installation walkthrough, see [Installing the Mailjet MCP Server](https://documentation.mailjet.com/hc/en-us/articles/42810091203867-Installing-the-Mailjet-MCP-Server).

## Documentation search or account data?

These are two different integrations:

| Integration | Purpose | Connection |
|  --- | --- | --- |
| Documentation MCP server | Search this documentation and inspect API descriptions. It does not retrieve your Mailjet account data. | Use `https://dev.mailjet.com/mcp` as the endpoint in a compatible MCP client. |
| Local Mailjet MCP server | Retrieve data from your Mailjet account, such as contacts, campaigns and statistics. | Install the server locally and configure your client with Mailjet API credentials, as described below. |


Use the local server when you want Claude to work with your account data, not just explain how the API works.

## Requirements

- A Mailjet account with an active API key and secret key.
- Claude Desktop installed, with permission to configure local MCP servers.
- Git, Node.js 20.11.1 or later and pnpm installed. Use a supported Node.js LTS release and check the [server repository](https://github.com/mailgun/mailjet-mcp-server) for current runtime requirements.
- Permission under your organization's policies to make the requested account data available to your AI client.


## Install the local server

Download the official repository and install its dependencies:

```shell
git clone https://github.com/mailgun/mailjet-mcp-server.git
cd mailjet-mcp-server
pnpm install
```

For installation help, see the Help Center's [download and installation steps](https://documentation.mailjet.com/hc/en-us/articles/42810091203867-Installing-the-Mailjet-MCP-Server#01MJETMCP003).

## Connect Claude Desktop

Open Claude Desktop's `claude_desktop_config.json` file:

| Operating system | Configuration file |
|  --- | --- |
| macOS | `~/Library/Application Support/Claude/claude_desktop_config.json` |
| Windows | `%APPDATA%\Claude\claude_desktop_config.json` |


Merge the following entry into your existing `mcpServers` object. Do not replace entries for other servers.

```json
{
  "mcpServers": {
    "mailjet": {
      "command": "node",
      "args": ["/absolute/path/to/mailjet-mcp-server/src/mailjet-mcp.js"],
      "env": {
        "MAILJET_API_KEY": "YOUR_PUBLIC_API_KEY:YOUR_PRIVATE_API_KEY"
      }
    }
  }
}
```

Replace the script path with the absolute path to your checkout; do not use `~` or shell variables in the path. On Windows, escape backslashes in JSON, for example `C:\\path\\to\\mailjet-mcp-server\\src\\mailjet-mcp.js`.

The `MAILJET_API_KEY` value contains your public API key and secret key joined by a colon. Replace the placeholders only in your local configuration.

Save the file and fully restart Claude Desktop. Claude launches the local server using the configured command; it does not connect to the documentation MCP endpoint for account access.

Claude starts its own server process from this configuration, so you don't need to keep a separate server running in a terminal. If you start the server manually, for example to test it, set `MAILJET_API_KEY` in your local environment first; otherwise startup fails.

The local server validates your API credentials with Mailjet when it starts, before Claude asks you to approve any tool. It needs working credentials and network access to the Mailjet API to complete startup.

## Credentials and permissions

Treat the API key and secret key as credentials. The example stores them as plain text in your local configuration file, so restrict access to that file. Do not paste credentials into an AI conversation, commit them to a repository, or include them in logs or screenshots. The JSON values are literal strings; shell variable references are not a substitute for credentials here.

The server exposes read-only tools: it retrieves account data rather than sending emails or changing Mailjet settings. That does not make the underlying API credentials read-only. Protect them and use an appropriate API key for the account or subaccount you intend to access.

Although the server runs locally, data returned to Claude can be processed by the AI provider. Review the requested tool and data access before approving it, and follow your organization's data-handling policies.

Remove the server entry from your client configuration when you no longer want that client to access the account. If credentials are exposed, revoke or rotate them in Mailjet.

## Check the connection

After restarting Claude Desktop, confirm that the Mailjet tools are available. For your first account query, choose a read-only task, such as retrieving campaign statistics.

When Claude asks to use a tool, review the request and choose **Allow once** for the initial check. Confirm that the response relates to the intended account. You can change or revoke permissions in Claude Desktop.

## Troubleshooting

| Problem | What to check |
|  --- | --- |
| Mailjet tools do not appear | Check that the configuration is valid JSON, the entry is inside `mcpServers`, and the script path is absolute. Fully restart Claude Desktop. |
| Node.js cannot be found | Ensure Node.js is installed and available to Claude Desktop. If necessary, set `command` to the absolute path to the Node.js executable. |
| The server cannot load its dependencies | Run `pnpm install` inside the server checkout, then restart Claude Desktop. |
| Authentication fails | Check that `MAILJET_API_KEY` is `PUBLIC_KEY:SECRET_KEY`, with a colon between the two values, and that both credentials belong to the intended active API key. Do not share the values when requesting help. |
| The server exits before showing tools | Startup includes an API authentication check. Check credentials, network connectivity and the client's MCP server logs; a process starting does not by itself confirm a successful connection. |


For the full walkthrough and further troubleshooting, refer to the [Mailjet Help Center setup guide](https://documentation.mailjet.com/hc/en-us/articles/42810091203867-Installing-the-Mailjet-MCP-Server). For source code and repository-specific requirements, see [mailgun/mailjet-mcp-server](https://github.com/mailgun/mailjet-mcp-server).