> For the complete documentation index, see [llms.txt](https://docs.monarchlinux.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.monarchlinux.com/basics/pentest-tools/caido-mcp-server.md).

# Caido MCP server

The `caido-mcp-server` package lets an MCP-compatible assistant work with traffic and other data in your local Caido instance. Caido must be running whenever the assistant uses the server.

## Install and authenticate

1. Install the server from the Monarch package repository:

   ```bash
   monarch pkg add caido-mcp-server
   ```

   If Caido itself is missing, install `caido-desktop` as well.
2. Open Caido and sign in. The examples below use its default local address, `http://127.0.0.1:8080`. If you changed Caido's listening address, use your address in both the login command and client configuration.
3. In a terminal under your normal user account, run:

   ```bash
   caido-mcp-server login -u http://127.0.0.1:8080
   ```

   Follow the browser prompt and approve the connection in Caido. Run this command again if you need to authenticate another user or Caido instance.

## Connect an MCP client

Add a **stdio** server to your MCP client's configuration. For clients that use a `mcpServers` JSON object, the entry is:

```json
{
  "mcpServers": {
    "caido": {
      "command": "/usr/bin/caido-mcp-server",
      "args": ["serve"],
      "env": {
        "CAIDO_URL": "http://127.0.0.1:8080"
      }
    }
  }
}
```

Use your client's configuration format if it differs. The package installs the executable at `/usr/bin/caido-mcp-server`. Restart the client after adding the entry, keep Caido open, and ask the assistant to list the Caido projects or HTTP requests to check the connection. Approve MCP tool calls only when you intend the requested action.

If the connection fails, check that Caido is running, the URL in `CAIDO_URL` matches the address used for `login`, and the client runs as the Linux user who authenticated. You can repeat `caido-mcp-server login -u <your-caido-url>` to renew access.

For client-specific examples and the available tools, see [Caido's MCP server guide](https://docs.caido.io/app/tutorials/mcp).