# Marrow MCP server

> Provides a runtime governance and proof layer for AI agents to enforce policies and record evidence before and after consequential actions.

- Repository: https://github.com/getmarrow/marrow-mcp
- Page: https://hostedmcp.org/servers/getmarrow/marrow
- Transport: stdio
- Stars: 7
- License: MIT
- Latest version: 3.9.98

## Install

### Claude Code

```sh
claude mcp add --env 'MARROW_API_KEY=<YOUR_MARROW_API_KEY>' marrow -- npx -y @getmarrow/mcp
```

### Cursor (`~/.cursor/mcp.json`)

```json
{
  "mcpServers": {
    "marrow": {
      "command": "npx",
      "args": [
        "-y",
        "@getmarrow/mcp"
      ],
      "env": {
        "MARROW_API_KEY": "<YOUR_MARROW_API_KEY>"
      }
    }
  }
}
```

### VS Code (`.vscode/mcp.json`)

```json
{
  "servers": {
    "marrow": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@getmarrow/mcp"
      ],
      "env": {
        "MARROW_API_KEY": "<YOUR_MARROW_API_KEY>"
      }
    }
  }
}
```

### VS Code CLI

```sh
code --add-mcp '{"name":"marrow","type":"stdio","command":"npx","args":["-y","@getmarrow/mcp"],"env":{"MARROW_API_KEY":"<YOUR_MARROW_API_KEY>"}}'
```

### Claude Desktop (`claude_desktop_config.json`)

```json
{
  "mcpServers": {
    "marrow": {
      "command": "npx",
      "args": [
        "-y",
        "@getmarrow/mcp"
      ],
      "env": {
        "MARROW_API_KEY": "<YOUR_MARROW_API_KEY>"
      }
    }
  }
}
```

### Codex

```sh
codex mcp add marrow --env 'MARROW_API_KEY=<YOUR_MARROW_API_KEY>' -- npx -y @getmarrow/mcp
```

### Codex config.toml (`~/.codex/config.toml`)

```toml
[mcp_servers.marrow]
command = "npx"
args = ["-y", "@getmarrow/mcp"]

[mcp_servers.marrow.env]
MARROW_API_KEY = "<YOUR_MARROW_API_KEY>"
```

### Gemini CLI

```sh
gemini mcp add -s user -e 'MARROW_API_KEY=<YOUR_MARROW_API_KEY>' marrow npx -- -y @getmarrow/mcp
```

### Gemini settings.json (`~/.gemini/settings.json`)

```json
{
  "mcpServers": {
    "marrow": {
      "command": "npx",
      "args": [
        "-y",
        "@getmarrow/mcp"
      ],
      "env": {
        "MARROW_API_KEY": "<YOUR_MARROW_API_KEY>"
      }
    }
  }
}
```

## Environment variables

| Name | Required | Secret | Description |
|---|---|---|---|
| `MARROW_API_KEY` | yes | yes | Named Marrow agent API key. Keep it in trusted secret storage. |

## Tools (17)

- `marrow_agent_runtime`
- `marrow_arbitrate`
- `marrow_coordinate`
- `marrow_replay_compare`
- `marrow_decision_brief`
- `marrow_think`
- `marrow_commit`
- `marrow_workflow_gate`
- `marrow_completion_contracts`
- `marrow_evaluate_completion_contract`
- `marrow_agent_status`
- `marrow_value_report`
- `marrow_buyer_proof`
- `marrow_governance_timeline`
- `marrow_decision_trace`
- `marrow_fleet_lessons`
- `marrow_model_usage`

## FAQ

### What does Marrow AI do for AI agents?

It acts as a control layer that applies policy and prior lessons before consequential actions, then records the evidence and outcome afterward.

### Which AI clients are compatible with Marrow?

It works with MCP-compatible clients such as Claude Code, Claude Desktop, Cursor, and others.

### Is Marrow AI supported on Windows?

Native Windows is not currently supported; users should use WSL instead.