# Countersign MCP server

> Provides a cross-vendor kill switch and spend guard to manage and audit financial transactions for AI agents.

- Repository: https://github.com/countersign-network/packages
- Page: https://hostedmcp.org/servers/countersign-network/countersign
- Transport: stdio
- Stars: 1
- Latest version: 0.2.2

## Install

### Claude Code

```sh
claude mcp add --env 'COUNTERSIGN_API_KEY=<YOUR_COUNTERSIGN_API_KEY>' --env 'COUNTERSIGN_URL=<COUNTERSIGN_URL>' countersign -- npx -y @countersign/mcp
```

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

```json
{
  "mcpServers": {
    "countersign": {
      "command": "npx",
      "args": [
        "-y",
        "@countersign/mcp"
      ],
      "env": {
        "COUNTERSIGN_API_KEY": "<YOUR_COUNTERSIGN_API_KEY>",
        "COUNTERSIGN_URL": "<COUNTERSIGN_URL>"
      }
    }
  }
}
```

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

```json
{
  "servers": {
    "countersign": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@countersign/mcp"
      ],
      "env": {
        "COUNTERSIGN_API_KEY": "<YOUR_COUNTERSIGN_API_KEY>",
        "COUNTERSIGN_URL": "<COUNTERSIGN_URL>"
      }
    }
  }
}
```

### VS Code CLI

```sh
code --add-mcp '{"name":"countersign","type":"stdio","command":"npx","args":["-y","@countersign/mcp"],"env":{"COUNTERSIGN_API_KEY":"<YOUR_COUNTERSIGN_API_KEY>","COUNTERSIGN_URL":"<COUNTERSIGN_URL>"}}'
```

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

```json
{
  "mcpServers": {
    "countersign": {
      "command": "npx",
      "args": [
        "-y",
        "@countersign/mcp"
      ],
      "env": {
        "COUNTERSIGN_API_KEY": "<YOUR_COUNTERSIGN_API_KEY>",
        "COUNTERSIGN_URL": "<COUNTERSIGN_URL>"
      }
    }
  }
}
```

### Codex

```sh
codex mcp add countersign --env 'COUNTERSIGN_API_KEY=<YOUR_COUNTERSIGN_API_KEY>' --env 'COUNTERSIGN_URL=<COUNTERSIGN_URL>' -- npx -y @countersign/mcp
```

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

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

[mcp_servers.countersign.env]
COUNTERSIGN_API_KEY = "<YOUR_COUNTERSIGN_API_KEY>"
COUNTERSIGN_URL = "<COUNTERSIGN_URL>"
```

### Gemini CLI

```sh
gemini mcp add -s user -e 'COUNTERSIGN_API_KEY=<YOUR_COUNTERSIGN_API_KEY>' -e 'COUNTERSIGN_URL=<COUNTERSIGN_URL>' countersign npx -- -y @countersign/mcp
```

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

```json
{
  "mcpServers": {
    "countersign": {
      "command": "npx",
      "args": [
        "-y",
        "@countersign/mcp"
      ],
      "env": {
        "COUNTERSIGN_API_KEY": "<YOUR_COUNTERSIGN_API_KEY>",
        "COUNTERSIGN_URL": "<COUNTERSIGN_URL>"
      }
    }
  }
}
```

## Environment variables

| Name | Required | Secret | Description |
|---|---|---|---|
| `COUNTERSIGN_API_KEY` | yes | yes | API key for the Core (self-serve one at https://app.countersign.network/start or POST /signup). |
| `COUNTERSIGN_URL` | yes | no | Base URL of the Countersign Core to govern (hosted or self-hosted). |

## Tools (5)

- `countersign_request_spend`
- `countersign_freeze`
- `countersign_apply_policy`
- `countersign_ledger`
- `countersign_unfreeze`

## FAQ

### Does Countersign take custody of my funds?

No, Countersign only manages policies, freezes, and the ledger; it does not hold custody of any funds.

### How quickly can I freeze an agent?

You can freeze all agents across every backend in under one second.