Countersign

Overview

Countersign is a Model Context Protocol server that provides a kill switch and spend guard for AI agents handling money across multiple wallet vendors. Any MCP-compatible AI assistant can call Countersign's tools directly, letting the model decide when to engage spending controls during conversations or agent runs.

The server runs locally via the npm package @countersign/mcp, which communicates over stdio on your machine. You'll need to provide COUNTERSIGN_URL and COUNTERSIGN_API_KEY environment variables to authenticate. The latest release is v0.2.2, with source code available at countersign-network/packages on GitHub.

Countersign appears in the Finance category on mcp.site and integrates with MCP clients including Claude Desktop, Claude Code, Cursor, VS Code, Windsurf, Zed and others across the ecosystem. If you maintain Countersign, claim this listing to verify ownership, earn the Verified badge, and keep information up to date.

Installation

// claude_desktop_config.json
{
  "mcpServers": {
    "countersign": {
      "command": "npx",
      "args": [
        "-y",
        "@countersign/mcp"
      ],
      "env": {
        "COUNTERSIGN_URL": "<countersign-url>",
        "COUNTERSIGN_API_KEY": "<countersign-api-key>"
      }
    }
  }
}

Requires COUNTERSIGN_URL, COUNTERSIGN_API_KEY