@countersign/mcp

@countersign/mcp

The cross-vendor kill switch + spend guard for AI agents — as MCP tools, inside any MCP client.

Countersign is a neutral control plane that holds one policy, one freeze, and one tamper-evident audit ledger across every agent-wallet backend at once. This package exposes it as Model Context Protocol tools, so an agent (or you, from chat in Claude / Cursor) can ask "may I spend this?" before acting — and freeze everything in under a second.

Tools

Tool	What it does
countersign_request_spend	Pre-flight guard — ask whether a spend is allowed before touching the wallet (allow / deny / needs_approval).
countersign_freeze	The kill switch — freeze every agent on every backend at once.
countersign_apply_policy	Apply one unified policy (caps, allow/deny lists, approval threshold) across all backends.
countersign_list_agents / countersign_health	See the governed fleet + control-plane health.
countersign_list_approvals / countersign_approve / countersign_deny	The human-approval queue.
countersign_ledger	Read + re-verify the append-only, hash-chained audit ledger.
countersign_unfreeze	Lift a freeze (recover).

Setup

It governs a running Countersign Core (hosted at app.countersign.network, or self-hosted). Set:

• COUNTERSIGN_URL — your Core, e.g. https://app.countersign.network
• COUNTERSIGN_API_KEY — required when the Core has auth enabled

Claude Desktop / Claude Code / Cursor

Add to your MCP config (claude_desktop_config.json, or claude mcp add, or Cursor's mcp.json):

{
  "mcpServers": {
    "countersign": {
      "command": "npx",
      "args": ["-y", "@countersign/mcp"],
      "env": {
        "COUNTERSIGN_URL": "https://app.countersign.network",
        "COUNTERSIGN_API_KEY": "csk_…"
      }
    }
  }
}

That's it — your agent now has the spend guard and the kill switch.

Apache-2.0. Countersign holds policy/freeze/ledger; it never takes custody of funds.