@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.
| 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. The hosted Core at app.countersign.network is paused since
2026-09-18 and answers 503, so point this at a Core you run yourself. Set:
COUNTERSIGN_URL — your Core, e.g. https://app.countersign.networkCOUNTERSIGN_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.
Show it (the "powered by" badge)
If Countersign guards your agent, say so — it tells users (and other agents) that spending is governed,
and points the next operator at the same kill switch. Drop this in your README:
[](https://countersign.network)
Listing in MCP registries (distribution)
Countersign spreads by being easy to discover wherever agent builders look for tools. The metadata below
is ready to submit to the common registries — copy it as-is.
- Official MCP registry (
registry.modelcontextprotocol.io / the mcp-registry repo) — entry:
{
"name": "io.github.countersign-network/countersign",
"description": "Cross-vendor kill switch + spend guard for AI agents that spend money — one policy, one freeze, one tamper-evident ledger across every wallet/card backend.",
"homepage": "https://countersign.network",
"repository": "https://github.com/countersign-network/countersign",
"packages": [
{ "registry": "npm", "name": "@countersign/mcp", "runtime": "npx" }
],
"license": "Apache-2.0"
}
- mcp.so — submit
@countersign/mcp; category Finance / Security / Agents.
- Smithery —
npx-launched server; env COUNTERSIGN_URL (default https://app.countersign.network) + optional COUNTERSIGN_API_KEY.
- awesome-mcp-servers lists — one-liner:
Countersign — cross-vendor spend guard + sub-second kill switch + tamper-evident ledger for AI agents that move money (Coinbase, Turnkey, Openfort, Visa card). Testnet.
Standard listing fields:
| Field | Value |
|---|
| Server id | countersign |
| Launch | npx -y @countersign/mcp |
| Tools | countersign_request_spend, countersign_freeze, countersign_apply_policy, countersign_list_agents, countersign_health, countersign_list_approvals, countersign_approve, countersign_deny, countersign_ledger, countersign_unfreeze |
| Tags | payments · security · kill-switch · spend-guard · agent-payments · wallet |
Nothing here is auto-submitted — listings are made deliberately by a maintainer.
Apache-2.0. Countersign holds policy/freeze/ledger; it never takes custody of funds. Testnet only.