Attest MCP Server

Trust scanning for agent payments — right inside your AI agent.

attest-mcp is a Model Context Protocol server that lets any MCP-compatible agent (Claude, Cursor, Windsurf, VS Code, and more) scan an agent payment endpoint and get back a letter grade A–F with a clear safety verdict before authorizing a single cent.

It covers the agentic payment protocols in use today: x402, MPP, AP2, L402, and HTTP 402.

Powered by Attest. The scoring engine runs entirely on Attest's servers — this package is a thin client that relays requests, so installing it never exposes any proprietary grading logic.

Why

Autonomous agents are starting to pay for things on their own. A single malicious or misconfigured endpoint can drain funds through impersonation, a blocklisted payout wallet, bait-and-switch pricing, or a broken payment handshake. attest-mcp gives your agent a fast, deterministic safety check it can run as a step in its payment loop.

Tools

Tool	What it does
`attest_scan`	Runs a full scan on a payment endpoint URL and returns a grade (A–F), a composite score (0–100), a verdict, danger flags, price, and a link to the full report. Call this before paying an unfamiliar endpoint.
`attest_grade`	Fast lookup of the most recent grade for a host that has already been scanned. Good for a quick pre-check.

Requirements

Node.js 18 or newer
Any MCP-compatible client

No API key required.

Quick start

Run it directly with npx (no install needed):

npx attest-mcp

The server speaks MCP over stdio, so you normally don't run it by hand — you point your MCP client at it using one of the configs below.

Client setup

Claude Desktop

Edit claude_desktop_config.json (Settings → Developer → Edit Config):

{
  "mcpServers": {
    "attest": {
      "command": "npx",
      "args": ["-y", "attest-mcp"]
    }
  }
}

Cursor

Add to ~/.cursor/mcp.json (or Settings → MCP → Add new server):

{
  "mcpServers": {
    "attest": {
      "command": "npx",
      "args": ["-y", "attest-mcp"]
    }
  }
}

Windsurf

Add to ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "attest": {
      "command": "npx",
      "args": ["-y", "attest-mcp"]
    }
  }
}

VS Code

Add to .vscode/mcp.json in your workspace:

{
  "servers": {
    "attest": {
      "command": "npx",
      "args": ["-y", "attest-mcp"]
    }
  }
}

Any other MCP client

Use the command npx -y attest-mcp with the stdio transport.

Remote server (no install)

Prefer not to install anything? Attest also runs a hosted MCP server you can connect to over Streamable HTTP:

https://attestagent.org/api/mcp

Point any remote-MCP-capable client at that URL.

Usage example

Once connected, just ask your agent in natural language:

"Before you pay, scan https://api.example.com/paid-resource with Attest."

The agent calls attest_scan and gets back something like:

{
  "host": "api.example.com",
  "grade": "A",
  "composite": 95,
  "danger": false,
  "verdict": "Valid endpoint, established host.",
  "priceHuman": "0.01 USDC",
  "reportUrl": "https://attestagent.org/r/abc-123"
}

Configuration

Environment variable	Default	Description
`ATTEST_BASE_URL`	`https://attestagent.org`	Override the Attest API base URL. Only needed for self-hosting or testing.

Security & privacy

No secrets, no accounts, no API keys. The server holds no credentials.
No proprietary logic ships here. Grading happens server-side; this package only relays requests and formats responses.
Inputs are validated before any request is made.
Outbound only. The server makes HTTPS requests to the Attest API and speaks MCP over stdio — it opens no inbound ports.
Scanned URLs and results are logged to Attest's public directory. Do not scan endpoints whose URL or response contains private or sensitive information. See attestagent.org/legal.

Contributing

Issues and pull requests are welcome — see CONTRIBUTING.md.

Attest