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.
Links
Contributing
Issues and pull requests are welcome — see CONTRIBUTING.md.
License
MIT © Attest
