Vouch MCP server

Vouch

A per-call payment trust & reputation API for AI agents — monetized over x402.

When an autonomous agent is about to pay a merchant, API, or counterparty, it asks Vouch one question first: is this safe to pay? Vouch returns an explainable trust score, and charges a fraction of a cent per call in USDC — no accounts, no API keys, no Stripe. Billing is the x402 protocol itself.

Why

The agentic-commerce rails (Coinbase x402, AWS, Visa, Mastercard, Agnic) are being built by giants. The governance layer — should this agent trust this counterparty with money? — is the named #1 blocker to autonomous spend and is wide open. Vouch is a thin, self-serve pick-and-shovel on top of those rails.

Every call makes the product better: checks and community reports accrete into a reputation dataset that compounds with usage — the moat a bootstrapped team can actually build.

How it works

agent ──POST /v1/check { target }──▶  x402 paywall (402 → pay USDC → retry)
                                          │
                                          ▼
                          ┌─────────── scoring engine ───────────┐
                          │ transport · domain heuristics ·       │
                          │ threat feed · reputation (D1)         │
                          └───────────────────────────────────────┘
                                          │
                            { score, risk, reasons[] }

Scoring is a weighted average of independent signals, with a safety override: any single hard-negative signal (e.g. a threat-feed hit) caps the overall score so one strong red flag can't be averaged away.

Use it from your agent

Vouch is a real MCP server, an x402-paid HTTP API, and a tiny SDK — pick whichever fits your stack. Nothing needs an account or API key.

MCP (free tools, works in any MCP client)

Point your client at the Streamable-HTTP endpoint — it exposes vouchscore and vouchreport, and ships model-facing instructions so the agent knows to check a counterparty before it pays:

{
  "mcpServers": {
    "vouch": { "type": "streamable-http", "url": "https://vouch.futuronoti.workers.dev/mcp" }
  }
}

For clients that only speak stdio, bridge it with npx mcp-remote https://vouch.futuronoti.workers.dev/mcp. Vouch is also listed in the official MCP registry as io.github.notifuturo/vouch.

Free HTTP (curl)

curl -s https://vouch.futuronoti.workers.dev/v1/score \
  -H 'content-type: application/json' -d '{"target":"https://some-merchant.com"}'
# → {"target":"...","host":"some-merchant.com","score":91,"risk":"low"}

Gate a payment with the SDK (one line)

import { assertTrusted } from "vouch-sdk";

await assertTrusted("https://some-merchant.com", { minScore: 75 }); // free; throws if risky
await payTheMerchant();

Shortened. The full README is on GitHub.