402coffee-mcp

402coffee-mcp

MCP server for 402.coffee — the trust layer for agent payments (x402 · Base · USDC).

Give any MCP client (Claude Desktop, Claude Code, Cursor, …) the tools to check an agent before trusting it with money, and to pay for the decision-grade products directly over x402.

Tools

Tool	Cost	What
verify_agent	free	Current certs + free on-chain USDC activity summary for any wallet
check_credential	free	Portable credential + local Ed25519 signature verification
list_tests	free	The machine-readable menu (tests, prices, products)
arbiter_policy	free	The published arbiter policy
escrow_info	free	The full-escrow product (1% on release)
behavioural_test_info	free	How to run the adversarial scam/recipient tests safely
score_wallet	$0.10	Deterministic 0–100 risk score, tier A–F, itemized evidence
score_batch	$0.50	Up to 25 wallets per payment
certify	$0.25/$0.75	Certify this wallet's x402 client → public cert + README badge
arbiter_verify	$0.25/$0.60	Signed release/refund/escalate delivery verdict any escrow can execute

Install (Claude Desktop / any MCP client)

{
  "mcpServers": {
    "402coffee": {
      "command": "npx",
      "args": ["-y", "402coffee-mcp"],
      "env": { "PAYER_PRIVATE_KEY": "0x…" }
    }
  }
}

PAYER_PRIVATE_KEY is optional — free tools work without it. To enable the paid tools, use a throwaway wallet holding a little USDC on Base (gasless EIP-3009 — no ETH needed). Signing is local and non-custodial; the key never leaves the process, and the server only ever pays api.402.coffee.

Safety notes

• Paid tools have fixed, published prices ($0.10–$0.75); the server never auto-pays anything else.
• The adversarial behavioural tests (scam/recipient) are deliberately not wired to the auto-payer — a blind auto-paying client signs the bait and fails them by design. behavioural_test_info explains the correct flow.
• Arbiter verdicts are verified locally (Ed25519, keys at /.well-known/jwks.json) before being returned.

MIT · docs · integrations · examples