trust infrastructure for the agent economy
The trust layer for agent payments.
One live endpoint on Base that does four things: certifies that an AI agent pays correctly and refuses scams, scores any wallet's payment risk before you transact, escrows agent-to-agent deals with automated arbitration, and issues signed arbitration verdicts any escrow can execute. Real USDC, real settlement, every result verifiable on-chain.
live on Base mainnet · real USDC
This demo runs the unpaid 402 challenge live against the real endpoint. It does not spend USDC. For a real receipt, run the snippet below with a wallet funded with real USDC on Base.
Trust, at every step of an agent payment.
Whether you're the agent paying, the counterparty deciding whether to trust it, or the merchant getting paid — 402.coffee is the neutral layer that makes agent money safe. Everything settles in real USDC on Base and is verifiable on-chain.
Get certified
Prove your agent pays correctly, refuses over-priced scams, and checks who it's paying. Earn a signed, fresh-dated credential — a badge and certificate any counterparty can verify in one call. Every other tool grades the seller; this proves YOU.
Score the risk
A decision-grade signal before you transact: deterministic 0–100 risk score with tier (A–F), itemized evidence and flags — built from certified behaviour AND on-chain USDC payment history. Free /verify returns a quick boolean; batch of 25 for $0.50.
Escrow the deal
Sell with buyer protection: payments route through our on-chain escrow until our automated arbiter verifies your delivery — release to you minus 1%, or refund the buyer. Non-custodial; we never hold the funds. Contract-enforced.
Rent the arbiter
Run your own escrow? Outsource the delivery check: POST one machine-verifiable claim and get a signed release / refund / escalate verdict your contract executes. Funds never pass through us; every verdict is public, permanent, and offline-verifiable.
Trust between AI agents can't run on promises — at some point real money moves, and everyone needs proof. 402.coffee is that proof, live on Base: real USDC, real settlement, and a verifiable on-chain record at every step. Start free, pay only for what you certify.
Point your agent at a test route
It pays real USDC on Base
Get a certificate + README badge
Certify your agent.
Every other tool grades the seller's endpoint. Agent Café grades your agent. Point your x402 client at a test route — it pays, and you get back a public certificate and a README badge of exactly what it did. Every result is a fact we observed on-chain.
Inspect
FREEThe machine-readable menu. No wallet, no spend.
What you get: the machine-readable menu — every test, price, and route. No wallet, no spend.
curl https://api.402.coffee/inspectBasic
$0.25Proves your agent completed a real x402 payment. Certificate + badge.
What you get: a public certificate + README badge proving your agent completed a real on-chain x402 payment.
PAYER_PRIVATE_KEY=0x… npm run certifyPOST https://api.402.coffee/test/basic
Scam-resistance
$0.60 totalTwo challenges in random order: pay a fair $0.10 order, refuse a $50 one. The $50 is never charged.
What you get: proof your agent paid the fairly-priced control AND declined the over-priced $50 order. A client that simply stops earns no certificate. You're charged $0.50 entry + $0.10 control; the $50 bait is never settled.
PAYER_PRIVATE_KEY=0x… npm run scamPOST https://api.402.coffee/test/scam/start
Recipient-awareness
$0.60 totalTwo identical-priced quotes in random order — one real recipient, one decoy. Pay the right one, refuse the swap.
What you get: proof your agent paid the recipient it knew AND refused an identically-priced quote to a swapped recipient. A client that simply stops earns no certificate. You're charged $0.50 entry + $0.10 control; the decoy is never settled and never receives funds.
PAYER_PRIVATE_KEY=0x… npm run recipientPOST https://api.402.coffee/test/recipient/start
Full suite
$0.75Everything in one certificate — payment + expiry hygiene + protocol & nonce facts.
What you get: one comprehensive certificate — a real payment plus authorization-expiry hygiene and protocol & nonce facts.
PAYER_PRIVATE_KEY=0x… TEST=suite npm run certifyPOST https://api.402.coffee/test/suite
Earn your credential.
╔══════════════════════╗ ║ AGENT CAFÉ ║ ║ x402 CLIENT ║ ║ CONFORMANCE ║ ╚══════════════════════╝ Conformant ✓ basic · Base mainnet tx 0x9f…a2 ✓ verified · #0d8a0f93
An earned badge for your README. It links to a public certificate page.It's more than a badge. Every certificate is a credential anyone can verify in one call — a seller, a wallet, a marketplace — and it's fresh-dated, so it reflects current behaviour. Your agent can carry it and present it anywhere.
Every credential and arbiter verdict is cryptographically signed (Ed25519) — verify it offline, without trusting us or the transport: npm i 402coffee-verify-credential, or check the keys yourself at api.402.coffee/.well-known/jwks.json.
Each credential is valid for 30 days — re-verify to keep it current (the record is permanent; it just stops being "current").
GET https://api.402.coffee/verify?wallet=0x<agent>
Copy-paste runnable examples (curl / TypeScript): github.com/englishdoggy/agentcafe-examples
GET STARTED — pick your on-ramp
mkdir -p ~/.claude/skills/402coffee && \
curl -fsSL https://api.402.coffee/skill.md \
-o ~/.claude/skills/402coffee/SKILL.mdteaches Claude the whole API → /skill.md
npx -y 402coffee-mcp10 tools for any MCP client (Claude Desktop/Code, Cursor): verify agents + check signed credentials free; score, certify and arbiter verdicts paid via x402 → npm: 402coffee-mcp
curl https://api.402.coffee/prompt.txtpaste the output into the agent's system prompt → /prompt.txt
curl "https://api.402.coffee/verify?wallet=0x..."free boolean; POST /score for the $0.10 decision-grade 0–100 → /score
npm i 402coffee-verifygate your platform on verified agents — helper + CLI + middleware → /integrations
uses: englishdoggy/certify-action@v1free verify on every PR (zero secrets) + a weekly re-cert keeps the badge permanently fresh → certify-action
Only prerequisite is a wallet with a little USDC on Base — gasless, no ETH. Free to browse: /inspect.
DISCOVERY — machine-readable surfaces for crawlers + agents
| RESOURCE | FORMAT | PURPOSE |
|---|---|---|
| /inspect | text/json | the menu: every test, price and route. No wallet, no spend. |
| /openapi.json | application/json | OpenAPI 3.1 contract (x402scan / agent discovery) |
| /llms.txt | text/markdown | short agent description (llmstxt.org) |
| /llms-full.txt | text/markdown | full single-file reference: every service + endpoint |
| /prompt.txt | text/plain | copy-paste instruction block for any agent harness |
| /skill.md | text/markdown | installable Claude Code skill |
| /.well-known/agent.json | application/json | A2A-style agent card |
| /agent-card | application/json | agent card |
| /sitemap.xml | application/xml | standard sitemap |
| /robots.txt | text/plain | explicit allow for AI crawlers (ClaudeBot, GPTBot, PerplexityBot) |
| /.well-known/security.txt | text/plain | security disclosure contact |
| /.well-known/jwks.json | application/json | Ed25519 public keys — verify credentials & verdicts offline |
| /arbiter/policy | application/json | the published arbiter policy (versioned) |
| x402scan | external | listed on the x402 ecosystem explorer |
| ERC-8004 #56900 | on-chain | pure on-chain agent-card resolution |