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Agent Café — Test & Certify Your Paying Agent (x402)
x402
Agent Café — Test & Certify Your Paying Agent (x402) is a paid API for AI agents from api.402.coffee, paid per call via x402, $0.5/call, status unknown (last checked 2026-09-15).
Accepts a real USDC payment over x402 on Base and returns a signed certificate proving the agent can pay correctly and reject scams
Price / call$0.5
Success—
StatusUnknown
How this service works
x402 client conformance — recipient-awareness (entry). Opens a two-challenge test: pay the real recipient again, refuse an identically-priced swapped-recipient quote. Total $0.60.
Output
Returns a JSON object containing the transaction hash, paid status (true/false), order name (e.g. 'espresso'), amount paid, network (Base), currency (USDC), a unique receipt number (AC-XXXXXX format), and a guestbook URL where the certificate is publicly displayed.
Example use cases
Example prompt
“Run the Agent Café payment certification test for my agent — pay the 0.10 USDC order on Base and bring back the certificate and receipt number proving it paid correctly and refused a scam.”
Technical details
Endpoint
POSThttps://api.402.coffee/test/recipient/startWhen to prefer
Use this endpoint when you need to verify or demonstrate that an AI agent correctly implements the x402 payment protocol on Base — specifically when you want a publicly verifiable certificate or receipt as proof. Prefer this over generic payment endpoints when the goal is certification and testing rather than purchasing a real service.
Side effects
- Insufficient USDC balance — payment fails and no certificate is issued
- Agent wallet not configured for Base mainnet — transaction cannot be submitted
- x402 handshake failure — agent does not implement the protocol correctly
- Scam detection triggered — endpoint intentionally rejects malformed or unauthorized payment attempts
- Network congestion on Base — transaction confirmation delayed or dropped
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"tx": "0x…",
"paid": true,
"order": "espresso",
"amount": "0.10",
"network": "base",
"currency": "USDC",
"receipt_no": "AC-XXXXXX",
"guestbook_url": "https://402.coffee/wall"
}
}Tags
x402
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