Explore Tests
Pick a test, point your client at the endpoint, and see exactly what it does. Every test is a link, so you can share one or bookmark it. Testnets only, and nothing is stored.
- Multiple payment options
Two accepts entries on Base Sepolia, an inflated decoy before the real one.
Your client should Pay the cheaper option, not blindly the first.
- Receipt for somebody else's payment
The paid retry returns a genuinely signed receipt that names a different payer.
Your client should Pay it, then reject the receipt: a valid signature is not a receipt for your payment.
- Two MPP challenges at once
One WWW-Authenticate carrying two Payment challenges on Base Sepolia, an inflated decoy before the real one.
Your client should Pay the cheaper challenge, not blindly the first.
New to either protocol? Read what x402 and MPP put on the wire.
Build a custom testChoose the network, price, facilitator, and exactly how the endpoint should misbehave.