x402 Integration Test

The zero-to-settle flow: from no x402 code to a real settled payment on Base L2, in three steps.

Developers integrating x402 usually stitch together verification, settlement and error-handling from scratch, with no unified way to prove the wiring works before going live. This flow fixes that: a spec-correct sample payload, a two-stage verification against the real facilitator, and a real 0.001 USDC settlement with an on-chain receipt you can paste into your PR.

Live test settlements
0
per hour
Settled 24h
0
real txs on Base
Sample payloads 24h
0
generated
Cost to you
$0.00
we pay the test tx

Step 1 — Generate a spec-correct payment free

A fresh TransferWithAuthorization (EIP-712, USDC on Base L2) signed with a throwaway test key. Same struct, domain and envelope a real paying agent produces.



Paste-ready verify command:







Step 2 — Verify it, both depths free


Stage A checks the EIP-712 signature alone. Stage B adds the on-chain truth: nonce replay and
live USDC balance. The throwaway wallet fails Stage B honestly — that categorized refusal
(INSUFFICIENT_FUNDS) is exactly what your integration must handle.










Step 3 — Settle a real payment real money


One click settles a real 0.001 USDC from AgentPay’s funded test wallet to the AgentPay
treasury — through the same verify/settle machinery every paying agent uses. You get the tx hash and
explorer link. Rate-limited: 6/hour, 2 per IP. Costs you nothing.








The API, if you’d rather script it




EndpointMethodWhat it does


/facilitator/integrate/sampleGETMock EIP-712 v2 payment + paste-ready curl


/facilitator/integrate/verify-demoPOSTRuns a payment through both verify depths


/facilitator/integrate/live-settlePOSTReal 0.001 USDC settle, tx receipt


/facilitator/integrate/statsGETSuccessful test settlements per hour





Building a real integration? Grab a signing scaffold at
/facilitator/scaffold, see the full
error catalogue at /facilitator/reasons, and
read the App Kits docs for SDK options.