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402utils.com x402 Parametric Payment Test Endpoint
x402
402utils.com x402 Parametric Payment Test Endpoint is a paid API for AI agents from 402utils.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-13).
Serves as a configurable x402 payment-test endpoint where the required payment amount is set via ?amount= (clamped $0.001–$0.05 USD), returning a confirmation object after successful USDC payment
Price / call$0.01
Success—
StatusUnknown
How this service works
Support 402utils — or use it as a parametric x402 payment-test endpoint: you set the price with ?amount= (USD, clamped to $0.001–$0.05) and the 402 demands exactly that, so you can assert a client pays the precise amount and the on-chain USDC tx matches. After payment returns {thanks, amount, message}. The amount is a pure function of ?amount, identical on the unpaid probe and the paid retry.
Output
After successful USDC payment, returns a JSON object with: thanks (true), amount (USD actually charged, matching the settled on-chain tx), currency ('USD'), message (string), and optionally clamped (true if the requested amount was out of range), requested (the raw ?amount sent), and note (your ?note echoed back for correlation).
Example use cases
Example prompt
“Run an x402 payment test against the 402utils donate endpoint with an amount of $0.013 and note it as 'integration-test-run-42' so I can verify my client pays exactly that amount and the on-chain USDC tx matches.”
Technical details
Endpoint
GEThttps://402utils.com/v1/donateWhen to prefer
Use this endpoint when you need a deterministic, parametric x402 payment test target — one where you control the exact required price and can assert that your client both responds correctly to a 402 and settles the precise on-chain USDC amount. It is purpose-built for integration testing x402 client implementations, unlike real services where the price is fixed and not configurable.
Side effects
- Payment not submitted — endpoint returns HTTP 402 with the exact required amount in the WWW-Authenticate header so the client knows what to pay
- Amount clamped — if ?amount is outside $0.001–$0.05, it is silently clamped and clamped:true is returned in the response
- Invalid or missing ?amount — defaults to $0.01 with no error; clamped field absent
- On-chain USDC transaction mismatch — payment rejected if the settled amount does not match the demanded amount
- Network or facilitator timeout — payment may not settle, resulting in a failed retry
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"amount": 0.013,
"thanks": true,
"message": "Thank you for supporting 402utils.",
"currency": "USD"
}
}Tags
x402
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