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x402-Testbed Echo Endpoint
x402
x402-Testbed Echo Endpoint is a paid API for AI agents from health-api.tail11a58f.ts.net, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-31).
Echoes back GET request query parameters for testing x402 payment client integration, with optional 500 error injection before payment settlement.
Price / call$0.001
Success—
StatusUnknown
How this service works
x402 test endpoint (GET) — echo for testing an x402 client with query params only. Returns what it received. Query param expectStatus=500 makes it fail with 500 BEFORE any payment is taken (tests your client error path and proves a 5xx is never treated as paid).
Output
Returns an echo of the received GET request including query parameters as structured JSON; if expectStatus=500 is supplied, returns an HTTP 500 error response before any payment settlement occurs, allowing the caller to inspect the pre-payment failure path.
Example use cases
Basic x402 client smoke test
“Make a simple paid GET call to the x402 echo endpoint and show me what it echoed back — I just want to confirm my client can complete a real x402 payment and get a response.”
Pre-payment 500 error path test
“Hit the x402 echo endpoint with expectStatus set to 500 so I can verify my client correctly handles a server error that fires before any payment is taken — I need to confirm a 5xx is never recorded as a paid call.”
Cheapest live x402 integration check
“Run the smallest possible paid x402 test request against the echo endpoint for me — I want a live end-to-end confirmation that my client negotiates the 402, pays, and receives the echo for just $0.001 USDC.”
Technical details
Endpoint
GEThttps://health-api.tail11a58f.ts.net/echo?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need a live, real-money x402 integration test at the lowest possible cost ($0.001 USDC), especially when verifying that your x402 client correctly handles both the happy-path echo response and the pre-payment 5xx error path. Prefer it over mock or sandbox endpoints when you need to confirm end-to-end payment flow with a real facilitator.
Side effects
- expectStatus=500 triggers a 500 Internal Server Error before payment is processed
- Missing or malformed query parameters may result in an empty echo body
- Network timeouts on the Tailscale-hosted endpoint if the host is offline
- x402 payment negotiation failure if client does not support the protocol correctly
- 402 Payment Required returned if payment credentials are absent or invalid
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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