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x402 Testbed — Chaos/Failure Injection Endpoint
x402
x402 Testbed — Chaos/Failure Injection 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).
Injects controlled server-side failures (HTTP 500) before payment is processed, allowing x402 clients to verify they never treat a 5xx response as a successful paid call.
Price / call$0.001
Success—
StatusUnknown
How this service works
x402 test endpoint (GET) — failure injection with query params only. Query param failRate (0-1): the request fails with 500 BEFORE payment is taken, so you can test that your x402 client never treats a 5xx as paid and retries without double-paying.
Output
When failure is injected (based on failRate probability), the endpoint returns an HTTP 500 error before any payment is deducted. This lets the caller verify that their x402 client correctly identifies the failure as pre-payment and does not record or retry the call as a paid transaction.
Example use cases
Pre-payment 500 retry safety check
“Hit the x402 chaos endpoint with failRate set to 1.0 so every request fails before payment — I want to confirm my client never marks a 500 as paid and retries without charging again.”
Probabilistic failure integration test
“Run 20 calls to the x402 chaos endpoint with a failRate of 0.5 and track how my client handles the mix of successes and injected failures — I need to make sure it never double-pays on any of the 500s.”
CI pipeline fault-injection gate
“As part of my CI pipeline, call the x402 chaos endpoint with failRate 0.9 to make sure our payment client's error-handling passes before we ship — confirm no duplicate charges occur on any of the failures.”
Technical details
Endpoint
GEThttps://health-api.tail11a58f.ts.net/chaos?utm_source=zero.xyzWhen to prefer
Use this endpoint specifically when building or validating an x402 payment client and you need to confirm it handles pre-payment server errors (5xx) without double-charging. It is the canonical tool for chaos/fault-injection testing in the x402 protocol stack, distinct from the echo sibling endpoint which tests successful paid round-trips.
Side effects
- Injected 500 at configured failRate — expected behavior, not a true error
- failRate out of [0,1] range may cause undefined behavior
- Network timeout if the Tailscale node is unreachable
- No payment taken on any 500 response by design — if payment IS deducted, that is an x402 client bug
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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