Chaos testing mocks: delay, ?error=, and simulated 429

Happy-path mocks hide retry bugs. Pro plans add two layers: query params on any mock call, and a collection Chaos profile that stays on until you turn it off.

Use ?delay=500 for loading states and ?error=503 or ?error=422 for error UI. ?error=429 returns a simulated rate limit with Retry-After.

Chaos profile vs ?error=

Chaos can apply failure %, min/max latency, and “429 after N requests” in a window. When Failure % is active, chaos may run before a one-off ?error= test — set Failure % to 0 (or disable chaos) to verify a specific status.

Error response templates supply the JSON body for both chaos failures and ?error= responses; the status code comes from the trigger.