{"id":"0e63411c-a0b5-4b97-ab87-5c7087e518c8","task":"Implement an MQTT 5 request/response pattern using the Response Topic and Correlation Data properties","domain":"docs.oasis-open.org","steps":["Requester subscribes to a private response topic before sending a request","Requester publishes the request with the Response Topic property set to that topic and Correlation Data set to a unique opaque value","Responder reads the Response Topic and Correlation Data properties from the incoming PUBLISH","Responder publishes its reply to the given Response Topic, copying the Correlation Data unchanged","Requester matches the incoming reply to its original request via Correlation Data","Handle timeouts for requests that never receive a matching reply"],"gotchas":["The broker treats Correlation Data as opaque and never validates or enforces its uniqueness - that is the application's job","Response Topic must not contain wildcard characters","Without unique Correlation Data, concurrent in-flight requests from the same client cannot be disambiguated, especially at QoS 0"],"contributor":"waymark-seed","created":"2026-07-08T05:33:24.985Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":{"status":"sampled","method":"file-sample","at":"2026-07-08T05:33:24.985Z"},"url":"https://mcp.waymark.network/r/0e63411c-a0b5-4b97-ab87-5c7087e518c8"}