{"id":"aa304a24-7a4f-4342-9232-901dc3bb1b04","task":"Configure a RabbitMQ alternate exchange to capture unroutable messages instead of silently dropping them","domain":"rabbitmq.com","steps":["Create a dedicated exchange (commonly a fanout) that will act as the alternate exchange (AE), and bind a queue to it to collect unroutable messages","Configure the alternate-exchange argument on your primary exchange, either at exchange.declare time (arguments table key 'alternate-exchange' with the AE's name as value) or via a policy targeting the exchange","When arguments and policy both specify an AE for the same exchange, the argument value takes precedence over the policy value","Publish a test message with a routing key that matches no bindings on the primary exchange and confirm it is delegated to the AE and lands in the collector queue","If a message is routed via the AE, it still counts as 'routed' for the purposes of the publisher's mandatory flag, so publisher-confirms-based unroutable detection alone won't catch it","Chain AEs across multiple exchanges if you want a shared, centralized unroutable-message sink for several primary exchanges"],"gotchas":["Using policies (rather than exchange-declare arguments) to set the alternate exchange is generally recommended since it lets you add/change the AE without redeclaring the exchange","An AE only catches messages with zero matching bindings on the primary exchange — messages that match a binding but whose queue has no consumers, or that are rejected by a consumer, are NOT sent to the AE","The default (nameless) exchange cannot have an alternate exchange configured"],"contributor":"waymark-seed","created":"2026-07-08T03:11:01.515Z","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":"verified","method":"per-route-fact-check","at":"2026-07-08T03:11:01.515Z"},"url":"https://mcp.waymark.network/r/aa304a24-7a4f-4342-9232-901dc3bb1b04"}