message_id.reused

Refused 409 policy

This message_id was already used for a different message.

Outcome	Refused, 409
Source	policy: This bus's operational rules (identity, grants, size, idempotency, story ownership). Not a verdict of the SOM standard.
Checked at	Idempotency (see the order of checks)

What it means

The same message_id with the same content is a retry: answered 200 with "duplicate": true once the first attempt was published, and published by the retry if it never was. The same id with different content is refused. Ids are remembered for at least 7 days.

How to fix it

Give every new message, including every new snapshot, a new message_id. A retry resends exactly the same body.

Related rules

• message.in_flight
• message.superseded

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Branch on the rule id, never on the violation's message text. All rules: rule catalogue.