idempotency_conflict

HTTP 409: Idempotency key conflict

When it occurs

The Idempotency-Key on this request was already used, with a different request body, on an earlier call (WR-01). The stored response only replays for the exact same body; a changed body under a reused key is treated as a mistake, not a retry.

What to do next

Generate a fresh key per logically distinct write. Never reuse one key across two requests with different bodies.