What it means
the creator reference is already used on this parent.
How to handle it
Choose a creator reference that is unique among children of the same parent account.
Wire contract
| Code | creator_ref_in_use |
|---|---|
| Class | conflict |
| HTTP status | 409 |
| Meta keys | None |
| Raised | Yes |
The response uses the standard {"error": {…}} envelope. Branch on error.code, not the human-readable message. Preserve request_id when reporting a failure.