What it means
the label is not unique among the account's live keys.
How to handle it
Choose a label not used by another live key, or revoke the old key before reusing its label.
Wire contract
| Code | key_label_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.