Poll a device-flow for completion (RFC 8628 §3.4)
Use when: caller (typically a CLI) is polling for the user to approve the device-code flow it started — returns the access_token + refresh_token once approved, or a structured error code (authorization_pending / slow_down / expired_token / access_denied) while still pending
Per RFC 8628, errors during the polling phase use a 400 status with a stable error code the CLI branches on: authorization_pending (keep polling), slow_down (back off), expired_token (start a new flow), access_denied (user clicked Deny). Successful approval returns 200 with the issued token pair.
Authorizations
Verlon API key (newly minted keys are prefixed sk-vrln-; legacy verlon_* and layer_* keys from prior prefix migrations continue to validate). Generated from the dashboard under Settings → API Keys, or via verlon key create in the CLI.
Body
Response
Access + refresh token pair issued.

