- session_id (clm_sess_...) in browser URL — identifies login attempt
- user_code (ABCD-EFGH) visual confirmation — shown in both terminal and browser
- device_code (secret) — CLI polls with this, never displayed
- CLI accepts stdin paste of JWT token while polling (race)
- Web page handles both ?session= and ?code= params
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>