API overview
Bare minimum: how to authenticate, how endpoints split, and the double-/v1 trap.
Authentication
All protocols use HTTP header Authorization: Bearer <your API key> (same as console handoff).
Double /v1 warning
OpenAI-compatible clients need a /v1 suffix on the base URL; Claude Code’s ANTHROPIC_BASE_URL must be the gateway root (no /v1) or paths become /v1/v1/… and return 404.