> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sydium.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Authentication

Authenticate with an opaque API key sent as `Authorization: Bearer sk_live_...` (prod) or `sk_test_...` (staging). Keys are scoped (e.g. `posts:write`, `analytics:read`); a key can never exceed the issuing member's team role.