Authentication

You create an API key in the dashboard; it starts with gk_sk_. Both text protocols accept a Bearer token; Anthropic Messages also accepts x-api-key.

OpenAI-compatible header

Authorization: Bearer YOUR_API_KEY

Anthropic-compatible headers

x-api-key: YOUR_API_KEY
anthropic-version: 2023-06-01

Model access

• A key works only while it is active, not expired and within its quota.
• If a key is restricted to a list of models, every other model returns HTTP 403.
• One key can be used with several allowed models.
• Use separate keys with separate quotas for production, development and CI.

Security

Keep the key on your server or in a secrets manager. Never put it into client-side JavaScript, a mobile app, a repository, a screenshot or a support message. Delete the key in the dashboard if it may have leaked.