Authentication

Every request to the router needs a valid API key. Two headers are accepted interchangeably:

# These two requests are identical to the router:
curl https://api.basemnt.ai/v1/models -H "Authorization: Bearer sk-..."
curl https://api.basemnt.ai/v1/models -H "x-api-key: sk-..."

Creating keys

Keys are scoped to a project and created in the dashboard under Settings → API keys. A key carries the quota of the plan it belongs to; requests are metered per request, never per token.

Error responses

Invalid or missing keys return a standard error body. The shape matches the protocol family of the endpoint you called (OpenAI-style on /v1/chat/completions, Anthropic-style on /v1/messages), with an x-request-id header for support.

{
  "error": {
    "type": "authentication_error",
    "message": "Invalid API key"
  }
}

Keeping keys out of code

Prefer env vars over config files. All the agent guides work by setting OPENAI_BASE_URL / ANTHROPIC_BASE_URL and the matching key variable — nothing else changes.