Authentication

Send your Nimbus API key as a Bearer token or x-api-key header — both work on either endpoint.

Get a key

Sign in at nimbusapi.net → Dashboard → API Keys → New key. Keys start with sk-nim-. Keep them secret — treat them like production database credentials.

OpenAI-style

The OpenAI SDK and any OpenAI-compatible client sends the key as a Bearer token:

http

Authorization: Bearer sk-nim-YOUR_KEY

Anthropic-style

The Anthropic SDK uses two headers — the API key and the wire-format version:

http

x-api-key: sk-nim-YOUR_KEY
anthropic-version: 2023-06-01

Key scopes and spend caps

Every key can carry a hard USD spend cap and an optional model allow-list, both configured from the dashboard. When a key hits its cap, Nimbus returns HTTP 402 Payment Required and stops forwarding to upstream providers — no surprise overages, no manual throttling required.

Use per-environment keys (one for local, one for staging, one for prod) so a leaked dev key can't drain your production budget. Rotate any key from the dashboard; the old value is revoked instantly.