Getting started

Authentication

Send your API key, read request IDs, and how spend limits affect requests.

API keys

Every API request needs a GreenTokens key. Keys start with sk-gt-, are created on the API Keys page of the dashboard, and are shown in full only once. We store only a hash.

Send the key in either header. Use whichever your SDK or tool sends by default:

curl https://api.greentokens.io/v1/models \
  -H "Authorization: Bearer $GREENTOKENS_API_KEY"

Sending both headers with different keys is rejected with 401. Never put a key in frontend code or a public repository: anyone holding it can spend your balance.

Spend limits, pausing and revoking

Each key can carry its own controls, set on the API Keys page:

Daily and monthly spend limits. Once a limit is reached, requests with that key return 402 until the period resets.
Pause. A paused key returns 401 until you resume it.
Revoke. Permanent. Create a new key to replace it.

A good default is one key per application, agent or environment, each with its own limit, so one runaway loop can't drain your whole balance.

Request IDs

Every response carries an x-request-id header. The same ID appears in the Requests log of your dashboard. Include it when you contact support so we can find the exact call.

curl -i https://api.greentokens.io/v1/chat/completions \
  -H "Authorization: Bearer $GREENTOKENS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "claude-sonnet-5", "messages": [{"role": "user", "content": "Hi"}]}'

# HTTP/2 200
# x-request-id: 3f9c2a1e-…