What's in the API docs
Turnstile publishes a full reference for the public API (application programming interface) at Turnstile API reference. It covers authentication, versioning, and every resource area, including quotes, subscriptions, invoices, customers, contracts, and billable metrics.
Authentication and requests
Requests are authenticated with an API key, sent as an Authorization: Bearer header or an X-API-Key header. Include a Turnstile-Version header on every request so your integration keeps working as the API evolves. Every mutation (a request that creates or changes data) requires an Idempotency-Key header, so a retried request cannot create a duplicate.
Access your API key in your Turnstile account from Settings > API keys > +Create new key.
Rate limits
Turnstile allows 100 requests per minute per API key, with a 1,000-requests-per-minute backstop across your account.
Note: Usage events have their own dedicated endpoint and are documented separately. See Adding usage via the Turnstile API.