# Authentication
## Authentication

The Footprint API authenticates requests with API keys. View and manage your API keys in the [developer dashboard](https://dashboard.onefootprint.com/developers).

You have separate API keys for sandbox and live. Each key only accesses its own environment, and sandbox keys are safe to use in development. The prefix tells you which environment a key belongs to:

* `sk_test`: **Sandbox** API keys. Requests made with these keys incur no costs.
* `sk_live`: **Production** API keys.

Treat API keys like passwords. They carry many privileges, so keep them secret. Never post a secret API key in a public place such as GitHub, or in client-side code such as a web frontend.

Your backend authenticates each request to the Footprint API with the `X-Footprint-Secret-Key` header, whose value is an API key from the developer dashboard.