Get Started

Authentication

API keys, the Authorization header, and base URL.

Every request needs an API key. Keys are tied to a single Furnace account, so requests never touch another account’s data.

Get a key

Create an API key in Furnace under Account Settings → API keys. Keys start with f_. Copy it once and store it somewhere safe — you can revoke and recreate keys at any time.

Send it with every request

Pass your key in the Authorization header:

Authorization: Bearer f_your_key_here

The base URL is your Furnace Client API host, for example https://api.getfurnace.io. All endpoints live under /v1/.

curl -sS 'https://api.getfurnace.io/v1/mailboxes' \
  -H 'Authorization: Bearer f_your_key_here'

If a key is wrong

A missing, revoked, expired, or unknown key returns 401 with an authentication_error. Double-check the header format and that the key is still active.

Next: Quickstart.