Firebase Authentication API keys
Firebase Auth API credentials belong in configuration, not in a commit. This page covers where to create one, what it looks like, and how APIKeyConnect stores it without ever being able to read it.
The facts
- Category
- Authentication & Security
- API host
identitytoolkit.googleapis.com- Key format
AIzaxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx- Env variable
FIREBASE · FIREBASE_AUTH · NEXT_PUBLIC_FIREBASE · VITE_FIREBASE- Sensitivity
- Critical
- Create a key
- https://console.firebase.google.com/project/_/settings/general — The Web API key is under Your apps → Web app → SDK setup and configuration.
- Documentation
- https://firebase.google.com/docs/auth
A leaked key here can move money, delete data, or impersonate your organisation. Rotate immediately if one is ever exposed, and never let one reach a client bundle.
Kinds of Firebase Authentication key
Web API Key
How APIKeyConnect stores it
The key is encrypted in your browser with AES-256-GCM, under a key derived from your master password with PBKDF2-SHA-256 at 600,000 iterations. The password never leaves your device, and the server holds ciphertext it has no way to open.
What the server can see — and what this design does not protect against — is written out in full on the security page. That section exists because a page with no limits section is marketing.
Questions
Where do I get a Firebase Authentication API key?
Firebase Authentication issues keys from https://console.firebase.google.com/project/_/settings/general. The Web API key is under Your apps → Web app → SDK setup and configuration. Once you have it, store it in APIKeyConnect rather than in a .env file you might commit — the key is encrypted on your device with a master password we never receive.
What does a Firebase Authentication API key look like?
Firebase Authentication keys follow the pattern AIzaxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx. Knowing the shape is useful for spotting one that has been pasted into a commit, a log line, or a support ticket — the places keys leak from most often.
What environment variable should I use for Firebase Authentication?
Most projects use FIREBASE, FIREBASE_AUTH, NEXT_PUBLIC_FIREBASE, VITE_FIREBASE. APIKeyConnect recognises these names, so importing an existing .env maps the value onto Firebase Authentication automatically instead of leaving it as an unlabelled string, and generating a .env writes it back under the same name.
How dangerous is a leaked Firebase Authentication key?
Critical sensitivity. A leaked key here can move money, delete data, or impersonate your organisation. Rotate immediately if one is ever exposed, and never let one reach a client bundle.
Can APIKeyConnect see my Firebase Authentication key?
No. The key is encrypted in your browser with AES-256-GCM under a key derived from your master password (PBKDF2-SHA-256, 600,000 iterations). The password never leaves your device and the server stores ciphertext it cannot open. What the server can see is documented in full on the security page, including what this design does not protect against.