firebase-edge-auth/README.md

Firebase token decoder for edge runtimes

# Firebase Edge Auth

Firebase token decoder for edge runtimes, written in TypeScript.

## Installation

```bash
npm install firebase-edge-auth
```

## Usage

```typescript
import { decodeFirebaseToken, FirebaseTokenError } from "firebase-edge-auth";

const projectId = "your-firebase-project-id";
const token = "user-provided-token";

try {
  const decodedToken = await decodeFirebaseToken(token, projectId);
  console.log("Decoded token:", decodedToken);
} catch (error) {
  if (error instanceof FirebaseTokenError) {
    console.error("Token verification failed:", error.message);
  } else {
    console.error("Unexpected error:", error);
  }
}
```

## API

### `decodeFirebaseToken(token: string, projectId: string): Promise<FirebaseTokenPayload>`

Decodes and verifies a Firebase JWT token.

- `token`: The Firebase JWT token to decode.
- `projectId`: Your Firebase project ID.

Returns a Promise that resolves to the decoded token payload if verification succeeds, or rejects with a `FirebaseTokenError` if verification fails.

### `FirebaseTokenPayload`

An interface representing the decoded token payload:

```typescript
interface FirebaseTokenPayload {
  aud: string;
  iss: string;
  sub: string;
  auth_time: number;
  exp: number;
  iat: number;
  [key: string]: any;
}
```

### `FirebaseTokenError`

A custom error class for Firebase token verification failures.

## License

MIT