> ## Documentation Index
> Fetch the complete documentation index at: https://bluebubbles.anmho.com/llms.txt
> Use this file to discover all available pages before exploring further.

# FCM API reference — BlueBubbles SDK

> Retrieve your server's Firebase Cloud Messaging client config and register devices to receive push notifications from BlueBubbles Server.

Firebase Cloud Messaging (FCM) is the push notification system BlueBubbles uses to wake up client apps when new iMessages arrive. Instead of keeping a persistent connection open, the server sends an FCM push notification to your registered device, which then fetches the new data over the REST API. The FCM service in the SDK gives you two operations: fetching the server's FCM client configuration (needed to initialize Firebase on the client side) and registering a device to receive those notifications.

Access the service through `client.fcm`.

<Note>
  To use FCM with the BlueBubbles Server, you must have Firebase configured on
  your server. Follow the [BlueBubbles Server setup guide](https://bluebubbles.app)
  to upload your FCM credentials before calling these endpoints.
</Note>

***

## FCM client configuration

### `getFcmClientConfig()`

Returns the FCM client configuration from your BlueBubbles Server. Use this configuration to initialize the Firebase SDK on your client application so it can register for push notifications through the correct Firebase project.

**Signature**

```typescript theme={null}
client.fcm.getFcmClientConfig(): CancelablePromise<any>
```

**Example**

```typescript theme={null}
const config = await client.fcm.getFcmClientConfig();

// Use the returned config to initialize Firebase on your client
// e.g., initializeApp(config.data) in a React Native or web app
console.log(config.data);
```

<Tip>
  Fetch the FCM client config once at app startup and cache it. The configuration
  only changes when the server administrator rotates the Firebase credentials.
</Tip>

***

## Device registration

### `registerDevice()`

Registers a device with the BlueBubbles Server so it can receive FCM push notifications. You generate the FCM `identifier` (also called a registration token) by authenticating with Google Firebase on the client side, then pass it to this endpoint so the server knows where to send notifications.

**Signature**

```typescript theme={null}
client.fcm.registerDevice({
  requestBody,
}: {
  requestBody?: Record<string, any>;
}): CancelablePromise<any>
```

**Request body parameters**

<ParamField body="name" type="string" required>
  A human-readable name for the device being registered. This helps you
  identify registered devices in the server UI. Example: `"pixel5a"`.
</ParamField>

<ParamField body="identifier" type="string" required>
  The FCM registration token generated when your client app authenticates with
  Google Firebase. The server uses this token to route push notifications to
  your specific device.
</ParamField>

**Example**

```typescript theme={null}
// After authenticating with Firebase on the client and obtaining a token:
const fcmToken = await getFCMToken(); // your Firebase client call

await client.fcm.registerDevice({
  requestBody: {
    name: "pixel5a",
    identifier: fcmToken,
  },
});
```

```typescript theme={null}
// Re-register when the FCM token is refreshed by Firebase
messaging().onTokenRefresh(async (newToken) => {
  await client.fcm.registerDevice({
    requestBody: {
      name: deviceName,
      identifier: newToken,
    },
  });
});
```

<Warning>
  FCM registration tokens expire and are rotated by Google Firebase. Listen for
  token refresh events in your Firebase client and call `registerDevice()` again
  with the new token to avoid missing notifications.
</Warning>