---
title: FCM
description: Send mobile push through Firebase Cloud Messaging (current HTTP API).
icon: Bell
source: "src/transports/fcm.ts"
---

Send device-token push through Firebase Cloud Messaging for native Android and iOS clients.
The transport uses the current FCM HTTP API with a service-account JWT — no Google SDK.
Use [Web Push](./webpush) when you have a browser Push API subscription instead.

<Callout title="The one rule">Pass `token` in push options — not a Web Push `subscription`.</Callout>

## Quick start

<Steps>
  <Step title="Configure the transport">

```ts
import { createPushSender } from "sently/push";
import { FcmTransport } from "sently/transports/fcm";

const push = createPushSender({
  transport: new FcmTransport({
    projectId: process.env.FCM_PROJECT_ID!,
    clientEmail: process.env.FCM_CLIENT_EMAIL!,
    privateKey: process.env.FCM_PRIVATE_KEY!,
  }),
});
```

  </Step>
  <Step title="Verify credentials, then send">

```ts
const check = await push.verify();
console.log(check.ok, check.message);

const result = await push.send({
  token: deviceRegistrationToken,
  title: "Hello",
  body: "World",
});
console.log(result.messageId, result.status, result.provider);
```

  </Step>
</Steps>

## Configuration

| Option | Type | Default or requirement |
| --- | --- | --- |
| `projectId` | `string` | required |
| `clientEmail` | `string` | service account email |
| `privateKey` | `string` | PEM private key (env / secrets only) |
| `getAccessToken` | `() => Promise<string>` | optional override for tests |

Literal `\n` sequences in `privateKey` env strings are normalized to newlines.
The transport mints a short-lived OAuth2 token with scope `firebase.messaging` — no Google SDK.

## Troubleshooting

<Accordions>
  <Accordion title="Can I pass a browser subscription?">
    No. `FcmTransport` requires `token`. Use `WebPushTransport` for VAPID subscriptions.
  </Accordion>
  <Accordion title="Where do I get the private key?">
    Download a Firebase / GCP service account JSON and pass `project_id`, `client_email`, and `private_key` from that file via environment variables.
  </Accordion>
</Accordions>

## Learn more

- [Push channel](/docs/channels/push)
- [Push options](/docs/reference/push-options)
- [Web Push](./webpush)

## Next

<Cards>
  <Card title="Push channel" href="/docs/channels/push" />
  <Card title="Web Push" href="/docs/transports/webpush" />
</Cards>