fastify-firebase

Fastify v5+ plugin for firebase-admin. Full TypeScript support.

• Works with service account JSON or Application Default Credentials (GCP)
• Supports databaseURL, storageBucket, and custom app name
• Accepts both camelCase and snake_case cert keys
• Singleton Firebase app with auto-cleanup on close
• Zero config on Cloud Run / Cloud Functions

Install

npm i fastify-firebase

Usage

With service account cert

import Fastify from 'fastify';
import fastifyFirebase from 'fastify-firebase';
import cert from './firebase.json';

const app = Fastify();
app.register(fastifyFirebase, cert);

app.get('/users', async (req, reply) => {
  const snapshot = await req.server.firebase.firestore().collection('Users').get();
  reply.send(snapshot.docs.map((doc) => doc.data()));
});

app.listen({port: 3000});

On GCP (Cloud Run, Cloud Functions) no cert needed

app.register(fastifyFirebase); // uses Application Default Credentials

With extra options

app.register(fastifyFirebase, {
  ...cert,
  name: 'my-app',                              // custom app name (default: 'default')
  databaseURL: 'https://my-app.firebaseio.com', // for Realtime Database
  storageBucket: 'my-app.appspot.com',           // for Cloud Storage
});

Options

| Option | Type | Description | |---|---|---| | projectId / project_id | string | Firebase project ID | | privateKey / private_key | string | Service account private key | | clientEmail / client_email | string | Service account email | | name | string | Firebase app name (default: 'default') | | databaseURL | string | Realtime Database URL | | storageBucket | string | Cloud Storage bucket |

All options are optional when using Application Default Credentials on GCP. When providing a cert, all three cert fields are required.

Migration from v2.x

• BREAKING: Registering without options no longer throws uses Application Default Credentials instead
• New options: databaseURL, storageBucket
• Firebase app is now deleted on Fastify close (auto-cleanup)
• Error messages are more specific

Migration from v1.x

• Requires Fastify v5+
• ESM-only (import/export)
• Plugin is async/Promise-based

Links

• Generate a private key
• Firebase Console - Service Accounts
• Fastify · fastify-plugin · firebase-admin

License

MIT