Firebase Firestore Database

Status: Production Ready Last Updated: 2026-01-25 Dependencies: None (standalone skill) Latest Versions: [email protected], [email protected]

Quick Start (5 Minutes)

1. Install Firebase SDK

# Client SDK (web/mobile)
npm install firebase

# Admin SDK (server/backend)
npm install firebase-admin

2. Initialize Firebase (Client)

// src/lib/firebase.ts
import { initializeApp } from 'firebase/app';
import { getFirestore } from 'firebase/firestore';

const firebaseConfig = {
  apiKey: process.env.FIREBASE_API_KEY,
  authDomain: process.env.FIREBASE_AUTH_DOMAIN,
  projectId: process.env.FIREBASE_PROJECT_ID,
  storageBucket: process.env.FIREBASE_STORAGE_BUCKET,
  messagingSenderId: process.env.FIREBASE_MESSAGING_SENDER_ID,
  appId: process.env.FIREBASE_APP_ID,
};

const app = initializeApp(firebaseConfig);
export const db = getFirestore(app);

3. Initialize Firebase Admin (Server)

// src/lib/firebase-admin.ts
import { initializeApp, cert, getApps } from 'firebase-admin/app';
import { getFirestore } from 'firebase-admin/firestore';

// Initialize only once
if (!getApps().length) {
  initializeApp({
    credential: cert({
      projectId: process.env.FIREBASE_PROJECT_ID,
      clientEmail: process.env.FIREBASE_CLIENT_EMAIL,
      // Replace escaped newlines in private key
      privateKey: process.env.FIREBASE_PRIVATE_KEY?.replace(/\\n/g, '\n'),
    }),
  });
}

export const adminDb = getFirestore();

CRITICAL:

• Never expose FIREBASE_PRIVATE_KEY in client code
• Use Admin SDK for server-side operations (bypasses security rules)
• Use Client SDK for authenticated user operations

Core Operations

Document CRUD (Client SDK - Modular v9+)

import {
  collection,
  doc,
  addDoc,
  getDoc,
  getDocs,
  setDoc,
  updateDoc,
  deleteDoc,
  query,
  where,
  orderBy,
  limit,
  serverTimestamp,
  Timestamp,
} from 'firebase/firestore';
import { db } from './firebase';

// CREATE - Auto-generated ID
const docRef = await addDoc(collection(db, 'users'), {
  name: 'John Doe',
  email: '[email protected]',
  createdAt: serverTimestamp(),
});
console.log('Created document with ID:', docRef.id);

// CREATE - Specific ID
await setDoc(doc(db, 'users', 'user-123'), {
  name: 'Jane Doe',
  email: '[email protected]',
  createdAt: serverTimestamp(),
});

// READ - Single document
const docSnap = await getDoc(doc(db, 'users', 'user-123'));
if (docSnap.exists()) {
  console.log('Document data:', docSnap.data());
} else {
  console.log('No such document!');
}

// READ - Collection with query
const q = query(
  collection(db, 'users'),
  where('email', '==', '[email protected]'),
  orderBy('createdAt', 'desc'),
  limit(10)
);
const querySnapshot = await getDocs(q);
querySnapshot.forEach((doc) => {
  console.log(doc.id, ' => ', doc.data());
});

// UPDATE - Merge fields (doesn't overwrite entire document)
await updateDoc(doc(db, 'users', 'user-123'), {
  name: 'Jane Smith',
  updatedAt: serverTimestamp(),
});

// UPDATE - Set with merge (creates if doesn't exist)
await setDoc(doc(db, 'users', 'user-123'), {
  lastLogin: serverTimestamp(),
}, { merge: true });

// DELETE
await deleteDoc(doc(db, 'users', 'user-123'));

Document CRUD (Admin SDK)

import { adminDb } from './firebase-admin';
import { FieldValue, Timestamp } from 'firebase-admin/firestore';

// CREATE
const docRef = await adminDb.collection('users').add({
  name: 'John Doe',
  createdAt: FieldValue.serverTimestamp(),
how to use firebase-firestore
CursorClaude CodeClineCodexWindsurfGooseGitHub CopilotVS CodeGemini CLIKiloOpencodeKimi CLIRoo ClineAiderContinueZedBolt.newLovablev0Replit AgentSweepSmol DeveloperDevinCavemanAmpAntigravity
How to use firebase-firestore on Cursor
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1
Prerequisites
Before installing skills in Cursor, ensure your development environment meets these requirements:
›Cursor installed and configured on your development machine
›Node.js version 16.0+ with npm package manager (verify with node --version)
›Active project directory or workspace where you want to add firebase-firestore
2
Execute installation command
Execute the skills CLI command in your project's root directory to begin installation:
$npx skills add https://github.com/jezweb/claude-skills --skill firebase-firestorecopy
The skills CLI fetches firebase-firestore from GitHub repository jezweb/claude-skills and configures it for Cursor.
3
Select Cursor when prompted
The CLI will show a list of available agents. Use arrow keys to navigate and space to select Cursor:
◆ Which agents do you want to install to?
│
│ ── Universal (.agents/skills) ── always included ────
│   • Amp
│   • Antigravity
│   • Cline
│   • Codex
│ ●Cursor(selected)
│   • Cursor
│   • Windsurf
4
Verify installation
Confirm successful installation by checking the skill directory location:
.cursor/skills/firebase-firestore
Reload or restart Cursor to activate firebase-firestore. Access the skill through slash commands (e.g., /firebase-firestore) or your agent's skill management interface.
⚠
Security & Verification Notice
We perform automated surface-level scans (Gen AI Scanner, Socket, Snyk) during installation. These checks detect common vulnerabilities but do not guarantee complete security. Always review skill source code and verify the publisher's reputation before production use.
Skills execute code in your development environment. Always verify the publisher's identity, review recent commits, and test in isolated environments before production deployment.
Additional Resources
›View source code on GitHub›Skills CLI documentation›Learn more about Cursor›What are agent skills?