---

name: using-firebase description: Comprehensive Firebase development guidance for GCP-hosted applications. Covers Firestore database operations (CRUD, queries, transactions, data modeling), Cloud Functions (1st and 2nd generation, TypeScript and Python, all trigger types), Firebase CLI operations, emulator setup and data persistence, security rules (Firestore and Storage), authentication integration, hosting configuration, and GCP service integration. Use when working with Firebase projects, deploying Cloud Functions, querying Firestore, setting up triggers (Firestore, Auth, Storage, HTTP, Callable, Scheduled, Pub/Sub), managing security rules, configuring hosting rewrites/headers, managing secrets, or integrating with GCP services like BigQuery and Cloud Tasks. Triggers include firebase, firestore, cloud functions, firebase functions, firebase hosting, firebase auth, firebase storage, firebase emulator, firebase deploy, firebase init, firebase rules, callable function, scheduled function, onDocumentCreated, onRequest, onCall, onSchedule. allowed-tools:

• Bash
• Read
• Write
• Edit
• WebFetch
• Glob
• Grep metadata: version: 1.0.0 last-updated: 2025-12-27 author: Claude Skills Community

---

Firebase Development Skill

Table of Contents

• Quick Start
• Scope
• Task Navigation
• Scripts
• Cloud Functions Generation
• Assets
• Common Workflows
• Pre-Deployment Checklist
• Emulator Ports
• Key Decisions

Quick Start

1. New project: Run scripts/init_project.sh [project-id]
2. Local development: Run scripts/start_emulators.sh
3. Deploy: Run scripts/deploy.sh

Scope

Use this skill for: Firebase development including Firestore CRUD/queries, Cloud Functions (1st/2nd gen), Firebase CLI, emulator setup, security rules, authentication, hosting, and GCP integration.

Do not use for: Pure GCP without Firebase, AWS/Azure services, non-serverless architectures, self-hosted solutions, or complex relational queries (use Cloud SQL instead).

Task Navigation

| Task | Action | |------|--------| | Initialize Firebase project | scripts/init_project.sh | | Start local emulators | scripts/start_emulators.sh | | Deploy to production | scripts/deploy.sh | | Deploy functions only | scripts/deploy_functions.sh | | Set up Python functions | python scripts/setup_python_functions.py | | Manage secrets | scripts/manage_secrets.sh | | Export Firestore data | scripts/export_firestore.sh | | Import Firestore data | scripts/import_firestore.sh |

| Topic | Reference | |-------|-----------| | CLI commands | references/cli-commands.md | | Firestore CRUD, queries, modeling | references/firestore.md | | Cloud Functions triggers | references/functions-triggers.md | | Error handling, optimization | references/functions-patterns.md | | Security rules | references/security-rules.md | | Authentication | references/auth-integration.md | | Hosting configuration | references/hosting-config.md | | GCP integration | references/gcp-integration.md |

Scripts

For complete CLI reference, see references/cli-commands.md.

init_project.sh

Initialize Firebase project with Firestore, Functions, Hosting, Storage, Emulators.

./scripts/init_project.sh              # Interactive
./scripts/init_project.sh my-project   # Specific project

start_emulators.sh

Start emulator suite with data persistence.

./scripts/start_emulators.sh                    # Auto-persistence
./scripts/start_emulators.sh --debug            # Enable debugging
./scripts/start_emulators.sh --import ./backup  # Import data
./scripts/start_emulators.sh --only functions,firestore

deploy.sh

Deploy with safety confirmations.

./scripts/deploy.sh                     # Full deploy
./scripts/deploy.sh --dry-run           # Preview only
./scripts/deploy.sh --only hosting      # Specific target
./scripts/deploy.sh --force             # Skip confirmation

deploy_functions.sh

Deploy Cloud Functions with granular control.

./scripts/deploy_functions.sh                    # All functions
./scripts/deploy_functions.sh myFunction         # Single function
./scripts/deploy_functions.sh --codebase python  # Specific codebase

manage_secrets.sh

Manage Cloud Functions secrets for 2nd gen functions. Uses GCP Secret Manager for secure storage. Prefer this script over direct gcloud commands for Firebase-integrated secret management with proper function access binding.

Secret lifecycle: Create secrets before first deploy, update via set (creates new version), bind to functions via runWith({ secrets: [...] }), and rotate by setting new values.

./scripts/manage_secrets.sh set API_KEY      # Set secret (creates or updates)
./scripts/manage_secrets.sh get API_KEY      # View metadata and versions
./scripts/manage_secrets.sh list             # List all project secrets
./scripts/manage_secrets.sh delete API_KEY   # Delete secret and all versions

export_firestore.sh / import_firestore.sh

Backup and restore Firestore data.

./scripts/export_firestore.sh --emulator              # From emulator
./scripts/export_firestore.sh --output gs://bucket    # Production to GCS
./scripts/import_firestore.sh --input ./data --emulator

setup_python_functions.py

Create Python Cloud Functions project.

python scripts/setup_python_functions.py --path python-functions --codebase python

Cloud Functions Generation

Use 2nd generation (recommended):

• HTTP, Firestore, Storage, Scheduled, Pub/Sub triggers
• Higher concurrency, longer timeouts

Use 1st generation only for:

• Auth onCreate/onDelete triggers (not available in 2nd gen)

2nd Gen Example (TypeScript)

import { onDocumentCreated } from "firebase-functions/v2/firestore";
import { onRequest } from "firebase-functions/v2/https";

export const onUserCreated = onDocumentCreated("users/{userId}", (event) => {
  console.log("New user:", event.params.userId, event.data?.data());
});

export const api = onRequest({ cors: true }, (req, res) => {
  res.json({ status: "ok" });
});

1st Gen Auth Trigger

import * as functions from "firebase-functions/v1";

export const onUserCreate = functions.auth.user().onCreate((user) => {
  console.log("New user:", user.uid);
  return null;
});

See references/functions-triggers.md for all trigger types with TypeScript and Python examples.

Assets

| File | Use | |------|-----| | assets/firebase.json.template | Copy to firebase.json and customize | | assets/firestore.rules.template | Copy to firestore.rules | | assets/storage.rules.template | Copy to storage.rules | | assets/tsconfig.functions.json | Copy to functions/tsconfig.json |

Common Workflows

New Project Setup

1. Run scripts/init_project.sh
2. Copy templates from assets/ directory
3. Start emulators: scripts/start_emulators.sh

Add Python Functions

1. Run python scripts/setup_python_functions.py
2. Update firebase.json with provided config
3. Deploy: scripts/deploy_functions.sh --codebase python

Security Rules Development

1. Start with assets/firestore.rules.template
2. Test with emulator
3. Deploy: firebase deploy --only firestore:rules

See references/security-rules.md for patterns.

Production Deployment

1. Set secrets: scripts/manage_secrets.sh set API_KEY
2. Dry run: scripts/deploy.sh --dry-run
3. Deploy: scripts/deploy.sh

Pre-Deployment Checklist

Before deploying to production, verify:

• [ ] Security Rules: Tested rules in emulator, no open access patterns
• [ ] Secrets: All required secrets configured via scripts/manage_secrets.sh list
• [ ] Environment: Correct project selected (firebase use)
• [ ] Functions: All functions tested locally with emulator
• [ ] Indexes: Firestore indexes deployed (firebase deploy --only firestore:indexes)
• [ ] Dry Run: scripts/deploy.sh --dry-run shows expected changes
• [ ] App Check: Enabled for production apps (prevents abuse)
• [ ] Billing: Budget alerts configured in GCP Console
• [ ] Monitoring: Cloud Logging and Error Reporting enabled

Emulator Ports

| Service | Port | |---------|------| | Auth | 9099 | | Functions | 5001 | | Firestore | 8080 | | Storage | 9199 | | Hosting | 5000 | | UI | 4000 |

Key Decisions

Firestore Data Modeling

• Embed data read together that rarely changes
• Reference data that changes frequently or is shared
• Subcollections for parent-child relationships
• Root collections for cross-document queries

See references/firestore.md for patterns.

TypeScript vs Python Functions

• TypeScript: JavaScript teams, Firebase client SDK integration
• Python: ML/data science, Python ecosystem

Both can coexist via multiple codebases in firebase.json.