Skill for converting an installed Firebase Extension (or extension source) into a standalone Cloud Functions for Firebase codebase or publishable npm package, including V1 to V2 trigger upgrades, lifecycle hooks, and declarative security

Extension to Functions Codebase & npm Package Migration Overview Migrates a Firebase Extension into either: 1. A local Cloud Functions codebase ( functions/src/ for app integration). 1. A publishable npm package (reusable open source package exporting V2 functions). Leverages native Cloud Functions features (declarative IAM, Parameterized Config, SDK Lifecycle Hooks) and modernizes 1st Gen triggers to 2nd Gen using the Destructuring Compatibility Shim. Target Migration Workflows Target A: Local Functions Codebase (End User App Integration) Output: Code under functions/src/ . Config in .env . Deployment: firebase deploy only functions . Target B: Publishable npm Package / Shareable Package Output: Reusable npm package exporting V2 functions. Configuration: package.json specifying exports map, engines: { "node": " =22" } , and peerDependencies: { "firebase functions": " =6.0.0" } . Usage: Consumers install package and re export functions in index.ts ( export from "<package name " ). Core Rules & Constraints 1. Declarative IAM & APIs (Zero Local Overhead) Use native SDK declarations instead of manual gcloud scripts or console instructions: Use requiresRole("roles/...") for required GCP IAM permissions. Use requiresAPI("service.googleapis.com", "Description") for Google APIs. 2. Global Parameter Access Restriction Never call .value() at top level module load scope. Initialize global SDK instances inside onInit() or lazy getters: 3. V2 Concurrency & Cost Parity V2 enables concurrency (up to 80 requests). To preserve V1 single concurrency pricing, set cpu: "gcf gen1" . Step by Step Migration Execution Step 1: Inventory Extension Resources 1. extension.yaml : params → defineString , defineInt , defineBoolean , defineSecret . apis → requiresAPI(...) . roles → requiresRole(...) . lifecycleEvents → afterFirstDeploy & afterRedeploy . resources → Upgrade 1st Gen triggers to 2nd Gen ( onDocumentWritten , onTaskDispatched , onRequest ). 1. Files & Scripts : Preserve devDependencies, test framework ( jest ), and test scripts. Step 2: Configure package.json Set name: "<package name " , engines: { "node": " =22" } . Set peerDependencies : Configure exports map targeting ESM/CommonJS and TypeScript declarations ( lib/index.js , lib/index.d.ts ). Step 3: Upgrade Triggers from V1 to V2 Firestore: Use onDocumentWritten from firebase functions/v2/firestore . Tasks: Use onTaskDispatched from firebase functions/v2/tasks . Remove EXT INSTANCE ID when enqueueing tasks. HTTP: Use onRequest from firebase functions/v2/https . Apply Destructuring Compatibility Shim ( { change, context } , { snapshot, context } ) where legacy 1st Gen handlers expect (change, context) . Step 4: Convert Lifecycle Events Map extension lifecycle events to SDK lifecycle hooks in src/index.ts : onInstall → afterFirstDeploy({ task: { function: "initTask" } }) onUpdate / onConfigure → afterRedeploy({ task: { function: "setupTask" } }) Step 5: Package README & Export Instructions Generate README.md containing: 1. Installation instructions ( npm install ). 1. Re export snippet ( export from "<package name " ). 1. Parameterized Configuration .env reference table. 1. What Changed (Extension vs Package) comparison table. Reminder: NEVER execute npm publish .

extension-to-functions-codebase