How to Deploy Firebase Cloud Functions with the CLI

1// functions/package.json — check and update the engines field
2{
3  "name": "functions",
4  "scripts": {
5    "build": "tsc",
6    "serve": "npm run build && firebase emulators:start --only functions",
7    "deploy": "firebase deploy --only functions"
8  },
9  "engines": {
10    "node": "20"
11  },
12  "main": "lib/index.js"
13}

1# Deploy all functions
2firebase deploy --only functions
3
4# What happens:
5# 1. Runs npm install in functions/
6# 2. Runs the build script (tsc for TypeScript)
7# 3. Uploads the bundle to Google Cloud
8# 4. Creates/updates each exported function
9# 5. Outputs the URL for each HTTP function

1# Deploy a single function
2firebase deploy --only functions:processOrder
3
4# Deploy multiple specific functions
5firebase deploy --only functions:processOrder,functions:stripeWebhook
6
7# Deploy functions along with Firestore rules
8firebase deploy --only functions,firestore:rules
9
10# Deploy everything except functions
11firebase deploy --except functions

1# Error: "EBADENGINE" or "Unsupported engine"
2# Fix: Update engines.node in functions/package.json to 18, 20, or 22
3
4# Error: "Functions did not deploy properly"
5# Fix: Check the build output for TypeScript errors. Run:
6cd functions && npm run build
7# Fix any compilation errors, then deploy again
8
9# Error: "Quota Exceeded while trying to update"
10# Fix: Deploy in smaller batches (10 or fewer functions at a time):
11firebase deploy --only functions:fn1,functions:fn2,functions:fn3
12
13# Error: "Cloud Build API has not been used in project"
14# Fix: Enable the API at:
15# https://console.cloud.google.com/apis/library/cloudbuild.googleapis.com
16
17# Error: "Permission denied" or "Insufficient permissions"
18# Fix: Ensure you are logged in with the right account:
19firebase login --reauth

1# View recent logs for all functions
2firebase functions:log
3
4# View logs for a specific function
5firebase functions:log --only processOrder
6
7# Follow logs in real-time (like tail -f)
8firebase functions:log --follow
9
10# View logs in the browser
11# Firebase Console > Functions > Logs
12# or Google Cloud Console > Cloud Logging

1# The CLI prompts when it detects orphaned functions:
2# ? Would you like to proceed with deletion? Selecting no will continue
3# the rest of the deployments. (y/N)
4
5# Manually delete a function via CLI
6firebase functions:delete processOrder
7
8# Delete a function in a specific region
9firebase functions:delete processOrder --region=europe-west1
10
11# Delete from Firebase Console:
12# Functions > click function > Delete button