How to Access Config Variables in Firebase Cloud Functions

1# functions/.env — applies to all deployed environments
2STRIPE_WEBHOOK_URL=https://api.stripe.com/v1/webhooks
3APP_NAME=MyFirebaseApp
4MAX_RETRIES=3
5
6# functions/.env.local — emulator only, overrides .env
7STRIPE_WEBHOOK_URL=http://localhost:4242/webhook
8APP_NAME=MyFirebaseApp-Dev

1import { defineString, defineInt } from "firebase-functions/params";
2import { onRequest } from "firebase-functions/v2/https";
3
4// Define parameters — CLI prompts if not set
5const stripeWebhookUrl = defineString("STRIPE_WEBHOOK_URL", {
6  description: "The Stripe webhook endpoint URL",
7  default: "https://api.stripe.com/v1/webhooks",
8});
9
10const maxRetries = defineInt("MAX_RETRIES", {
11  description: "Maximum retry attempts for failed operations",
12  default: 3,
13});
14
15export const processPayment = onRequest(async (req, res) => {
16  const url = stripeWebhookUrl.value();
17  const retries = maxRetries.value();
18
19  res.json({ webhook: url, maxRetries: retries });
20});

1import { defineSecret } from "firebase-functions/params";
2import { onRequest } from "firebase-functions/v2/https";
3
4const stripeApiKey = defineSecret("STRIPE_API_KEY");
5const openaiKey = defineSecret("OPENAI_API_KEY");
6
7export const createCharge = onRequest(
8  { secrets: [stripeApiKey, openaiKey] },
9  async (req, res) => {
10    // Secrets are available via .value() at runtime
11    const stripe = require("stripe")(stripeApiKey.value());
12    const charge = await stripe.charges.create({
13      amount: 1000,
14      currency: "usd",
15      source: req.body.token,
16    });
17
18    res.json({ chargeId: charge.id });
19  }
20);

1# Step 1: Export existing config to .env format
2firebase functions:config:export
3# This creates a .env file with your existing config values
4
5# Step 2: Replace in code
6# BEFORE (deprecated):
7# const apiKey = functions.config().stripe.key;
8
9# AFTER (v2 — choose one approach):
10# Option A: process.env
11# const apiKey = process.env.STRIPE_KEY;
12
13# Option B: defineSecret (recommended for secrets)
14# const apiKey = defineSecret("STRIPE_KEY");
15# Then access with apiKey.value() inside the function

1# functions/.env.local — emulator-only overrides
2STRIPE_API_KEY=sk_test_fake_key_for_local_dev
3OPENAI_API_KEY=sk-test-fake-key
4
5# Start the emulator
6firebase emulators:start --only functions
7
8# Your functions will use the .env.local values