chore: upgrade Firebase Functions to Node.js 22 and firebase-functions v7

Node.js 20 is being decommissioned 2026-10-30. This upgrades the runtime
to Node.js 22 (LTS), bumps firebase-functions from v6 to v7, removes the
deprecated functions.config() fallback, and aligns the TS target to ES2022.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/firebase.json

@@ -1,7 +1,7 @@
 {
   "functions": {
     "source": ".",
-    "runtime": "nodejs20",
+    "runtime": "nodejs22",
     "ignore": [
       "node_modules",
       "src",

backend/package-lock.json

@@ -21,7 +21,7 @@
         "express": "^4.18.2",
         "express-rate-limit": "^7.1.5",
         "firebase-admin": "^13.4.0",
-        "firebase-functions": "^6.4.0",
+        "firebase-functions": "^7.0.5",
         "helmet": "^7.1.0",
         "joi": "^17.11.0",
         "jsonwebtoken": "^9.0.2",
@@ -4649,9 +4649,9 @@
       }
     },
     "node_modules/firebase-functions": {
-      "version": "6.4.0",
-      "resolved": "https://registry.npmjs.org/firebase-functions/-/firebase-functions-6.4.0.tgz",
-      "integrity": "sha512-Q/LGhJrmJEhT0dbV60J4hCkVSeOM6/r7xJS/ccmkXzTWMjo+UPAYX9zlQmGlEjotstZ0U9GtQSJSgbB2Z+TJDg==",
+      "version": "7.0.5",
+      "resolved": "https://registry.npmjs.org/firebase-functions/-/firebase-functions-7.0.5.tgz",
+      "integrity": "sha512-uG2dR5AObLuUrWWjj/de5XxNHCVi+Ehths0DSRcLjHJdgw1TSejwoZZ5na6gVrl3znNjRdBRy5Br5UlhaIU3Ww==",
       "license": "MIT",
       "dependencies": {
         "@types/cors": "^2.8.5",
@@ -4664,10 +4664,24 @@
         "firebase-functions": "lib/bin/firebase-functions.js"
       },
       "engines": {
-        "node": ">=14.10.0"
+        "node": ">=18.0.0"
       },
       "peerDependencies": {
-        "firebase-admin": "^11.10.0 || ^12.0.0 || ^13.0.0"
+        "@apollo/server": "^5.2.0",
+        "@as-integrations/express4": "^1.1.2",
+        "firebase-admin": "^11.10.0 || ^12.0.0 || ^13.0.0",
+        "graphql": "^16.12.0"
+      },
+      "peerDependenciesMeta": {
+        "@apollo/server": {
+          "optional": true
+        },
+        "@as-integrations/express4": {
+          "optional": true
+        },
+        "graphql": {
+          "optional": true
+        }
       }
     },
     "node_modules/flat-cache": {

backend/package.json

@@ -53,7 +53,7 @@
     "express": "^4.18.2",
     "express-rate-limit": "^7.1.5",
     "firebase-admin": "^13.4.0",
-    "firebase-functions": "^6.4.0",
+    "firebase-functions": "^7.0.5",
     "helmet": "^7.1.0",
     "joi": "^17.11.0",
     "jsonwebtoken": "^9.0.2",

backend/src/config/env.ts

@@ -1,6 +1,5 @@
 import dotenv from 'dotenv';
 import Joi from 'joi';
-import * as functions from 'firebase-functions';
 
 // Load environment variables from .env file (for local development)
 dotenv.config();
@@ -10,46 +9,7 @@ dotenv.config();
 // - firebase functions:secrets:set for sensitive data (recommended)
 // - defineString() and defineSecret() in function definitions (automatically available in process.env)
 // - .env files for local development
-// MIGRATION NOTE: functions.config() is deprecated and will be removed Dec 31, 2025
-// We keep it as a fallback for backward compatibility during migration
-let env = { ...process.env };
-
-// MIGRATION: Firebase Functions v1 uses functions.config(), v2 uses process.env with defineString()/defineSecret()
-// When using defineString() and defineSecret() in function definitions, values are automatically
-// available in process.env. This fallback is only for backward compatibility during migration.
-try {
-  const functionsConfig = functions.config();
-  if (functionsConfig && Object.keys(functionsConfig).length > 0) {
-    console.log('[CONFIG DEBUG] functions.config() fallback available (migration in progress)');
-    // Merge functions.config() values into env (process.env takes precedence - this is correct)
-    let fallbackCount = 0;
-    Object.keys(functionsConfig).forEach(key => {
-      if (typeof functionsConfig[key] === 'object' && functionsConfig[key] !== null) {
-        // Handle nested config like functions.config().llm.provider
-        Object.keys(functionsConfig[key]).forEach(subKey => {
-          const envKey = `${key.toUpperCase()}_${subKey.toUpperCase()}`;
-          if (!env[envKey]) {
-            env[envKey] = String(functionsConfig[key][subKey]);
-            fallbackCount++;
-          }
-        });
-      } else {
-        // Handle flat config
-        const envKey = key.toUpperCase();
-        if (!env[envKey]) {
-          env[envKey] = String(functionsConfig[key]);
-          fallbackCount++;
-        }
-      }
-    });
-    if (fallbackCount > 0) {
-      console.log(`[CONFIG DEBUG] Using functions.config() fallback for ${fallbackCount} values (migration in progress)`);
-    }
-  }
-} catch (error) {
-  // functions.config() might not be available in v2, that's okay
-  console.log('[CONFIG DEBUG] functions.config() not available (this is normal for v2 with defineString/defineSecret)');
-}
+const env = { ...process.env };
 
 // Environment validation schema
 const envSchema = Joi.object({
@@ -183,7 +143,6 @@ const envSchema = Joi.object({
 }).unknown();
 
 // Validate environment variables
-// Use the merged env object (process.env + functions.config() fallback)
 const { error, value: envVars } = envSchema.validate(env);
 
 // Enhanced error handling for serverless environments

backend/src/index.ts

@@ -182,7 +182,6 @@ app.use('/monitoring', monitoringRoutes);
 app.use('/api/audit', auditRoutes);
 
 
-import * as functions from 'firebase-functions';
 import { onRequest } from 'firebase-functions/v2/https';
 import { defineString, defineSecret } from 'firebase-functions/params';
 

backend/tsconfig.json

@@ -1,8 +1,8 @@
 {
   "compilerOptions": {
-    "target": "ES2020",
+    "target": "ES2022",
     "module": "commonjs",
-    "lib": ["ES2020"],
+    "lib": ["ES2022"],
     "outDir": "./dist",
     "rootDir": "./src",
     "strict": true,