improvement(performance): use redis for session data (#934)

Author: waleedlatif1

apps/sim/lib/auth.ts

@@ -25,6 +25,7 @@ import { quickValidateEmail } from '@/lib/email/validation'
 import { env, isTruthy } from '@/lib/env'
 import { isBillingEnabled, isProd } from '@/lib/environment'
 import { createLogger } from '@/lib/logs/console/logger'
+import { getRedisClient } from '@/lib/redis'
 import { getEmailDomain } from '@/lib/urls/utils'
 import { db } from '@/db'
 import * as schema from '@/db/schema'
@@ -72,14 +73,55 @@ export const auth = betterAuth({
     provider: 'pg',
     schema,
   }),
+  // Conditionally use Redis for session storage only if Redis is available
+  ...(env.REDIS_URL
+    ? {
+        secondaryStorage: {
+          get: async (key: string) => {
+            try {
+              const redis = getRedisClient()
+              if (!redis) return null
+              const value = await redis.get(`auth:${key}`)
+              return value || null
+            } catch (error) {
+              logger.error('Redis get error:', error)
+              return null
+            }
+          },
+          set: async (key: string, value: string, ttl?: number) => {
+            try {
+              const redis = getRedisClient()
+              if (!redis) return
+              if (ttl) {
+                await redis.setex(`auth:${key}`, ttl, value)
+              } else {
+                await redis.set(`auth:${key}`, value)
+              }
+            } catch (error) {
+              logger.error('Redis set error:', error)
+            }
+          },
+          delete: async (key: string) => {
+            try {
+              const redis = getRedisClient()
+              if (!redis) return
+              await redis.del(`auth:${key}`)
+            } catch (error) {
+              logger.error('Redis delete error:', error)
+            }
+          },
+        },
+      }
+    : {}),
   session: {
     cookieCache: {
       enabled: true,
-      maxAge: 24 * 60 * 60, // 24 hours in seconds
+      // Use shorter cache with Redis (5 min), longer without (1 hour)
+      maxAge: env.REDIS_URL ? 5 * 60 : 60 * 60,
     },
     expiresIn: 30 * 24 * 60 * 60, // 30 days (how long a session can last overall)
     updateAge: 24 * 60 * 60, // 24 hours (how often to refresh the expiry)
-    freshAge: 60 * 60, // 1 hour (or set to 0 to disable completely)
+    freshAge: env.REDIS_URL ? 0 : 6 * 60 * 60, // 0 with Redis, 6 hours without Redis
   },
   databaseHooks: {
     session: {

apps/sim/lib/env.ts

@@ -29,7 +29,7 @@ export const env = createEnv({
 
     // Database & Storage
     POSTGRES_URL:                         z.string().url().optional(),            // Alternative PostgreSQL connection string
-    REDIS_URL:                            z.string().url().optional(),            // Redis connection string for caching/sessions
+    REDIS_URL:                            z.string().url().optional(),            // Redis connection string for caching/sessions (optional - improves performance)
 
     // Payment & Billing
     BILLING_ENABLED:                      z.boolean().optional(),                 // Enable billing enforcement and usage tracking