feat(sessions): remove redis as priority option for session data

[waleedlatif1]

This reverts commit 833e700.

Summary

Brief description of what this PR does and why.

Fixes #(issue)

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation
• Other: ___________

Testing

How has this been tested? What should reviewers focus on?

Checklist

• Code follows project style guidelines
• Self-reviewed my changes
• Tests added/updated and passing
• No new warnings introduced
• I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)

Screenshots/Videos

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Preview	Comments	Updated (UTC)
sim	Building	Preview	Comment	Oct 11, 2025 1:01am

1 Skipped Deployment

Project	Deployment	Preview	Comments	Updated (UTC)
docs	Skipped			Oct 11, 2025 1:01am

[greptile-apps]

Greptile Overview

Summary

Reverts PR #1592 which attempted to add Redis as a priority session storage option but introduced critical bugs.

Key issues fixed by this revert:

• Critical bug in OTP storage: The fallback OTP storage tried to access (global as any).inMemoryCache which was undefined (it's a module-level const in redis.ts, not a global), completely breaking OTP functionality when Redis was unavailable
• Misuse of lock functions: Used releaseLock() to delete OTP cache entries instead of proper cache cleanup
• Added complexity: The Redis secondary storage in betterAuth added an extra failure point without clear benefits

Changes:

• otp/route.ts: Removes hacky fallback that accessed undefined global variables, restores proper Redis-only OTP storage with clean error handling
• auth.ts: Removes secondaryStorage configuration, simplifying session management back to database-only
• redis.ts: Restores proper in-memory cache encapsulation with fallback logic contained within exported functions

Confidence Score: 5/5

• This PR is safe to merge - it fixes critical bugs by reverting problematic changes
• Clean revert that removes broken code. The original PR #1592 introduced a critical bug where OTP storage accessed undefined (global as any).inMemoryCache, breaking authentication when Redis was unavailable. This revert restores working functionality with proper abstraction boundaries.
• No files require special attention - all changes properly restore previous working state

Important Files Changed

File Analysis

Filename	Score	Overview
apps/sim/app/api/chat/[identifier]/otp/route.ts	1/5	Reverted hacky OTP storage implementation that accessed undefined global.inMemoryCache, breaking OTP functionality when Redis unavailable
apps/sim/lib/auth.ts	5/5	Removed Redis secondaryStorage configuration from betterAuth, reverting to database-only session storage
apps/sim/lib/redis.ts	4/5	Restored in-memory cache fallback for Redis operations with proper encapsulation

Sequence Diagram

sequenceDiagram
    participant Client
    participant OTPRoute as OTP Route
    participant Redis as Redis/Cache
    participant DB as Database (auth.ts)
    
    Note over OTPRoute,Redis: Before Revert (Broken)
    Client->>OTPRoute: POST /api/chat/[id]/otp
    OTPRoute->>Redis: Check Redis availability
    alt Redis available
        Redis-->>OTPRoute: Redis client
        OTPRoute->>Redis: Store OTP with expiry
    else Redis unavailable
        OTPRoute->>Redis: markMessageAsProcessed()
        Note over OTPRoute: Access (global as any).inMemoryCache
        Note over OTPRoute: ❌ undefined - breaks OTP storage
    end
    
    Note over OTPRoute,DB: After Revert (Fixed)
    Client->>OTPRoute: POST /api/chat/[id]/otp
    OTPRoute->>Redis: Check Redis availability
    alt Redis available
        Redis-->>OTPRoute: Redis client
        OTPRoute->>Redis: Store OTP with expiry
    else Redis unavailable
        OTPRoute->>Redis: markMessageAsProcessed()
        Note over Redis: ✓ Uses module-level inMemoryCache
        Redis-->>OTPRoute: OTP stored in fallback cache
    end
    
    Note over DB: Session Storage (Before Revert)
    Client->>DB: Session request
    DB->>Redis: Check secondaryStorage (Redis)
    alt Redis available
        Redis-->>DB: Session data
    else Redis fails
        DB->>DB: Fall back to database
    end
    
    Note over DB: Session Storage (After Revert)
    Client->>DB: Session request
    DB->>DB: Use database only
    Note over DB: Simpler, more reliable

Loading

_{3 files reviewed, no comments}

_{Edit Code Review Agent Settings | Greptile}