# Summary of Changes

## 1. Added TODO Comment in Code
**File:** `obp-api/src/main/scala/code/api/util/RateLimitingUtil.scala`

Added a TODO comment at line 154 explaining the optimization opportunity:
- Remove redundant EXISTS check since GET returns None for non-existent keys
- This would reduce Redis operations from 2 to 1 (25% reduction per request)
- Includes example of simplified code

**Change:** Only added comment lines, no formatting changes.

## 2. Documentation Created
**File:** `REDIS_RATE_LIMITING_DOCUMENTATION.md`

Comprehensive documentation covering:
- Overview and architecture
- Configuration parameters
- Rate limiting mechanisms (authorized and anonymous)
- Redis data structure (keys, values, TTL)
- Implementation details of core functions
- API response headers
- Monitoring and debugging commands
- Error handling
- Performance considerations

**Note:** All Lua script references have been removed as requested.

## 3. Files Removed
- `REDIS_OPTIMIZATION_ANSWER.md` - Deleted (contained Lua-based optimization suggestions)

## Key Insight

**Q: Can we just use INCR instead of SET, INCR, and EXISTS?**

**A: Partially, yes:**
- ✅ EXISTS is redundant - GET returns None when key doesn't exist (25% reduction)
- ❌ Can't eliminate SETEX - INCR doesn't set TTL, and we need TTL for automatic counter reset
- Current pattern (SETEX for first call, INCR for subsequent calls) is correct for the Jedis wrapper

The TODO comment marks where the EXISTS optimization should be implemented.
