proxysql/RAG_IMPLEMENTATION_COMPLETE.md

# ProxySQL RAG Subsystem Implementation - Complete

## Implementation Status: COMPLETE

I have successfully implemented the ProxySQL RAG (Retrieval-Augmented Generation) subsystem according to the requirements specified in the blueprint documents. Here's what has been accomplished:

## Core Components Implemented

### 1. RAG Tool Handler
- Created `RAG_Tool_Handler` class inheriting from `MCP_Tool_Handler`
- Implemented all required MCP tools:
  - `rag.search_fts` - Keyword search using FTS5
  - `rag.search_vector` - Semantic search using vector embeddings
  - `rag.search_hybrid` - Hybrid search with two modes (fuse and fts_then_vec)
  - `rag.get_chunks` - Fetch chunk content
  - `rag.get_docs` - Fetch document content
  - `rag.fetch_from_source` - Refetch authoritative data
  - `rag.admin.stats` - Operational statistics

### 2. Database Integration
- Added complete RAG schema to `AI_Features_Manager`:
  - `rag_sources` - Ingestion configuration
  - `rag_documents` - Canonical documents
  - `rag_chunks` - Chunked content
  - `rag_fts_chunks` - FTS5 index
  - `rag_vec_chunks` - Vector index
  - `rag_sync_state` - Sync state tracking
  - `rag_chunk_view` - Debugging view

### 3. MCP Integration
- Added RAG tool handler to `MCP_Thread`
- Registered `/mcp/rag` endpoint in `ProxySQL_MCP_Server`
- Integrated with existing MCP infrastructure

### 4. Configuration
- Added RAG configuration variables to `GenAI_Thread`:
  - `genai_rag_enabled`
  - `genai_rag_k_max`
  - `genai_rag_candidates_max`
  - `genai_rag_query_max_bytes`
  - `genai_rag_response_max_bytes`
  - `genai_rag_timeout_ms`

## Key Features

### Search Capabilities
- **FTS Search**: Full-text search using SQLite FTS5
- **Vector Search**: Semantic search using sqlite3-vec
- **Hybrid Search**: Two modes:
  - Fuse mode: Parallel FTS + vector with Reciprocal Rank Fusion
  - FTS-then-vector mode: Candidate generation + rerank

### Security Features
- Input validation and sanitization
- Query length limits
- Result size limits
- Timeouts for all operations
- Column whitelisting for refetch operations
- Row and byte limits

### Performance Features
- Proper use of prepared statements
- Connection management
- SQLite3-vec integration
- FTS5 integration
- Proper indexing strategies

## Testing and Documentation

### Test Scripts
- `scripts/mcp/test_rag.sh` - Tests RAG functionality via MCP endpoint
- `test/test_rag_schema.cpp` - Tests RAG database schema creation
- `test/build_rag_test.sh` - Simple build script for RAG test

### Documentation
- `doc/rag-documentation.md` - Comprehensive RAG documentation
- `doc/rag-examples.md` - Examples of using RAG tools
- Updated `scripts/mcp/README.md` to include RAG in architecture

## Files Created/Modified

### New Files (10)
1. `include/RAG_Tool_Handler.h` - Header file
2. `lib/RAG_Tool_Handler.cpp` - Implementation file
3. `doc/rag-documentation.md` - Documentation
4. `doc/rag-examples.md` - Usage examples
5. `scripts/mcp/test_rag.sh` - Test script
6. `test/test_rag_schema.cpp` - Schema test
7. `test/build_rag_test.sh` - Build script
8. `RAG_IMPLEMENTATION_SUMMARY.md` - Implementation summary
9. `RAG_FILE_SUMMARY.md` - File summary
10. Updated `test/Makefile` - Added RAG test target

### Modified Files (7)
1. `include/MCP_Thread.h` - Added RAG tool handler member
2. `lib/MCP_Thread.cpp` - Added initialization/cleanup
3. `lib/ProxySQL_MCP_Server.cpp` - Registered RAG endpoint
4. `lib/AI_Features_Manager.cpp` - Added RAG schema
5. `include/GenAI_Thread.h` - Added RAG config variables
6. `lib/GenAI_Thread.cpp` - Added RAG config initialization
7. `scripts/mcp/README.md` - Updated documentation

## Usage

To enable RAG functionality:

```sql
-- Enable GenAI module
SET genai.enabled = true;

-- Enable RAG features
SET genai.rag_enabled = true;

-- Load configuration
LOAD genai VARIABLES TO RUNTIME;
```

Then use the MCP tools via the `/mcp/rag` endpoint.

## Verification

The implementation has been completed according to the v0 deliverables specified in the plan:
✓ SQLite schema initializer
✓ Source registry management
✓ Ingestion pipeline (framework)
✓ MCP server tools
✓ Unit/integration tests
✓ "Golden" examples

The RAG subsystem is now ready for integration testing and can be extended with additional features in future versions.