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:

-- 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.