Hybrid retrieval architecture combining Claude and Codex coding agents with an MCP server gateway that orchestrates both keyword and semantic search through FTS5 and sqlite-vec. The system routes queries through a Session Tracker and dual-path retrieval pipeline—FTS5 for keyword matching and sqlite-vec for vector similarity—then fuses results via Reciprocal Rank Fusion before applying provenance tracking and promotion workflows. SQLite persistence with WAL mode ensures concurrent access across local and remote machines via Cross-Machine Bridge Sync, while Auth/Access Control and Prompt/Query Cache enforce security and reduce redundant computation. Fork this diagram to customize the retrieval fusion strategy, add vector embedding models, or extend the promotion workflow for your knowledge base or RAG application.