Dev.to
7/19/2026

How I Built a RAG Chatbot Into My Portfolio with LangGraph, PGVector & MCP
Short summary
Rehbar Khan breaks down how he built an AI terminal chatbot for his portfolio using LangGraph, pgvector on Neon Postgres, and GitHub MCP for live data. The architecture uses a score-threshold retriever to prevent hallucinations, a LangGraph StateGraph for tool routing, and Redis for session memory. Code snippets cover chunking, retrieval, graph construction, and MCP client setup.
- •RAG chatbot architecture with LangGraph, pgvector, and MCP integration
- •Score-threshold retrieval drops irrelevant matches to prevent hallucinations
- •GitHub MCP tool fetches live activity; Redis handles conversation memory
Generated with AI, which can make mistakes.
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