repo-graphrag-mcp: Instructions file for Codex

Repo GraphRAG MCP Usage Guide

"Repo GraphRAG MCP" extracts entities (classes, functions, etc.) and relationships from repository code and documentation to build a knowledge graph. Vectorizes and indexes all text. Combines graph search and vector search to answer questions and generate implementation plans with understanding of code structure.

Prerequisites

• Python 3.11 or higher
• uv package manager

1. Install dependencies:

cd repo-graphrag-mcp

uv sync

1. Configure environment variables: Copy .env.example to create a .env file

Note: Assumes users have already set up their environment. Refer to repo-graphrag-mcp/.env.example only when MCP startup or operation errors occur.

Three Tools

1. graph_create - Analyze repository to build/update knowledge graph and vector index
2. graph_query - Answer questions about the repository using the knowledge graph
3. graph_plan - Generate implementation plans with understanding of existing code structure

All tools are invoked with the graph: prefix in user requests.

Tool 1: graph_create

Purpose: Analyze a directory to build a knowledge graph and vector index.

Parameters:

• read_dir_path (required): Absolute path to the directory to analyze
• storage_name (optional): Name of the storage (default: "storage")

Usage Examples:

graph: /home/user/myproject my_project
graph: C:\projects\webapp webapp_storage
graph: /path/to/repo  # Uses default storage name "storage"

Behavior:

• First run: Processes all files and creates storage
• Subsequent runs: Processes only changed/new/deleted files (incremental update)
• Storage is created relative to the MCP server directory

Processed File Types: Code files are fixed. Other types can be modified in .env.

• Code: .py, .cpp, .h, .java, .rs, .c, .cs, .go, .rb, .js, .jsx, .kt, .kts, .ts, .tsx, .html, .htm, .css
• Documents (default): .txt, .md, .rst, and special files: readme, changelog (case insensitive)
• Excluded (default): pycache, .git, .github, .venv, node_modules, .DS_Store, Thumbs.db, robots.txt, bac, backup, temp, tmp