LightRAG

Serve layer · HKUDS/LightRAG · README (zh)

LightRAG is a simple, fast Retrieval-Augmented Generation framework with a dual-layer architecture managing both knowledge graphs (KG) and vector embeddings. Suited for legal, medical, financial document analysis; an efficient alternative to GraphRAG.

Key Features

Capability	Description
Deep context	Graph indexing captures semantic dependencies between entities
Dual-level retrieval	Combines detailed facts and abstract concepts
Efficient & low-cost	Fewer LLM calls during index and query
Incremental updates	New data merges into existing graph without full rebuild
Multimodal (v1.5+)	MinerU / Docling for PDF, images, tables, formulas

Query Modes

Mode	Use
local	Local entities and direct attributes
global	Macro topics, cross-document relations
hybrid	local + global (workflow P0 default)
naive	Vector chunks only, no KG
mix	Full fusion (LightRAG server default)

Workflow

P0 query_text uses mode: hybrid, only_need_context: true. See MCP Tools · LightRAG.

Installation

uv (recommended)

curl -LsSf https://astral.sh/uv/install.sh | sh
uv tool install "lightrag-hku[api]"

From source

git clone https://github.com/HKUDS/LightRAG.git
cd LightRAG && make dev && source .venv/bin/activate
cd lightrag_webui && bun install --frozen-lockfile && bun run build && cd ..
make env-base
lightrag-server

Docker Compose

git clone https://github.com/HKUDS/LightRAG.git
cd LightRAG && cp env.example .env && docker compose up

Key Configuration

• Four LLM roles: EXTRACT, QUERY, KEYWORDS, VLM — configure per role
• Embedding: Must be fixed before indexing; cannot change at query time; recommend BAAI/bge-m3 locally
• Rerank: Improves quality; adds ~1–2s; deploy locally when possible

Team Deployment

Component	Path	Notes
LightRAG API	Project/LightRAG	lightrag-server, default http://127.0.0.1:9621
daniel-lightrag-mcp	Project/daniel-lightrag-mcp	MCP bridge, 22 tools
Start script	StartScript/MCP_LightRAG_start.sh	HTTP bridge, port 9622

cd Project/LightRAG && lightrag-server
bash StartScript/MCP_LightRAG_start.sh

{ "daniel-lightrag": { "url": "http://127.0.0.1:9622/mcp/" } }

Related

• GitHub · arXiv
• MCP Tools · Host setup