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🚀 LightRAG: Simple and Fast Retrieval-Augmented Generation

LightRAG Image

This repository hosts the code of LightRAG. The structure of this code is based on nano-graphrag. LightRAG Diagram

🎉 News

Algorithm Flowchart

LightRAG Indexing Flowchart Figure 1: LightRAG Indexing Flowchart - Img Caption : Source LightRAG Retrieval and Querying Flowchart Figure 2: LightRAG Retrieval and Querying Flowchart - Img Caption : Source

Install

  • Install from source (Recommend)
cd LightRAG
pip install -e .
  • Install from PyPI
pip install lightrag-hku

Quick Start

  • Video demo of running LightRAG locally.
  • All the code can be found in the examples.
  • Set OpenAI API key in environment if using OpenAI models: export OPENAI_API_KEY="sk-...".
  • Download the demo text "A Christmas Carol by Charles Dickens":
curl https://raw.githubusercontent.com/gusye1234/nano-graphrag/main/tests/mock_data.txt > ./book.txt

Use the below Python snippet (in a script) to initialize LightRAG and perform queries:

import os
from lightrag import LightRAG, QueryParam
from lightrag.llm import gpt_4o_mini_complete, gpt_4o_complete

#########
# Uncomment the below two lines if running in a jupyter notebook to handle the async nature of rag.insert()
# import nest_asyncio
# nest_asyncio.apply()
#########

WORKING_DIR = "./dickens"


if not os.path.exists(WORKING_DIR):
    os.mkdir(WORKING_DIR)

rag = LightRAG(
    working_dir=WORKING_DIR,
    llm_model_func=gpt_4o_mini_complete  # Use gpt_4o_mini_complete LLM model
    # llm_model_func=gpt_4o_complete  # Optionally, use a stronger model
)

with open("./book.txt") as f:
    rag.insert(f.read())

# Perform naive search
print(rag.query("What are the top themes in this story?", param=QueryParam(mode="naive")))

# Perform local search
print(rag.query("What are the top themes in this story?", param=QueryParam(mode="local")))

# Perform global search
print(rag.query("What are the top themes in this story?", param=QueryParam(mode="global")))

# Perform hybrid search
print(rag.query("What are the top themes in this story?", param=QueryParam(mode="hybrid")))
Using Open AI-like APIs
  • LightRAG also supports Open AI-like chat/embeddings APIs:
async def llm_model_func(
    prompt, system_prompt=None, history_messages=[], keyword_extraction=False, **kwargs
) -> str:
    return await openai_complete_if_cache(
        "solar-mini",
        prompt,
        system_prompt=system_prompt,
        history_messages=history_messages,
        api_key=os.getenv("UPSTAGE_API_KEY"),
        base_url="https://api.upstage.ai/v1/solar",
        **kwargs
    )

async def embedding_func(texts: list[str]) -> np.ndarray:
    return await openai_embedding(
        texts,
        model="solar-embedding-1-large-query",
        api_key=os.getenv("UPSTAGE_API_KEY"),
        base_url="https://api.upstage.ai/v1/solar"
    )

rag = LightRAG(
    working_dir=WORKING_DIR,
    llm_model_func=llm_model_func,
    embedding_func=EmbeddingFunc(
        embedding_dim=4096,
        max_token_size=8192,
        func=embedding_func
    )
)
Using Hugging Face Models
  • If you want to use Hugging Face models, you only need to set LightRAG as follows:
from lightrag.llm import hf_model_complete, hf_embedding
from transformers import AutoModel, AutoTokenizer
from lightrag.utils import EmbeddingFunc

# Initialize LightRAG with Hugging Face model
rag = LightRAG(
    working_dir=WORKING_DIR,
    llm_model_func=hf_model_complete,  # Use Hugging Face model for text generation
    llm_model_name='meta-llama/Llama-3.1-8B-Instruct',  # Model name from Hugging Face
    # Use Hugging Face embedding function
    embedding_func=EmbeddingFunc(
        embedding_dim=384,
        max_token_size=5000,
        func=lambda texts: hf_embedding(
            texts,
            tokenizer=AutoTokenizer.from_pretrained("sentence-transformers/all-MiniLM-L6-v2"),
            embed_model=AutoModel.from_pretrained("sentence-transformers/all-MiniLM-L6-v2")
        )
    ),
)
Using Ollama Models

Overview

If you want to use Ollama models, you need to pull model you plan to use and embedding model, for example nomic-embed-text.

Then you only need to set LightRAG as follows:

from lightrag.llm import ollama_model_complete, ollama_embedding
from lightrag.utils import EmbeddingFunc

# Initialize LightRAG with Ollama model
rag = LightRAG(
    working_dir=WORKING_DIR,
    llm_model_func=ollama_model_complete,  # Use Ollama model for text generation
    llm_model_name='your_model_name', # Your model name
    # Use Ollama embedding function
    embedding_func=EmbeddingFunc(
        embedding_dim=768,
        max_token_size=8192,
        func=lambda texts: ollama_embedding(
            texts,
            embed_model="nomic-embed-text"
        )
    ),
)

Increasing context size

In order for LightRAG to work context should be at least 32k tokens. By default Ollama models have context size of 8k. You can achieve this using one of two ways:

Increasing the num_ctx parameter in Modelfile.

  1. Pull the model:
ollama pull qwen2
  1. Display the model file:
ollama show --modelfile qwen2 > Modelfile
  1. Edit the Modelfile by adding the following line:
PARAMETER num_ctx 32768
  1. Create the modified model:
ollama create -f Modelfile qwen2m

Setup num_ctx via Ollama API.

Tiy can use llm_model_kwargs param to configure ollama:

rag = LightRAG(
    working_dir=WORKING_DIR,
    llm_model_func=ollama_model_complete,  # Use Ollama model for text generation
    llm_model_name='your_model_name', # Your model name
    llm_model_kwargs={"options": {"num_ctx": 32768}},
    # Use Ollama embedding function
    embedding_func=EmbeddingFunc(
        embedding_dim=768,
        max_token_size=8192,
        func=lambda texts: ollama_embedding(
            texts,
            embed_model="nomic-embed-text"
        )
    ),
)

Fully functional example

There fully functional example examples/lightrag_ollama_demo.py that utilizes gemma2:2b model, runs only 4 requests in parallel and set context size to 32k.

Low RAM GPUs

In order to run this experiment on low RAM GPU you should select small model and tune context window (increasing context increase memory consumption). For example, running this ollama example on repurposed mining GPU with 6Gb of RAM required to set context size to 26k while using gemma2:2b. It was able to find 197 entities and 19 relations on book.txt.

Query Param

class QueryParam:
    mode: Literal["local", "global", "hybrid", "naive"] = "global"
    only_need_context: bool = False
    response_type: str = "Multiple Paragraphs"
    # Number of top-k items to retrieve; corresponds to entities in "local" mode and relationships in "global" mode.
    top_k: int = 60
    # Number of tokens for the original chunks.
    max_token_for_text_unit: int = 4000
    # Number of tokens for the relationship descriptions
    max_token_for_global_context: int = 4000
    # Number of tokens for the entity descriptions
    max_token_for_local_context: int = 4000

Batch Insert

# Batch Insert: Insert multiple texts at once
rag.insert(["TEXT1", "TEXT2",...])

Incremental Insert

# Incremental Insert: Insert new documents into an existing LightRAG instance
rag = LightRAG(
     working_dir=WORKING_DIR,
     llm_model_func=llm_model_func,
     embedding_func=EmbeddingFunc(
          embedding_dim=embedding_dimension,
          max_token_size=8192,
          func=embedding_func,
     ),
)

with open("./newText.txt") as f:
    rag.insert(f.read())

Using Neo4J for Storage

  • For production level scenarios you will most likely want to leverage an enterprise solution
  • for KG storage. Running Neo4J in Docker is recommended for seamless local testing.
  • See: https://hub.docker.com/_/neo4j
export NEO4J_URI="neo4j://localhost:7687"
export NEO4J_USERNAME="neo4j"
export NEO4J_PASSWORD="password"

# When you launch the project be sure to override the default KG: NetworkX
# by specifying kg="Neo4JStorage".

# Note: Default settings use NetworkX
# Initialize LightRAG with Neo4J implementation.
WORKING_DIR = "./local_neo4jWorkDir"

rag = LightRAG(
    working_dir=WORKING_DIR,
    llm_model_func=gpt_4o_mini_complete,  # Use gpt_4o_mini_complete LLM model
    graph_storage="Neo4JStorage", #<-----------override KG default
    log_level="DEBUG"  #<-----------override log_level default
)

see test_neo4j.py for a working example.

Insert Custom KG

rag = LightRAG(
     working_dir=WORKING_DIR,
     llm_model_func=llm_model_func,
     embedding_func=EmbeddingFunc(
          embedding_dim=embedding_dimension,
          max_token_size=8192,
          func=embedding_func,
     ),
)

custom_kg = {
    "entities": [
        {
            "entity_name": "CompanyA",
            "entity_type": "Organization",
            "description": "A major technology company",
            "source_id": "Source1"
        },
        {
            "entity_name": "ProductX",
            "entity_type": "Product",
            "description": "A popular product developed by CompanyA",
            "source_id": "Source1"
        }
    ],
    "relationships": [
        {
            "src_id": "CompanyA",
            "tgt_id": "ProductX",
            "description": "CompanyA develops ProductX",
            "keywords": "develop, produce",
            "weight": 1.0,
            "source_id": "Source1"
        }
    ],
    "chunks": [
        {
            "content": "ProductX, developed by CompanyA, has revolutionized the market with its cutting-edge features.",
            "source_id": "Source1",
        },
        {
            "content": "PersonA is a prominent researcher at UniversityB, focusing on artificial intelligence and machine learning.",
            "source_id": "Source2",
        },
        {
            "content": "None",
            "source_id": "UNKNOWN",
        },
    ],
}

rag.insert_custom_kg(custom_kg)

Delete Entity

#  Delete Entity: Deleting entities by their names
rag = LightRAG(
     working_dir=WORKING_DIR,
     llm_model_func=llm_model_func,
     embedding_func=EmbeddingFunc(
          embedding_dim=embedding_dimension,
          max_token_size=8192,
          func=embedding_func,
     ),
)

rag.delete_by_entity("Project Gutenberg")

Multi-file Type Support

The textract supports reading file types such as TXT, DOCX, PPTX, CSV, and PDF.

import textract

file_path = 'TEXT.pdf'
text_content = textract.process(file_path)

rag.insert(text_content.decode('utf-8'))

Graph Visualization

Graph visualization with html
  • The following code can be found in examples/graph_visual_with_html.py
import networkx as nx
from pyvis.network import Network

# Load the GraphML file
G = nx.read_graphml('./dickens/graph_chunk_entity_relation.graphml')

# Create a Pyvis network
net = Network(notebook=True)

# Convert NetworkX graph to Pyvis network
net.from_nx(G)

# Save and display the network
net.show('knowledge_graph.html')
Graph visualization with Neo4j
  • The following code can be found in examples/graph_visual_with_neo4j.py
import os
import json
from lightrag.utils import xml_to_json
from neo4j import GraphDatabase

# Constants
WORKING_DIR = "./dickens"
BATCH_SIZE_NODES = 500
BATCH_SIZE_EDGES = 100

# Neo4j connection credentials
NEO4J_URI = "bolt://localhost:7687"
NEO4J_USERNAME = "neo4j"
NEO4J_PASSWORD = "your_password"

def convert_xml_to_json(xml_path, output_path):
    """Converts XML file to JSON and saves the output."""
    if not os.path.exists(xml_path):
        print(f"Error: File not found - {xml_path}")
        return None

    json_data = xml_to_json(xml_path)
    if json_data:
        with open(output_path, 'w', encoding='utf-8') as f:
            json.dump(json_data, f, ensure_ascii=False, indent=2)
        print(f"JSON file created: {output_path}")
        return json_data
    else:
        print("Failed to create JSON data")
        return None

def process_in_batches(tx, query, data, batch_size):
    """Process data in batches and execute the given query."""
    for i in range(0, len(data), batch_size):
        batch = data[i:i + batch_size]
        tx.run(query, {"nodes": batch} if "nodes" in query else {"edges": batch})

def main():
    # Paths
    xml_file = os.path.join(WORKING_DIR, 'graph_chunk_entity_relation.graphml')
    json_file = os.path.join(WORKING_DIR, 'graph_data.json')

    # Convert XML to JSON
    json_data = convert_xml_to_json(xml_file, json_file)
    if json_data is None:
        return

    # Load nodes and edges
    nodes = json_data.get('nodes', [])
    edges = json_data.get('edges', [])

    # Neo4j queries
    create_nodes_query = """
    UNWIND $nodes AS node
    MERGE (e:Entity {id: node.id})
    SET e.entity_type = node.entity_type,
        e.description = node.description,
        e.source_id = node.source_id,
        e.displayName = node.id
    REMOVE e:Entity
    WITH e, node
    CALL apoc.create.addLabels(e, [node.entity_type]) YIELD node AS labeledNode
    RETURN count(*)
    """

    create_edges_query = """
    UNWIND $edges AS edge
    MATCH (source {id: edge.source})
    MATCH (target {id: edge.target})
    WITH source, target, edge,
         CASE
            WHEN edge.keywords CONTAINS 'lead' THEN 'lead'
            WHEN edge.keywords CONTAINS 'participate' THEN 'participate'
            WHEN edge.keywords CONTAINS 'uses' THEN 'uses'
            WHEN edge.keywords CONTAINS 'located' THEN 'located'
            WHEN edge.keywords CONTAINS 'occurs' THEN 'occurs'
           ELSE REPLACE(SPLIT(edge.keywords, ',')[0], '\"', '')
         END AS relType
    CALL apoc.create.relationship(source, relType, {
      weight: edge.weight,
      description: edge.description,
      keywords: edge.keywords,
      source_id: edge.source_id
    }, target) YIELD rel
    RETURN count(*)
    """

    set_displayname_and_labels_query = """
    MATCH (n)
    SET n.displayName = n.id
    WITH n
    CALL apoc.create.setLabels(n, [n.entity_type]) YIELD node
    RETURN count(*)
    """

    # Create a Neo4j driver
    driver = GraphDatabase.driver(NEO4J_URI, auth=(NEO4J_USERNAME, NEO4J_PASSWORD))

    try:
        # Execute queries in batches
        with driver.session() as session:
            # Insert nodes in batches
            session.execute_write(process_in_batches, create_nodes_query, nodes, BATCH_SIZE_NODES)

            # Insert edges in batches
            session.execute_write(process_in_batches, create_edges_query, edges, BATCH_SIZE_EDGES)

            # Set displayName and labels
            session.run(set_displayname_and_labels_query)

    except Exception as e:
        print(f"Error occurred: {e}")

    finally:
        driver.close()

if __name__ == "__main__":
    main()

LightRAG init parameters

Parameter Type Explanation Default
working_dir str Directory where the cache will be stored lightrag_cache+timestamp
kv_storage str Storage type for documents and text chunks. Supported types: JsonKVStorage, OracleKVStorage JsonKVStorage
vector_storage str Storage type for embedding vectors. Supported types: NanoVectorDBStorage, OracleVectorDBStorage NanoVectorDBStorage
graph_storage str Storage type for graph edges and nodes. Supported types: NetworkXStorage, Neo4JStorage, OracleGraphStorage NetworkXStorage
log_level Log level for application runtime logging.DEBUG
chunk_token_size int Maximum token size per chunk when splitting documents 1200
chunk_overlap_token_size int Overlap token size between two chunks when splitting documents 100
tiktoken_model_name str Model name for the Tiktoken encoder used to calculate token numbers gpt-4o-mini
entity_extract_max_gleaning int Number of loops in the entity extraction process, appending history messages 1
entity_summary_to_max_tokens int Maximum token size for each entity summary 500
node_embedding_algorithm str Algorithm for node embedding (currently not used) node2vec
node2vec_params dict Parameters for node embedding {"dimensions": 1536,"num_walks": 10,"walk_length": 40,"window_size": 2,"iterations": 3,"random_seed": 3,}
embedding_func EmbeddingFunc Function to generate embedding vectors from text openai_embedding
embedding_batch_num int Maximum batch size for embedding processes (multiple texts sent per batch) 32
embedding_func_max_async int Maximum number of concurrent asynchronous embedding processes 16
llm_model_func callable Function for LLM generation gpt_4o_mini_complete
llm_model_name str LLM model name for generation meta-llama/Llama-3.2-1B-Instruct
llm_model_max_token_size int Maximum token size for LLM generation (affects entity relation summaries) 32768
llm_model_max_async int Maximum number of concurrent asynchronous LLM processes 16
llm_model_kwargs dict Additional parameters for LLM generation
vector_db_storage_cls_kwargs dict Additional parameters for vector database (currently not used)
enable_llm_cache bool If TRUE, stores LLM results in cache; repeated prompts return cached responses TRUE
addon_params dict Additional parameters, e.g., {"example_number": 1, "language": "Simplified Chinese", "entity_types": ["organization", "person", "geo", "event"]}: sets example limit and output language example_number: all examples, language: English
convert_response_to_json_func callable Not used convert_response_to_json
embedding_cache_config dict Configuration for question-answer caching. Contains three parameters:
- enabled: Boolean value to enable/disable cache lookup functionality. When enabled, the system will check cached responses before generating new answers.
- similarity_threshold: Float value (0-1), similarity threshold. When a new question's similarity with a cached question exceeds this threshold, the cached answer will be returned directly without calling the LLM.
- use_llm_check: Boolean value to enable/disable LLM similarity verification. When enabled, LLM will be used as a secondary check to verify the similarity between questions before returning cached answers.
Default: {"enabled": False, "similarity_threshold": 0.95, "use_llm_check": False}

Error Handling

Click to view error handling details

The API includes comprehensive error handling:

  • File not found errors (404)
  • Processing errors (500)
  • Supports multiple file encodings (UTF-8 and GBK)

Evaluation

Dataset

The dataset used in LightRAG can be downloaded from TommyChien/UltraDomain.

Generate Query

LightRAG uses the following prompt to generate high-level queries, with the corresponding code in example/generate_query.py.

Prompt
Given the following description of a dataset:

{description}

Please identify 5 potential users who would engage with this dataset. For each user, list 5 tasks they would perform with this dataset. Then, for each (user, task) combination, generate 5 questions that require a high-level understanding of the entire dataset.

Output the results in the following structure:
- User 1: [user description]
    - Task 1: [task description]
        - Question 1:
        - Question 2:
        - Question 3:
        - Question 4:
        - Question 5:
    - Task 2: [task description]
        ...
    - Task 5: [task description]
- User 2: [user description]
    ...
- User 5: [user description]
    ...

Batch Eval

To evaluate the performance of two RAG systems on high-level queries, LightRAG uses the following prompt, with the specific code available in example/batch_eval.py.

Prompt
---Role---
You are an expert tasked with evaluating two answers to the same question based on three criteria: **Comprehensiveness**, **Diversity**, and **Empowerment**.
---Goal---
You will evaluate two answers to the same question based on three criteria: **Comprehensiveness**, **Diversity**, and **Empowerment**.

- **Comprehensiveness**: How much detail does the answer provide to cover all aspects and details of the question?
- **Diversity**: How varied and rich is the answer in providing different perspectives and insights on the question?
- **Empowerment**: How well does the answer help the reader understand and make informed judgments about the topic?

For each criterion, choose the better answer (either Answer 1 or Answer 2) and explain why. Then, select an overall winner based on these three categories.

Here is the question:
{query}

Here are the two answers:

**Answer 1:**
{answer1}

**Answer 2:**
{answer2}

Evaluate both answers using the three criteria listed above and provide detailed explanations for each criterion.

Output your evaluation in the following JSON format:

{{
    "Comprehensiveness": {{
        "Winner": "[Answer 1 or Answer 2]",
        "Explanation": "[Provide explanation here]"
    }},
    "Empowerment": {{
        "Winner": "[Answer 1 or Answer 2]",
        "Explanation": "[Provide explanation here]"
    }},
    "Overall Winner": {{
        "Winner": "[Answer 1 or Answer 2]",
        "Explanation": "[Summarize why this answer is the overall winner based on the three criteria]"
    }}
}}

Overall Performance Table

Agriculture CS Legal Mix
NaiveRAG LightRAG NaiveRAG LightRAG NaiveRAG LightRAG NaiveRAG LightRAG
Comprehensiveness 32.4% 67.6% 38.4% 61.6% 16.4% 83.6% 38.8% 61.2%
Diversity 23.6% 76.4% 38.0% 62.0% 13.6% 86.4% 32.4% 67.6%
Empowerment 32.4% 67.6% 38.8% 61.2% 16.4% 83.6% 42.8% 57.2%
Overall 32.4% 67.6% 38.8% 61.2% 15.2% 84.8% 40.0% 60.0%
RQ-RAG LightRAG RQ-RAG LightRAG RQ-RAG LightRAG RQ-RAG LightRAG
Comprehensiveness 31.6% 68.4% 38.8% 61.2% 15.2% 84.8% 39.2% 60.8%
Diversity 29.2% 70.8% 39.2% 60.8% 11.6% 88.4% 30.8% 69.2%
Empowerment 31.6% 68.4% 36.4% 63.6% 15.2% 84.8% 42.4% 57.6%
Overall 32.4% 67.6% 38.0% 62.0% 14.4% 85.6% 40.0% 60.0%
HyDE LightRAG HyDE LightRAG HyDE LightRAG HyDE LightRAG
Comprehensiveness 26.0% 74.0% 41.6% 58.4% 26.8% 73.2% 40.4% 59.6%
Diversity 24.0% 76.0% 38.8% 61.2% 20.0% 80.0% 32.4% 67.6%
Empowerment 25.2% 74.8% 40.8% 59.2% 26.0% 74.0% 46.0% 54.0%
Overall 24.8% 75.2% 41.6% 58.4% 26.4% 73.6% 42.4% 57.6%
GraphRAG LightRAG GraphRAG LightRAG GraphRAG LightRAG GraphRAG LightRAG
Comprehensiveness 45.6% 54.4% 48.4% 51.6% 48.4% 51.6% 50.4% 49.6%
Diversity 22.8% 77.2% 40.8% 59.2% 26.4% 73.6% 36.0% 64.0%
Empowerment 41.2% 58.8% 45.2% 54.8% 43.6% 56.4% 50.8% 49.2%
Overall 45.2% 54.8% 48.0% 52.0% 47.2% 52.8% 50.4% 49.6%

Reproduce

All the code can be found in the ./reproduce directory.

Step-0 Extract Unique Contexts

First, we need to extract unique contexts in the datasets.

Code
def extract_unique_contexts(input_directory, output_directory):

    os.makedirs(output_directory, exist_ok=True)

    jsonl_files = glob.glob(os.path.join(input_directory, '*.jsonl'))
    print(f"Found {len(jsonl_files)} JSONL files.")

    for file_path in jsonl_files:
        filename = os.path.basename(file_path)
        name, ext = os.path.splitext(filename)
        output_filename = f"{name}_unique_contexts.json"
        output_path = os.path.join(output_directory, output_filename)

        unique_contexts_dict = {}

        print(f"Processing file: {filename}")

        try:
            with open(file_path, 'r', encoding='utf-8') as infile:
                for line_number, line in enumerate(infile, start=1):
                    line = line.strip()
                    if not line:
                        continue
                    try:
                        json_obj = json.loads(line)
                        context = json_obj.get('context')
                        if context and context not in unique_contexts_dict:
                            unique_contexts_dict[context] = None
                    except json.JSONDecodeError as e:
                        print(f"JSON decoding error in file {filename} at line {line_number}: {e}")
        except FileNotFoundError:
            print(f"File not found: {filename}")
            continue
        except Exception as e:
            print(f"An error occurred while processing file {filename}: {e}")
            continue

        unique_contexts_list = list(unique_contexts_dict.keys())
        print(f"There are {len(unique_contexts_list)} unique `context` entries in the file {filename}.")

        try:
            with open(output_path, 'w', encoding='utf-8') as outfile:
                json.dump(unique_contexts_list, outfile, ensure_ascii=False, indent=4)
            print(f"Unique `context` entries have been saved to: {output_filename}")
        except Exception as e:
            print(f"An error occurred while saving to the file {output_filename}: {e}")

    print("All files have been processed.")

Step-1 Insert Contexts

For the extracted contexts, we insert them into the LightRAG system.

Code
def insert_text(rag, file_path):
    with open(file_path, mode='r') as f:
        unique_contexts = json.load(f)

    retries = 0
    max_retries = 3
    while retries < max_retries:
        try:
            rag.insert(unique_contexts)
            break
        except Exception as e:
            retries += 1
            print(f"Insertion failed, retrying ({retries}/{max_retries}), error: {e}")
            time.sleep(10)
    if retries == max_retries:
        print("Insertion failed after exceeding the maximum number of retries")

Step-2 Generate Queries

We extract tokens from the first and the second half of each context in the dataset, then combine them as dataset descriptions to generate queries.

Code
tokenizer = GPT2Tokenizer.from_pretrained('gpt2')

def get_summary(context, tot_tokens=2000):
    tokens = tokenizer.tokenize(context)
    half_tokens = tot_tokens // 2

    start_tokens = tokens[1000:1000 + half_tokens]
    end_tokens = tokens[-(1000 + half_tokens):1000]

    summary_tokens = start_tokens + end_tokens
    summary = tokenizer.convert_tokens_to_string(summary_tokens)

    return summary

Step-3 Query

For the queries generated in Step-2, we will extract them and query LightRAG.

Code
def extract_queries(file_path):
    with open(file_path, 'r') as f:
        data = f.read()

    data = data.replace('**', '')

    queries = re.findall(r'- Question \d+: (.+)', data)

    return queries

Code Structure

.
├── .github/
│   ├── workflows/
│   │   └── linting.yaml
├── examples/
│   ├── batch_eval.py
│   ├── generate_query.py
│   ├── graph_visual_with_html.py
│   ├── graph_visual_with_neo4j.py
│   ├── insert_custom_kg.py
│   ├── lightrag_api_openai_compatible_demo.py
│   ├── lightrag_api_oracle_demo..py
│   ├── lightrag_azure_openai_demo.py
│   ├── lightrag_bedrock_demo.py
│   ├── lightrag_hf_demo.py
│   ├── lightrag_lmdeploy_demo.py
│   ├── lightrag_nvidia_demo.py
│   ├── lightrag_ollama_demo.py
│   ├── lightrag_openai_compatible_demo.py
│   ├── lightrag_openai_demo.py
│   ├── lightrag_oracle_demo.py
│   ├── lightrag_siliconcloud_demo.py
│   └── vram_management_demo.py
├── lightrag/
│   ├── api/
│   │   ├── lollms_lightrag_server.py
│   │   ├── ollama_lightrag_server.py
│   │   ├── openai_lightrag_server.py
│   │   ├── azure_openai_lightrag_server.py
│   │   └── requirements.txt
│   ├── kg/
│   │   ├── __init__.py
│   │   ├── oracle_impl.py
│   │   └── neo4j_impl.py
│   ├── __init__.py
│   ├── base.py
│   ├── lightrag.py
│   ├── llm.py
│   ├── operate.py
│   ├── prompt.py
│   ├── storage.py
│   └── utils.py
├── reproduce/
│   ├── Step_0.py
│   ├── Step_1_openai_compatible.py
│   ├── Step_1.py
│   ├── Step_2.py
│   ├── Step_3_openai_compatible.py
│   └── Step_3.py
├── .gitignore
├── .pre-commit-config.yaml
├── get_all_edges_nx.py
├── LICENSE
├── README.md
├── requirements.txt
├── setup.py
├── test_neo4j.py
└── test.py

Install with API Support

LightRAG provides optional API support through FastAPI servers that add RAG capabilities to existing LLM services. You can install LightRAG with API support in two ways:

1. Installation from PyPI

pip install "lightrag-hku[api]"

2. Installation from Source (Development)

# Clone the repository
git clone https://github.com/HKUDS/lightrag.git

# Change to the repository directory
cd lightrag

# Install in editable mode with API support
pip install -e ".[api]"

Prerequisites

Before running any of the servers, ensure you have the corresponding backend service running:

For LoLLMs Server

  • LoLLMs must be running and accessible
  • Default connection: http://localhost:9600
  • Configure using --lollms-host if running on a different host/port

For Ollama Server

  • Ollama must be running and accessible
  • Default connection: http://localhost:11434
  • Configure using --ollama-host if running on a different host/port

For OpenAI Server

  • Requires valid OpenAI API credentials set in environment variables
  • OPENAI_API_KEY must be set

For Azure OpenAI Server

Azure OpenAI API can be created using the following commands in Azure CLI (you need to install Azure CLI first from https://docs.microsoft.com/en-us/cli/azure/install-azure-cli):

# Change the resource group name, location and OpenAI resource name as needed
RESOURCE_GROUP_NAME=LightRAG
LOCATION=swedencentral
RESOURCE_NAME=LightRAG-OpenAI

az login
az group create --name $RESOURCE_GROUP_NAME --location $LOCATION
az cognitiveservices account create --name $RESOURCE_NAME --resource-group $RESOURCE_GROUP_NAME  --kind OpenAI --sku S0 --location swedencentral
az cognitiveservices account deployment create --resource-group $RESOURCE_GROUP_NAME  --model-format OpenAI --name $RESOURCE_NAME --deployment-name gpt-4o --model-name gpt-4o --model-version "2024-08-06"  --sku-capacity 100 --sku-name "Standard"
az cognitiveservices account deployment create --resource-group $RESOURCE_GROUP_NAME  --model-format OpenAI --name $RESOURCE_NAME --deployment-name text-embedding-3-large --model-name text-embedding-3-large --model-version "1"  --sku-capacity 80 --sku-name "Standard"
az cognitiveservices account show --name $RESOURCE_NAME --resource-group $RESOURCE_GROUP_NAME --query "properties.endpoint"
az cognitiveservices account keys list --name $RESOURCE_NAME -g $RESOURCE_GROUP_NAME

The output of the last command will give you the endpoint and the key for the OpenAI API. You can use these values to set the environment variables in the .env file.

Configuration Options

Each server has its own specific configuration options:

LoLLMs Server Options

Parameter Default Description
--host 0.0.0.0 RAG server host
--port 9621 RAG server port
--model mistral-nemo:latest LLM model name
--embedding-model bge-m3:latest Embedding model name
--lollms-host http://localhost:9600 LoLLMS backend URL
--working-dir ./rag_storage Working directory for RAG
--max-async 4 Maximum async operations
--max-tokens 32768 Maximum token size
--embedding-dim 1024 Embedding dimensions
--max-embed-tokens 8192 Maximum embedding token size
--input-file ./book.txt Initial input file
--log-level INFO Logging level

Ollama Server Options

Parameter Default Description
--host 0.0.0.0 RAG server host
--port 9621 RAG server port
--model mistral-nemo:latest LLM model name
--embedding-model bge-m3:latest Embedding model name
--ollama-host http://localhost:11434 Ollama backend URL
--working-dir ./rag_storage Working directory for RAG
--max-async 4 Maximum async operations
--max-tokens 32768 Maximum token size
--embedding-dim 1024 Embedding dimensions
--max-embed-tokens 8192 Maximum embedding token size
--input-file ./book.txt Initial input file
--log-level INFO Logging level

OpenAI Server Options

Parameter Default Description
--host 0.0.0.0 RAG server host
--port 9621 RAG server port
--model gpt-4 OpenAI model name
--embedding-model text-embedding-3-large OpenAI embedding model
--working-dir ./rag_storage Working directory for RAG
--max-tokens 32768 Maximum token size
--max-embed-tokens 8192 Maximum embedding token size
--input-dir ./inputs Input directory for documents
--log-level INFO Logging level

OpenAI AZURE Server Options

Parameter Default Description
--host 0.0.0.0 Server host
--port 9621 Server port
--model gpt-4 OpenAI model name
--embedding-model text-embedding-3-large OpenAI embedding model
--working-dir ./rag_storage Working directory for RAG
--max-tokens 32768 Maximum token size
--max-embed-tokens 8192 Maximum embedding token size
--input-dir ./inputs Input directory for documents
--enable-cache True Enable response cache
--log-level INFO Logging level

Example Usage

LoLLMs RAG Server

# Custom configuration with specific model and working directory
lollms-lightrag-server --model mistral-nemo --port 8080 --working-dir ./custom_rag

# Using specific models (ensure they are installed in your LoLLMs instance)
lollms-lightrag-server --model mistral-nemo:latest --embedding-model bge-m3 --embedding-dim 1024

Ollama RAG Server

# Custom configuration with specific model and working directory
ollama-lightrag-server --model mistral-nemo:latest --port 8080 --working-dir ./custom_rag

# Using specific models (ensure they are installed in your Ollama instance)
ollama-lightrag-server --model mistral-nemo:latest --embedding-model bge-m3 --embedding-dim 1024

OpenAI RAG Server

# Using GPT-4 with text-embedding-3-large
openai-lightrag-server --port 9624 --model gpt-4 --embedding-model text-embedding-3-large

Azure OpenAI RAG Server

# Using GPT-4 with text-embedding-3-large
azure-openai-lightrag-server --model gpt-4o --port 8080 --working-dir ./custom_rag --embedding-model text-embedding-3-large

Important Notes:

  • For LoLLMs: Make sure the specified models are installed in your LoLLMs instance
  • For Ollama: Make sure the specified models are installed in your Ollama instance
  • For OpenAI: Ensure you have set up your OPENAI_API_KEY environment variable
  • For Azure OpenAI: Build and configure your server as stated in the Prequisites section

For help on any server, use the --help flag:

lollms-lightrag-server --help
ollama-lightrag-server --help
openai-lightrag-server --help
azure-openai-lightrag-server --help

Note: If you don't need the API functionality, you can install the base package without API support using:

pip install lightrag-hku

API Endpoints

All servers (LoLLMs, Ollama, OpenAI and Azure OpenAI) provide the same REST API endpoints for RAG functionality.

Query Endpoints

POST /query

Query the RAG system with options for different search modes.

curl -X POST "http://localhost:9621/query" \
    -H "Content-Type: application/json" \
    -d '{"query": "Your question here", "mode": "hybrid"}'

POST /query/stream

Stream responses from the RAG system.

curl -X POST "http://localhost:9621/query/stream" \
    -H "Content-Type: application/json" \
    -d '{"query": "Your question here", "mode": "hybrid"}'

Document Management Endpoints

POST /documents/text

Insert text directly into the RAG system.

curl -X POST "http://localhost:9621/documents/text" \
    -H "Content-Type: application/json" \
    -d '{"text": "Your text content here", "description": "Optional description"}'

POST /documents/file

Upload a single file to the RAG system.

curl -X POST "http://localhost:9621/documents/file" \
    -F "file=@/path/to/your/document.txt" \
    -F "description=Optional description"

POST /documents/batch

Upload multiple files at once.

curl -X POST "http://localhost:9621/documents/batch" \
    -F "files=@/path/to/doc1.txt" \
    -F "files=@/path/to/doc2.txt"

DELETE /documents

Clear all documents from the RAG system.

curl -X DELETE "http://localhost:9621/documents"

Utility Endpoints

GET /health

Check server health and configuration.

curl "http://localhost:9621/health"

Development

Running in Development Mode

For LoLLMs:

uvicorn lollms_lightrag_server:app --reload --port 9621

For Ollama:

uvicorn ollama_lightrag_server:app --reload --port 9621

For OpenAI:

uvicorn openai_lightrag_server:app --reload --port 9621

For Azure OpenAI:

uvicorn azure_openai_lightrag_server:app --reload --port 9621

API Documentation

When any server is running, visit:

Testing API Endpoints

You can test the API endpoints using the provided curl commands or through the Swagger UI interface. Make sure to:

  1. Start the appropriate backend service (LoLLMs, Ollama, or OpenAI)
  2. Start the RAG server
  3. Upload some documents using the document management endpoints
  4. Query the system using the query endpoints

Important Features

Automatic Document Vectorization

When starting any of the servers with the --input-dir parameter, the system will automatically:

  1. Scan the specified directory for documents
  2. Check for existing vectorized content in the database
  3. Only vectorize new documents that aren't already in the database
  4. Make all content immediately available for RAG queries

This intelligent caching mechanism:

  • Prevents unnecessary re-vectorization of existing documents
  • Reduces startup time for subsequent runs
  • Preserves system resources
  • Maintains consistency across restarts

Example Usage

LoLLMs RAG Server

# Start server with automatic document vectorization
# Only new documents will be vectorized, existing ones will be loaded from cache
lollms-lightrag-server --input-dir ./my_documents --port 8080

Ollama RAG Server

# Start server with automatic document vectorization
# Previously vectorized documents will be loaded from the database
ollama-lightrag-server --input-dir ./my_documents --port 8080

OpenAI RAG Server

# Start server with automatic document vectorization
# Existing documents are retrieved from cache, only new ones are processed
openai-lightrag-server --input-dir ./my_documents --port 9624

Azure OpenAI RAG Server

# Start server with automatic document vectorization
# Existing documents are retrieved from cache, only new ones are processed
azure-openai-lightrag-server --input-dir ./my_documents --port 9624

Important Notes:

  • The --input-dir parameter enables automatic document processing at startup
  • Documents already in the database are not re-vectorized
  • Only new documents in the input directory will be processed
  • This optimization significantly reduces startup time for subsequent runs
  • The working directory (--working-dir) stores the vectorized documents database

Star History

Star History Chart

Contribution

Thank you to all our contributors!

🌟Citation

@article{guo2024lightrag,
title={LightRAG: Simple and Fast Retrieval-Augmented Generation},
author={Zirui Guo and Lianghao Xia and Yanhua Yu and Tu Ao and Chao Huang},
year={2024},
eprint={2410.05779},
archivePrefix={arXiv},
primaryClass={cs.IR}
}

Thank you for your interest in our work!