simple-graph-retriever 1.0.0rc17

A simple graph-based retriever using Neo4j and Qdrant

Simple Graph Retriever

A Python SDK for indexing a graph database (Neo4j or FalkorDB) into a vector database (Qdrant) and performing retrieval-augmented generation (RAG) tasks against it.

This SDK handles the heavy lifting of graph processing, including:

• Community Detection: Uses the Leiden algorithm to identify communities within your graph structure.
• Chunking: Breaks down nodes and their local context into "chunks" suitable for embedding.
• Vector Indexing: Embeds and indexes both community summaries and individual chunks into Qdrant.
• Graph Retrieval: Retrieves relevant subgraphs based on a natural language query, with fine-grained control over the expansion process.

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Table of Contents

• Simple Graph Retriever
  • Table of Contents
  • 1. Installation
  • 2. Configuration
    • Common Configuration
    • Neo4j Specific Configuration
    • FalkorDB Specific Configuration
    • Example .env files
  • 3. Usage
    • Initializing the Client
    • Indexing the Graph
    • Retrieving a Subgraph
      • Basic Retrieval
      • Advanced Retrieval with Graph Expansion Control
  • 4. Project Structure
  • 5. Contributing
  • 6. License

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1. Installation

To install the SDK, clone this repository and use pip. You can choose which database driver to install using optional dependencies.

Install with Neo4j support:

pip install simple_graph_retriever[neo4j]==1.0.0-rc.17

Install with FalkorDB support:

pip install simple_graph_retriever[falkordb]==1.0.0-rc.17

Install with support for both:

pip install simple_graph_retriever[all]==1.0.0-rc.17

2. Configuration

The SDK is configured via environment variables, which are loaded from a .env file in your project's root directory. You must configure either Neo4j or FalkorDB.

Common Configuration

Variable	Default Value	Description
GRAPH_DATABASE_TYPE	neo4j	The type of database to use: neo4j or falkordb.
QDRANT_URL	http://localhost:6333	The URL for your Qdrant vector database instance.
QDRANT_API_KEY	None	Optional: The API key for authenticating with your Qdrant instance.
QDRANT_CHUNKS_COLLECTION	chunks	The name of the collection for storing graph chunks.
QDRANT_COMMUNITIES_COLLECTION	communities	The name of the collection for storing community summaries.
EMBEDDER_URL	http://localhost:8080	The URL of the text embedding service. It must accept a POST request with {"inputs": ["text"]}.
VECTOR_SIZE	384	The dimension of the vectors produced by your embedding model.
LOGLEVEL	INFO	The logging level for the SDK (DEBUG, INFO, WARNING, ERROR).

Neo4j Specific Configuration

Variable	Default Value	Description
NEO4J_URI	bolt://localhost:7687	The URI for your Neo4j database.
NEO4J_USER	neo4j	The username for your Neo4j database.
NEO4J_PASSWORD	password	The password for your Neo4j database.

FalkorDB Specific Configuration

Variable	Default Value	Description
FALKORDB_HOST	localhost	The host for your FalkorDB instance.
FALKORDB_PORT	6379	The port for your FalkorDB instance.
FALKORDB_PASSWORD	None	Optional: Password for Redis/FalkorDB.
FALKORDB_KEY	graph	The key (graph name) used in FalkorDB.

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Example .env files

Option A: Using Neo4j

GRAPH_DATABASE_TYPE="neo4j"
NEO4J_URI="bolt://localhost:7687"
NEO4J_USER="neo4j"
NEO4J_PASSWORD="your_secure_password"

QDRANT_URL="http://localhost:6333"
EMBEDDER_URL="http://localhost:8080/embed"

Option B: Using FalkorDB

GRAPH_DATABASE_TYPE="falkordb"
FALKORDB_HOST="localhost"
FALKORDB_PORT="6379"

QDRANT_URL="http://localhost:6333"
EMBEDDER_URL="http://localhost:8080/embed"

3. Usage

Initializing the Client

The main entry point is the GraphRetrievalClient. It automatically loads settings from your .env file and initializes the appropriate database driver (Neo4j or FalkorDB) based on your configuration.

from graph_retrieval_sdk.client import GraphRetrievalClient

# Initialize the client (backend determined by env vars)
client = GraphRetrievalClient()

Indexing the Graph

The index() method runs the full, idempotent pipeline to populate Qdrant with data from your connected graph database.

# This runs the full pipeline:
# 1. Community detection
# 2. Chunk creation
# 3. Chunk and Community indexing
client.index()

print("Indexing complete!")

To completely reset your vector index, use the clear_index() method. Warning: This is a destructive operation that deletes and recreates the Qdrant collections.

client.clear_index()

Retrieving a Subgraph

Use the retrieve_graph() method to query your indexed graph. The RetrievalConfig model allows for fine-grained control over the process.

Basic Retrieval

from graph_retrieval_sdk.models import RetrievalConfig
import json

query = "Who was the emperor of Rome?"
config = RetrievalConfig()

subgraph = client.retriever.retrieve_graph(query, config)

if subgraph:
    print(f"Retrieved {len(subgraph[0]['nodes'])} nodes and {len(subgraph[0]['relationships'])} relationships.")

Advanced Retrieval with Graph Expansion Control

Customize the RetrievalConfig to tune the retrieval and expansion behavior.

from graph_retrieval_sdk.models import RetrievalConfig

query = "Tell me about the Roman emperors and their families, but exclude servants."

advanced_config = RetrievalConfig(
    # --- Retrieval Settings ---
    max_communities=5,
    max_chunks=15,

    # --- Graph Expansion Settings ---
    max_hops=2,
    community_expansion_limit=5,

    # --- Relationship Filtering ---
    allowed_rel_types=["HAS_SON", "MARRIED_TO", "SUCCESSOR_OF"],
    denied_rel_types=["HAS_SERVANT"]
)

subgraph = client.retriever.retrieve_graph(query, advanced_config)

if subgraph:
    print(f"Retrieved {len(subgraph[0]['nodes'])} nodes with advanced configuration.")

# Close the client connection when done
client.close()

4. Project Structure

The project is organized as a standard Python package:

├── graph_retrieval_sdk/
│   ├── __init__.py
│   ├── client.py         # Main client class
│   ├── config.py         # Configuration and logging setup
│   ├── indexer.py        # Logic for indexing the graph
│   ├── retriever.py      # Logic for retrieving subgraphs
│   ├── db/               # Database adapters
│   │   ├── neo4j.py
│   │   └── falkordb.py
│   └── models.py         # Pydantic models (e.g., RetrievalConfig)
├── examples/
├── pyproject.toml        # Project metadata and dependencies
└── README.md             # This file

5. Contributing

Contributions are welcome! Please feel free to submit a pull request or open an issue.

6. License

This project is licensed under the MIT License.