LangChain

A high-performance LangChain integration for ZeusDB, bringing enterprise-grade vector search capabilities to your LangChain applications.

Features

🚀 High Performance

• Rust-powered vector database backend

• Advanced HNSW indexing for sub-millisecond search

• Product Quantization for 4x-256x memory compression

• Concurrent search with automatic parallelization

🎯 LangChain Native

• Full VectorStore API compliance

• Async/await support for all operations

• Seamless integration with LangChain retrievers

• Maximal Marginal Relevance (MMR) search

🏢 Enterprise Ready

• Structured logging with performance monitoring

• Index persistence with complete state preservation

• Advanced metadata filtering

• Graceful error handling and fallback mechanisms

Quick Start

Installation

pip install -qU langchain-zeusdb

Getting Started

This example uses OpenAIEmbeddings, which requires an OpenAI API key - Get your OpenAI API key here

If you prefer, you can also use this package with any other embedding provider (Hugging Face, Cohere, custom functions, etc.).

pip install langchain-openai

import os
import getpass

os.environ['OPENAI_API_KEY'] = getpass.getpass('OpenAI API Key:')

Basic Usage

from langchain_zeusdb import ZeusDBVectorStore
from langchain_openai import OpenAIEmbeddings
from zeusdb import VectorDatabase

# Initialize embeddings
embeddings = OpenAIEmbeddings(model="text-embedding-3-small")

# Create ZeusDB index
vdb = VectorDatabase()
index = vdb.create(
    index_type="hnsw",
    dim=1536,
    space="cosine"
)

# Create vector store
vector_store = ZeusDBVectorStore(
    zeusdb_index=index,
    embedding=embeddings
)

# Add documents
from langchain_core.documents import Document

docs = [
    Document(page_content="ZeusDB is fast", metadata={"source": "docs"}),
    Document(page_content="LangChain is powerful", metadata={"source": "docs"}),
]

vector_store.add_documents(docs)

# Search
results = vector_store.similarity_search("fast database", k=2)
print(f"Found the following {len(results)} results:")
print(results)

Expected results:

Found the following 2 results:
[Document(id='ea2b4f13-b0b7-4cef-bb91-0fc4f4c41295', metadata={'source': 'docs'}, page_content='ZeusDB is fast'), Document(id='33dc1e87-a18a-4827-a0df-6ee47eabc7b2', metadata={'source': 'docs'}, page_content='LangChain is powerful')]

Factory Methods

For convenience, you can create and populate a vector store in a single step:

Example 1: - Create from texts (creates index and adds texts in one step)

vector_store_texts = ZeusDBVectorStore.from_texts(
    texts=["Hello world", "Goodbye world"],
    embedding=embeddings,
    metadatas=[{"source": "text1"}, {"source": "text2"}]
)

print("texts store count:", vector_store_texts.get_vector_count())         # -> 2
print("texts store peek:", vector_store_texts.zeusdb_index.list(2))        # [('id1', {...}), ('id2', {...})]

# Search the texts-based store
results = vector_store_texts.similarity_search("Hello", k=1)
print(f"Found in texts store: {results[0].page_content}")                  # -> "Hello world"

Expected results:

texts store count: 2
texts store peek: [('e9c39b44-b610-4e00-91f3-bf652e9989ac', {'source': 'text1', 'text': 'Hello world'}), ('d33f210c-ed53-4006-a64a-a9eee397fec9', {'source': 'text2', 'text': 'Goodbye world'})]
Found in texts store: Hello world

Example 2: - Create from documents (creates index and adds documents in one step)

new_docs = [
    Document(page_content="Python is great", metadata={"source": "python"}),
    Document(page_content="JavaScript is flexible", metadata={"source": "js"}),
]

vector_store_docs = ZeusDBVectorStore.from_documents(
    documents=new_docs,
    embedding=embeddings
)

print("docs store count:", vector_store_docs.get_vector_count())           # -> 2
print("docs store peek:", vector_store_docs.zeusdb_index.list(2))          # [('id3', {...}), ('id4', {...})]

# Search the documents-based store
results = vector_store_docs.similarity_search("Python", k=1)
print(f"Found in docs store: {results[0].page_content}")                   # -> "Python is great"

Expected results:

docs store count: 2
docs store peek: [('aab2d1c1-7e02-4817-8dd8-6fb03570bb6f', {'text': 'Python is great', 'source': 'python'}), ('9a8a82cb-0e70-456c-9db2-556e464de14e', {'text': 'JavaScript is flexible', 'source': 'js'})]
Found in docs store: Python is great

Advanced Features

ZeusDB’s enterprise-grade capabilities are fully integrated into the LangChain ecosystem, providing quantization, persistence, advanced search features and many other enterprise capabilities.

Memory-Efficient Setup with Quantization

For large datasets, use Product Quantization to reduce memory usage:

# Create quantized index for memory efficiency
quantization_config = {
    'type': 'pq',
    'subvectors': 8,
    'bits': 8,
    'training_size': 10000
}

vdb = VectorDatabase()
index = vdb.create(
    index_type="hnsw",
    dim=1536,
    space="cosine",
    quantization_config=quantization_config
)

vector_store = ZeusDBVectorStore(
    zeusdb_index=index,
    embedding=embeddings
)

Please refer to our documentation for helpful configuration guidelines and recommendations for setting up quantization.

Persistence

ZeusDB persistence lets you save a fully populated index to disk and load it later with complete state restoration. This includes vectors, metadata, HNSW graph, and (if enabled) Product Quantization models.

What gets saved:

• Vectors & IDs

• Metadata

• HNSW graph structure

• Quantization config, centroids, and training state (if PQ is enabled)

How to Save your vector store

# Save index
vector_store.save_index("my_index.zdb")

How to Load your vector store

# Load index
loaded_store = ZeusDBVectorStore.load_index(
    path="my_index.zdb",
    embedding=embeddings
)

# Verify after load
print("vector count:", loaded_store.get_vector_count())
print("index info:", loaded_store.info())
print("store peek:", loaded_store.zeusdb_index.list(2))

Notes

• The path is a directory, not a single file. Ensure the target is writable.

• Saved indexes are cross-platform and include format/version info for compatibility checks.

• If you used PQ, both the compression model and state are preserved—no need to retrain after loading.

• You can continue to use all vector store APIs (similarity_search, retrievers, etc.) on the loaded_store.

For further details (including file structure, and further comprehensive examples), see the documentation.

Advanced Search Options

Use these to control scoring, diversity, metadata filtering, and retriever integration for your searches.

Similarity search with scores

Returns (Document, raw_distance) pairs from ZeusDB — lower distance = more similar.
If you prefer normalized relevance in [0, 1], use similarity_search_with_relevance_scores.

# Similarity search with scores
results_with_scores = vector_store.similarity_search_with_score(
    query="machine learning",
    k=5
)

print(results_with_scores)

Expected results:

[
  (Document(id='ac0eaf5b-9f02-4ce2-8957-c369a7262c61', metadata={'source': 'docs'}, page_content='LangChain is powerful'), 0.8218843340873718),
  (Document(id='faae3adf-7cf3-463c-b282-3790b096fa23', metadata={'source': 'docs'}, page_content='ZeusDB is fast'), 0.9140053391456604)
]

MMR search for diversity

MMR (Maximal Marginal Relevance) balances two forces: relevance to the query and diversity among selected results, reducing near-duplicate answers. Control the trade-off with lambda_mult (1.0 = all relevance, 0.0 = all diversity).

# MMR search for diversity
mmr_results = vector_store.max_marginal_relevance_search(
    query="AI applications",
    k=5,
    fetch_k=20,
    lambda_mult=0.7  # Balance relevance vs diversity
)

print(mmr_results)

Search with metadata filtering

Filter results using document metadata you stored when adding docs

# Search with metadata filtering
results = vector_store.similarity_search(
    query="database performance",
    k=3,
    filter={"source": "documentation"}
)

For supported metadata query types and operators, please refer to the documentation.

As a Retriever

Turning the vector store into a retriever gives you a standard LangChain interface that chains (e.g., RetrievalQA) can call to fetch context. Under the hood it uses your chosen search type (similarity or mmr) and search_kwargs.

# Convert to retriever for use in chains
retriever = vector_store.as_retriever(
    search_type="mmr",
    search_kwargs={"k": 3, "lambda_mult": 0.8}
)

# Use with LangChain Expression Language (LCEL) - requires only langchain-core
from langchain_core.prompts import ChatPromptTemplate
from langchain_core.output_parsers import StrOutputParser
from langchain_core.runnables import RunnablePassthrough
from langchain_openai import ChatOpenAI

def format_docs(docs):
    return "\n\n".join([d.page_content for d in docs])

template = """Answer the question based only on the following context:
{context}

Question: {question}
"""

prompt = ChatPromptTemplate.from_template(template)
llm = ChatOpenAI()

# Create a chain using LCEL
chain = (
    {"context": retriever | format_docs, "question": RunnablePassthrough()}
    | prompt
    | llm
    | StrOutputParser()
)

# Use the chain
answer = chain.invoke("What is ZeusDB?")
print(answer)

Expected results:

ZeusDB is a fast database management system.

Async Support

ZeusDB supports asynchronous operations for non-blocking, concurrent vector operations.

When to use async: web servers (FastAPI/Starlette), agents/pipelines doing parallel searches, or notebooks where you want non-blocking/concurrent retrieval. If you’re writing simple scripts, the sync methods are fine.

Those are asynchronous operations - the async/await versions of the regular synchronous methods. Here’s what each one does:

1. await vector_store.aadd_documents(documents) - Asynchronously adds documents to the vector store (async version of add_documents())

2. await vector_store.asimilarity_search("query", k=5) - Asynchronously performs similarity search (async version of similarity_search())

3. await vector_store.adelete(ids=["doc1", "doc2"]) - Asynchronously deletes documents by their IDs (async version of delete())

The async versions are useful when:

• You’re building async applications (using asyncio, FastAPI, etc.)

• You want non-blocking operations that can run concurrently

• You’re handling multiple requests simultaneously

• You want better performance in I/O-bound applications

For example, instead of blocking while adding documents:

# Synchronous (blocking)
vector_store.add_documents(docs)  # Blocks until complete

# Asynchronous (non-blocking) 
await vector_store.aadd_documents(docs)  # Can do other work while this runs

All operations support async/await:

Script version (python my_script.py):

import asyncio
from langchain_zeusdb import ZeusDBVectorStore
from langchain_openai import OpenAIEmbeddings
from langchain_core.documents import Document
from zeusdb import VectorDatabase

# Setup
embeddings = OpenAIEmbeddings(model="text-embedding-3-small")
vdb = VectorDatabase()
index = vdb.create(index_type="hnsw", dim=1536, space="cosine")
vector_store = ZeusDBVectorStore(zeusdb_index=index, embedding=embeddings)

docs = [
    Document(page_content="ZeusDB is fast", metadata={"source": "docs"}),
    Document(page_content="LangChain is powerful", metadata={"source": "docs"}),
]

async def main():
    # Add documents asynchronously
    ids = await vector_store.aadd_documents(docs)
    print("Added IDs:", ids)
    
    # Run multiple searches concurrently
    results_fast, results_powerful = await asyncio.gather(
        vector_store.asimilarity_search("fast", k=2),
        vector_store.asimilarity_search("powerful", k=2),
    )
    print("Fast results:", [d.page_content for d in results_fast])
    print("Powerful results:", [d.page_content for d in results_powerful])
    
    # Delete documents asynchronously
    deleted = await vector_store.adelete(ids=ids[:1])
    print("Deleted first doc:", deleted)

if __name__ == "__main__":
    asyncio.run(main())

Colab/Notebook/Jupyter version (top-level await):

from langchain_zeusdb import ZeusDBVectorStore
from langchain_openai import OpenAIEmbeddings
from langchain_core.documents import Document
from zeusdb import VectorDatabase
import asyncio

# Setup
embeddings = OpenAIEmbeddings(model="text-embedding-3-small")
vdb = VectorDatabase()
index = vdb.create(index_type="hnsw", dim=1536, space="cosine")
vector_store = ZeusDBVectorStore(zeusdb_index=index, embedding=embeddings)

docs = [
    Document(page_content="ZeusDB is fast", metadata={"source": "docs"}),
    Document(page_content="LangChain is powerful", metadata={"source": "docs"}),
]

# Add documents asynchronously
ids = await vector_store.aadd_documents(docs)
print("Added IDs:", ids)

# Run multiple searches concurrently
results_fast, results_powerful = await asyncio.gather(
    vector_store.asimilarity_search("fast", k=2),
    vector_store.asimilarity_search("powerful", k=2),
)
print("Fast results:", [d.page_content for d in results_fast])
print("Powerful results:", [d.page_content for d in results_powerful])

# Delete documents asynchronously
deleted = await vector_store.adelete(ids=ids[:1])
print("Deleted first doc:", deleted)

Expected results:

Added IDs: ['9c440918-715f-49ba-9b97-0d991d29e997', 'ad59c645-d3ba-4a4a-a016-49ed39514123']
Fast results: ['ZeusDB is fast', 'LangChain is powerful']
Powerful results: ['LangChain is powerful', 'ZeusDB is fast']
Deleted first doc: True

Monitoring and Observability

Performance Monitoring

# Get index statistics
stats = vector_store.get_zeusdb_stats()
print(f"Index size: {stats.get('total_vectors', '0')} vectors")
print(f"Dimension: {stats.get('dimension')} | Space: {stats.get('space')} | Index type: {stats.get('index_type')}")

# Benchmark search performance
performance = vector_store.benchmark_search_performance(
    query_count=100,
    max_threads=4
)
print(f"Search QPS: {performance.get('parallel_qps', 0):.0f}")

# Check quantization status
if vector_store.is_quantized():
    progress = vector_store.get_training_progress()
    print(f"Quantization training: {progress:.1f}% complete")
else:
    print("Index is not quantized")

Expected results:

Index size: 2 vectors
Dimension: 1536 | Space: cosine | Index type: HNSW
Search QPS: 53807
Index is not quantized

Enterprise Logging

ZeusDB includes enterprise-grade structured logging that works automatically with smart environment detection:

import logging

# ZeusDB automatically detects your environment and applies appropriate logging:
# - Development: Human-readable logs, WARNING level
# - Production: JSON structured logs, ERROR level  
# - Testing: Minimal output, CRITICAL level
# - Jupyter: Clean readable logs, INFO level

# Operations are automatically logged with performance metrics
vector_store.add_documents(docs)
# Logs: {"operation":"vector_addition","total_inserted":2,"duration_ms":45}

# Control logging with environment variables if needed
# ZEUSDB_LOG_LEVEL=debug ZEUSDB_LOG_FORMAT=json python your_app.py

To learn more about the full features of ZeusDB’s enterprise logging capabilities please read the following documentation.

Configuration Options

Index Parameters

vdb = VectorDatabase()
index = vdb.create(
    index_type="hnsw",           # Index algorithm
    dim=1536,                    # Vector dimension
    space="cosine",              # Distance metric: cosine, l2, l1
    m=16,                        # HNSW connectivity
    ef_construction=200,         # Build-time search width
    expected_size=100000,        # Expected number of vectors
    quantization_config=None     # Optional quantization
)

Search Parameters

results = vector_store.similarity_search(
    query="search query",
    k=5,                         # Number of results
    ef_search=None,              # Runtime search width (auto if None)
    filter={"key": "value"}      # Metadata filter
)

Error Handling

The integration includes comprehensive error handling:

try:
    results = vector_store.similarity_search("query")
    print(results)
except Exception as e:
    # Graceful degradation with logging
    print(f"Search failed: {e}")
    # Fallback logic here

Requirements

• Python: 3.10 or higher

• ZeusDB: 0.0.8 or higher

• LangChain Core: 0.3.74 or higher

Installation from Source

git clone https://github.com/zeusdb/langchain-zeusdb.git
cd langchain-zeusdb/libs/zeusdb
pip install -e .

Performance Benchmarks

In internal benchmarks, ZeusDB has demonstrated exceptional performance for large-scale vector search workloads.

Operation	Performance	Notes
Index Creation	1M+ vectors/min	Depends on vector dimension
Search Latency	<1ms	Sub-millisecond for most queries
Memory Usage	50-90% reduction	With Product Quantization
Concurrent QPS	10,000+	Multi-threaded search

⚠️ Note: These figures represent internal benchmark results under specific test conditions. Actual performance may vary depending on hardware, vector dimensions, dataset size, and workload characteristics.

Use Cases

• RAG Applications: High-performance retrieval for question answering

• Semantic Search: Fast similarity search across large document collections

• Recommendation Systems: Vector-based content and collaborative filtering

• Embeddings Analytics: Analysis of high-dimensional embedding spaces

• Real-time Applications: Low-latency vector search for production systems

Compatibility

LangChain Versions

• LangChain Core: 0.3.74+

Distance Metrics

• Cosine: Default, normalized similarity

• Euclidean (L2): Geometric distance

• Manhattan (L1): City-block distance

Embedding Models

Compatible with any embedding provider:

• OpenAI (text-embedding-3-small, text-embedding-3-large)

• Hugging Face Transformers

• Cohere Embeddings

• Custom embedding functions

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Making vector search fast, scalable, and developer-friendly.