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zeusdb

LangChain ZeusDB Integration

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)
API Reference:Document

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())
API Reference:Document

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)
API Reference:Document

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 .

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

Support​


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