Vector store integrations | LangChain English

Overview

A vector store stores embedded data and performs similarity search.

flowchart LR

    subgraph "📥 Indexing phase (store)"
        A[📄 Documents] --> B[🔢 Embedding model]
        B --> C[🔘 Embedding vectors]
        C --> D[(Vector store)]
    end

    subgraph "📤 Query phase (retrieval)"
        E[❓ Query text] --> F[🔢 Embedding model]
        F --> G[🔘 Query vector]
        G --> H[🔍 Similarity search]
        H --> D
        D --> I[📄 Top-k results]
    end

    classDef process fill:#E5F4FF,stroke:#006DDD,stroke-width:2px,color:#030710
    class A,B,C,D,E,F,G,H,I process

Interface

LangChain provides a unified interface for vector stores, allowing you to:

addDocuments - Add documents to the store.
delete - Remove stored documents by ID.
similaritySearch - Query for semantically similar documents.

This abstraction lets you switch between different implementations without altering your application logic.

Initialization

Most vectorstores in LangChain accept an embedding model as an argument when initializing the vector store.

import { OpenAIEmbeddings } from "@langchain/openai";
import { MemoryVectorStore } from "@langchain/classic/vectorstores/memory";

const embeddings = new OpenAIEmbeddings({
  model: "text-embedding-3-small",
});
const vectorStore = new MemoryVectorStore(embeddings);

Adding documents

You can add documents to the vector store by using the addDocuments function.

import { Document } from "@langchain/core/documents";
const document = new Document({
  pageContent: "Hello world",
});
await vectorStore.addDocuments([document]);

Deleting documents

You can delete documents from the vector store by using the delete function.

await vectorStore.delete({
  filter: {
    pageContent: "Hello world",
  },
});

Similarity search

Issue a semantic query using similaritySearch, which returns the closest embedded documents:

const results = await vectorStore.similaritySearch("Hello world", 10);

Many vector stores support parameters like:

k — number of results to return
filter — conditional filtering based on metadata

Similarity metrics & indexing

Embedding similarity may be computed using:

Cosine similarity
Euclidean distance
Dot product

Efficient search often employs indexing methods such as HNSW (Hierarchical Navigable Small World), though specifics depend on the vector store.

Metadata filtering

Filtering by metadata (e.g., source, date) can refine search results:

vectorStore.similaritySearch("query", 2, { source: "tweets" });

Support for metadata-based filtering varies between implementations. Check the documentation of your chosen vector store for details.

Top integrations

Select embedding model:

Install dependencies:

npm

yarn

pnpm

npm install @langchain/openai @langchain/core

yarn add @langchain/openai @langchain/core

pnpm add @langchain/openai @langchain/core

Add environment variables:

OPENAI_API_KEY=your-api-key

Instantiate the model:

import { OpenAIEmbeddings } from "@langchain/openai";

const embeddings = new OpenAIEmbeddings({
  model: "text-embedding-3-large"
});

Install dependencies

npm

yarn

pnpm

npm install @langchain/openai @langchain/core

yarn add @langchain/openai @langchain/core

pnpm add @langchain/openai @langchain/core

Add environment variables:

AZURE_OPENAI_API_INSTANCE_NAME=<YOUR_INSTANCE_NAME>
AZURE_OPENAI_API_KEY=<YOUR_KEY>
AZURE_OPENAI_API_VERSION="2024-02-01"

Instantiate the model:

import { AzureOpenAIEmbeddings } from "@langchain/openai";

const embeddings = new AzureOpenAIEmbeddings({
  azureOpenAIApiEmbeddingsDeploymentName: "text-embedding-ada-002"
});

Install dependencies:

npm

yarn

pnpm

npm i @langchain/aws

yarn add @langchain/aws

pnpm add @langchain/aws

Add environment variables:

BEDROCK_AWS_REGION=your-region

Instantiate the model:

import { BedrockEmbeddings } from "@langchain/aws";

const embeddings = new BedrockEmbeddings({
  model: "amazon.titan-embed-text-v1"
});

Install dependencies:

npm

yarn

pnpm

npm i @langchain/google-genai

yarn add @langchain/google-genai

pnpm add @langchain/google-genai

Add environment variables:

GOOGLE_API_KEY=your-api-key

Instantiate the model:

import { GoogleGenerativeAIEmbeddings } from "@langchain/google-genai";

const embeddings = new GoogleGenerativeAIEmbeddings({
  model: "gemini-embedding-001"
});

Install dependencies:

npm

yarn

pnpm

npm i @langchain/google-vertexai

yarn add @langchain/google-vertexai

pnpm add @langchain/google-vertexai

Add environment variables:

GOOGLE_APPLICATION_CREDENTIALS=credentials.json

Instantiate the model:

import { VertexAIEmbeddings } from "@langchain/google-vertexai";

const embeddings = new VertexAIEmbeddings({
  model: "gemini-embedding-001"
});

Install dependencies:

npm

yarn

pnpm

npm install @langchain/mistralai @langchain/core

yarn add @langchain/mistralai @langchain/core

pnpm add @langchain/mistralai @langchain/core

Add environment variables:

MISTRAL_API_KEY=your-api-key

Instantiate the model:

import { MistralAIEmbeddings } from "@langchain/mistralai";

const embeddings = new MistralAIEmbeddings({
  model: "mistral-embed"
});

Install dependencies:

npm

yarn

pnpm

npm i @langchain/cohere

yarn add @langchain/cohere

pnpm add @langchain/cohere

Add environment variables:

COHERE_API_KEY=your-api-key

Instantiate the model:

import { CohereEmbeddings } from "@langchain/cohere";

const embeddings = new CohereEmbeddings({
  model: "embed-english-v3.0"
});

Install dependencies:

npm

yarn

pnpm

npm install @langchain/ollama @langchain/core

yarn add @langchain/ollama @langchain/core

pnpm add @langchain/ollama @langchain/core

Instantiate the model:

import { OllamaEmbeddings } from "@langchain/ollama";

const embeddings = new OllamaEmbeddings({
  model: "llama2",
  baseUrl: "http://localhost:11434", // Default value
});

Install dependencies:

npm

yarn

pnpm

npm install @langchain/mongodb @langchain/core

yarn add @langchain/mongodb @langchain/core

pnpm add @langchain/mongodb @langchain/core

Add environment variables:

VOYAGE_API_KEY=your-api-key

Instantiate the model:

import { VoyageEmbeddings } from "@langchain/mongodb";

const embeddings = new VoyageEmbeddings({
  model: "voyage-4"
});

OpenAI

Install dependencies:

npm

yarn

pnpm

npm install @langchain/openai @langchain/core

yarn add @langchain/openai @langchain/core

pnpm add @langchain/openai @langchain/core

Add environment variables:

OPENAI_API_KEY=your-api-key

Instantiate the model:

import { OpenAIEmbeddings } from "@langchain/openai";

const embeddings = new OpenAIEmbeddings({
  model: "text-embedding-3-large"
});

Azure

Install dependencies

npm

yarn

pnpm

npm install @langchain/openai @langchain/core

yarn add @langchain/openai @langchain/core

pnpm add @langchain/openai @langchain/core

Add environment variables:

AZURE_OPENAI_API_INSTANCE_NAME=<YOUR_INSTANCE_NAME>
AZURE_OPENAI_API_KEY=<YOUR_KEY>
AZURE_OPENAI_API_VERSION="2024-02-01"

Instantiate the model:

import { AzureOpenAIEmbeddings } from "@langchain/openai";

const embeddings = new AzureOpenAIEmbeddings({
  azureOpenAIApiEmbeddingsDeploymentName: "text-embedding-ada-002"
});

AWS

Install dependencies:

npm

yarn

pnpm

npm i @langchain/aws

yarn add @langchain/aws

pnpm add @langchain/aws

Add environment variables:

BEDROCK_AWS_REGION=your-region

Instantiate the model:

import { BedrockEmbeddings } from "@langchain/aws";

const embeddings = new BedrockEmbeddings({
  model: "amazon.titan-embed-text-v1"
});

Google Gemini

Install dependencies:

npm

yarn

pnpm

npm i @langchain/google-genai

yarn add @langchain/google-genai

pnpm add @langchain/google-genai

Add environment variables:

GOOGLE_API_KEY=your-api-key

Instantiate the model:

import { GoogleGenerativeAIEmbeddings } from "@langchain/google-genai";

const embeddings = new GoogleGenerativeAIEmbeddings({
  model: "gemini-embedding-001"
});

Gemini Enterprise Agent Platform

Install dependencies:

npm

yarn

pnpm

npm i @langchain/google-vertexai

yarn add @langchain/google-vertexai

pnpm add @langchain/google-vertexai

Add environment variables:

GOOGLE_APPLICATION_CREDENTIALS=credentials.json

Instantiate the model:

import { VertexAIEmbeddings } from "@langchain/google-vertexai";

const embeddings = new VertexAIEmbeddings({
  model: "gemini-embedding-001"
});

MistralAI

Install dependencies:

npm

yarn

pnpm

npm install @langchain/mistralai @langchain/core

yarn add @langchain/mistralai @langchain/core

pnpm add @langchain/mistralai @langchain/core

Add environment variables:

MISTRAL_API_KEY=your-api-key

Instantiate the model:

import { MistralAIEmbeddings } from "@langchain/mistralai";

const embeddings = new MistralAIEmbeddings({
  model: "mistral-embed"
});

Cohere

Install dependencies:

npm

yarn

pnpm

npm i @langchain/cohere

yarn add @langchain/cohere

pnpm add @langchain/cohere

Add environment variables:

COHERE_API_KEY=your-api-key

Instantiate the model:

import { CohereEmbeddings } from "@langchain/cohere";

const embeddings = new CohereEmbeddings({
  model: "embed-english-v3.0"
});

Ollama

Install dependencies:

npm

yarn

pnpm

npm install @langchain/ollama @langchain/core

yarn add @langchain/ollama @langchain/core

pnpm add @langchain/ollama @langchain/core

Instantiate the model:

import { OllamaEmbeddings } from "@langchain/ollama";

const embeddings = new OllamaEmbeddings({
  model: "llama2",
  baseUrl: "http://localhost:11434", // Default value
});

Voyage AI

Install dependencies:

npm

yarn

pnpm

npm install @langchain/mongodb @langchain/core

yarn add @langchain/mongodb @langchain/core

pnpm add @langchain/mongodb @langchain/core

Add environment variables:

VOYAGE_API_KEY=your-api-key

Instantiate the model:

import { VoyageEmbeddings } from "@langchain/mongodb";

const embeddings = new VoyageEmbeddings({
  model: "voyage-4"
});

Select vector store:

Manual embedding

Automated embedding

npm

yarn

pnpm

npm install @langchain/mongodb mongodb @langchain/core

yarn add @langchain/mongodb mongodb @langchain/core

pnpm add @langchain/mongodb mongodb @langchain/core

import { MongoDBAtlasVectorSearch } from "@langchain/mongodb"
import { MongoClient } from "mongodb";

const client = new MongoClient(process.env.MONGODB_ATLAS_URI!);
const collection = client
  .db(process.env.MONGODB_ATLAS_DB_NAME)
  .collection(process.env.MONGODB_ATLAS_COLLECTION_NAME);

const vectorStore = new MongoDBAtlasVectorSearch(embeddings, {
  collection,
  indexName: "vector_index",
  textKey: "text",
  embeddingKey: "embedding",
});

npm

yarn

pnpm

npm install @langchain/mongodb mongodb @langchain/core

yarn add @langchain/mongodb mongodb @langchain/core

pnpm add @langchain/mongodb mongodb @langchain/core

import { MongoDBAtlasVectorSearch } from "@langchain/mongodb"
import { MongoClient } from "mongodb";

const client = new MongoClient(process.env.MONGODB_ATLAS_URI!);
const collection = client
  .db(process.env.MONGODB_ATLAS_DB_NAME)
  .collection(process.env.MONGODB_ATLAS_COLLECTION_NAME);

const vectorStore = new MongoDBAtlasVectorSearch({ collection });

npm

yarn

pnpm

npm install @langchain/pinecone @langchain/core @pinecone-database/pinecone

yarn add @langchain/pinecone @langchain/core @pinecone-database/pinecone

pnpm add @langchain/pinecone @langchain/core @pinecone-database/pinecone

import { PineconeStore } from "@langchain/pinecone";
import { Pinecone as PineconeClient } from "@pinecone-database/pinecone";

const pinecone = new PineconeClient();
const vectorStore = new PineconeStore(embeddings, {
  pineconeIndex,
  maxConcurrency: 5,
});

npm

yarn

pnpm

npm install @langchain/redis @langchain/core redis

yarn add @langchain/redis @langchain/core redis

pnpm add @langchain/redis @langchain/core redis

import { RedisVectorStore } from "@langchain/redis";

const vectorStore = new RedisVectorStore(embeddings, {
  redisClient: client,
  indexName: "langchainjs-testing",
});

npm

yarn

pnpm

npm install @langchain/qdrant @langchain/core

yarn add @langchain/qdrant @langchain/core

pnpm add @langchain/qdrant @langchain/core

import { QdrantVectorStore } from "@langchain/qdrant";

const vectorStore = await QdrantVectorStore.fromExistingCollection(embeddings, {
  url: process.env.QDRANT_URL,
  collectionName: "langchainjs-testing",
});

npm

yarn

pnpm

npm i @oracle/langchain-oracledb @langchain/core

yarn add @oracle/langchain-oracledb @langchain/core

pnpm add @oracle/langchain-oracledb @langchain/core

import oracledb from "oracledb";
import { OracleEmbeddings, OracleVS } from "@oracle/langchain-oracledb";

const connection = await oracledb.getConnection({
  user: process.env.ORACLE_USER,
  password: process.env.ORACLE_PASSWORD,
  connectionString: process.env.ORACLE_DSN,
});

const embeddings = new OracleEmbeddings(connection, {
  provider: "database",
  model: process.env.DEMO_ONNX_MODEL ?? "DEMO_MODEL",
});

const vectorStore = new OracleVS(embeddings, {
  client: connection,
  tableName: "DEMO_VECTORS",
  query: "Find support tickets mentioning service outages.",
  distanceStrategy: "DOT",
});
await vectorStore.initialize();

npm

yarn

pnpm

npm install @langchain/weaviate @langchain/core weaviate-client

yarn add @langchain/weaviate @langchain/core weaviate-client

pnpm add @langchain/weaviate @langchain/core weaviate-client

typescript

import { WeaviateStore } from "@langchain/weaviate";

const vectorStore = new WeaviateStore(embeddings, {
    client: weaviateClient,
    indexName: "Langchainjs_test",
});

Memory

MongoDB

Manual embedding

Automated embedding

npm

yarn

pnpm

npm install @langchain/mongodb mongodb @langchain/core

yarn add @langchain/mongodb mongodb @langchain/core

pnpm add @langchain/mongodb mongodb @langchain/core

import { MongoDBAtlasVectorSearch } from "@langchain/mongodb"
import { MongoClient } from "mongodb";

const client = new MongoClient(process.env.MONGODB_ATLAS_URI!);
const collection = client
  .db(process.env.MONGODB_ATLAS_DB_NAME)
  .collection(process.env.MONGODB_ATLAS_COLLECTION_NAME);

const vectorStore = new MongoDBAtlasVectorSearch(embeddings, {
  collection,
  indexName: "vector_index",
  textKey: "text",
  embeddingKey: "embedding",
});

npm

yarn

pnpm

npm install @langchain/mongodb mongodb @langchain/core

yarn add @langchain/mongodb mongodb @langchain/core

pnpm add @langchain/mongodb mongodb @langchain/core

import { MongoDBAtlasVectorSearch } from "@langchain/mongodb"
import { MongoClient } from "mongodb";

const client = new MongoClient(process.env.MONGODB_ATLAS_URI!);
const collection = client
  .db(process.env.MONGODB_ATLAS_DB_NAME)
  .collection(process.env.MONGODB_ATLAS_COLLECTION_NAME);

const vectorStore = new MongoDBAtlasVectorSearch({ collection });

Pinecone

npm

yarn

pnpm

npm install @langchain/pinecone @langchain/core @pinecone-database/pinecone

yarn add @langchain/pinecone @langchain/core @pinecone-database/pinecone

pnpm add @langchain/pinecone @langchain/core @pinecone-database/pinecone

import { PineconeStore } from "@langchain/pinecone";
import { Pinecone as PineconeClient } from "@pinecone-database/pinecone";

const pinecone = new PineconeClient();
const vectorStore = new PineconeStore(embeddings, {
  pineconeIndex,
  maxConcurrency: 5,
});

Redis

npm

yarn

pnpm

npm install @langchain/redis @langchain/core redis

yarn add @langchain/redis @langchain/core redis

pnpm add @langchain/redis @langchain/core redis

import { RedisVectorStore } from "@langchain/redis";

const vectorStore = new RedisVectorStore(embeddings, {
  redisClient: client,
  indexName: "langchainjs-testing",
});

Qdrant

npm

yarn

pnpm

npm install @langchain/qdrant @langchain/core

yarn add @langchain/qdrant @langchain/core

pnpm add @langchain/qdrant @langchain/core

import { QdrantVectorStore } from "@langchain/qdrant";

const vectorStore = await QdrantVectorStore.fromExistingCollection(embeddings, {
  url: process.env.QDRANT_URL,
  collectionName: "langchainjs-testing",
});

Oracle AI Database

npm

yarn

pnpm

npm i @oracle/langchain-oracledb @langchain/core

yarn add @oracle/langchain-oracledb @langchain/core

pnpm add @oracle/langchain-oracledb @langchain/core

import oracledb from "oracledb";
import { OracleEmbeddings, OracleVS } from "@oracle/langchain-oracledb";

const connection = await oracledb.getConnection({
  user: process.env.ORACLE_USER,
  password: process.env.ORACLE_PASSWORD,
  connectionString: process.env.ORACLE_DSN,
});

const embeddings = new OracleEmbeddings(connection, {
  provider: "database",
  model: process.env.DEMO_ONNX_MODEL ?? "DEMO_MODEL",
});

const vectorStore = new OracleVS(embeddings, {
  client: connection,
  tableName: "DEMO_VECTORS",
  query: "Find support tickets mentioning service outages.",
  distanceStrategy: "DOT",
});
await vectorStore.initialize();

Weaviate

npm

yarn

pnpm

npm install @langchain/weaviate @langchain/core weaviate-client

yarn add @langchain/weaviate @langchain/core weaviate-client

pnpm add @langchain/weaviate @langchain/core weaviate-client

typescript

import { WeaviateStore } from "@langchain/weaviate";

const vectorStore = new WeaviateStore(embeddings, {
    client: weaviateClient,
    indexName: "Langchainjs_test",
});

LangChain.js integrates with a variety of vector stores. You can check out a full list below:

All vector stores

Vectorstore	Downloads
`WeaviateStore`
`PineconeStore`
`MongoDBAtlasVectorSearch`
`QdrantVectorStore`
`RedisVectorStore`
`OracleVS`
`PGVectorStore`
`Cloudflare vectorize`
`TurbopufferVectorStore`
`Google cloud SQL for postgresql`
`Azure Cosmos DB for MongoDB vCore (deprecated)`
`Azure Cosmos DB for NoSQL`
`Azure DocumentDB`
`Neo4jVectorStore`
`SAP HANA Cloud Vector Engine`
`LambdaDB`
`Infino`
`YDB`
`langchain`	N/A