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*   Faiss

On this page

Faiss
=====

Compatibility

Only available on Node.js.

[Faiss](https://github.com/facebookresearch/faiss) is a library for efficient similarity search and clustering of dense vectors.

Langchainjs supports using Faiss as a vectorstore that can be saved to file. It also provides the ability to read the saved file from [Python's implementation](https://python.langchain.com/docs/integrations/vectorstores/faiss#saving-and-loading).

Setup[​](#setup "Direct link to Setup")
---------------------------------------

Install the [faiss-node](https://github.com/ewfian/faiss-node), which is a Node.js bindings for [Faiss](https://github.com/facebookresearch/faiss).

*   npm
*   Yarn
*   pnpm

    npm install -S faiss-node

    yarn add faiss-node

    pnpm add faiss-node

To enable the ability to read the saved file from [Python's implementation](https://python.langchain.com/docs/integrations/vectorstores/faiss#saving-and-loading), the [pickleparser](https://github.com/ewfian/pickleparser) also needs to install.

*   npm
*   Yarn
*   pnpm

    npm install -S pickleparser

    yarn add pickleparser

    pnpm add pickleparser

Usage[​](#usage "Direct link to Usage")
---------------------------------------

tip

See [this section for general instructions on installing integration packages](/v0.2/docs/how_to/installation#installing-integration-packages).

*   npm
*   Yarn
*   pnpm

    npm install @langchain/openai @langchain/community

    yarn add @langchain/openai @langchain/community

    pnpm add @langchain/openai @langchain/community

### Create a new index from texts[​](#create-a-new-index-from-texts "Direct link to Create a new index from texts")

    import { FaissStore } from "@langchain/community/vectorstores/faiss";import { OpenAIEmbeddings } from "@langchain/openai";export const run = async () => {  const vectorStore = await FaissStore.fromTexts(    ["Hello world", "Bye bye", "hello nice world"],    [{ id: 2 }, { id: 1 }, { id: 3 }],    new OpenAIEmbeddings()  );  const resultOne = await vectorStore.similaritySearch("hello world", 1);  console.log(resultOne);};

#### API Reference:

*   [FaissStore](https://v02.api.js.langchain.com/classes/langchain_community_vectorstores_faiss.FaissStore.html) from `@langchain/community/vectorstores/faiss`
*   [OpenAIEmbeddings](https://v02.api.js.langchain.com/classes/langchain_openai.OpenAIEmbeddings.html) from `@langchain/openai`

### Create a new index from a loader[​](#create-a-new-index-from-a-loader "Direct link to Create a new index from a loader")

    import { FaissStore } from "@langchain/community/vectorstores/faiss";import { OpenAIEmbeddings } from "@langchain/openai";import { TextLoader } from "langchain/document_loaders/fs/text";// Create docs with a loaderconst loader = new TextLoader("src/document_loaders/example_data/example.txt");const docs = await loader.load();// Load the docs into the vector storeconst vectorStore = await FaissStore.fromDocuments(  docs,  new OpenAIEmbeddings());// Search for the most similar documentconst resultOne = await vectorStore.similaritySearch("hello world", 1);console.log(resultOne);

#### API Reference:

*   [FaissStore](https://v02.api.js.langchain.com/classes/langchain_community_vectorstores_faiss.FaissStore.html) from `@langchain/community/vectorstores/faiss`
*   [OpenAIEmbeddings](https://v02.api.js.langchain.com/classes/langchain_openai.OpenAIEmbeddings.html) from `@langchain/openai`
*   [TextLoader](https://v02.api.js.langchain.com/classes/langchain_document_loaders_fs_text.TextLoader.html) from `langchain/document_loaders/fs/text`

### Deleting vectors[​](#deleting-vectors "Direct link to Deleting vectors")

    import { FaissStore } from "@langchain/community/vectorstores/faiss";import { OpenAIEmbeddings } from "@langchain/openai";import { Document } from "@langchain/core/documents";const vectorStore = new FaissStore(new OpenAIEmbeddings(), {});const ids = ["2", "1", "4"];const idsReturned = await vectorStore.addDocuments(  [    new Document({      pageContent: "my world",      metadata: { tag: 2 },    }),    new Document({      pageContent: "our world",      metadata: { tag: 1 },    }),    new Document({      pageContent: "your world",      metadata: { tag: 4 },    }),  ],  {    ids,  });console.log(idsReturned);/*  [ '2', '1', '4' ]*/const docs = await vectorStore.similaritySearch("my world", 3);console.log(docs);/*[  Document { pageContent: 'my world', metadata: { tag: 2 } },  Document { pageContent: 'your world', metadata: { tag: 4 } },  Document { pageContent: 'our world', metadata: { tag: 1 } }]*/await vectorStore.delete({ ids: [ids[0], ids[1]] });const docs2 = await vectorStore.similaritySearch("my world", 3);console.log(docs2);/*[ Document { pageContent: 'your world', metadata: { tag: 4 } } ]*/

#### API Reference:

*   [FaissStore](https://v02.api.js.langchain.com/classes/langchain_community_vectorstores_faiss.FaissStore.html) from `@langchain/community/vectorstores/faiss`
*   [OpenAIEmbeddings](https://v02.api.js.langchain.com/classes/langchain_openai.OpenAIEmbeddings.html) from `@langchain/openai`
*   [Document](https://v02.api.js.langchain.com/classes/langchain_core_documents.Document.html) from `@langchain/core/documents`

### Merging indexes and creating new index from another instance[​](#merging-indexes-and-creating-new-index-from-another-instance "Direct link to Merging indexes and creating new index from another instance")

    import { FaissStore } from "@langchain/community/vectorstores/faiss";import { OpenAIEmbeddings } from "@langchain/openai";export const run = async () => {  // Create an initial vector store  const vectorStore = await FaissStore.fromTexts(    ["Hello world", "Bye bye", "hello nice world"],    [{ id: 2 }, { id: 1 }, { id: 3 }],    new OpenAIEmbeddings()  );  // Create another vector store from texts  const vectorStore2 = await FaissStore.fromTexts(    ["Some text"],    [{ id: 1 }],    new OpenAIEmbeddings()  );  // merge the first vector store into vectorStore2  await vectorStore2.mergeFrom(vectorStore);  const resultOne = await vectorStore2.similaritySearch("hello world", 1);  console.log(resultOne);  // You can also create a new vector store from another FaissStore index  const vectorStore3 = await FaissStore.fromIndex(    vectorStore2,    new OpenAIEmbeddings()  );  const resultTwo = await vectorStore3.similaritySearch("Bye bye", 1);  console.log(resultTwo);};

#### API Reference:

*   [FaissStore](https://v02.api.js.langchain.com/classes/langchain_community_vectorstores_faiss.FaissStore.html) from `@langchain/community/vectorstores/faiss`
*   [OpenAIEmbeddings](https://v02.api.js.langchain.com/classes/langchain_openai.OpenAIEmbeddings.html) from `@langchain/openai`

### Save an index to file and load it again[​](#save-an-index-to-file-and-load-it-again "Direct link to Save an index to file and load it again")

    import { FaissStore } from "@langchain/community/vectorstores/faiss";import { OpenAIEmbeddings } from "@langchain/openai";// Create a vector store through any method, here from texts as an exampleconst vectorStore = await FaissStore.fromTexts(  ["Hello world", "Bye bye", "hello nice world"],  [{ id: 2 }, { id: 1 }, { id: 3 }],  new OpenAIEmbeddings());// Save the vector store to a directoryconst directory = "your/directory/here";await vectorStore.save(directory);// Load the vector store from the same directoryconst loadedVectorStore = await FaissStore.load(  directory,  new OpenAIEmbeddings());// vectorStore and loadedVectorStore are identicalconst result = await loadedVectorStore.similaritySearch("hello world", 1);console.log(result);

#### API Reference:

*   [FaissStore](https://v02.api.js.langchain.com/classes/langchain_community_vectorstores_faiss.FaissStore.html) from `@langchain/community/vectorstores/faiss`
*   [OpenAIEmbeddings](https://v02.api.js.langchain.com/classes/langchain_openai.OpenAIEmbeddings.html) from `@langchain/openai`

### Load the saved file from [Python's implementation](https://python.langchain.com/docs/integrations/vectorstores/faiss#saving-and-loading)[​](#load-the-saved-file-from-pythons-implementation "Direct link to load-the-saved-file-from-pythons-implementation")

    import { FaissStore } from "@langchain/community/vectorstores/faiss";import { OpenAIEmbeddings } from "@langchain/openai";// The directory of data saved from Pythonconst directory = "your/directory/here";// Load the vector store from the directoryconst loadedVectorStore = await FaissStore.loadFromPython(  directory,  new OpenAIEmbeddings());// Search for the most similar documentconst result = await loadedVectorStore.similaritySearch("test", 2);console.log("result", result);

#### API Reference:

*   [FaissStore](https://v02.api.js.langchain.com/classes/langchain_community_vectorstores_faiss.FaissStore.html) from `@langchain/community/vectorstores/faiss`
*   [OpenAIEmbeddings](https://v02.api.js.langchain.com/classes/langchain_openai.OpenAIEmbeddings.html) from `@langchain/openai`

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*   [Setup](#setup)
*   [Usage](#usage)
    *   [Create a new index from texts](#create-a-new-index-from-texts)
    *   [Create a new index from a loader](#create-a-new-index-from-a-loader)
    *   [Deleting vectors](#deleting-vectors)
    *   [Merging indexes and creating new index from another instance](#merging-indexes-and-creating-new-index-from-another-instance)
    *   [Save an index to file and load it again](#save-an-index-to-file-and-load-it-again)
    *   [Load the saved file from Python's implementation](#load-the-saved-file-from-pythons-implementation)

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