VecStore-js

A simple, fast, and pluggable vector database for the browser.

VecStore-js brings the power of local, privacy-preserving semantic search to your client-side applications. It uses local embeddings and stores data directly in the user's browser via IndexedDB, making it perfect for offline-first AI features, browser extensions, and web apps where data privacy is critical.

Features

• 🧠 Local Semantic Search: No server calls needed. All processing happens in the browser.
• 🚀 High Performance: Powered by HNSW (Hierarchical Navigable Small World) for fast, approximate nearest-neighbor search, implemented in WebAssembly.
• 🔌 Pluggable Components: Easily switch between search algorithms (HNSW, Cosine Similarity) and embedding models.
• 🔒 Privacy-First: User data never leaves the browser.
• offline Offline-First: Caches models and data for use without an internet connection.
• 📦 Lightweight: Small footprint, designed for the client-side.

Installation

npm install vecstore-js

Quick Start

This example shows how to set up a vector store, add documents, and perform a semantic search.

import { VecStore, TransformerEmbedder, HNSWSearchAlgorithm } from 'vecstore-js';

// 1. Create an embedder to convert text to vectors
// This will download a model on first run and cache it in IndexedDB.
const embedder = await TransformerEmbedder.create();

// 2. Create the vector store with the HNSW algorithm for performance
const store = new VecStore({ 
  embedder, 
  search: new HNSWSearchAlgorithm()
});

// 3. Initialize the store (required for indexed search algorithms like HNSW)
await store.initialize();

// 4. Add documents. They are indexed immediately.
await store.addDocument('doc1', 'The Eiffel Tower is a famous landmark in Paris.');
await store.addDocument('doc2', 'Pasta is a staple of Italian cuisine.');
await store.addDocument('doc3', 'Machine learning is a subset of artificial intelligence.');

// 5. Perform a semantic search
const query = 'What are some popular foods in Europe?';
const results = await store.query(query, 2);

console.log(results);
/*
[
  {
    id: 'doc2',
    vector: [ ... ],
    content: 'Pasta is a staple of Italian cuisine.',
    score: 0.891
  },
  {
    id: 'doc1',
    vector: [ ... ],
    content: 'The Eiffel Tower is a famous landmark in Paris.',
    score: 0.763
  }
]
*/

Choosing a Search Algorithm

VecStore.js has a pluggable architecture. You can choose the best search algorithm for your needs.

HNSW (Default & Recommended)

For most applications, HNSW is the best choice. It's much faster than exact search, especially with thousands of documents.

import { HNSWSearchAlgorithm } from 'vecstore-js';

const store = new VecStore({ 
  embedder, 
  search: new HNSWSearchAlgorithm({
    // Optional: Tune HNSW parameters for your use case
    maxElements: 50000, // Max documents to store
    efSearch: 100,      // Search quality/speed tradeoff
  })
});
await store.initialize(); // Don't forget to initialize!

Cosine Similarity (Simple & Exact)

For small datasets or when you need exact (but slower) results, you can use simple cosine similarity.

import { CosineSearchAlgorithm } from 'vecstore-js';

const store = new VecStore({ 
  embedder, 
  search: new CosineSearchAlgorithm()
});
await store.initialize(); // Don't forget to initialize!

API Reference

VecStore

new VecStore(options)

• options.embedder: Embedder (required) - An instance of an embedder.
• options.search?: SearchAlgorithm - The search algorithm to use. Defaults to CosineSearchAlgorithm.
• options.store?: StorageAdapter - A custom storage adapter. Defaults to IDBStorageAdapter.
• options.dbName?: string - The name for the IndexedDB database. Defaults to 'vecstore'.
• options.storeContent?: boolean - Whether to store the original document content. Defaults to true.

store.initialize()

Initializes the store. Required when using an IndexedSearchAlgorithm like HNSW. It loads existing documents from storage into the search index.

store.addDocument(id, content, metadata?)

• id: string - A unique ID for the document.
• content: string - The text content to be embedded and indexed.
• metadata?: Record<string, any> - Optional object for storing extra data.

store.query(query, topK?)

• query: string - The text to search for.
• topK?: number - The number of similar documents to return. Defaults to 5.

License

MIT