Files
lancedb/nodejs
Jack Ye 8373318e89 feat: support FM-Index scalar index for substring search (#3532)
Adds an FM-Index — a scalar index over string and binary columns that
accelerates substring search (`contains(col, 'needle')`), distinct from
the tokenized `FTS` index — across the Rust core and the Python and
TypeScript bindings.

## Rust

- `Index::Fm(FmIndexBuilder)` and `IndexType::Fm`.
- `make_index_params` maps `Index::Fm` to Lance's
`ScalarIndexParams::for_builtin(BuiltinIndexType::Fm)`.
- `supported_fm_data_type` validates
`Utf8`/`LargeUtf8`/`Binary`/`LargeBinary` columns.
- `list_indices` round-trips the type (`"Fm"` → `IndexType::Fm`); the
remote wire type is `"FM"`.

## Python

Adds `lancedb.index.Fm`, accepted by `create_index`:

```python
from lancedb.index import Fm

await tbl.create_index("text", config=Fm())
```

## TypeScript

Adds the `Index.fm()` factory:

```ts
await tbl.createIndex("text", { config: Index.fm() });
```
2026-06-10 12:28:20 -07:00
..
2025-03-21 10:56:29 -07:00
2025-01-29 08:27:07 -08:00

LanceDB JavaScript SDK

A JavaScript library for LanceDB.

Installation

npm install @lancedb/lancedb

This will download the appropriate native library for your platform. We currently support:

  • Linux (x86_64 and aarch64 on glibc and musl)
  • MacOS (Intel and ARM/M1/M2)
  • Windows (x86_64 and aarch64)

Usage

Basic Example

import * as lancedb from "@lancedb/lancedb";
const db = await lancedb.connect("data/sample-lancedb");
const table = await db.createTable("my_table", [
  { id: 1, vector: [0.1, 1.0], item: "foo", price: 10.0 },
  { id: 2, vector: [3.9, 0.5], item: "bar", price: 20.0 },
]);
const results = await table.vectorSearch([0.1, 0.3]).limit(20).toArray();
console.log(results);

The quickstart contains more complete examples.

Development

See CONTRIBUTING.md for information on how to contribute to LanceDB.