Files
lancedb/nodejs
mikemikimike be3215a6ae feat(nodejs): add JSON field helper (#4082)
## Issue

Fixes #4063

## Background

The Node.js SDK currently requires callers to know the Arrow extension
metadata needed to represent JSON fields. This makes a common LanceDB
schema type unnecessarily verbose and easy to get wrong.

## Changes

- Add `makeJsonField(name, nullable = true)` to create a UTF-8 Arrow
field with the `arrow.json` extension metadata.
- Re-export the helper from the public Node.js entry point.
- Add coverage for the default nullable behavior, explicit non-nullable
fields, and the extension metadata.
- Add the generated TypeDoc function page and public globals entry,
including a usage example.

## Implementation

The helper uses the existing Apache Arrow `Field` type and sets
`ARROW:extension:name` to `arrow.json`, matching the metadata convention
already used by LanceDB.

## Compatibility

This is an additive Node.js API. Existing schema construction and Arrow
behavior are unchanged.

## Verification

- `pnpm test -- arrow.test.ts --runInBand` — 236 tests passed.
- `pnpm exec biome ci lancedb/arrow.ts lancedb/index.ts
__test__/arrow.test.ts` — passed.
- `git diff --check` — passed.

## Not run / known limitations

- `pnpm build` and `pnpm run docs` were attempted after expanding the
checkout. Both are blocked locally by the native binding build/type
declarations: Cargo did not complete, and TypeDoc reported the missing
generated `nodejs/lancedb/native` module. The docs files were generated
from the updated TypeScript comments; full build and docs validation are
left to CI.
2026-09-15 18:01:42 -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.