@deepkit/bson

BSON

@deepkit/bson is a high-performance TS implementation of a parser and serializer for BSON, the MongoDB Binary JSON format. It's the fastest JS BSON parser, even faster than native JSON.parse/stringify.

Deepkit has reimplemented it because it's a high-performance framework and both the official JS (js-bson) and C++ (bson-ext) packages are too slow. How slow? When converting 10k elements in an array, js-bson takes 25ms, bson-ext takes 31ms, whiles JSON.parse takes only 5ms. This makes the official BSON parser 5x slower than native JSON.parse. deepkit/type-bson on the other hand takes only 2ms and is therefore 13x faster.

Benchmark

Parsing BSON buffer that contains an array with 10k objects.

Method	Time (ms)
official native bson-ext	31ms
official js-bson	25ms
deepkit/bson generic v2	6ms
deepkit/bson generic v3	4ms
JSON.parse	5ms
deepkit/type JIT	2ms

Serializing an array with 10k objects.

Method	Time (ms)
official native bson-ext	39ms
official js-bson	33ms
JSON.stringify	5ms
deepkit/bson JIT	2ms

"deepkit/bson JIT" means a parser/serializer based on a schema like so:

import {t} from '@deepkit/type';
import {getBSONDecoder} from '@deepkit/bson';

interface Model {
    username: string;
    tags: string[];
    priority: number;
}

const decoder = getBSONDecoder<Model>();
const bson = new Buffer([]);

const document = decoder(bson);

whereas "deepkit/type generic" means schema-less:

import {parseObject, ParserV2, ParserV3} from '@deepkit/bson';
const bson = new Buffer([]);

const object1 = parseObject(new ParserV2(bson));

const object2 = parseObject(new ParserV3(bson));

Differences

There are a couple of differences to the official serializer.

• ObjectId is deserialized as string.
• UUID is deserialized as string.
• BigInt is supported and serialized as long.
• Unlimited size BigInt supported (serialised as binary)
• Long is deserialized as BigInt.

Changelog

1.0.19 (2025-09-22)

Bug Fixes

• create-app: correct file path for client-rpc npm script in create-app (#659) (50a665f)
• mongo: stop printing verbose stuff in mongosh (d579a5a)
• type-compiler: ensure typed imports are grouped and not too high up, but placed right in front of the origin import (9f666c1)
• website: blog post url (a84a272)
• website: bullet/code/codeBlock + toc on blog posts (c11bb27)
• website: docs (e098f57)
• website: hotkeys help in admin text editor + render links/code/u/s/i marks (293bbb7)
• website: resolving paths in prod build (877698f)
• website: translation urls (f1ef954)
• workflow: ensure stopwatch context is correctly set and tracked (b9e528c)
• workflow: make stopwatch required, normalize frame name (0168db0)

Features

• rpc: allow configuring baseUrl callback in RpcHttpFetch (2f0f55d)
• website: add translations (chinese, korean, japanese, german) (4ab7058)
• website: page SSR and better responsive design for mobile (586f2a5)