@atcute/cbor

deterministic CBOR codec for AT Protocol.

npm install @atcute/cbor

this library implements DASL's DRISL format used by AT Protocol for encoding records and repository data.

usage

encoding

import { encode } from '@atcute/cbor';

const record = {
	$type: 'app.bsky.feed.post',
	createdAt: '2024-08-18T03:18:24.000Z',
	langs: ['en'],
	text: 'hello world!',
};

const cbor = encode(record);
// -> Uint8Array(90)

decoding

import { decode, decodeFirst } from '@atcute/cbor';

const record = decode(cborBytes);
// -> { $type: 'app.bsky.feed.post', ... }

// decode from a buffer containing multiple values
const [value, remainder] = decodeFirst(cborBytes);

notes

• undefined values are omitted from maps (making it easier to construct objects)
• bytes and CID links use lazy wrappers (BytesWrapper, CidLinkWrapper) compatible with atproto's lex-json format
• use toBytes/fromBytes and toCidLink/fromCidLink to convert between lex-json and raw types
• integers must be within JavaScript's safe integer range (no bigint support)

based on microcbor.