TQ1 codec

TQ1 is an optional Node-only package for JSON-compatible snapshots and related data.

npm install @domstamp/tq1

import { encodeTq1, decodeTq1 } from '@domstamp/tq1';

const payload = encodeTq1(snapshot, {
  compressionLevel: 9,
  maxDepth: 512
});

const restored = decodeTq1(payload);

Encoding

TQ1 interns repeated strings into an envelope-level table, represents arrays and objects with tagged sequences, serializes the envelope as JSON, then applies deterministic gzip transport.

It rejects:

• cyclic graphs;
• NaN and infinite numbers;
• undefined, symbols, functions, and other non-JSON values;
• nesting deeper than the configured limit.

Compression level must be an integer from -1 through 9. Depth cannot exceed exported MAX_TQ1_DEPTH (1_024).

Defensive decoding

const value = decodeTq1(payload, {
  limits: {
    maxCompressedBytes: 8 * 1024 * 1024,
    maxExpandedBytes: 32 * 1024 * 1024,
    maxDepth: 256,
    maxStrings: 200_000,
    maxArrayLength: 1_000_000,
    maxObjectProperties: 1_000_000
  }
});

Defaults are intentionally generous for large snapshots:

Limit	Default
Compressed bytes	64 MiB
Expanded bytes	256 MiB
Depth	512
Strings	1,000,000
Array items	10,000,000
Object properties	10,000,000

Choose smaller limits at trust boundaries.

The decoder validates gzip output, envelope identity, version, tags, indices, duplicate object keys, scalar types, and structural limits. Object keys including __proto__ are reconstructed with own-property definitions and cannot mutate the output prototype.

Errors

Tq1Error.code is one of:

• INVALID_DATA
• LIMIT_EXCEEDED
• UNSUPPORTED_VERSION

TQ1 format version and Domstamp schema version are separate compatibility surfaces.