# msgpack/msgpack

MessagePack is an extremely efficient object serialization library. It's like JSON, but very fast and small.

Repository: https://github.com/msgpack/msgpack
Canonical: https://ross.abutalabs.com/products/msgpack
Homepage: http://msgpack.org/
License Family: other
Last push: 2024-08-10T11:11:44+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 6012, "days_push": 753, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 7494, forks 528 (observed 2026-08-28T04:10:00.318385+00:00)

## What it is
MessagePack is an efficient binary object serialization format, like JSON but faster and more compact. This repository hosts the format specification; implementations exist in over 50 languages in separate repositories.

## Use cases
- serialize objects to a compact binary format instead of json
- exchange data between services written in different languages
- reduce message size for caching and message queues
- fast serialization for high-throughput data pipelines
- encode structured data for embedded or resource-constrained systems

## When to choose
- you need json-like semantics with much smaller payloads and faster encoding
- you need cross-language data exchange with broad implementation support
- you are building performance-sensitive caching, messaging, or logging systems

## When to avoid
- you need human-readable output or easy debugging in text form
- you need rich schemas or self-describing typed contracts like protobuf or avro
- you only serialize within a single language with a native format

## Facets
- artifact type: library
- maturity: stable
- function: serialization
- domain: developer-tools, apis
- platform: cross-platform
- tags: binary-format, json-alternative, specification, multi-language, data-engineering

## Member repositories
- msgpack/msgpack (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:10:00.318385+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:37:34.024203+00:00, confidence not recorded.
  - readme: https://github.com/msgpack/msgpack (fetched 2026-08-28T04:10:00.318385+00:00, sha 45971d5bc265)
  - homepage: http://msgpack.org/ (fetched 2026-08-29T08:33:15.638036+00:00, sha 190e0c81910b)
- Data as of 2026-08-30T08:39:29.467469+00:00.