# msgpack/msgpack-java

MessagePack serializer implementation for Java / msgpack.org[Java]

Repository: https://github.com/msgpack/msgpack-java
Canonical: https://ross.abutalabs.com/products/msgpack-java
Homepage: http://msgpack.org/
Language: Java
License: Apache-2.0
License Family: permissive
Last push: 2026-08-21T17:58:30+00:00

## Health v2 (maintenance only)
Score: 84/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 98, release rhythm 58, longevity 100
- inputs: {"age_days": 5544, "days_push": 12, "days_rel": 122, "gap_med": 166, "n_releases_24m": 4}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1473, forks 322 (observed 2026-08-28T04:04:49.564955+00:00)

## What it is
MessagePack serializer implementation for the JVM, providing fast and compact binary serialization as an alternative to JSON. It supports all MessagePack types including the extension format and integrates with Jackson ObjectMapper for serializing Java objects.

## Use cases
- serialize Java objects to a compact binary format
- replace JSON with a faster and smaller wire format
- exchange data between Java and other languages using MessagePack
- serialize and deserialize POJOs via Jackson databind
- encode small integers and short strings efficiently
- build high-performance data pipelines on the JVM

## When to choose
- you need a fast, compact binary alternative to JSON in Java, Scala, or Kotlin
- you want Jackson-compatible serialization with MessagePack encoding
- you need cross-language data exchange using the MessagePack spec
- you need support for MessagePack extension types

## When to avoid
- you need human-readable serialization like JSON or YAML
- your project is not on the JVM
- you rely on the deprecated v06 template-based serialization API

## Facets
- artifact type: library
- maturity: stable
- function: serialization
- domain: developer-tools, apis
- platform: jvm, cross-platform
- tags: messagepack, binary-format, jackson-integration, maven, data-engineering

## Member repositories
- msgpack/msgpack-java (main) score 84

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:49.564955+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 2026-08-30T04:34:38.711204+00:00, confidence not recorded.
  - readme: https://github.com/msgpack/msgpack-java (fetched 2026-08-28T04:04:49.564955+00:00, sha 985da1837355)
  - homepage: http://msgpack.org/ (fetched 2026-08-29T11:42:10.015078+00:00, sha 190e0c81910b)
- Data as of 2026-08-30T08:39:29.467469+00:00.