# immutables/immutables

Java annotation processor to create immutable objects and builders, for records too. Sweep boilerplate code under the rug!

Repository: https://github.com/immutables/immutables
Canonical: https://ross.abutalabs.com/products/immutables
Homepage: http://immutables.org
Language: Java
License: Apache-2.0
License Family: permissive
Topics: java, annotation-processor, jackson, gson, immutable-objects, guava, builder, immutables, immutable-datastructures, immutable-collections, records
Last push: 2026-07-31T22:02:56+00:00

## Health v2 (maintenance only)
Score: 92/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 95, release rhythm 84, longevity 100
- inputs: {"age_days": 4805, "days_push": 33, "days_rel": 108, "gap_med": 18.0, "n_releases_24m": 11}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3570, forks 295 (observed 2026-08-28T04:08:10.657221+00:00)

## What it is
A Java annotation processor that generates immutable value classes, builders, and copy-with methods from interfaces, abstract classes, and records. It eliminates boilerplate while supporting Jackson/Gson JSON integration and extensive customization via styles.

## Use cases
- generate builders for java records
- create immutable value objects in java
- reduce boilerplate for data classes
- generate immutable collections wrappers
- jackson serialization for immutable classes
- generate with* copy methods for value objects

## When to choose
- you want thread-safe immutable data types without hand-writing builders
- you need generated builders for records or abstract value types
- you want JSON (Jackson/Gson) support for immutable models
- you prefer annotation-processor codegen over runtime reflection

## When to avoid
- you use Kotlin or another language with built-in data classes
- you need mutable entities like JPA/Hibernate entities
- your build cannot tolerate annotation processing overhead

## Facets
- artifact type: library
- maturity: active
- function: serialization, developer-tools
- domain: developer-tools, programming-languages
- platform: jvm
- tags: annotation-processor, immutable-objects, builder-pattern, jackson, gson, java-records, boilerplate-reduction

## Member repositories
- immutables/immutables (main) score 92

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:10.657221+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 2026-08-29T18:34:07.622613+00:00, confidence not recorded.
  - readme: https://github.com/immutables/immutables (fetched 2026-08-28T04:08:10.657221+00:00, sha 97d907b028f3)
  - homepage: http://immutables.org (fetched 2026-08-29T09:27:41.112792+00:00, sha bc452f16efaf)
- Data as of 2026-08-30T08:39:29.467469+00:00.