# babyfish-ct/jimmer

The most advanced ORM of JVM, for both java & kotlin

Repository: https://github.com/babyfish-ct/jimmer
Canonical: https://ross.abutalabs.com/products/jimmer
Homepage: https://jimmer.org
Language: Java
License: Apache-2.0
License Family: permissive
Topics: data, immutable, immutable-collections, immutable-datastructures, java, fetch, jdbc, orm, draft, immer, cache, redis, caffine, redis-cache, kotlin, graphql, orm-framework, orm-library, orms
Last push: 2026-08-26T13:29:36+00:00

## Health v2 (maintenance only)
Score: 95/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 99, release rhythm 86, longevity 100
- inputs: {"age_days": 1583, "days_push": 7, "days_rel": 15, "gap_med": 3, "n_releases_24m": 94}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1662, forks 154 (observed 2026-08-28T04:05:18.665401+00:00)

## What it is
Jimmer is a modern ORM framework for the JVM supporting both Java and Kotlin, built around immutable entities and type-safe query DSLs. It reads and writes arbitrarily shaped object graphs as a whole, with built-in caching, DTO code generation, and GraphQL-style fetching.

## Use cases
- query relational databases with a type-safe DSL instead of raw SQL
- fetch nested object graphs without N+1 queries
- save complex object graphs with batched upserts
- generate DTOs and OpenAPI/TypeScript contracts at compile time
- add multi-layer caching with automatic cache consistency for entities
- serve GraphQL APIs backed by a relational database
- build Spring Boot backends with advanced SQL features like CTEs and recursive queries

## When to choose
- you want a modern, type-safe ORM on the JVM for Java or Kotlin
- your application reads and writes deeply nested object graphs
- you need built-in object/association caching with consistency maintenance
- you want compile-time DTO generation and GraphQL-style fetching

## When to avoid
- you need a traditional POJO-based ORM like JPA/Hibernate with existing entity mappings
- you work outside the JVM ecosystem
- you prefer hand-written SQL or lightweight query builders over a full ORM
- your project depends on libraries requiring mutable POJO entities

## Facets
- artifact type: framework
- maturity: active
- function: orm, database, caching, graphql, serialization
- domain: databases, backend, web-development, developer-tools
- platform: jvm, cross-platform
- tags: immutable-entities, type-safe-dsl, dto-language, graph-queries, spring-boot, jdbc, cache-consistency, no-n-plus-1, code-generation

## Member repositories
- babyfish-ct/jimmer (main) score 95

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:18.665401+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 2026-08-30T03:44:33.570911+00:00, confidence not recorded.
  - readme: https://github.com/babyfish-ct/jimmer (fetched 2026-08-28T04:05:18.665401+00:00, sha 0ac7b391ae7a)
  - homepage: https://jimmer.org (fetched 2026-08-29T11:16:47.093496+00:00, sha 0664caa30e05)
  - site_page: https://jimmer.org/releases (fetched 2026-08-29T11:16:47.102513+00:00, sha b855b4824564)
- Data as of 2026-08-30T08:39:29.467469+00:00.