# ninjaframework/ninja

Ninja is a full stack web framework for Java. Rock solid, fast and super productive.

Repository: https://github.com/ninjaframework/ninja
Canonical: https://ross.abutalabs.com/products/ninjaframework-ninja
Homepage: http://www.ninjaframework.org
Language: Java
License: Apache-2.0
License Family: permissive
Topics: java, webframework, restful, ninja, ninjaframework
Last push: 2026-04-03T18:40:39+00:00

## Health v2 (maintenance only)
Score: 66/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 75, release rhythm 35, longevity 100
- inputs: {"age_days": 5198, "days_push": 152, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1901, forks 509 (observed 2026-08-28T04:05:51.600011+00:00)

## What it is
Ninja is a full stack web framework for Java built on mature technologies like Servlets, Guice, JPA, Flyway, and Maven. It provides routing, controllers, Freemarker templating, JSON/XML rendering, validation, WebSockets, and a share-nothing architecture for easy horizontal scaling.

## Use cases
- build a restful json microservice in java
- java full stack web application framework
- serve html pages with freemarker templates in java
- build a json api with validation in java
- horizontally scalable stateless java web app
- websocket server in java
- crud web app with jpa and database migrations

## When to choose
- you want a batteries-included Java web framework on proven tech (Servlets, Guice, JPA)
- you need both server-rendered HTML and RESTful JSON APIs in one app
- you value stateless share-nothing scaling and simple deployment
- you prefer statically typed Java with strong IDE support

## When to avoid
- you need a framework with a large, fast-growing ecosystem and community (Spring Boot, Quarkus, Micronaut are more active)
- you want reactive or non-blocking I/O as the core model
- you need cutting-edge features or frequent releases - development pace is slow
- you prefer Kotlin or a non-Java JVM language with first-class support

## Facets
- artifact type: framework
- maturity: maintenance
- function: web-framework, routing, templating, middleware, websocket, json, orm, caching, form-handling, state-management
- domain: web-development, backend, apis, web-design
- platform: jvm, cross-platform
- tags: full-stack, restful, freemarker, guice, jpa, maven, servlet, microservices, share-nothing-scaling, web-server

## Member repositories
- ninjaframework/ninja (main) score 66

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:51.600011+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 2026-08-30T03:11:57.337869+00:00, confidence not recorded.
  - readme: https://github.com/ninjaframework/ninja (fetched 2026-08-28T04:05:51.600011+00:00, sha 5491344b138b)
  - homepage: http://www.ninjaframework.org (fetched 2026-08-29T10:51:15.815988+00:00, sha 6bda5f087536)
  - site_page: https://www.ninjaframework.org/documentation/getting_started/installing_ninja.html (fetched 2026-08-29T10:51:15.825200+00:00, sha 4573bc1ac670)
  - site_page: https://www.ninjaframework.org/documentation/basic_concepts/basic_concepts.html (fetched 2026-08-29T10:51:15.827216+00:00, sha f8139de97425)
  - site_page: https://www.ninjaframework.org/documentation/configuration_and_modes.html (fetched 2026-08-29T10:51:15.829657+00:00, sha 607d3210e398)
  - site_page: https://www.ninjaframework.org/documentation/html_templating/getting_started.html (fetched 2026-08-29T10:51:15.831781+00:00, sha 9fec997f7061)
  - site_page: https://www.ninjaframework.org/documentation/working_with_json_jsonp.html (fetched 2026-08-29T10:51:15.833385+00:00, sha fecbd367853a)
  - site_page: https://www.ninjaframework.org/documentation/working_with_xml.html (fetched 2026-08-29T10:51:15.835091+00:00, sha 2b2512a0d6b1)
  - site_page: https://www.ninjaframework.org/documentation/websockets.html (fetched 2026-08-29T10:51:15.836658+00:00, sha f44074aaae68)
  - site_page: https://www.ninjaframework.org/documentation/validation.html (fetched 2026-08-29T10:51:15.838441+00:00, sha f5d03b115aa2)
- Data as of 2026-08-30T08:39:29.467469+00:00.