# networknt/light-4j

A fast, lightweight and more productive microservices framework

Repository: https://github.com/networknt/light-4j
Canonical: https://ross.abutalabs.com/products/light-4j
Language: Java
License: Apache-2.0
License Family: permissive
Topics: microservice, microservice-framework, openapi, swagger, consul, zookeeper, fast, lightweight, cloud, docker, cloud-native, java, java8, msa, java11, service-mesh
Last push: 2026-08-26T21:39:28+00:00

## Health v2 (maintenance only)
Score: 94/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 85, longevity 100
- inputs: {"age_days": 3645, "days_push": 7, "days_rel": 20, "gap_med": 71.5, "n_releases_24m": 13}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3671, forks 624 (observed 2026-08-28T04:08:13.542973+00:00)

## What it is
Light-4J is a fast, lightweight, cloud-native microservices framework for Java built on the Undertow HTTP core. It offers a small memory footprint and high throughput compared to heavier platforms like Spring Boot, with built-in cross-cutting concerns such as an embedded API gateway, OpenAPI support, and service discovery integrations.

## Use cases
- build high-throughput REST microservices in Java
- replace Spring Boot with a lighter, faster framework
- build cloud-native Java services for containers and Kubernetes
- embed an API gateway with security and rate limiting in a Java service
- generate and validate OpenAPI/Swagger specifications for Java APIs
- reduce memory footprint and production cost of Java backend services

## When to choose
- you need very low latency and high throughput in Java
- you want a small memory footprint to lower cloud costs
- you are building microservices for containerized/cloud-native deployment
- you prefer explicit control over cross-cutting concerns instead of Spring's magic
- you want OpenAPI-first design with built-in validation

## When to avoid
- your team is heavily invested in the Spring ecosystem and tooling
- you need a large ecosystem of third-party integrations and community plugins
- you prefer mainstream, widely-documented frameworks for hiring and onboarding
- you are building a simple monolith where a microservices framework is overkill

## Facets
- artifact type: framework
- maturity: active
- function: web-framework, api-framework, http-server, middleware, routing, api-gateway, microservices
- domain: microservices, backend, web-development, apis, cloud-computing
- platform: jvm, cloud, windows
- tags: undertow, openapi, cloud-native, spring-boot-alternative, service-mesh, high-performance, docker, linux, macos

## Member repositories
- networknt/light-4j (main) score 94

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:13.542973+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 2026-08-29T18:31:19.162274+00:00, confidence not recorded.
  - readme: https://github.com/networknt/light-4j (fetched 2026-08-28T04:08:13.542973+00:00, sha e1c8c4337ef3)
- Data as of 2026-08-30T08:39:29.467469+00:00.