# helidon-io/helidon

Java libraries for writing microservices

Repository: https://github.com/helidon-io/helidon
Canonical: https://ross.abutalabs.com/products/helidon
Homepage: https://helidon.io
Language: Java
License: Apache-2.0
License Family: permissive
Topics: java, microservice-framework, microprofile, netty, reactive
Last push: 2026-08-26T20:37:26+00:00

## Health v2 (maintenance only)
Score: 99/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 98, longevity 100
- inputs: {"age_days": 2928, "days_push": 7, "days_rel": 15, "gap_med": 12.0, "n_releases_24m": 43}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3813, forks 610 (observed 2026-08-28T04:08:20.719273+00:00)

## What it is
Helidon is an open-source Java framework of libraries for writing cloud-native microservices, offering both a lightweight Helidon SE API and a MicroProfile/Jakarta EE-based Helidon MP flavor. Its WebServer is built on Java virtual threads, providing high-throughput request handling with simple blocking-style code, plus observability, security, and GraalVM native image support.

## Use cases
- build a lightweight REST microservice in Java
- write MicroProfile/JAX-RS services without an application server
- create high-concurrency HTTP services using virtual threads
- compile a Java microservice to a GraalVM native executable
- add health checks, metrics, and OpenTelemetry tracing to Java services
- build cloud-native Java apps deployable on Kubernetes

## When to choose
- you want a lightweight, fast Java microservices framework with few dependencies
- you prefer MicroProfile/Jakarta EE APIs like JAX-RS and CDI without a full app server
- you want virtual-thread-based, thread-per-request simplicity with reactive-level throughput
- you need built-in observability, fault tolerance, and Kubernetes-friendly deployment

## When to avoid
- your team works primarily in non-JVM languages
- you need a full application server with legacy Java EE features
- you rely on Helidon SE 3.x asynchronous APIs, which changed significantly in Helidon 4
- you want the largest ecosystem and community, where Spring Boot or Quarkus may fit better

## Facets
- artifact type: framework
- maturity: active
- function: web-framework, http-server, microservices, middleware, monitoring, security, configuration-management
- domain: microservices, backend, web-development, cloud-computing, developer-tools
- platform: jvm, cross-platform, cloud
- tags: virtual-threads, microprofile, netty, graalvm, cloud-native, rest, jax-rs, observability, docker, kubernetes

## Member repositories
- helidon-io/helidon (main) score 99

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:20.719273+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 2026-08-29T18:26:35.967651+00:00, confidence not recorded.
  - readme: https://github.com/helidon-io/helidon (fetched 2026-08-28T04:08:20.719273+00:00, sha a528cef2bd3b)
  - homepage: https://helidon.io (fetched 2026-08-29T09:21:36.052703+00:00, sha 8537dd4f456a)
  - site_page: https://helidon.io/docs/v4 (fetched 2026-08-29T09:21:36.062383+00:00, sha 461e9497e652)
  - site_page: https://helidon.io/docs/v4/get-started (fetched 2026-08-29T09:21:36.064327+00:00, sha 2f1763733033)
  - site_page: https://helidon.io/docs/v4/se/introduction (fetched 2026-08-29T09:21:36.066047+00:00, sha 35ce815dc0be)
  - site_page: https://helidon.io/docs/v4/mp/introduction (fetched 2026-08-29T09:21:36.067595+00:00, sha 4723d5221cd0)
- Data as of 2026-08-30T08:39:29.467469+00:00.