# kubernetes-sigs/kubebuilder

Kubebuilder - SDK for building Kubernetes APIs using CRDs

Repository: https://github.com/kubernetes-sigs/kubebuilder
Canonical: https://ross.abutalabs.com/products/kubebuilder
Homepage: http://book.kubebuilder.io
Language: Go
License: Apache-2.0
License Family: permissive
Topics: k8s-sig-api-machinery
Last push: 2026-08-24T23:55:40+00:00

## Health v2 (maintenance only)
Score: 92/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 77, longevity 100
- inputs: {"age_days": 3094, "days_push": 9, "days_rel": 79, "gap_med": 31, "n_releases_24m": 20}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 9294, forks 1696 (observed 2026-08-28T04:10:30.407921+00:00)

## What it is
Kubebuilder is an SDK and scaffolding framework for building Kubernetes APIs and controllers in Go using custom resource definitions (CRDs). It generates project boilerplate on top of controller-runtime and controller-tools, following the canonical patterns used to build core Kubernetes APIs.

## Use cases
- scaffold a kubernetes operator in go
- create custom resource definitions and controllers
- build a kubernetes api extension
- generate webhook and controller boilerplate
- learn kubernetes api design patterns
- bootstrap a controller-runtime project

## When to choose
- you are writing Kubernetes operators or controllers in Go
- you want canonical, best-practice scaffolding for CRD-based APIs
- you want a plugin architecture and integration with controller-runtime

## When to avoid
- you only need to deploy apps to Kubernetes rather than extend its API
- you are building operators in non-Go languages without the plugin ecosystem
- you want a lightweight client library only - use client-go directly

## Facets
- artifact type: framework
- maturity: stable
- function: sdk, developer-tools, middleware
- domain: developer-tools, cloud-computing, infrastructure-as-code, apis
- platform: go, cli, cross-platform
- tags: kubernetes, crd, operator, controller-runtime, scaffolding, api-machinery, k8s-sig-api-machinery, code-generation

## Member repositories
- kubernetes-sigs/kubebuilder (main) score 92

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:10:30.407921+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 2026-08-29T17:22:32.348075+00:00, confidence not recorded.
  - readme: https://github.com/kubernetes-sigs/kubebuilder (fetched 2026-08-28T04:10:30.407921+00:00, sha 1ed20f461220)
  - homepage: http://book.kubebuilder.io (fetched 2026-08-29T08:22:36.665859+00:00, sha b4815eb0c200)
- Data as of 2026-08-30T08:39:29.467469+00:00.