# kubernetes-sigs/prometheus-adapter

An implementation of the custom.metrics.k8s.io API using Prometheus

Repository: https://github.com/kubernetes-sigs/prometheus-adapter
Canonical: https://ross.abutalabs.com/products/prometheus-adapter
Language: Go
License: Apache-2.0
License Family: permissive
Topics: k8s-sig-instrumentation
Last push: 2026-07-24T19:09:27+00:00

## Health v2 (maintenance only)
Score: 65/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 94, release rhythm 8, longevity 100
- inputs: {"age_days": 3403, "days_push": 40, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2090, forks 570 (observed 2026-08-28T04:06:12.284478+00:00)

## What it is
A Kubernetes API adapter that implements the custom.metrics.k8s.io, resource, and external metrics APIs backed by Prometheus queries. It enables Horizontal Pod Autoscalers and other Kubernetes components to scale based on arbitrary Prometheus metrics.

## Use cases
- autoscale kubernetes pods based on custom prometheus metrics
- implement custom.metrics.k8s.io api on a cluster running prometheus
- use external metrics from prometheus in hpa scaling rules
- replace metrics-server with prometheus-backed resource metrics
- query prometheus metrics through the kubernetes metrics api

## When to choose
- your cluster already runs prometheus and you need custom metrics for autoscaling
- you want HPA scaling based on application-level or external metrics
- you need a Kubernetes Metrics API implementation without running metrics-server

## When to avoid
- you don't use prometheus or have no metrics pipeline
- you only need basic CPU/memory metrics, which metrics-server handles more simply
- you need a general-purpose monitoring dashboard rather than a metrics API adapter

## Facets
- artifact type: service
- maturity: active
- function: monitoring, api-framework, middleware
- domain: monitoring, cloud-computing
- platform: go, self-hosted
- tags: prometheus, custom-metrics-api, horizontal-pod-autoscaler, kubernetes-metrics, autoscaling, devops, containers, kubernetes, docker

## Member repositories
- kubernetes-sigs/prometheus-adapter (main) score 65

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:12.284478+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 2026-08-30T02:55:36.484768+00:00, confidence not recorded.
  - readme: https://github.com/kubernetes-sigs/prometheus-adapter (fetched 2026-08-28T04:06:12.284478+00:00, sha 9d0d8e8c5b9e)
- Data as of 2026-08-30T08:39:29.467469+00:00.