Karpenter is an open-source node provisioner for Kubernetes. It watches for pods the Kubernetes scheduler cannot place, evaluates their requirements, launches nodes that fit them, and removes or consolidates nodes that are no longer needed. Configuration centres on a declarative NodePool resource with customisable defaults. In this way Karpenter can help limit the compute cost of a cluster. Implementations exist for AWS, Azure and GCP, among others. The project is an alternative to commercial Kubernetes node-optimisation services such as CAST AI or Spot Ocean.
Karpenter originated at AWS and moved at the end of 2023 to the kubernetes-sigs organisation as a subproject of Kubernetes SIG Autoscaling; the AWS provider implementation is maintained separately by AWS. Kubernetes is hosted by the CNCF, part of the Linux Foundation (US). The software is licensed under the Apache License 2.0 and you run it yourself in your cluster; the project offers no separate hosted service.