SpinKube is an open-source project for running Spin (WebAssembly) applications natively on Kubernetes. Instead of wrapping each Wasm module in a container, it registers Wasm as a first-class workload type so the kubelet runs components directly on a Wasm runtime, cutting resource use and startup latency dramatically compared to container-based serverless stacks.
The stack has four main pieces. containerd-shim-spin is a containerd shim that executes Spin apps on Wasmtime when a pod’s runtime class targets it. The Spin Operator provides a SpinApp CRD so users can declare a Spin application as a Kubernetes resource. Runtime Class Manager (formerly KWasm) installs and configures the shim on each node. The Spin Plugin for kube streamlines building and deploying apps from a Spin project. Spin apps are distributed as OCI artifacts, so existing registries and image-signing workflows apply unchanged.
SpinKube was contributed by Fermyon, Microsoft, SUSE, and LiquidReply, and is a CNCF Sandbox project. It is useful for teams that want the density and cold-start profile of Wasm without abandoning Kubernetes as their control plane.
