---
name: "crun-fast-oci-runtime-c"
description: "Run low-memory, sub-millisecond container start times with C-based crun OCI runtime."
metadata:
  author: "Containers"
  version: "1.0.0"
  runtime_compatibility:
    - "codex"
    - "claude-code"
    - "cursor"
    - "windsurf"
triggers:
  - "configure crun containerd"
  - "benchmark crun vs runc"
  - "run wasm container crun"
permissions:
  fs_read: true
  fs_write: "workspace"
  shell_exec: false
  net_access: false
---

# crun Fast Lightweight C-Based OCI Container Runtime

Deploys and tunes crun (C replacement for runc): configuring cgroups v2 resource limits, Wasm/WASI integration, reduced memory footprint per container, and configuring crun in containerd and CRI-O.

## When to Invoke
Invoke this skill whenever you need to:
- configure crun containerd
- benchmark crun vs runc
- run wasm container crun

## Execution SOP & Rules
1. Install crun binary: ensure compiled with libsystemd and libseccomp support.
2. Configure containerd /etc/containerd/config.toml runtime binary path: default_runtime_name = 'crun'.
3. Enable Wasm handlers with --with-wasmedge or --with-wasmtime configure flags.
4. Benchmark container creation latency: crun creates containers in ~15ms vs ~45ms for runc.

## Verification Checklist
- Run local linting, syntax validation, and type-checks before reporting completion.
- Ensure all created or modified files adhere to workspace boundaries and avoid uncommitted secrets.
- Verify tests or build commands exit cleanly with return code 0.