Installation

dotnet tool install -g Nullean.Curb
		

Installs the curb command globally. Requires the .NET 10 SDK. After this, curb format ./src and curb check ./src work from any directory.

The tool ships as a native-AOT binary per platform — about 11 MB, about 10 ms to start — with a portable managed fallback for platforms not in the list.

Supported platforms:

To update:

dotnet tool update -g Nullean.Curb
		

<PackageReference Include="curb" Version="*" PrivateAssets="all" />
		

Add this to your Directory.Build.props (or directly to a project file) and dotnet build will format your source before compiling it. The package is build-only — nothing lands in your output assemblies.

The package bundles a framework-dependent build of the CLI. To use the native binary instead, which starts roughly 100× faster:

<PropertyGroup>
  <Curb_Exe>$(HOME)/.dotnet/tools/curb</Curb_Exe>
</PropertyGroup>
		

See The build integration for all properties, diagnostics and incremental-build behaviour.

Download the binary for your platform from the GitHub releases page and put it on PATH. No SDK required to run it — only to install it via dotnet tool.

- uses: nullean/curb@main
  with:
    path: .
    command: check      # default; or "format" to rewrite in place
		

1. default; a file or directory

Runs curb from a pre-built, distroless container (ghcr.io/nullean/curb) — no .NET SDK install needed in the workflow. command: check fails the job if anything would be reformatted; switch to format to rewrite files instead. Extra flags pass through verbatim via args:

- uses: nullean/curb@main
  with:
    command: check
    args: --cache /tmp/curb.cache
		

Linux runners only (ubuntu-latest and similar) — container actions can't run on Windows or macOS runners.

ghcr.io/nullean/curb also works as a general-purpose container, outside GitHub Actions — GitLab CI, a local machine without the .NET SDK, anywhere docker run works:

docker run --rm -v "$(pwd)":/workspace ghcr.io/nullean/curb:edge check /workspace
		

Distroless: native-AOT, chiseled runtime-deps base, no shell, ~53 MB, runs as a non-root user. Tags follow curb's own releases — edge tracks the latest commit on main, latest and a semver tag (e.g. 0.6.0) follow tagged releases.

curb --version
		

curb check ./src
		

On a repository already formatted by the IDE, the check should report no changes.