C#

C# is fully supported.

The Stainless C# SDK generator creates idiomatic, type-safe C# client libraries from your OpenAPI specification.

Example repositories:

• anthropics/anthropic-sdk-csharp
• trycourier/courier-csharp
• ArcadeAI/arcade-dotnet

Configuration

To generate a C# SDK, add the csharp target to your Stainless configuration file:

targets:
  csharp:
    package_name: MyCompany.Client
    edition: csharp.2025-10-08

Common configuration options

targets:
  csharp:
    package_name: MyCompany.Client

    # Specify the edition
    edition: csharp.2025-10-08

    # Configure publishing
    publish:
      nuget: true

For a complete list of configuration options, see the C# target reference.

Strong named assemblies

Strong-named assemblies are a .NET mechanism to give assemblies a unique ID. This provides several benefits, including the ability to have your assembly installed in the global assembly cache.

Although strong-naming uses cryptographic signatures, it is not intended to be used as a security mechanism. Microsoft recommends adding your public and private keys to your repository which Stainless will automatically do for you.

To enable strong-named assemblies, you will need a base64-encoded assembly originator key and corresponding public key. You can generate these keys on a Linux or Mac system (or on WSL) using the following commands:

export TEMP_SNK=$(mktemp)
sn -k $TEMP_SNK
cat $TEMP_SNK | base64 -w 1000 # this is your base64-encoded assembly originator key
sn -tp $TEMP_SNK | grep -oE '^[0-9a-f]+$' | tr -d '\n'; echo # this is your public key
rm $TEMP_SNK # cleanup

Once you have your keys, add them to your Stainless config like so:

targets:
  csharp:
    ...
    strong_name:
      originator_key: foo # your base64-encoded assembly originator key
      public_key: bar # your public key

When you add those keys to your Stainless config, an Open.snk file will be added to your C# repository automatically, and strong-name signing will be enabled at build and publish time.

Editions

Editions allow Stainless to make improvements to SDKs that aren’t backwards-compatible. You can explicitly opt in to new editions when you’re ready. See the SDK and config editions reference for more information.

csharp.2025-10-08

• Initial edition for C# (used by default if no edition is specified)

Publishing to NuGet

Publish your C# SDK to NuGet for distribution.

Before publishing, you need to link a production repository where Stainless will push your SDK code.

Get an API token

1. Log in or sign up at NuGet.
2. Select your username at the top right to open a dropdown.
3. Navigate to API Keys.
4. Create a new API key with the Push new packages and package versions privilege. Under Select Packages, either enter your package name or a glob (e.g. ”*”).

Add the token to your production repo

1. In your production repo, navigate to Secrets and variables > Actions > New repository secret. The URL should look like https://github.com/<org>/<repo>/settings/secrets/actions/new.
2. Add a new secret named NUGET_API_KEY with your API token.

Choose a package name and update your Stainless config

1. Choose an available package name. Suggested names are:

   • <company-name>
   • <company-name>.Client

   You can check whether the name is available by testing the link at https://www.nuget.org/packages/<package-name>.

2. Update the Stainless config with your package name and save.

   targets:
     csharp:
       package_name: <package-name>
       publish:
         nuget: true