Installation

OpenAPI Code Generator is distributed as a .NET tool via NuGet under the package name Nikcio.OpenApiCodeGen.

Prerequisites

• .NET 10 SDK or later

Global Tool

Install as a global tool available anywhere on your system:

dotnet tool install --global Nikcio.OpenApiCodeGen

After installation, the openapi-codegen command is available globally:

openapi-codegen --version

Updating

dotnet tool update --global Nikcio.OpenApiCodeGen

Uninstalling

dotnet tool uninstall --global Nikcio.OpenApiCodeGen

Local Tool

Install as a local tool scoped to your repository. This is recommended for team projects to ensure consistent versions:

# Create a tool manifest (if you don't have one)
dotnet new tool-manifest

# Install the tool
dotnet tool install Nikcio.OpenApiCodeGen

When installed locally, run the tool with dotnet tool run:

dotnet tool run openapi-codegen petstore.yaml -o Models.cs

Or restore and use directly after dotnet tool restore:

dotnet tool restore
openapi-codegen petstore.yaml -o Models.cs

Try It in the Browser

No installation needed to evaluate the generator — paste a spec (or load one from a URL) into the Playground and generate C# code right on the page.