What it is

docfx is a static site generator for .NET API documentation, and it lives in the .NET ecosystem. The project is written in C#, licensed under MIT, and published at dotnet.github.io/docfx. It is now a .NET Foundation project maintained by the community after Microsoft Learn stopped using it and ended support in November 2022. It builds technical documentation sites from landing pages, Markdown, .NET API reference docs, and REST API content.

The concrete problem it solves is the need to turn technical content, Markdown pages, and API documentation inputs into one browsable documentation site. Instead of manually assembling HTML pages, a team can define a docfx.json project file, run docfx build, and serve the generated site locally for review. The generated output is static, which is what a static site generator produces.

Key capabilities

• It generates static documentation sites from Markdown content and landing pages.
• It produces .NET API reference documentation from code, as indicated by its api, csharp, and dotnet topics.
• It supports REST API documentation, as listed in the README description.
• It uses a docfx.json project file to control the build of a documentation site.
• It includes templates that can be built with npm in the templates directory.
• It publishes nightly builds to GitHub Packages for users who need current development changes.
• It provides a local preview workflow through the --serve option and a localhost URL.

Who uses it and how

• .NET library maintainers use docfx to publish API reference documentation for .NET packages and projects.
• Documentation teams use it to combine Markdown landing pages with generated API references in one static site.
• Contributors use it locally by installing the global tool, initializing a sample project, building it, and serving it for review.
• People who modify docfx itself use Visual Studio, .NET SDK 8.x or 9.x, NodeJS 24.x, npm template builds, and dotnet test.
• Community users follow milestones, open discussions, file issues, and contribute through pull requests or help-wanted issues.

Getting started

Install docfx as a global .NET tool with dotnet tool install -g docfx, create a sample site with docfx init -y, then build and serve it with docfx build docfx_project\docfx.json --serve. Nightly builds are available from GitHub Packages, and stable releases are published through GitHub Releases.

When to use it — and when not to

Use docfx when you need a .NET-centered static documentation site and can accept community-driven maintenance after Microsoft Learn stopped using it and ended support in November 2022. Avoid it when you need a supported documentation publishing pipeline, a guaranteed release cadence, or a hosted service, because releases arrive only when maintainers see enough changes. The project description does not mention database, storage, SMTP, or hosting services, so self-hosters must operate the generator, templates, and the web host they choose.