What is mdx-tsc?

mdx-tsc brings type checking to MDX files, which are documents that mix regular Markdown text with embedded React components. Normal TypeScript tooling checks JavaScript and TypeScript code but does not understand MDX, so this project fills that gap. It works like the standard TypeScript compiler's command line tool, but for MDX, and it also ships a language server and a Visual Studio Code extension so problems show up directly in the editor. This repository is a monorepo containing three packages. The core one, called mdx-tsc, provides the command line tool and the language server, and is the place to start for anyone wanting to learn how to use it. The second package is the VS Code extension, which adds type and frontmatter warnings on top of the official MDX extension rather than replacing it, so both are meant to be installed together. The third package is a small playground project meant for trying the tool out inside an editor. The full usage documentation, including command line options, frontmatter schema details, and how to set up the editor, lives in the core package's own README rather than this top level one. To work on the project itself, you install dependencies and can build every package, run the test suite, lint the code, or format it, all through simple commands. To try the VS Code extension while developing, you can launch a special debug session that builds everything and opens the playground project in a separate development instance of the editor. Releases are done by hand rather than through an automated pipeline. Only the core mdx-tsc package is published to npm, versioned using a tool called changesets that tracks changes and bumps version numbers, while the VS Code extension is packaged into a file and uploaded to the Marketplace manually. The playground package stays private and is never published. The project is released under the MIT license, which allows free use, modification, and distribution, including for commercial purposes, as long as the original copyright notice is kept.