📢 DEPRECATION ANNOUNCEMENT: Polyglot Notebooks & .NET Interactive

[claudiaregio]

📢 DEPRECATION ANNOUNCEMENT: Polyglot Notebooks & .NET Interactive

The Polyglot Notebooks Extension will be deprecated March 27th, 2026.
.NET Interactive will be deprecated April 24th, 2026.

❓What This Means

• The Polyglot Notebooks extension will not be disabled or uninstalled from your VS Code.
• You can continue using the extension as is after its deprecation date if you don't uninstall it, but future VS Code updates may eventually break it.
• You can continue using .NET Interactive as a Jupyter kernel as is in other Jupyter frontends after its deprecation date if you don't uninstall it, but this may not work with future .NET SDK versions.
• No new features will be added to Polyglot Notebooks or .NET Interactive.
• Bugs for Polyglot Notebooks or .NET Interactive will not be fixed.
• Any security vulnerabilities reported for both Polyglot Notebooks and .NET Interactive before their respective deprecation dates will be addressed.
• Any security vulnerabilities reported for both Polyglot Notebooks and .NET Interactive after their respective deprecation dates will not be addressed.
• This repo will be archived April 24th, 2026.

✅ Recommended Action

1. Convert/migrate your existing notebooks.
   • If you were primarily working with C#: Use our newly introduced file-based apps! File-based apps let you build, run, and publish C# apps from a single C# file without creating a traditional project file. This makes file-based apps powerful for quick learning and experimenting just like Polyglot Notebooks! Follow your first tutorial here.
   • If you were primarily working with other languages: We recommend using the VS Code Jupyter extension with another Jupyter kernel of your choice for your notebook needs. It supports a wide range of languages and offers robust features for notebook development. You can file requests for new features or report bugs in their VS Code Jupyter GitHub Repo.
2. Uninstall the Polyglot Notebooks extension and/or uninstall .NET Interactive from your machine once you've migrated to another solution.

🙏 Thank You

We want to express our sincere gratitude to all the users who have supported and contributed to the Polyglot Notebooks Extension. Your feedback, bug reports, and feature requests have been invaluable in shaping the extension.

While Polyglot Notebooks and .NET Interactive may be deprecated, our mission to make C# development delightful and accessible continues in our flagship products; we're carrying that work forward through C# Dev Kit and the next generation of AI-powered coding experiences.

FAQ

Why are file-based apps being recommended for C# users?

We know notebooks are very unique and nothing can directly replace a notebook. However, for the use case we are continuing to invest in (a lightweight scratch pad for quick experiments, testing code, trying NuGet packages, etc.) file-based apps will provide that path going forward.

For all other scenarios where you may be using a notebook, using another Jupyter frontend and another kernel of your choice remains the recommended path.

What if I want to keep using C# or multiple languages in a notebook?

While we are stepping back from further investment in this area, both Polyglot Notebooks and .NET Interactive remain open-source. If there is a strong interest from the community, this is a great opportunity for new maintainers to fork the projects and evolve them further.

Other Questions?

If you have any questions, first please review the recently opened and recently closed to see if it has already been addressed. If it has not been addressed, please feel free to file a new issue and add the question label.