In preparation for Node.js stable to ship TypeScript stripping as an unflagged feature https://nodejs.org/api/typescript.html

We already provide support for TypeScript via tsx, documented here: https://www.11ty.dev/docs/languages/typescript/

Default Configuration File Names

• eleventy.config.ts
• eleventy.config.mts
• eleventy.config.cts

Default Data File Names

• *.11tydata.ts
• *.11tydata.mts
• *.11tydata.cts

Default TypeScript Template File Names

• *.11ty.ts
• *.11ty.mts
• *.11ty.cts

Dependency Tree Mapping

See https://github.com/11ty/eleventy-dependency-tree-esm and https://github.com/11ty/eleventy-dependency-tree for existing solutions.