typedthe

Typedthe is a statically typed templating language and runtime designed for generating text-based outputs such as HTML, XML, and other markup from typed data sources. It emphasizes type safety in template expressions, aiming to catch mismatches between data models and templates at compile time rather than at render time. The language provides a component-based architecture with a small standard library of UI primitives and a compiler that targets JavaScript.

Typedthe originated as an open-source project in the late 2010s, with initial releases around 2018. It was developed by a community of contributors seeking to pair strong typing with templating to reduce runtime errors in front-end code. Over successive versions, it added features such as slots, conditional rendering, and iteration constructs, while preserving a minimal runtime.

Its type system describes data passed to templates via explicit type annotations. Template blocks can declare their input types, and expressions are checked against those types. The escaping behavior is built-in to prevent injection vulnerabilities. The compiler can emit plain JavaScript or optimized templates that minimize DOM manipulation.

Key features include a component model with props and slots, type-checked expressions, automatic escaping, reusability through partials, and interop with existing JavaScript modules. Projects can integrate typedthe with build tools and static site generators.

Reception has been mixed in the broader web tooling ecosystem: proponents highlight improved reliability and maintainability, while critics note a learning curve and potential friction when modeling highly dynamic data. It remains a niche option alongside other templating approaches.