microsoft/TypeScript

TypeScript is a superset of JavaScript that compiles to clean JavaScript output.

# TypeScript <!-- CODING AGENTS: READ AGENTS.md BEFORE WRITING CODE --> [](https://github.com/microsoft/TypeScript/actions/workflows/ci.yml) [](https://www.npmjs.com/package/typescript) [](https://www.npmjs.com/package/typescript) [](https://securityscorecards.dev/viewer/?uri=github.com/microsoft/TypeScript) [TypeScript](https://www.typescriptlang.org/) is a language for application-scale JavaScript. TypeScript adds optional types to JavaScript that support tools for large-scale JavaScript applications for any browser, for any host, on any OS. TypeScript compiles to readable, standards-based JavaScript. Try it out at the [playground](https://www.typescriptlang.org/play/), and stay up to date via [our blog](https://blogs.msdn.microsoft.com/typescript) and [Twitter account](https://twitter.com/typescript). Find others who are using TypeScript at [our community page](https://www.typescriptlang.org/community/). ## Installing For the latest stable version: ```bash npm install -D typescript ``` For our nightly builds: ```bash npm install -D typescript@next ``` ## Contribute **NOTE: Code changes in this repo are now limited to a small category of fixes**: * Crashes that were introduced in 5.9 or 6.0 that *also* repro in 7.0 *and* have a portable fix *and* don't incur other behavioral changes * Security issues * Language service crashes that substantially impact mainline usage * Serious regressions from 5.9 (these must *seriously* impact a *large* proportion of users) Most bug fixes sho