# Webxdc User Guide ## Webxdc File Format - a **Webxdc app** is a **ZIP-file** with the extension `.xdc` - the ZIP-file must contain at least the file `index.html` - if the Webxdc app is started, `index.html` is opened in a restricted webview that allow accessing resources only from the ZIP-file ## Webxdc API Webxdc apps can do anything that is allowed in webviews - html, css, images, canvas, javascript and so on. There are some additional APIs available once `webxdc.js` is included (the file will be provided by the concrete implementations, no need to add `webxdc.js` to your ZIP-file): ``` Send

``` For a more advanved example, see https://github.com/r10s/webxdc-poll/ . ## Closing Remarks - older devices might not have the newest js features in their webview, you may want to transpile your code down to an older js version eg. with https://babeljs.io - there are tons of ideas for enhancements of the API and the file format, eg. in the future, we will may define icon- and manifest-files, allow to aggregate the state or add metadata.