MakeCode extensions

Extensions are PXT’s dynamic/static library mechanism for extending a target, such as the pxt-micro:bit:


Here is an example of a simple extension that extends the pxt-microbit target so that the micro:bit can drive a NeoPixel strip:


To see how this extension is surfaced, visit and select the “Extensions” option from the gear menu. You will see the extension “neopixel” listed in the available options. If you click on it, a new block category named “Neopixel” will be added to the editor.

In this scenario, PXT dynamically loads the neopixel extensions directly from GitHub, compiles it and incorporates it into the web app. Extensions also can be bundled with a web app (the analog of static linking). For dynamically loaded extensions, targets can provide a white list of approved extensions (see pxtarget.json).

Authoring extensions

Editor extensions

Extensions may provide an optional editor extension. An editor extension is an HTML page that gets loaded inside an iFrame by the editor. It allows to interact with the project or access serial data via messages. These editor extensions are hosted on GitHub pages.