This is a proof-of-concept of a SmallTalk like live coding system running in the browser, based on TypeScript. There’s no server side component at all (other than delivering static files). It’ll let you update your code in a built-in editor and it’ll hot-patch the running system so that your code starts working immediately, even if there are objects existing which currently running it.

Watch me talk about it!

Or use the version hosted on cowlark.com if you want to try it for real!


It’s an attempt to replicate the classic SmallTalk/Lisp paradigm which don’t distinguish between users and programmers: you can, if you wish, take the lid off the application suite you’re currently using and tinker with it, without recompilation, restarts, or even having to save your work.

Currently it’s a pile of fairly nasty hacks flying in loose formation, but it does actually work. Mostly.


It’s hosted on GitHub.


It uses the TypeScript LanguageServices API to do code transformation and compilation into Javascript. Your TypeScript is rewritten to match TypeTalk’s kinda weird object model, loaded, and methods are hot-patched into the objects already existing on the system.

There are limitations: TypeTalk ‘files’ may each contain a single class or interface, nothing else. So, type definitions, enums etc don’t work. You can’t have static initialisers. You can inherit from normal Javascript objects, but it’s dodgy as hell.

There’s no documentation other than this page.

To use, simply serve this directory in a web server and load the index.html page. No build stage is needed. The big files are deployed via CDN.

Please note that I developed it on Chrome, and it currently doesn’t work on Firefox; I don’t know why. Something to do with scoping and with{}, I think. TypeTalk’s code generation appears to cause Firefox’s debugger to go nuts which makes it very hard to debug.


Everything here except the contents of lib was written by me, David Given. Feel free to send me an email at dg@cowlark.com. You may also like to visit my website; there may or may not be something interesting there.

All of my stuff is © 2019 David Given and is open source software distributable under the terms of the Apache License.

The contents of lib contain TypeScript typings files, which are a mixture of Apache license or MIT depending whether they came from Microsoft or DefinitelyTyped. See the file headers for more information. Some of them have had tiny tweaks to remove namespace exports (as TypeTalk doesn’t use modules).

The backdrop is by jojo-ojoj from DeviantArt.