SynthOS is an interactive shell experience powered by generative AI, featuring a user interface that is entirely AI-generated. Similar to a wiki, it organizes everything into pages, but with a twist: these pages are self-modifying and can transform into anything. Each page includes a chat panel and a content viewer. Entering a command into the chat panel prompts the configured Large Language Model (LLM) to completely rewrite the current page. The page can morph into anything—from providing answers to questions to becoming a tool that assists you with complex tasks. It supports the latest language models like Claude-Opus-4.5 and GPT-5.2.
SynthOS has access to tools in the form of APIs and scripts. Built-in APIs enable SynthOS to read and write objects to local storage or make additional generative AI calls. Scripts are user-defined extensions that allow SynthOS to perform local actions on your machine. You can add scripts that let SynthOS start a build, make a Git commit, or run a cURL command.
You can create anything you want from animations:
To games:
To developer tools:
SynthOS is like a wiki for apps. You can save the apps you create to your pages directory;
To get started using SynthOS you'll need to first install a recent version of Node.js. I use version 22.20.0 but any version >20 should work.
Open a terminal window and run the following commands:
npm install --global synthos
synthos startThis will install the CLI and start the SynthOS server running. This terminal window needs to stay open to keep the server running. You should see a message saying SynthOS's server is running on http://localhost:4242. You can open your browser to that link and you should land on the settings page.
When the server first runs it's going to show you a settings dialog. You'll need to pick the model you;d like to use and configure it with a developer key.
For Opus (recomended) you'll want to sign up for a developer account at Anthropics Developer Platform You can then generate an API key here. For GPT-5.2 you can sign up for an OpenAI Developer account and then generate an API key here
Once you've configured your model you will be then sent to the home page. You can then specify any thing you want to create and it will be rendered to the display port.
You can make as many changes as you want to the app and you have controlls above the chat box that let you save the app to the pages gallery, reset the view port, or navigate to the pages gallery:
Each saved page is as stand alone HTML page that can be found in a .synthos folder in the directory where you started the server, There are system pages which can't be deleted but you can save changes to them and SynthOS will use those over the defaults. If you wish to delete a page/app just delete it from your .synthos folder:
There are a set of pre-built application templates that give you a good starting point.
The [application] template is great for creating tools:
The [markdown] template has a rich built-in markdown viewer:
The [sidebar] template allows for rich content that's not markdown based:
The [split-application] template has two panes with a movable splitter:
One of the more powerful capabilities of SynthOS is that it has built in APIs for things like storage that you're apps can use to persist data. You can use the API Explorer to test the API's out:
You can also create custom scripts that your apps can invoke vi a scripts API:
