Jac Extension
This extension provides support for the Jac programming language. It provides syntax highlighting and leverages the LSP to provide a rich editing experience.
Quick Start
All that is needed is to have jac installed (i.e. pip install jaclang) and the jac command line tool present in your environment.
Installation
For VS Code users:
- Open VS Code
- Go to Extensions (Ctrl+Shift+X or Cmd+Shift+X on Mac)
- Search for "Jac" in the marketplace
- Install the official "Jac" extension by JaseciLabs
Alternatively, install directly from the VS Code marketplace.
For Cursor users:
- Go to the latest Jaseci release page
- Download the latest
jaclang-extension-*.vsix file from the release assets
- Open Cursor
- Press
Ctrl+Shift+P (or Cmd+Shift+P on Mac)
- Type
>install from vsix and select the command
- Select the downloaded VSIX file
- The extension will be installed and ready to use
Debugging Jaclang
Note that it'll install python extention for vscode as a dependecy as it is needed to debug the python bytecode that jaclang produce.
To debug a jac file a launch.json file needs to created with the debug configurations. This can simply generated with:
- Goto the debug options at the left pannel.
- click "create a launch.json file"
- Select
Jac Debug Option
This will create a debug configration to run and debug a single jac file, Here is the default sinppit, modify it as your
preference to debug different types of applications or modules.
{
"version": "0.2.0",
"configurations": [
{
"type": "debugpy",
"request": "launch",
"name": "Run a jac file",
"program": "${command:extension.jaclang-extension.getJacPath}",
"args": "run ${file}"
}
]
}
This animated GIF bellow will demonstrate on the steps discuessed above.

To visualize the Jac graph while debugging, open the graph visualize view using the command jacvis: Visualize Jac Graph in the command palette, (shortcut for command palette is ctrl+shift+p)
Features
- Code completion
- Syntax highlighting
- Snippets
- Go to definition
- Document symbols, workspace symbols
- Variables hint, and documentation on hover
- Diagnostics
- Diagnostics