Jac Plugins

What is a JAC Plugin?

JAC is a powerful language that can be extended with plugins. JAC plugins are Python packages that extend the functionality of JAC. You can create custom commands, functions, and modules that can be used in JAC scripts.

TLDR Checkout the examples in the JAC Plugin Examples directory.

How to Create a JAC Plugin?

Let's create a simple plugin that will add a new command to Jac CLI. The command will be called hello and will print Hello, World! to the console.

Step 1: Create a new directory for your plugin. I will call mine my_plugin.

mkdir my_plugin
cd my_plugin

Step 2: Install necessary dependencies. (It is recommended to use a virtual environment)

pip install poetry

Step 3: Create a new Python package.

poetry init
# Fill in the details
# for compatible python version, use 3.12

Step 4: Add necessary dependencies.

poetry add jaclang
poetry add pytest --group dev

Step 5: Create the necessary folders and files.

mkdir my_plugin # Use the name of your plugin. This is where the plugin code will go.
touch my_plugin/__init__.py
touch my_plugin/plugin.py

Step 6: Link your plugin to Jaclang. Open the pyproject.toml file and add the following lines before [build-system]

[tool.poetry.plugins."jac"]
"my_plugin" = "my_plugin.plugin:JacCmd"

Step 7: Implement the plugin. Open my_plugin/plugin.py and add the following code.

from jaclang.cli.cmdreg import cmd_registry
from jaclang.runtimelib.default import hookimpl

class JacCmd:
    """Jac CLI."""

    @staticmethod
    @hookimpl
    def create_cmd() -> None:
        """Creating Jac CLI cmds."""

        @cmd_registry.register
        def hello():
            """Prints Hello, World!"""
            print("Hello, World!")

Step 8: Install the plugin.

poetry install

Step 9: Run the plugin.

jac hello

You should see Hello, World! printed to the console.

That's it! You have created your first JAC plugin. You can now extend JAC with your own custom commands.

Next Steps

• Now you can publish your plugin to PyPI and share it with the world. Follow the Publishing Python Packages guide to learn how to publish your plugin.
• Don't forget to create a nice README and add some examples to help users understand how to use your plugin.

Note: For more examples, check out the JAC Plugin Examples

Check out the MTLLM Plugin for a more complex example. Where we have created a plugin that adds LLM functionality to JAC.

If you have any questions, feel free to ask in the Community Channel.