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# Extensions

## Overview

xonsh is an extensible, user-patchable platform: third-party developers can build and distribute their own extensions without going through the xonsh release cycle, and end users can reshape any subsystem directly from their xonsh RC because every part of xonsh is a Python module. In the xonsh ecosystem these extensions are called xontribs.

A xontrib can be:

- a set of aliases — plain strings, lists, or callable Python functions

- a tab-completer for a single command or a whole API

- a prompt field (e.g. battery, container, version-control, kubernetes)

- a handler for session events such as `on_chdir`, `on_postcommand`, or `on_pre_prompt`

- a new environment variable or `$XONSH_*` setting

- a full subsystem — syntax-highlighting tokens, a history backend, an integration with an external tool, and so on

## Search and Install Xontribs

Two good places to look for xontribs published by the community:

- Awesome xontribs — curated list of xontribs.

- GitHub xontrib topic — every repository tagged with the `xontrib` topic on GitHub.

## Listing Known Xontribs

The `xontrib` command allows you to list the installed xontribs. This command will report if they are loaded in the current session. To display this information, pass the `list` action to the `xontrib` command:

    @ xontrib list
    abbrevs             not-loaded          Expand command abbreviations while typing in the Xonsh shell.
    clp                 not-loaded          Copy output to clipboard. Cross-platform.
    cmd_done            not-loaded          Show long running commands durations in prompt with option to send notification when terminal is not focused.
    jedi                not-loaded          Use Jedi as xonsh's python completer.
    output_search       not-loaded          Get identifiers, paths, URLs and words from the previous command output and use them for the next command in xonsh shell
    pipeliner           not-loaded          Let your pipe lines flow thru the Python code in xonsh.
    prompt_starship     not-loaded          Starship cross-shell prompt in xonsh shell.
    sh                  not-loaded          Paste and run commands from bash, zsh, fish, tcsh in xonsh shell.

    @ xontrib info sh
    Name: sh
    Source: xontrib.sh at /Users/snail/.local/xonsh-env/lib/python3.14/site-packages/xontrib/sh.py
    Description: Paste and run commands from bash, zsh, fish, tcsh in xonsh shell.
    Loaded: no

For programmatic access, you may also have this command print a JSON formatted string:

    @ $(@json xontrib list --json)['abbrevs']
    {'name': 'abbrevs',
     'loaded': False,
     'auto': False,
     'module': 'xontrib.abbrevs',
     'description': 'Expand command abbreviations while typing in the Xonsh shell.'}

## Loading Xontribs

Xontribs may be loaded in a few different ways: from your xonsh RC, dynamically at runtime with the `xontrib` command, or its Python API.

Extensions are loaded via the `xontrib load` command. This command may be run from anywhere in your xonsh RC or at any point after xonsh has started up.

    xontrib load myext mpl mypkg.show

Pass `-s` (`--suppress-warnings`) to load every xontrib that is installed and silently skip any name that isn’t. Useful in a xonsh RC that is shared across machines where only a subset of xontribs is installed.

The same can be done in Python as well

    from xonsh.xontribs import xontribs_load
    xontribs_load(['myext', 'mpl', 'mypkg.show'])

A xontrib can be unloaded from the current session using `xontrib unload`

    xontrib unload myext mpl mypkg.show

Xontribs can use setuptools entrypoints to mark themselves available for autoloading using the below format.

    [options.entry_points]
    xonsh.xontribs =
        xontrib_name = path.to.the.module

Here the module should contain `_load_xontrib_` function as described above.

Note

Please make sure that importing the xontrib module and calling `_load_xontrib_` is fast enough. Otherwise it will affect the shell’s startup time. Any other imports or heavy computations should be done in lazy manner whenever possible.

## Authoring Xontribs

The fastest way to start a new xontrib is the xontrib-template repository — a ready-to-publish skeleton, packaging metadata, and the entry point pre-wired for autoloading.

## Structure

Xontribs are modules with some special functions written in either xonsh (`*.xsh`) or Python (`*.py`).

Here is a template:

    from xonsh.built_ins import XonshSession

    def _load_xontrib_(xsh: XonshSession, **kwargs) -> dict:
        """
        this function will be called when loading/reloading the xontrib.

        Args:
            xsh: the current xonsh session instance, serves as the interface to manipulate the session.
                 This allows you to register new aliases, history backends, event listeners ...
            **kwargs: it is empty as of now. Kept for future proofing.
        Returns:
            dict: this will get loaded into the current execution context
        """

    def _unload_xontrib_(xsh: XonshSession, **kwargs) -> dict:
        """If you want your extension to be unloadable, put that logic here"""

Warning

The xontrib must implement `_unload_xontrib_` itself. If this function is not provided, any registered event handlers, environment variables, aliases, and completers will remain active after `xontribs unload/reload`.

This _load_xontrib_() function is called after your extension is imported, and the currently active `xonsh.built_ins.XonshSession` instance is passed as the argument.

Note

Xontribs without `_load_xontrib_` are still supported. But when such xontrib is loaded, variables listed in `__all__` are placed in the current execution context if defined.

Normally, these are stored and found in an implicit namespace package called `xontrib`. However, xontribs may be placed in any package or directory that is on the `$PYTHONPATH`.

If a module is in the `xontrib` namespace package, it can be referred to just by its module name. If a module is in any other package, then it must be referred to by its full package path, separated by `.` like you would in an import statement. Of course, a module in `xontrib` may be referred to with the full `xontrib.myext`. But just calling it `myext` is a lot shorter and one of the main advantages of placing an extension in the `xontrib` namespace package.

Here is a sample file system layout and what the xontrib names would be:

    |- xontrib/
       |- javert.xsh     # "javert", because in xontrib
       |- your.py        # "your",
       |- eyes/
          |- __init__.py
          |- scream.xsh  # "eyes.scream", because eyes is in xontrib
    |- mypkg/
       |- __init__.py    # a regular package with an init file
       |- other.py       # not a xontrib
       |- show.py        # "mypkg.show", full module name
       |- tell.xsh       # "mypkg.tell", full module name
       |- subpkg/
          |- __init__.py
          |- done.py     # "mypkg.subpkg.done", full module name

You can also use the xontrib template to easily create the layout for your xontrib package.

## Tell Us About Your Xontrib!

To register a xontrib, create a `PullRequest` at awesome-xontribs repository. Also, if you use Github to host your code, please add xonsh and xontrib to the topics.

All of this let’s users know that your xontrib is out there, ready to be used. Of course, you’re under no obligation to register your xontrib. Users will still be able to load your xontrib, as long as they have it installed.

## See also

- Events – using events in xontribs

- Environment – registering environment variables for your xontrib

- Tab-Completion – writing custom completers

- Awesome-xontribs – registry of community xontribs

- Xontrib template – quickstart template