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Automatic CLI

Every project built with pyrig gets a working command-line interface for free. The CLI is a Typer application that assembles itself at startup, so you get a runnable entry point without wiring anything up — and you can extend it with your own commands.

The entry point

A project gets its CLI from a console script that points to pyrig-runtime's entry point. pyrig adds this for you, but it is just a normal script entry in pyproject.toml:

[project.scripts]
my-project = "pyrig_runtime.rig.cli.main:main"

Running the script builds the Typer application and dispatches the requested command. The invoking project is detected from the name of the script that launched it (my-project above); converted to snake_case (my_project), that name is where the project's own commands are loaded from.

-v / -q adjust logging verbosity. Something like -vv or -qqq or even -vqqvqvq are also possible.

Adding your own commands

Define commands in your project's my_project.rig.cli.subcommands module:

  • every function defined directly there becomes a top-level command;
  • every module-level typer.Typer instance becomes a command group, named after its variable in kebab-case.
# src/my_project/rig/cli/subcommands.py
def greet(name: str) -> None:
    """Greet someone."""
    print(f"hello {name}")

$ uv run my-project greet world
hello world

Customizing the build

The application is built by a CLI class, which is itself a discoverable plugin. Define a subclass in your project's my_project.rig.cli.cli module to override any step of the build — the most-derived subclass is used automatically.

Shared commands

A shared command is available in every project that depends on pyrig-runtime, not just the package that defines it. The built-in version command is one: it is defined by pyrig-runtime, so every dependent project has it:

$ uv run my-project version
my-project 1.2.3

You can add your own. Define shared commands in your project's my_project.rig.cli.shared_subcommands module:

# src/my_project/rig/cli/shared_subcommands.py
def version2() -> None:
    """Print the version a different way."""
    ...

Once my_project is installed in an environment, version2 is available from every project in that environment that depends on pyrig-runtime — including pyrig-runtime's own CLI and any other dependent project, not only my_project:

uv run pyrig-runtime version2
uv run otherproject version2

When two packages define a shared command with the same name, the one registered last (in dependency order) wins, so a dependent package can override a built-in. This is simply Typer's default behavior.

See also