click-compose 2025.10.27

Composable Click callback utilities for building flexible CLI applications.

Composable Click callback utilities for building flexible CLI applications.

• Installation

• Quick Start

  • multi_callback

  • sequence_validator

• Documentation

Installation

$ pip install click-compose

Or with uv:

$ uv add click-compose

Quick Start

click-compose provides two main utilities for composing Click callbacks:

multi_callback

Combine multiple callbacks into a single callback that applies them in sequence:

import click
from click_compose import multi_callback

def validate_positive(ctx, param, value):
    if value <= 0:
        raise click.BadParameter("Must be positive")
    return value

def validate_max_100(ctx, param, value):
    if value > 100:
        raise click.BadParameter("Must be <= 100")
    return value

@click.command()
@click.option(
    "--count",
    type=int,
    callback=multi_callback([validate_positive, validate_max_100]),
)
def cmd(count):
    click.echo(f"Count: {count}")

sequence_validator

Apply a validator to each element in a sequence (useful with multiple=True):

import click
from click_compose import sequence_validator

def validate_positive(ctx, param, value):
    if value <= 0:
        raise click.BadParameter("Must be positive")
    return value

@click.command()
@click.option(
    "--numbers",
    multiple=True,
    type=int,
    callback=sequence_validator(validate_positive),
)
def cmd(numbers):
    click.echo(f"Sum: {sum(numbers)}")

Documentation

See the full documentation.