Builder API

Fluent, chainable keyboard construction with KeyboardBuilder. Supports validation hooks, button transforms, and programmatic row control.

Basic Usage

from pykeyboard import InlineButton, KeyboardBuilder

kb = (
    KeyboardBuilder()
    .add_button(InlineButton(text="Home", callback_data="home"))
    .add_button(InlineButton(text="Settings", callback_data="settings"))
    .new_row()
    .add_button(InlineButton(text="Help", callback_data="help"))
    .build_inline()
)

await message.reply("Menu:", reply_markup=kb)

Methods

Method	Returns	Description
`add_button(button)`	`self`	Add a button to the current row
`add_row(*buttons)`	`self`	Add a complete row of buttons
`new_row()`	`self`	Start a new row
`build_inline()`	`InlineKeyboard`	Build as inline keyboard
`build_reply(**kwargs)`	`ReplyKeyboard`	Build as reply keyboard
`add_pre_build_hook(fn)`	`self`	Hook called before build
`add_post_build_hook(fn)`	`self`	Hook called after build
`add_button_transform(fn)`	`self`	Transform applied to each button on build

Validation Hooks

def validate_no_empty(builder):
    """Reject keyboards with no buttons."""
    if not builder.rows:
        raise ValueError("Keyboard cannot be empty")

def add_prefix(button):
    """Add emoji prefix to all buttons."""
    button.text = "→ " + button.text
    return button

kb = (
    KeyboardBuilder()
    .add_pre_build_hook(validate_no_empty)
    .add_button_transform(add_prefix)
    .add_button(InlineButton(text="Click me", callback_data="x"))
    .build_inline()
)