Message Dialogs

bs.alert() and bs.confirm() open modal windows for notifications and yes/no decisions. Both are one-liners — no setup required.

Usage

Alert

bs.alert() shows a message with an OK button. It returns None when the user dismisses it.

bs.alert("File saved successfully.", title="Done")

Customize the button label or add an icon:

bs.alert("Session expired.", ok_text="Sign in again", icon="exclamation-circle")

Alert sound

severity="warning" and severity="danger" ring the system bell by default. All other severities are silent. Override with sound=:

bs.alert("Low battery.", severity="warning")        # rings bell
bs.alert("File saved.", severity="success")         # silent
bs.alert("Background sync done.", sound=False)      # force silent
bs.alert("Critical failure!", sound=True)           # force bell

Confirm

bs.confirm() shows a question with Confirm and Cancel buttons. Returns True when the user confirms, False when they cancel or close the dialog.

if bs.confirm("Overwrite existing file?"):
    save_file()

For destructive actions, use confirm_role="danger" — the button turns red and is not focused by default, so Enter does not accidentally trigger it:

if bs.confirm(
    "Delete 3 items permanently?",
    title="Confirm Delete",
    confirm_text="Delete",
    confirm_role="danger",
    icon="trash",
):
    delete_items()

The severity= parameter auto-derives the confirm button color:

# danger severity → red Confirm button
bs.confirm("Remove all data?", severity="danger", confirm_text="Remove")

# warning severity → warning-tinted Confirm button
bs.confirm("This will close all tabs.", severity="warning")

See also

Input Dialogs — dialogs that collect text, numbers, dates, and list selections.

Dialog — Dialog class for fully custom layouts and button sets.

API

The complete reference for alert() and confirm() lives on the Dialogs API page. At a glance:

alert	Show a message dialog with an OK button.
confirm	Show a confirmation dialog.

Full Example

with bs.App(title="Message Dialogs", size=(680, 300), padding=20, gap=16) as app:

    # ── Alert ──────────────────────────────────────────────────────────────
    bs.Label("Alert", font="heading-sm")
    with bs.HStack(gap=8):
        bs.Button("Alert (info)",    on_click=lambda: bs.alert("File saved.", severity="info"))
        bs.Button("Alert (success)", on_click=lambda: bs.alert("Upload complete.", severity="success"))
        bs.Button("Alert (warning)", on_click=lambda: bs.alert("Disk space low.", severity="warning"))
        bs.Button("Alert (danger)",  on_click=lambda: bs.alert("Connection lost.", severity="danger"))

    bs.Separator(fill="x")

    # ── Confirm ────────────────────────────────────────────────────────────
    bs.Label("Confirm", font="heading-sm")
    with bs.HStack(gap=8):
        bs.Button("Confirm",           on_click=lambda: bs.confirm("Overwrite the existing file?"))
        bs.Button("Confirm (danger)",  on_click=lambda: bs.confirm(
            "Delete 3 items permanently?",
            title="Confirm Delete",
            confirm_text="Delete",
            severity="danger"
        ))
        bs.Button("Confirm (warning)", on_click=lambda: bs.confirm(
            "This will close all open tabs.",
            severity="warning",
        ))

app.run()