stablyai/orca · error · RuntimeError

unsupported mouse button: {button}

Error message

unsupported mouse button: {button}

What it means

Raised by click_at (runtime.py:832) when the lowercased button string is not one of the supported keys 'left', 'right', 'middle'. The buttons map (runtime.py:830) binds these to AT-SPI mouse press/release event codes (b1/b3/b2). Any other value — including typos or extra buttons — is rejected before any event is synthesized.

Source

Thrown at native/computer-use-linux/runtime.py:832

        parsed = float(value)
    except (TypeError, ValueError):
        raise RuntimeError(f"{name} must be a positive number")
    if not math.isfinite(parsed) or parsed <= 0:
        raise RuntimeError(f"{name} must be a positive number")
    return parsed


def require_non_empty_string(value, name):
    if value is None or str(value) == "":
        raise RuntimeError(f"{name} is required")
    return str(value)


def click_at(x, y, button, count, modifiers=None):
    button = (button or "left").lower()
    buttons = {"left": ("b1p", "b1r"), "right": ("b3p", "b3r"), "middle": ("b2p", "b2r")}
    if button not in buttons:
        raise RuntimeError(f"unsupported mouse button: {button}")
    parsed_count = require_positive_integer(1 if count is None else count, "click_count")
    modifier_keys = click_modifier_keys(modifiers)
    if modifier_keys:
        modified_click_at(x, y, button, parsed_count, modifier_keys)
        return
    down, up = buttons[button]
    for _ in range(parsed_count):
        Atspi.generate_mouse_event(round(x), round(y), "abs")
        Atspi.generate_mouse_event(round(x), round(y), down)
        time.sleep(0.03)
        Atspi.generate_mouse_event(round(x), round(y), up)


def click_modifier_keys(raw):
    if raw is None:
        return []
    aliases = {
        "ctrl": "ctrl", "control": "ctrl", "cmdorctrl": "ctrl", "commandorcontrol": "ctrl",

View on GitHub (pinned to 1136503c6a)

Solutions

1. Use only 'left', 'right', or 'middle' for mouse_button.
2. Leave mouse_button unset to default to 'left' (click_at defaults None/or-falsy to 'left' at runtime.py:829).
3. For back/forward semantics, use keyboard shortcuts (hotkey) instead, since this AT-SPI backend does not expose extra buttons.

Example fix

// before
{"tool":"click","mouse_button":"back"}
// after
{"tool":"click","mouse_button":"right"}

SUPPORTED_BUTTONS = {"left", "right", "middle"}
button = (raw_button or "left").lower()
if button not in SUPPORTED_BUTTONS:
    button = "left"
op = {"tool": "click", "mouse_button": button}

def is_supported_button(value) -> bool:
    return (value or "left").lower() in {"left", "right", "middle"}

try:
    run_operation(op)
except RuntimeError as e:
    if "unsupported mouse button" in str(e):
        op["mouse_button"] = "left"
    else:
        raise

When it happens

Trigger: Calling the 'click' tool with operation['mouse_button'] set to an unsupported value such as 'back', 'forward', 'fourth', 'LEFT' (case is handled), or a numeric like '4'. Note: when click_count is omitted and modifiers absent and the action is performable via accessibility, click_at may not be reached; but any modifier or multi-click fallback path enforces this.

Common situations: An agent tries 'back'/'forward' mouse buttons (unsupported on this backend); a caller sends an integer button index instead of a named string; a typo like 'lef'.

Related errors

• click modifiers require modifier keys only
• {name} must be a positive number
• {name} is required
• direction is required
• unsupported scroll direction: {direction}

AI-assisted analysis of stablyai/orca@1136503c6a (2026-08-12). Data as JSON: /api/errors/5e6eb88db5915309. Report an issue: GitHub.