hermes-agent/tools/computer_use/schema.py
ddupont 413ee1a286 feat(computer-use): background focus-safe backend — set_value, structured windows, MIME detection
Extends the cua-driver computer-use backend to drive backgrounded macOS
windows without stealing keyboard or mouse focus from the foreground app.
All changes target the cua-driver MCP backend and the shared dispatcher.

## cua_backend.py

**Window-aware capture**: capture() now calls list_windows + get_window_state
instead of the removed capture tool. Prefers structuredContent.windows
(MCP 2024-11-05+ cua-driver) for zero-parse window enumeration; falls back
to regex-parsed text for older builds. Stores the selected (pid, window_id)
as sticky context so subsequent action calls do not need a redundant round-trip.

**Action routing**: click/scroll/type_text/key all carry the sticky pid
(and window_id for element-indexed clicks). type_text routes through
type_text_chars (individual key events) rather than AX attribute write --
WebKit AXTextFields reject attribute writes from backgrounded processes.

**Key parsing**: _parse_key_combo splits cmd+s-style strings into
(key, [modifiers]) and routes to hotkey (modifier present) or
press_key (bare key) -- cua-driver actual tool names.

**set_value method**: new set_value(value, element) calls the cua-driver
set_value MCP tool. For AXPopUpButton / HTML select in a backgrounded Safari,
AXPress opens the native macOS popup which closes immediately when the app is
non-frontmost; set_value AX-presses the matching child option directly
(no menu required, no focus steal).

**focus_app**: reimplemented as a pure window-selector (enumerates
list_windows, sets sticky pid/window_id) without ever raising the window
or stealing focus.

**list_apps**: fixed tool name from listApps to list_apps; handles plain-text
response via regex when structured data is absent.

**Structured-content extraction**: _extract_tool_result now surfaces
structuredContent from MCP results, enabling the list_windows window array
without text parsing.

**Helpers**: _parse_windows_from_text, _parse_elements_from_tree,
_split_tree_text, _parse_key_combo extracted as module-level functions.

## schema.py

Added set_value to the action enum with a description explaining when to
prefer it over click (select/popup elements, sliders, no focus steal).
Added value field for set_value payloads.

## tool.py

Routed set_value action through _dispatch to backend.set_value.
Added set_value to _DESTRUCTIVE_ACTIONS (approval-gated).
Fixed MIME-type detection in _capture_response: cua-driver may return
JPEG; detect from base64 magic bytes (/9j/ -> image/jpeg, else image/png)
rather than hardcoding image/png.

## agent/display.py + run_agent.py

Guard _detect_tool_failure and result-preview logic against non-string
function_result values: multimodal tool results (dicts with _multimodal=True)
are not string-sliceable; treat them as successes and fall back to str()
for length/preview.
2026-04-28 01:46:36 -07:00

191 lines
8.5 KiB
Python

"""Schema for the generic `computer_use` tool.
Model-agnostic. Any tool-calling model can drive this. Vision-capable models
should prefer `capture(mode='som')` then `click(element=N)` — much more
reliable than pixel coordinates. Pixel coordinates remain supported for
models that were trained on them (e.g. Claude's computer-use RL).
"""
from __future__ import annotations
from typing import Any, Dict
# One consolidated tool with an `action` discriminator. Keeps the schema
# compact and the per-turn token cost low.
COMPUTER_USE_SCHEMA: Dict[str, Any] = {
"name": "computer_use",
"description": (
"Drive the macOS desktop in the background — screenshots, mouse, "
"keyboard, scroll, drag — without stealing the user's cursor, "
"keyboard focus, or Space. Preferred workflow: call with "
"action='capture' (mode='som' gives numbered element overlays), "
"then click by `element` index for reliability. Pixel coordinates "
"are supported for models trained on them. Works on any window — "
"hidden, minimized, on another Space, or behind another app. "
"macOS only; requires cua-driver to be installed."
),
"parameters": {
"type": "object",
"properties": {
"action": {
"type": "string",
"enum": [
"capture",
"click",
"double_click",
"right_click",
"middle_click",
"drag",
"scroll",
"type",
"key",
"set_value",
"wait",
"list_apps",
"focus_app",
],
"description": (
"Which action to perform. `capture` is free (no side "
"effects). All other actions require approval unless "
"auto-approved. Use `set_value` for select/popup elements "
"and sliders — it selects the matching option directly "
"without opening the native menu (no focus steal)."
),
},
# ── capture ────────────────────────────────────────────
"mode": {
"type": "string",
"enum": ["som", "vision", "ax"],
"description": (
"Capture mode. `som` (default) is a screenshot with "
"numbered overlays on every interactable element plus "
"the AX tree — best for vision models, lets you click "
"by element index. `vision` is a plain screenshot. "
"`ax` is the accessibility tree only (no image; useful "
"for text-only models)."
),
},
"app": {
"type": "string",
"description": (
"Optional. Limit capture/action to a specific app "
"(by name, e.g. 'Safari', or bundle ID, "
"'com.apple.Safari'). If omitted, operates on the "
"frontmost app's window or the whole screen."
),
},
# ── click / drag / scroll targeting ────────────────────
"element": {
"type": "integer",
"description": (
"The 1-based SOM index returned by the last "
"`capture(mode='som')` call. Strongly preferred over "
"raw coordinates."
),
},
"coordinate": {
"type": "array",
"items": {"type": "integer"},
"minItems": 2,
"maxItems": 2,
"description": (
"Pixel coordinates [x, y] in logical screen space (as "
"returned by capture width/height). Only use this if "
"no element index is available."
),
},
"button": {
"type": "string",
"enum": ["left", "right", "middle"],
"description": "Mouse button. Defaults to left.",
},
"modifiers": {
"type": "array",
"items": {
"type": "string",
"enum": ["cmd", "shift", "option", "alt", "ctrl", "fn"],
},
"description": "Modifier keys held during the action.",
},
# ── drag ───────────────────────────────────────────────
"from_element": {"type": "integer",
"description": "Source element index (drag)."},
"to_element": {"type": "integer",
"description": "Target element index (drag)."},
"from_coordinate": {
"type": "array",
"items": {"type": "integer"},
"minItems": 2, "maxItems": 2,
"description": "Source [x,y] (drag; use when no element available).",
},
"to_coordinate": {
"type": "array",
"items": {"type": "integer"},
"minItems": 2, "maxItems": 2,
"description": "Target [x,y] (drag; use when no element available).",
},
# ── scroll ─────────────────────────────────────────────
"direction": {
"type": "string",
"enum": ["up", "down", "left", "right"],
"description": "Scroll direction.",
},
"amount": {
"type": "integer",
"description": "Scroll wheel ticks. Default 3.",
},
# ── set_value ──────────────────────────────────────────
"value": {
"type": "string",
"description": (
"For action='set_value': the value to set on the element. "
"For AXPopUpButton / select dropdowns, pass the option's "
"display label (e.g. 'Blue'). For sliders and other "
"AXValue-settable elements, pass the numeric or string value."
),
},
# ── type / key / wait ──────────────────────────────────
"text": {
"type": "string",
"description": "Text to type (respects the current layout).",
},
"keys": {
"type": "string",
"description": (
"Key combo, e.g. 'cmd+s', 'ctrl+alt+t', 'return', "
"'escape', 'tab'. Use '+' to combine."
),
},
"seconds": {
"type": "number",
"description": "Seconds to wait. Max 30.",
},
# ── focus_app ──────────────────────────────────────────
"raise_window": {
"type": "boolean",
"description": (
"Only for action='focus_app'. If true, brings the "
"window to front (DISRUPTS the user). Default false "
"— input is routed to the app without raising, "
"matching the background co-work model."
),
},
# ── return shape ───────────────────────────────────────
"capture_after": {
"type": "boolean",
"description": (
"If true, take a follow-up capture after the action "
"and include it in the response. Saves a round-trip "
"when you need to verify an action's effect."
),
},
},
"required": ["action"],
},
}
def get_computer_use_schema() -> Dict[str, Any]:
"""Return the generic OpenAI function-calling schema."""
return COMPUTER_USE_SCHEMA