computer-user
Codex-style computer use for DeepSeek Harness (DSH): read the screen and drive the
mouse & keyboard — screenshot → analyze with [picturereader] → click/type/keypress/scroll/
drag → verify. Windows only.
computer_screenshot captures the whole virtual screen (multi-monitor, DPI-aware) to a
PNG file and returns its path — feed it straight into picturereader's image_scan /
image_ocr to "see" the screen with any text-only model.- 8 more
computer_* tools operate the mouse & keyboard through bundled PowerShell +
Win32 SendInput (no native modules, no compilation, works in the DSH/EAC host process).
- A settings card (「电脑操作 / Computer Use」) puts a mode dropdown up front —
disabled / read-only / manual approval (
/computer) / automatic — with the rest
collapsed under a default-closed 高级设置 / Advanced section.
- Fully local — no external API calls: screenshot (PowerShell), analysis
(picturereader local scan/OCR), input (Win32 SendInput). Nothing leaves the machine.
Read the workflow in skills/computer-use.md (locate the
target window first, then OCR inside the window, then click once and verify).
- Verified on DeepSeek Harness EAC desktop (same DSH host kernel as the web app).
中文说明见 README.zh.md。
Works with pure text-only models + picturereader
computer-user does not need a multimodal model or any external vision API. Any
pure text-only LLM (e.g. DeepSeek V4 Flash) can drive the desktop end-to-end:
computer_screenshot dumps the screen to a local PNG (no vision needed to capture).- picturereader turns that PNG into structured text the text-only model can read:
image_scan (layout/colors/regions), image_ocr (real text), image_sample
(texture), all local (Windows OCR / PaddleOCR / RapidOCR — no cloud).
- The model "sees" via those descriptions, calls
computer_click / computer_type /
… at the reported coordinates, then screenshots again to verify.
So the loop is: screenshot (computer-user) → understand (picturereader) → act
(computer-user) → verify (both) — entirely with text tokens and zero external APIs.
See skills/computer-use.md for the locate-window → in-window
OCR → click-once workflow.
Tools
| Tool | What it does |
|---|
computer_screenshot | Save full virtual-screen PNG (region/scale optional) → {path,width,height,virtual_offset,scale} |
computer_click | Click at [x,y] (click / right_click / double_click) |
computer_type | Type arbitrary UTF-16 text — CJK included — via SendInput Unicode |
computer_keypress | Key chord, e.g. ["ctrl","c"], ["alt","tab"]; letters/digits use virtual keys so shortcuts work |
computer_scroll | Wheel scroll at [x,y]: up / down / left / right, clicks notches |
computer_drag | Press → interpolate → release, optional hold_keys |
computer_move_mouse | Move cursor without clicking |
computer_wait | Sleep ms (let UI settle) |
computer_get_cursor_position | Read current cursor [x,y] |
Coordinates are pixels relative to the virtual-screen origin (all monitors combined;
computer_screenshot returns it as virtual_offset). SetProcessDPIAware keeps
coordinates aligned with physical pixels on scaled displays.
Install
npm install computer-user
or in the DSH profile:
dsh plugin --profile web add computer-user
Then restart DSH (or use the EAC settings → Plugins → Manage screen). The tools appear for
any session; the settings card appears under Settings → Computer Use.
Pair with picturereader (recommended)
computer_screenshot → path
picturereader image_scan / image_ocr <path> # look
computer_click / type / ... # act
computer_screenshot → image_compare # verify
Settings card
The settings card (「电脑操作 / Computer Use」) uses the DSH settings-panel design
language — bordered card groups, capsule buttons, 32px inputs, chevron selects,
rotating-chevron disclosure — and guards scope.load() for hosts without a load
surface (EAC desktop shells).
- Mode dropdown at the top of the card:
disabled — every computer_* tool refuses.readonly — only screenshot / cursor-read / wait are allowed.manual — side-effecting tools need the session approved first via the /computer
slash command (one approval unlocks the session for later turns).auto — the LLM freely calls all tools.
- AI may change mode itself checkbox (below the dropdown, not in Advanced):
off by default; when on, the AI can switch modes via
computer_set_mode — changes are
written to the same settings namespace, so the dropdown stays in sync both ways.
- 高级设置 / Advanced (collapsed by default): screenshot output dir, default scale,
typing interval, scroll units, Reject code-as-text output (output guard, default on),
debug logging.
Output guard is a host-side filter on the LLM stream: if the model writes a fake
tool-call / XML markup as conversation text (e.g. computer_click({…}) or <invoke …>
typed out instead of a real call), that chunk is stripped and replaced with a one-time
coaching note; outputting the exact same text a second time passes through unblocked.
Turn it off in Advanced when you intentionally want code snippets in replies.
Safety
- Locate the target window first (DPI-aware GetWindowRect — see
skills/computer-use.md); desktop icons/background confuse
both OCR and clicks. Only work inside the target window.
- Always
computer_screenshot first and analyze it (picturereader) before acting.
- Click once, screenshot to verify; never blind click repeatedly (many UIs toggle).
- Use
manual mode with the /computer command to keep a human in the loop.
- If injected input is silently dropped, check security software (some AV suites filter
simulated input).
Verification & known limits
node --test unit suite: 39/39 green (tool registration, gates, arg validation,
output guard).- Real-machine safe-window smoke (throwaway window + cmd.exe, never the user's apps):
screenshot PNG correct; cursor read/move round-trip exact; typing
hello 中文 123!
read back verbatim; keypress Home/End navigation + insert verified (HEADzzzTAIL);
double-click word selection, click-to-clear, drag selection all asserted via control state.
- Headless integration: both
computer_screenshot and computer_get_cursor_position
called successfully by the model inside a real dsh --profile headless session.
- Headless real-scenario: model autonomously executed a 5-step task
(screenshot → image_scan → type "hello" → screenshot → image_ocr) inside
dsh --profile headless, coordinating picturereader and computer-user tools.
OCR confirmed the typed text appeared on screen.
- Wheel verified: all 9 tools (screenshot / click / type / keypress / scroll / drag /
move_mouse / wait / get_cursor_position) fully end-to-end verified. Wheel scroll position
changed and MouseWheel events fired correctly. Note: always-on-top IME toolbars (e.g.
Sogou Input floating bar) or other overlay windows can absorb wheel events if the cursor
lands on them — move the cursor to a clear area first (same as any cursor-based input).
- EAC compatibility: loads side-by-side with picturereader in the same host; static scan of
all built-in plugins shows zero
computer_* / computer-user namespace collisions.
Development
src/capture.ps1 DPI-aware multi-monitor screenshot (System.Drawing)
src/input.ps1 SendInput mouse/keyboard backend
src/ps.js PowerShell runner (base64 JSON, timeout, abort)
src/tools.js the 9 computer_* tool definitions + enabled/confirm gates
src/config.js settings namespace schema
src/index.js plugin entry (register tools + settings, hot reload)
client.js Web settings card (ModuleLoader bundle, zh/en)
scripts/ real-machine smoke scripts (safe-window)
tests/ node:test unit tests
License
MIT
