dsh-plugin-screenshot-tool

A WeChat-style screenshot button for the DeepSeek Harness Web UI. It sits in the composer's tool row, captures a region of the macOS screen with the native crosshair, puts the PNG on the clipboard and inserts it into the composer as a draft attachment — ready to send.

输入框工具栏里的微信式截图插件：原生框选屏幕区域，图片自动进剪贴板并直接放入输入框，按 Enter 即可发送。

Features

• Resident split button in the composer tool row: click the scissors to capture, click the caret to pick a capture mode (hidden window / visible window). The choice is remembered.
• Native region capture — macOS screencapture -i: drag to select, press Space to switch to window mode, Esc to cancel. No browser screen-share picker.
• Hidden-window mode (default): the Harness window is hidden while you select and restored afterwards, even on cancel, timeout or failure.
• Clipboard + composer attachment: the result is copied to the clipboard and a synthetic paste places the PNG into the composer draft. If no composer editor is present, the clipboard copy is the fallback.
• Screen Recording preflight: reads the macOS TCC database first. When capture is not allowed, the tool refuses instead of returning a wallpaper-only image, and offers a button that opens the Screen Recording settings pane.
• Light/dark aware: chrome colors use the host's --dsw-alias-* theme tokens only. UI text is localized (English and Simplified Chinese) through the Client locale service.

Requirements

• macOS 13 or newer (native capture and window hiding are macOS-only).
• DeepSeek Harness >= 0.2.2-rc.1 (Web GUI).
• Screen Recording permission for the Harness application (System Settings → Privacy & Security → Screen Recording), then quit and reopen the app.
• Automation → System Events permission for the hidden-window mode (System Settings → Privacy & Security → Automation). The first hidden capture asks once; without it the capture still works, just with the window visible, and the result card says so.

In a plain dsh web host there is no application window to hide, so the hidden-window mode degrades to a normal capture.

Install

dsh plugin add dsh-plugin-screenshot-tool

Then reload the Web GUI once. Other ways to install it:

# straight from the repository (works even when a registry mirror lags behind)
dsh plugin add https://github.com/haonan108/dsh-plugin-screenshot-tool

# from a local checkout
dsh plugin add /absolute/path/to/dsh-plugin-screenshot-tool

Uninstall with dsh plugin remove dsh-plugin-screenshot-tool (or remove the bundle from the profile's patch layer) and reload the page.

Usage

1. Click the scissors in the composer's tool row. The Harness window hides and macOS shows its selection crosshair.
2. Drag the region to capture (Space toggles window mode, Esc cancels).
3. The window comes back, the PNG is on the clipboard, and the image appears in the composer as a draft attachment. Press Enter to send.
4. Choose 「隐藏窗口截图」/「不隐藏窗口截图」 (“capture with the window hidden” / “with the window visible”) from the caret menu. The last choice becomes the default for the next click.

Privacy and security

• The plugin is two halves: a Host half (index.js) that runs in the Harness process and a browser half (client.js) rendered in the Web UI. It adds no agent tools and no model-facing prompt text.
• The Host half registers four loopback-only routes under /screenshot-tool/api/: capture, permission, permission-settings and a diagnostics health/hello pair. All of them refuse requests whose Sec-Fetch-Site shows another site's page, and the capture route serializes one native selection at a time.
• Screen Recording state is read from the system TCC database (/Library/Application Support/com.apple.TCC/TCC.db), which is world-readable; the query is limited to the kTCCServiceScreenCapture rows for this application. Nothing else is read.
• Each capture is written to a temporary file under /tmp/dsh-screenshot-tool/, put on the clipboard with osascript, and then deleted. The Host never keeps the image.
• The hidden-window mode asks System Events to hide and re-show the Harness window by its process id; it does not click, type, or read other applications.

Package layout

File	Role
package.json	Bundle manifest: dsh.bundle.patch plus dsh.client for the browser half
cordis.patch.yml	Inserts the screenshot-tool loader row
index.js	Host half: capture, clipboard, permissions, window hide/restore, HTTP routes
client.js	Browser half: split button in conversation.input.left, dropdown and result card in shell.overlay
locale/en.json, locale/zh.json	Plugin Manager title and description
icon.svg	WeChat-style green scissors icon

Both halves are plain JavaScript with no build step; client.js is a module-loader bundle whose factory id equals the package name.

License

MIT — see LICENSE.