dsh-image-viewer-pro

dsh-image-viewer-pro

A viewer for images inside a DeepSeek Harness conversation — not a close button with a picture behind it. Zoom, pan, rotate, a gallery, download, copy, a dialog you can drag, and open-with the apps already on the machine, in one layer. Wheel, drag, and rotate update on the compositor once per frame; the next image is decoded before it is shown, so a page turn does not flash at the wrong size. It replaces the stock preview that only offers Close.

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See it

The pictures below are the real viewer, opened on photographs made for this page. The GIF plays on GitHub; the MP4 link is the same take.

Zoom and pan. The wheel zooms around the pointer; dragging moves the picture.

zoom.mp4

Rotate. Each click turns 90°. The footer shows the angle.

rotate.mp4

Gallery. The side arrows and ← / → move through the images in the conversation. The new picture slides in from that side.

gallery.mp4

Move the dialog. Drag the title bar. The window stays inside the backdrop.

move.mp4

Copy and download. Copy writes a PNG and shows a toast; download saves the original.

actions.mp4

Why

The stock image preview in DSH 0.2.1-rc.2 only offers Close: no zoom, no pan, no rotate, no download, no switching between the images of one conversation. This plugin takes over content-image clicks in the capture phase and renders its own dialog — it does not depend on official slot contracts, so it stays working when image slots change.

The viewer improves looking; it cannot make an image appear. See Getting images into the conversation for prompt rules that get an agent to inline images in the first place.

Features

• Zoom — wheel zooms around the pointer. One mouse notch is about 12% and eases in over a few frames; trackpad ticks stay continuous. The footer shows − [percent] + and the percentage is editable (Enter applies, Esc reverts). A tap on ± matches one notch; holding ± zooms continuously (about one doubling every 0.7s). Keyboard + / - stays a 25% step. The scale stays within 5%–4000%.
• Pan — drag the canvas; double-click toggles fit ↔ actual size.
• Footer — the controls sit in three groups separated by hairlines: zoom, fit / 1:1, and rotate.
• Move the dialog — drag its title bar; the dialog stays inside the backdrop (never over the desktop's native title/menu bar) and is pulled back into bounds when the window is resized.
• Header info — the title row shows width × height | format | file size with values only; the format is uppercase (JPG/PNG/SVG/BMP/WEBP…) and the size switches between B, KB and MB (one decimal for KB/MB).
• Rotate — counterclockwise on the left, clockwise on the right, 90° per click, with the current angle centered between them.
• Download original — with progress; saves to the system downloads folder.
• Copy image — writes a PNG to the clipboard.
• Gallery — browse the other images in the same conversation with the round side arrows or ← / →; shows current / total. The incoming picture pushes in from the side you asked for and the previous one leaves the other way, about 420ms on the same curve as the dialog open. A second step settles the one already playing. Reduced motion still cuts straight across.
• Open — a local file uses a split button. The main face shows the default app's icon and opens the file with that app; the menu lists every associated app reported by session.workspacePathApplications (the default is marked) and ends with "Show file location". A remote http(s) image stays a new-tab button. blob: and data: sources hide it. Opening and revealing both go through the Host's session.openWorkspacePath.
• Native look — the backdrop covers the window content area (the app's own top toolbar included) but stops below the desktop frame's native title/menu bar on Windows (--dsh-frame-chrome-top), and the dialog moves only inside that area; both use DSH theme tokens, follow light/dark, and honour prefers-reduced-motion.

What it takes over

Only the click behaviour is intercepted: message content is not modified, no session data is written, and the page returns to normal after closing the dialog.

Getting images into the conversation

The viewer only improves looking. Whether an image appears at all is decided by what the agent emits: DSH renders Markdown images from the reply and image attachments from tool results, and this plugin takes over the click afterwards. Most agents summarise UI work in text ("the layout looks correct") and never inline a single picture — which is why the feature is easy to overlook.

Add the rules below to your global AGENTS.md, a project AGENTS.md, or the custom-instructions field. They are deliberately imperative: "inline every image" steers a model far more reliably than "you may attach screenshots".

Images always inline

## Images

- Any image you produce, find, or refer to (including screenshots) must be shown inline: `![description](<D:/absolute/path.png>)`.
- Show it without being asked. Never reply with only a file path or only a `present` file card — the image is part of the reply.
- Use an absolute path with forward slashes and wrap the destination in angle brackets. A relative path only resolves when the viewed session has a workspace root; otherwise it renders as a broken image.
- Download remote images into the workspace first, then inline the local file.
- Inline images only. Code, documents and spreadsheets follow the delivery rules of their own tools.

UI verification ends with a screenshot

## UI verification and screenshots

- Verify UI and interaction questions in a real session: open → snapshot/screenshot → operate → check Console/Network. Do not substitute reading source code or reasoning for verification.
- At the end of the verification, inline the key screenshots in the reply and state which step each one shows. Do not paste only paths.
- Save screenshots into the workspace and inline them with `![description](<D:/absolute/path.png>)`.
- Write local origins (`127.0.0.1`, `localhost`, any port) as inline code, never as clickable links, and note "open it in your system browser".

Why these constraints:

• DSH serves inline local images through an authenticated file route (GET /api/file?path=<absolute path>, mounted by its session media references). It accepts POSIX absolute paths and Windows drive-letter paths; DSH's own docs note that this route needs an HTTP(S) page, so desktop dsh-app: pages do not support it.
• Relative chat image paths only resolve when the viewed session has a workspace root, so absolute paths are the portable choice.
• Tool-result images (read_image, browser screenshots) already arrive as rendered attachments and are picked up as-is; the agent should still caption them instead of letting the picture speak for itself.

A quick way to test the whole chain: ask "screenshot it and inline it" for a page you can see. If the reply shows an image, click it — the viewer opens. If no image appears, check in order: Markdown syntax versus a bare path, an absolute path with forward slashes, and whether the file actually exists.

Shortcuts

Install

This is a plain-JavaScript DSH bundle (package.json declares dsh.bundle): nothing to build, no build-script approval, and a page refresh is enough (restart DSH once after the first install).

DSH plugin page

1. Open Plugins → Add plugin
2. Paste:

github:NingYuanLee/dsh-image-viewer-pro

3. Refresh or restart DSH when prompted.

CLI

Web profile (the one dsh web boots):

dsh plugin --profile web add github:NingYuanLee/dsh-image-viewer-pro

Desktop profile:

dsh plugin --profile desktop add github:NingYuanLee/dsh-image-viewer-pro

Use whatever profile you actually boot. A GitHub source install pulls the repository; this package has no prepare script, so pnpm never asks for allowBuilds.

Prebuilt Release tarball

dsh plugin --profile web add https://github.com/NingYuanLee/dsh-image-viewer-pro/releases/latest/download/dsh-image-viewer-pro.tgz

Uninstall

dsh plugin --profile web remove dsh-image-viewer-pro

Or disable / remove it from the Plugins page. Uninstalling restores the stock preview and never deletes sessions or images.

Compatibility

• Verified on DSH 0.2.1-rc.2 (Web GUI and desktop, both Web renderers).
• Declares engines.dsh: >=0.2.1-rc.2 <0.3.0-0 and engines.node: >=22.19.0, checked on install and profile boot.
• Uses the Host remote / remote.session services to open or reveal a local file. When those services are unavailable the action degrades to a notice and everything else keeps working.

Conformance with DSH plugin conventions

Checked against the official Packaging and installing plugins docs and the awesome-dsh-plugin listing requirements:

Development

git clone https://github.com/NingYuanLee/dsh-image-viewer-pro.git
cd dsh-image-viewer-pro
npm test

For local development, install the directory into a profile as a link: dependency; a page refresh reloads the client half (the first registration needs one restart).

Privacy

• No third-party requests, no access to model credentials.
• Download / copy only touch the current image. Opening or revealing a local file goes through DSH's Host-side capability.
• Interception only affects clicks: no message content is injected and no session record is modified.

Known limitations

• Icons, avatars and status images below 48px stay native (see the coverage table above).
• Remote cross-origin images are displayed by the browser directly; when their server does not allow CORS, download falls back to opening the image in a new tab and copy falls back to copying its URL.
• Icons are inline 16px SVG; the 1:1 glyph is dense at that size.
• Targets the DSH Web GUI and desktop client (same Web renderer).
• The gallery counts images currently rendered in the conversation scrollport; in extreme virtual-scrolling cases only mounted images can be browsed.

License

MIT © 2026 NingYuanLee