Image Previewer

An MCP (Model Context Protocol) server that previews base64-encoded images in a native GUI window using Slint.

Features

• Native GUI — Slint-based window, no Python or external runtime needed
• Window reuse — Same window updates in-place across multiple images
• Always-on-top — Optionally pin the preview window above other windows
• Show/hide — Toggle window visibility without losing state
• Format support — PNG, JPEG, WebP, GIF, TIFF, etc. (via sharp)

Requirements

• Node.js 18+

Installation

Claude Code

claude mcp add image-previewer -- npx mcp-image-previewer

Manual configuration

Add to your MCP client configuration:

{
  "mcpServers": {
    "image-previewer": {
      "command": "npx",
      "args": ["mcp-image-previewer"]
    }
  }
}

Tools

preview_image

Display a base64-encoded image in the viewer window.

Parameter	Type	Required	Description
data	string	Yes	Base64-encoded image data
mimeType	string	Yes	MIME type (e.g. image/png, image/jpeg)

show_window

Show or hide the preview window.

Parameter	Type	Required	Description
visible	boolean	Yes	true to show, false to hide

stay_on_top

Set whether the preview window stays on top of other windows (X11/Windows only).

Parameter	Type	Required	Description
enabled	boolean	Yes	true to enable, false to disable

Development

npm install
npm run build
npm start

License

MIT