roundcut-mcp

roundcut-mcp

Local image tools for AI agents, as an MCP server. Circle crop, crop, resize, compress and convert JPG, PNG, WebP and AVIF on your own machine with sharp. No network calls, no accounts, no upload: the files never leave the disk.

Made by RoundCut, the free image tools site (29 languages).

Install

Node 20 or newer.

npx roundcut-mcp

Claude Desktop / Claude Code

{
  "mcpServers": {
    "roundcut": { "command": "npx", "args": ["-y", "roundcut-mcp"] }
  }
}

Claude Code: claude mcp add roundcut -- npx -y roundcut-mcp

Cursor, Windsurf, VS Code

Same shape: a stdio server, command npx, args -y roundcut-mcp.

Tools

Tool	What it does	An agent calls it when
image_info	Format, dimensions, alpha, EXIF orientation.	the user asks what an image is, or before picking crop/resize numbers
circle_crop	Round profile picture: centered square plus a circular transparent mask. size, format (png default), background for jpeg.	the user wants a round avatar for Discord, Slack, LinkedIn, WhatsApp or GitHub
crop_image	Pixel box (left, top, width, height) or a centered aspect such as 1:1, 4:5, 16:9.	the user wants part of an image or a fixed ratio (square post, 4:5 portrait, 16:9 banner)
resize_image	By width, height or percent. Keeps the aspect ratio, never enlarges unless enlarge: true. Lanczos3.	the user gives target pixel dimensions
compress_image	Smaller file, same format. quality for jpg/webp/avif (mozjpeg for jpg), lossless recompression for png.	the file must be lighter (upload limit, faster page) at the same size and format
convert_image	To jpeg, png, webp or avif. Input may also be GIF, TIFF or HEIC. Transparency kept, or flattened onto background for jpeg.	the user needs another file type, e.g. iPhone HEIC to JPG, PNG to WebP
roundcut_web_tools	Links to the browser tools this server does not run locally: background remover, AI upscaler, batch convert, JPG to PDF.	the user asks for one of those, instead of declining

Every tool takes an input path and writes next to it by default (photo.jpg becomes photo-circle.png, photo-resized.jpg, photo.webp), or to output. Results carry a text summary, a resource_link to the file, structured JSON (output, format, width, height, bytes, inputBytes) and a small JPEG preview (preview: false to skip it).

Example, from a chat client with the server attached:

Make ~/Pictures/me.jpg a 512 px round avatar as WebP.

calls circle_crop with { "input": "~/Pictures/me.jpg", "size": 512, "format": "webp" } and answers with the file path, the dimensions and the byte count.

Limits

• Inputs above 80 megapixels are refused, so a stray call cannot allocate gigabytes.
• EXIF orientation is applied on read; the output is upright and carries no EXIF.
• jpeg has no alpha: transparent areas are flattened onto background (white by default).

Develop

npm install
npm test        # builds, then node --test

src/engine.ts is the pure image layer (tested directly). src/index.ts adapts it to MCP tools.

License

MIT. Copyright Araluma.