Bezelbub

The apps

iPhone, iPad, and Mac

Drop in a screenshot or screen recording and Bezelbub auto-detects the matching device and composites the frame. On iPhone and iPad: import from Photos or Files, or frame from any app's share sheet. On the Mac: drag and drop, or paste with ⌘V.

Every screenshot on this page was framed by Bezelbub.

How it ships

The app, the CLI, and the MCP server

What it does

Drag, detect, frame

New: alpha-channel video

Transparent backgrounds for framed videos

bezelbub frame --input demo.mp4 --background transparent --webm
# → demo-framed.mov (HEVC alpha) + demo-framed.webm (VP9 alpha)

Automation

The headless CLI

The same framing engine as the app, with no GUI and no interactive prompts. Install it with Homebrew:

brew install cwooddgr/tap/bezelbub

# Frame a screenshot — the device is auto-detected from its pixel size
bezelbub frame --input shot.png                 # → shot-framed.png

# Frame a screen recording — audio preserved, MP4 out
bezelbub frame --input demo.mp4                 # → demo-framed.mp4

# Which devices fit this screenshot?
bezelbub devices --input shot.png --json

# Or specify everything explicitly
bezelbub frame --input shot.png --device iphone17pro \
               --color "Cosmic Orange" --orientation portrait \
               --background "#1D1D1F" --output-size 50% --json

It's designed for non-interactive, programmatic use:

The full flag reference, exit-code table, and a ready-made Claude Code skill live in the CLI documentation on GitHub. The engine itself ships as BezelbubKit, a UI-free Swift package you can embed in your own tools.

New: Model Context Protocol

The MCP server

Bezelbub ships an MCP server — @dgr_labs/bezelbub-mcp on npm, listed in the official MCP registry as io.github.cwooddgr/bezelbub-mcp — so Claude and other MCP clients can produce device mockups directly. It frames screen recordings as well as screenshots, including transparent export, and it runs locally as a native tool on your Mac rather than a cloud API, so recordings are never uploaded.

Setup

The server runs on macOS and drives the bezelbub CLI, so install that first:

brew install cwooddgr/tap/bezelbub

For Claude Code, one command:

claude mcp add bezelbub -- npx -y @dgr_labs/bezelbub-mcp

For Claude Desktop, add the server to claude_desktop_config.json (Claude menu › Settings… › Developer › Edit Config), then restart the app:

{
  "mcpServers": {
    "bezelbub": {
      "command": "npx",
      "args": ["-y", "@dgr_labs/bezelbub-mcp"]
    }
  }
}

Any other MCP client that speaks stdio works the same way: run npx -y @dgr_labs/bezelbub-mcp as the server command. Requires macOS 14+ and Node 18+.

Tools

What it looks like in use

Prompts like these become tool calls, and the framed files are written to disk:

"Frame ~/Desktop/shot.png in an iPhone bezel for the press kit."
"Which devices fit a 1206×2622 screenshot?"
"Take the screen recording in ~/Demos and make a transparent
 framed version I can put on the website, with a WebM copy."

That last request becomes a frame_video call:

{
  "input_path": "/Users/you/Demos/demo.mp4",
  "background": "transparent",
  "webm": true
}
// → {"kind": "video", "transparent": true,
//    "output": "/Users/you/Demos/demo-framed.mov",
//    "webm": "/Users/you/Demos/demo-framed.webm", ...}

Errors carry the CLI's suggestions — valid device ids, a device's color list, nearest screen sizes — enough for the agent to fix its next call without a human.

The bezel catalog

Supported devices

Every device comes in each color Apple ships it in, and the bezel art is the same art Apple publishes in its Design Resources.

Get Bezelbub

Free on the App Store for Mac, iPhone, and iPad. The CLI installs with Homebrew, and the MCP server with npm.

brew install cwooddgr/tap/bezelbub

On the blog: the introduction, the video framing release, the transparent video export, and the MCP server.