Vellum

A tray-resident macOS screenshot helper. Capture a region or the full screen, extract the text, describe what's on screen, and chat about it — all running locally on your Mac.

100% Local

Runs Gemma 4 E4B on-device

Vision-capable open model running through llama.cpp. No API keys, no accounts, no data leaves your machine. Your screenshots and chats stay on your Mac.

Install

$curl -fsSL https://www.arunkant.com/vellum/install.sh | bash

Requirements

macOS on Apple Silicon (arm64). Intel Macs not supported yet.
~5 GB of free disk space for the local Gemma 4 model weights (downloaded on first launch).

How it works

Lives in the menu-bar tray — no dock icon.
⌘⇧1 for region capture, ⌘⇧2 for full screen.
Local vision model extracts text and describes what's on screen.
Chat about the capture; search across past screenshots and conversations.

Note: Vellum is not code-signed or notarized. The installer downloads the latest release from GitHub and removes the macOS quarantine flag so Gatekeeper allows it to launch. Inspect the install.sh source before running it if you'd like.