Scrawl: Building a Tool for Humans and Agents

Fri, 26 Jun 2026 00:00:00 +0000

🎬 Also available as a blog walkthrough video with a narrated walkthrough.

TL;DR: I watched someone present across half a dozen apps, drawing on screen to make their points, and I wanted the same thing. Instead of spending an afternoon trialing tools, I built exactly what I wanted with an AI agent. The result is Scrawl, a tiny macOS overlay that lets you draw on top of any app. Then I did the part that interests me more: I gave it a second front door. Scrawl has a small loopback control API and a thin MCP wrapper, so an AI agent can operate it with the same calls a person makes through the toolbar. Two front doors, one shared core. In 2026 that is how I think tools should be built.

Disclaimer: I’m a solutions architect who builds things to understand them. This is a builder’s field report on a tool I wrote for my own use, not authoritative guidance on macOS development. Scrawl is a personal project. If I’ve got something wrong, tell me.

The Itch

I was watching a colleague present. They moved across slides, a browser, a terminal, and a diagram, and the whole time they were drawing on the screen to make a point. A circle here, an arrow there, an underline on the line that mattered. It made the talk easy to follow, and I wanted to be able to do the same thing.

schristoph.online

Scrawl: Building a Tool for Humans and Agents

The Itch