Hi Product Hunt. FlowPeek is a small macOS menu bar app that draws the Mermaid diagram you are already looking at, right where it sits. Like a lot of people here, I have been enjoying solving my own problems with tools like Claude Code and Codex lately, and this one came out of something that kept getting in my way. Diagrams arrive as source code all day now: in terminal output, in pull requests, in what an agent just printed. Reading them meant the same loop every time. Copy, switch windows, paste into mermaid.live, look, close. So I tried to fit the habit rather than replace it. You are already copying the source, so the copy is the trigger: copy it, double tap Option, and it draws. In a terminal it goes further and needs no copy at all, because FlowPeek reads the buffer through the accessibility API and puts a faint frame around each Mermaid block on screen. Option click opens it. In Finder, .mmd files preview with the space bar. A few things it deliberately does not do. Mermaid is bundled, so drawing a diagram makes no network request at all. The only permission it asks for is Accessibility, not Screen Recording and not Input Monitoring. Nothing it reads is logged, and only diagrams it actually drew are kept, in a searchable shelf you can cap or switch off. It is free and MIT licensed, macOS 14 or later. Supported terminals today are Terminal.app, iTerm2 and Ghostty; if yours is missing, please open an issue and I will look into it seriously.

FlowPeek

Preview Mermaid diagrams where they already are

Preview Mermaid diagrams where they already are