Oh My Mermaid

The oh-my-mermaid GitHub org publishes this plugin from a marketplace called oh-my-mermaid. We list it here because people look for a way to get architecture diagrams out of a codebase. We didn’t write it and haven’t reviewed it.

omm-scan gets your agent to read your project and write architecture docs as Mermaid diagrams into a .omm/ folder. It writes them as “perspectives,” which are different ways to look at the same code: overall structure, data flow, outside integrations, and more. It only picks the ones that fit your project. omm-view starts a web viewer so you can click through the diagrams in your browser.

Before you install, know three things.

First, each skill checks for the omm command. If it’s missing, the skill installs the oh-my-mermaid npm package globally on your machine.

Second, omm-push signs you in with GitHub and uploads everything in your .omm/ folder to ohmymermaid.com, along with your current git commit hash. That sends a description of your codebase to a third party. The upstream skill file says the free cloud plan allows one project.

Third, omm-view starts a web server on your machine with no sign-in. It isn’t limited to your own computer, so other devices on the same network may be able to open it while it runs. Stop it when you’re done.

Upstream also documents an npm route for Claude Code: npm install -g oh-my-mermaid && omm setup claude.