omm

Your codebase,
always readable.

Vibe coding makes you move fast — but the architecture quietly bloats. oh-my-mermaid keeps a living diagram of your codebase, automatically.

InstallSee how it works
diagram.mmdpreview.omm / auth-flow / diagram.mmd1graph LR23 Client --> GW[Gateway]4 GW --> Auth[Auth Svc]5 GW --> Svc[Data Svc]6 Svc --> DB[(Database)]7/omm-scanClientGatewayAuth SvcData SvcDatabase4 nodes · 4 edges

The problem

01

You move fast

AI writes code faster than you can think. Modules pile up. Dependencies multiply.

02

Architecture drifts

Nobody updated the diagram. Nobody knows what connects to what anymore.

03

You lose the map

Your own codebase becomes a black box. Debugging becomes guessing.

How it works

1

Init once

Run omm init. The CLI scans your project and generates a .omm/ directory with structured Mermaid diagrams for each architectural domain.

$ omm init
2

Claude Code keeps it fresh

Two Claude Code skills — /omm-init and /omm-scan — let the AI analyze your code and write diagrams directly via the CLI. Architecture stays in sync as you build.

$ /omm-scan
3

View in the browser

Spin up the local viewer. Real-time updates via SSE. Drill into any diagram, see diffs between versions, and navigate cross-diagram references.

$ omm serve

Features

Living diagrams

Every diagram is plain text (.mmd). Committed to git. Diffable. Reviewable.

Diff visualization

See exactly what changed between two versions — added nodes in green, removed in red.

Cross-diagram links

Reference another diagram with @class-name. Click to drill down. Navigate up with breadcrumbs.

Claude Code skills

omm-init and omm-scan ship as Claude Code skills. AI writes the diagrams, CLI owns the files.

Real-time viewer

File watcher + SSE means the browser updates the moment you save a diagram.

Zero server deps

Node.js http module only. Mermaid and Markdown rendered client-side via CDN.

Install

Global$ npm install -g oh-my-mermaid
One-shot$ npx oh-my-mermaid init
Dev dependency$ npm install -D oh-my-mermaid

CLI

omm initCreate .omm/ and install Claude Code skills
omm listList all architecture classes
omm show <class>Print all fields for a class
omm diff <class>Show diagram diff from previous version
omm refs <class>Show which classes reference this one
omm serveStart the local web viewer on :3000
omm statusSummary: class count, last updated