Atlas / Skills / oh-my-mermaid / Omm Scan

Omm ScanSAFE

skills/oh-my-mermaid/omm-scan

Turn complex codebases into clear, navigable architecture diagrams with Claude Code.

Verdict
SAFE
Grade
B
Trust score
89 /100
Version
—
Hosts
1 documented
License
MIT
Stars
2,503
01

Overview

Turn complex codebases into clear, navigable architecture diagrams with Claude Code.

Read from source at commit a306c32c4012OBSERVED · 2026-10-09
02

Host compatibility

What the documentation claims. We have not run a compatibility test.

HostStatusNotes
codexmentioned
03

What it tells the agent

The instruction file, verbatim from the audited commit — this is the text the model reads, and the surface the audit's instruction layer examines. Quoted here so you can judge it without cloning anything.

---
name: omm-scan
description: Scan codebase architecture and generate/update .omm/ documentation. Use when the user says "omm scan", "scan architecture", "update architecture", "refresh diagrams".
---

# omm-scan — Perspective-Based Architecture Scanner

## Purpose

Analyze the codebase and generate `.omm/` architecture documentation using **perspective-driven recursive analysis**.

- A **perspective** is a top-level element — a distinct way to look at the architecture.
- Each element in a diagram gets analyzed recursively. If it has internal structure, it becomes a **child element** (subdirectory with its own diagram). If not, it stays a leaf.
- The filesystem determines nesting. Element IDs in diagrams match child directory names. The viewer resolves groups from the filesystem.

## Prerequisites

```bash
command -v omm || npm install -g oh-my-mermaid
```

If the install fails, tell the user: "Please run `npm install -g oh-my-mermaid` in your terminal, then try again."

---

## Step 0: Check Language

```bash
omm config language
```

Write field content (description, context, constraint, concern, todo, note) in the configured language. Default is English. Element IDs, directory names, and diagram node IDs are always English kebab-case.

## Step 1: Explore the Codebase

Use Glob and Read to understand the project:

- Read `package.json`, `pyproject.toml`, or equivalent manifests
- List top-level directories to identify module boundaries
- Read key entry points (main, index, app files)
- Look for route definitions, service layers, database connections, external integrations

## Step 2: Select Perspectives

From the catalog below, choose which perspectives are meaningful for this codebase.

### Perspective Catalog

| Perspective | When to create | What it answers |
| --- | --- | --- |
| `overall-architecture` | **Always** | What exists and how pieces relate |
| `request-lifecycle` | Any server/API | How a request enters and gets handled end-to-end |
| `data-flow` | Any data processing, DB usage | Where data comes from, transforms, and lands |
| `dependency-map` | Complex module graph | What depends on what, what's shared |
| `external-integrations` | External APIs/services | What the system connects to and why |
| `state-transitions` | Stateful features (frontend or backend) | How state changes and what triggers it |
| `route-page-map` | Frontend with routing | Page structure and navigation flow |
| `command-surface` | CLI tools | Command hierarchy and dispatch |
| `extension-points` | Plugin/extension systems | Extension architecture and registry |
| `pipeline` | ML/data pipelines | Stage topology and data flow |
| `orchestration` | Event-driven/queue systems | Publisher, subscriber, broker topology |
| `storage` | 2+ storage systems | Storage topology (DB, cache, queue, object store) |

Don't force perspectives that don't exist in the code.

## Step 3: Generate Perspectives with Recursive Drill-Down

For each selected perspective, follow this recursive process:

### 3a. Write the perspective diagram

Element IDs match child directory names. The viewer resolves nesting from the filesystem.

```bash
omm write <perspective> diagram - <<'MERMAID'
graph LR
    renderer["Renderer\nsrc/renderer/"]
    renderer -->|"IPC invoke/on"| main-process["Main Process\nsrc/main/"]
    main-process -->|"spawn PTY"| engine-system["Engine System\nsrc/main/engine/"]
    main-process -->|"read/write JSON"| data-store["Data Store\nsrc/main/store.ts"]
    main-process -->|"xterm.js"| terminal-dock["Terminal Dock\nsrc/renderer/src/panel/"]
MERMAID
```

### 3b. Write the other 6 fields

Each as a separate `omm write` command: description, context, constraint, concern, todo, note.

### 3c. Recursive drill-down: analyze every element

**For every element in the diagram:**

1. **Analyze** the code it represents (Glob + Read the relevant files/directories)

2. **Write description for every node — no exceptions.** This creates the element directory. Optionally write other fields (context, constraint, concern, todo, note) if relevant — Write in the configured language.

   ```bash
   omm write <perspective>/<element-name> description - <<'EOF'
   (what this element does, which files/dirs it covers)
   EOF
   ```

3. **Decide leaf or group:**
   - **Distinct internal components found** → write a diagram and recurse deeper (it becomes a group)
   - **No meaningful sub-components** (single file, trivial wrapper, external system) → write remaining fields only (it stays a leaf)

4. **If group** — write diagram and recurse:

   ```bash
   omm write <perspective>/<element-name> diagram - <<'MERMAID'
   graph LR
       (internal elements)
   MERMAID
   ```

   Then repeat step 3c for each element in this diagram.

### Example recursion

```text
overall-architecture (perspective)
  elements: renderer, main-process, engine-system, data-store, terminal-dock

  → analyze renderer (src/renderer/)
    → finds: App.tsx, components/, hooks/, stores/, world/
    → group → write diagram with: components, stores, world
      → analyze components → 15 .tsx files, no sub-structure → leaf
      → analyze stores → 4 zustand stores → leaf
      → analyze world → OfficeCanvas + PixiJS logic → leaf

  → analyze main-process (src/main/)
    → finds: ipc.ts, auth/, engine/, terminal-session-service.ts, store.ts
    → group → write diagram with: auth, engine, terminal-session
      → analyze auth → auth-service.ts, callback-server.ts → leaf
      → analyze engine → claude-code.ts, codex.ts → leaf

  → analyze data-store (src/main/store.ts)
    → single file → leaf

  → analyze terminal-dock (src/renderer/src/panel/)
    → TerminalDock.tsx, DockManager → leaf
```

## Step 4: Summarize

Report what was created/updated and suggest `omm view` to view.

## Diagram Rules

- **Element IDs must match the child directory name.** Use kebab-case: `main-process`, `data-store`, `terminal-dock`.
- **Element labels use two-line format**: name + file path, separ
04

Trust audit

SAFEgrade B · trust 89/100 Nothing in the source contradicts what it says it does. Grade A is reserved for packages that have also passed the behavioural sandbox.

LayerWhat it checksResult
L0Provenance & inventoryPASS
L1Static analysis of the codeNA
L2Instruction surface (what it tells the agent)PASS
L3Class-specific surfacePASS
L4Behavioural (sandbox)SKIPPED

What the source does

Filesystem
none-observed
Network
none-observed
Shell
none-observed
Dependencies
pinned
Secrets in source
none-found

Findings (0)

No findings outside the package's declared scope.

Gates applied: no_behavioural_pass.

Audited 2026-10-09 · audit v0.4.1 · source sha a306c32c4012full audit observations/trust-audit/skill/oh-my-mermaid__omm-scan.json · Report an issue / request a re-scan
05

Audit history

Every audit this skill has had.

DateSourceVerdictGradeScoreChange
2026-10-09a306c32c4012SAFEB89first audit
06

Questions

What does the Omm Scan skill do?

Turn complex codebases into clear, navigable architecture diagrams with Claude Code.

Is Omm Scan safe to install?

The audit found nothing in the source that contradicts what it says it does, and graded it B (89/100). Grade A is held back for packages that have also passed a sandboxed behavioural run, which is why a clean skill reads B.

What can Omm Scan access on my machine?

The audit observed no filesystem, network or shell use at all in its source.

Which assistants does Omm Scan work with?

Its documentation mentions codex. That is what the text claims, not a compatibility test we ran.

How current is this page?

The grade is for one exact copy of the source (a306c32c4012), read on 2026-10-09. The repository is watched, and a new audit runs when it changes — this is the first audit.

Advertisement