diagram

diagram is a command for Claude Code from TheDecipherist/claude-code-mastery-project-starter-kit. It costs 17 tokens per session (2,766 once invoked), scanned A, original, MIT.

A code-scanning diagram generator that creates plain-text maps of a project's architecture, APIs, database, and deployment setup. The diagrams use box-drawing characters, so they work in terminals, Markdown, and code reviews.

In plain words
What is it for?
Use it to map services and data flow, list API endpoints, describe database structures, or document servers, containers, and regions.
Why use it?
It documents what the code actually contains instead of relying on outdated hand-drawn diagrams. It can show proposed diagrams first or replace existing ones when explicitly asked.

Command for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/thedecipherist/claude-code-mastery-project-starter-kit/diagram
Clone the repo
git clone --depth 1 https://github.com/TheDecipherist/claude-code-mastery-project-starter-kit

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for diagram

README.md
[![agentmods](https://agentmods.dev/badge/commands/thedecipherist/claude-code-mastery-project-starter-kit/diagram.svg)](https://agentmods.dev/commands/thedecipherist/claude-code-mastery-project-starter-kit/diagram)
Your own site
<a href="https://agentmods.dev/commands/thedecipherist/claude-code-mastery-project-starter-kit/diagram"><img src="https://agentmods.dev/badge/commands/thedecipherist/claude-code-mastery-project-starter-kit/diagram.svg" alt="Measured on agentmods" height="20"></a>
Per session 17 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,766 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00017 $0.02766
Opus 5 $0.00009 $0.01383
Sonnet 5 $0.00003 $0.00553
Haiku 4.5 $0.00002 $0.00277

Measured 6d ago against content hash 9e35c4f7255d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

diagram scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/commands/diagram.md · 302 lines

How it starts

The opening of the file, as written. The whole thing — 302 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Generate Diagram

Scan the actual project and generate/update diagrams based on what exists in code.

Type: $ARGUMENTS

Available types:

  • architecture — System overview: services, connections, data flow → updates project-docs/ARCHITECTURE.md
  • api — API routes map: all endpoints grouped by resource → updates project-docs/ARCHITECTURE.md
  • database — Database schema: collections, indexes, relationships → updates project-docs/ARCHITECTURE.md
  • infrastructure — Deployment topology: servers, containers, regions → updates project-docs/INFRASTRUCTURE.md
  • all — Generate all diagram types

If --update is passed, replace existing diagrams in-place. Otherwise, show the diagram and ask before writing.

Diagram Format

ALL diagrams use ASCII box-drawing characters. No Mermaid, no SVG, no external tools. ASCII works in every terminal, every markdown renderer, every code review.

Box characters: ┌ ┐ └ ┘ │ ─ ├ ┤ ┬ ┴ ┼
Arrows: → ← ↑ ↓ ──> <── ───>

Type: architecture

Scan the project and generate a system overview diagram.

What to scan:

  1. src/ directory structure — identify services, handlers, adapters

    find src/ -name "*.ts" -o -name "*.tsx" 2>/dev/null | head -50
    
  2. Entry points — find all server/app files

    grep -rl "app.listen\|createServer\|express()\|fastify()\|Hono()" src/ 2>/dev/null
    
  3. Route definitions — find where endpoints are defined

    grep -rn "app\.\(get\|post\|put\|delete\|patch\)\|router\.\(get\|post\|put\|delete\|patch\)" src/ 2>/dev/null
    
  4. Database usage — find which services access the database

    grep -rl "queryOne\|queryMany\|insertOne\|updateOne\|bulkOps\|batch\|StrictDB\|MongoClient\|PrismaClient" src/ 2>/dev/null
    
  5. External service calls — find adapters and API calls

    grep -rl "fetch(\|axios\|got(" src/ 2>/dev/null
    
  6. Package.json — check for framework indicators

    • next → Next.js app
    • express → Express API
    • fastify → Fastify API
    • hono → Hono API

Read the full file on GitHub · 302 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 6d ago First seen · 302 lines · 17 tokens per session scan A 9e35c4f7255d

Subscribe to this mod's changes

diagram is a command published in the GitHub repository TheDecipherist/claude-code-mastery-project-starter-kit (337 stars, last pushed 2mo ago), licensed MIT. It adds 17 tokens to every session and 2,766 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.