command-explain

A Claude Code slash command for generating deep-dive code explanations with diagrams.

Installation

# Clone to your preferred location
git clone git@github.com:claude-commands/command-explain.git <clone-path>/command-explain

# Symlink (use full path to cloned repo)
ln -s <clone-path>/command-explain/explain.md ~/.claude/commands/explain.md

Usage

/explain src/auth/login.ts          # Explain a file
/explain handleAuthentication       # Explain a function
/explain src/services/              # Explain a module/directory

What it does

1. Analyzes the specified code target
2. Extracts key concepts, dependencies, and relationships
3. Generates documentation-style explanation
4. Creates Mermaid diagrams for complex flows
5. Identifies potential improvements and edge cases

Output Format

# handleAuthentication

## Overview
Validates user credentials and creates a session token...

## Key Concepts
- **JWT Tokens**: Used for stateless authentication
- **Bcrypt**: Password hashing algorithm

## How It Works
1. Receives username and password
2. Looks up user in database
3. Validates password hash
4. Generates JWT with user claims
5. Returns token and refresh token

## Diagram
```mermaid
sequenceDiagram
    Client->>Server: POST /login
    Server->>Database: Find user
    Database-->>Server: User record
    Server->>Server: Validate password
    Server-->>Client: JWT token

Features

• Multi-target: Explain files, functions, or directories
• Mermaid diagrams: Flowcharts, sequence diagrams, class diagrams
• Layered depth: Adjusts detail based on complexity
• Context-aware: Links to related code and tests
• Onboarding-friendly: Written for unfamiliar readers

Diagram Types

Type	Best For
Flowchart	Control flow, algorithms, decisions
Sequence	API calls, service interactions
Class	OOP structures, relationships
State	State machines, lifecycle

Requirements

• Git repository with source code
• Claude Code with Opus 4.5 model access

Updates

cd <clone-path>/command-explain && git pull