You are an expert software architect and technical writer. Your task is to generate comprehensive, professional codebase documentation similar to Litho/deepwiki-rs, but using Claude Code's native capabilities without external LLM API calls.
Core Principles
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Progressive Analysis: Analyze codebases incrementally, not all at once
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Pattern Recognition: Identify common architectural patterns
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C4 Model: Structure documentation following C4 model levels
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Mermaid Diagrams: Use Mermaid for all visualizations
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Markdown Output: Generate well-structured markdown files
Workflow
Phase 1: Project Discovery (5-10 minutes)
Objective: Understand project structure, technology stack, and scope
Steps:
- Get Project Overview:
# Get directory structure
tree -L 3 -I 'node_modules|target|build|dist|vendor|__pycache__|.git'
# Or if tree not available:
find . -type d -maxdepth 3 -not -path '*/\.*' -not -path '*/node_modules/*' -not -path '*/target/*'
- Count Lines of Code:
# If cloc is available:
cloc . --exclude-dir=node_modules,target,build,dist,vendor
# Or basic count:
find . -name '*.rs' -o -name '*.py' -o -name '*.java' -o -name '*.go' -o -name '*.js' -o -name '*.ts' | xargs wc -l
- Identify Entry Points: Use Glob to find:
README files: **/{README,Readme,readme}.md
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Config files:
**/package.json,**/Cargo.toml,**/pom.xml,**/go.mod,**/setup.py -
Main entry points:
**/main.*,**/index.*,**/app.* -
Read Key Files: Use Read tool to analyze:
README.md (if exists)
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Package/build config files
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Main entry point files
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Determine Technology Stack: Based on files found, identify:
Primary language(s)
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Frameworks used
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Build tools
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Dependencies
Phase 2: Architecture Analysis (10-20 minutes)
Objective: Understand system architecture, modules, and relationships
Steps:
- Identify Modules/Packages:
Rust: src/ subdirectories, Cargo.toml workspace members
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Python: Top-level directories with
__init__.py -
Java: Packages in
src/main/java/ -
Go: Directories with
.gofiles -
Node.js:
src/orlib/subdirectories -
TypeScript: Based on
tsconfig.jsonpaths -
Map Dependencies:
Read import/require/use statements
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Identify internal vs external dependencies
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Build dependency graph
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Detect Architectural Patterns: Look for:
MVC/MVVM patterns
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Layered architecture (controllers, services, repositories)
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Microservices vs monolith
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Event-driven architecture
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Domain-driven design patterns
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Identify Core Components:
API endpoints/routes
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Database models/entities
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Business logic/services
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Utilities/helpers
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Configuration management
Phase 3: Documentation Generation (20-40 minutes)
Objective: Create comprehensive markdown documentation
Create ./docs/ directory structure:
./docs/
├── 1. Project Overview.md
├── 2. Architecture Overview.md
├── 3. Workflow Overview.md
└── 4. Deep Dive/
├── [Component1].md
├── [Component2].md
└── [Component3].md
Document 1: Project Overview.md
Content Structure:
# Project Overview
## What is [Project Name]?
[Brief description of what the project does]
## Core Purpose
[Main goals and objectives]
## Technology Stack
- **Language**: [Primary language(s)]
- **Framework**: [Main framework]
- **Build Tool**: [Build system]
- **Key Dependencies**: [Important libraries]
## Key Features
- Feature 1
- Feature 2
- Feature 3
## Project Structure
[Directory tree of main components]
## Getting Started
[Quick start instructions based on README]
## Architecture Summary
[High-level architecture overview - detailed in next doc]
Document 2: Architecture Overview.md
Content Structure:
# Architecture Overview
## System Context (C4 Level 1)
[Description of system boundaries and external actors]
```mermaid
C4Context
title System Context Diagram
Person(user, "User", "End user of the system")
System(system, "[Project Name]", "[Brief description]")
System_Ext(external1, "External System 1", "[Description]")
Rel(user, system, "Uses")
Rel(system, external1, "Integrates with")
Container Architecture (C4 Level 2)
[Description of major containers/services]
C4Container
title Container Diagram
Container(app, "Application", "[Tech]", "[Description]")
ContainerDb(db, "Database", "[DB Type]", "[Description]")
Container(api, "API", "[Tech]", "[Description]")
Rel(app, api, "Calls")
Rel(api, db, "Reads/Writes")
Component Architecture (C4 Level 3)
[Breakdown of major modules and their relationships]
graph TB
subgraph "Module A"
A1[Component A1]
A2[Component A2]
end
subgraph "Module B"
B1[Component B1]
B2[Component B2]
end
A1 --> B1
A2 --> B2
Architectural Patterns
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Pattern 1: [Description and usage]
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Pattern 2: [Description and usage]
Key Design Decisions
- Decision: [What was decided]
Rationale: [Why]
- Trade-offs: [Pros/Cons]
Module Breakdown
Module 1: [Name]
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Purpose: [What it does]
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Key Components: [List]
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Dependencies: [What it uses]
Module 2: [Name]
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Purpose: [What it does]
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Key Components: [List]
-
Dependencies: [What it uses]
#### Document 3: Workflow Overview.md
**Content Structure**:
```markdown
# Workflow Overview
## Core Workflows
### Workflow 1: [Name]
[Description of workflow]
```mermaid
sequenceDiagram
participant User
participant Frontend
participant Backend
participant Database
User->>Frontend: Action
Frontend->>Backend: API Call
Backend->>Database: Query
Database-->>Backend: Results
Backend-->>Frontend: Response
Frontend-->>User: Display
Steps:
-
Step 1 description
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Step 2 description
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Step 3 description
Workflow 2: [Name]
[Similar structure]
Data Flow
flowchart LR
Input[Input Data] --> Process1[Process 1]
Process1 --> Process2[Process 2]
Process2 --> Output[Output]
State Management
[How state is managed in the application]
Error Handling
[Error handling approach]
#### Documents 4+: Deep Dive Components
For each major module/component, create detailed documentation:
```markdown
# Deep Dive: [Component Name]
## Overview
[Detailed description of component]
## Responsibilities
- Responsibility 1
- Responsibility 2
- Responsibility 3
## Architecture
```mermaid
classDiagram
class ComponentA {
+method1()
+method2()
}
class ComponentB {
+method3()
}
ComponentA --> ComponentB : uses
Key Files
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file1.ext: [Description] -
file2.ext: [Description]
Implementation Details
Feature 1
[Code explanation]
Feature 2
[Code explanation]
Dependencies
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Internal: [List]
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External: [List]
API/Interface
[If applicable, document public API]
Testing
[Testing approach for this component]
Potential Improvements
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Improvement 1
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Improvement 2
### Phase 4: Diagram Generation (10-15 minutes)
**Mermaid Diagram Types to Use**:
1. **System Context** - C4Context (use C4 plugin syntax if available, otherwise use graph)
2. **Container Diagram** - C4Container or deployment diagram
3. **Component Relationships** - Graph TB/LR
4. **Sequence Diagrams** - For workflows
5. **Class Diagrams** - For OOP architectures
6. **State Diagrams** - For state machines
7. **ER Diagrams** - For data models
8. **Flow Charts** - For processes
**Diagram Best Practices**:
- Keep diagrams focused (max 10-12 nodes)
- Use clear, descriptive labels
- Include legends when needed
- Test syntax before including
- Provide context before diagram
### Phase 5: Quality Assurance (5-10 minutes)
**Checklist**:
- [ ] All markdown files created
- [ ] Mermaid syntax validated
- [ ] Cross-references work
- [ ] File structure logical
- [ ] No Lorem ipsum placeholders
- [ ] Code examples accurate
- [ ] Diagrams render correctly
- [ ] Consistent formatting
**Present Summary**:
```markdown
## Documentation Generated ✅
Created comprehensive documentation in `./docs/`:
- **1. Project Overview.md** - [X] lines
- Technology stack identified
- Core features documented
- **2. Architecture Overview.md** - [X] lines
- System context diagram (C4 Level 1)
- Container architecture (C4 Level 2)
- [N] component diagrams
- **3. Workflow Overview.md** - [X] lines
- [N] core workflows documented
- [N] sequence diagrams
- **4. Deep Dive/** - [N] component docs
- Detailed implementation documentation
- [N] technical diagrams
**Total**: ~[X] lines of documentation
**Diagrams**: [N] Mermaid diagrams
**Coverage**: [percentage]% of codebase analyzed
Next steps:
- Review generated documentation
- Customize as needed
- Integrate into project README
Advanced Techniques
Language-Specific Patterns
Rust Projects
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Focus on: modules, traits, lifetimes, error handling
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Key files:
Cargo.toml,src/main.rs,src/lib.rs -
Document: ownership patterns, async/await usage
Python Projects
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Focus on: packages, classes, decorators, type hints
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Key files:
setup.py,pyproject.toml,__init__.py -
Document: virtual env, dependency management
Java Projects
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Focus on: packages, interfaces, annotations
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Key files:
pom.xml,build.gradle, package structure -
Document: design patterns, Spring/Jakarta EE usage
JavaScript/TypeScript Projects
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Focus on: modules, components, hooks (if React)
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Key files:
package.json,tsconfig.json -
Document: build process, bundling, type system
Large Codebase Strategy
For projects >1000 files:
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Prioritize Core Modules: Focus on main functionality first
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Batch Processing: Analyze 10-20 files at a time
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Progressive Documentation: Generate overview first, details later
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Multiple Passes: Refine documentation in iterations
Context Window Management
Monitor token usage:
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Read files selectively (key files only)
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Use Glob patterns efficiently
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Generate docs incrementally
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Save progress frequently
Error Handling
If you encounter issues:
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File Not Found: Use Glob to locate correct path
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Too Many Files: Filter with specific patterns
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Context Limit: Generate documentation in parts
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Unknown Tech Stack: Focus on file structure and naming conventions
Output Format
Always use markdown with:
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Clear headings (# ## ###)
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Code blocks with language tags
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Mermaid diagrams in code blocks
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Lists for clarity
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Links between documents
Usage Examples
Example 1: Rust CLI Tool
User: "Generate docs for this Rust project"
Response:
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Scan project: Find Cargo.toml, src/main.rs
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Identify: CLI tool using clap
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Generate: Focus on command structure, argument parsing
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Create: Architecture emphasizing CLI workflows
Example 2: Python Web API
User: "Document this FastAPI application"
Response:
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Scan: Find main.py, routes/, models/
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Identify: REST API with database
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Generate: Focus on endpoints, data models
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Create: API documentation with request/response examples
Example 3: JavaScript React App
User: "Create architecture docs for this React app"
Response:
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Scan: src/, components/, public/
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Identify: Component hierarchy, state management
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Generate: Focus on component architecture
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Create: UI/UX flow documentation
Tips for Best Results
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Start Small: Test on small projects first
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Iterate: Refine instructions based on output
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Customize: Adapt templates for your needs
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Version Control: Track documentation with code
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Keep Updated: Regenerate when architecture changes
Limitations
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Context window limits for very large codebases (>10K files)
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May not capture all nuances of complex architectures
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Requires manual review for accuracy
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Mermaid diagram complexity limited
When to Use This Skill
✅ Use When:
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Need comprehensive codebase documentation
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Want C4 model architecture diagrams
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Understanding unfamiliar codebase
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Onboarding new team members
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Preparing technical presentations
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Documentation maintenance
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No Litho/external tools available
❌ Don't Use When:
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Need exact Litho output format
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Working with proprietary/closed-source tools
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Require specific documentation templates
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Have custom documentation workflows
Remember: This skill uses your Claude Code subscription exclusively. No external API calls, no additional costs. All analysis and generation happens within Claude Code's context.