---

name: code-documentation description: Updates or creates project documentation in the correct location. Use when documenting features, architecture, setup instructions, or API changes. Writes clear, concise documentation without verbosity. allowed-tools: Read, Glob, Grep, Edit, Write

Code Documentation

Updates project documentation with clear, focused content.

Documentation Locations

This Repository Structure

• CLAUDE.md - Instructions for Claude Code (project structure, commands, architecture)
• README.md (root) - Project overview, quick start
• src/README.md - BFF application documentation (architecture, setup, API endpoints)
• src/backend/ - Backend code (Express, TypeScript)
• src/frontend/ - Frontend code (React, TypeScript)
• Code comments - Only when logic isn't self-evident

Location Decision Tree

1. Claude Code instructions → CLAUDE.md
2. Workspace-level commands and architecture → CLAUDE.md
3. BFF application setup, API endpoints, development → src/README.md
4. Backend/frontend-specific architecture → src/README.md (relevant section)
5. Function/class behavior → Code comments (sparingly)

Writing Guidelines

Be Concise

Bad: "This function is responsible for the task of processing user input data by validating it and then transforming it into the appropriate format."

Good: "Validates and transforms user input."

Use Direct Language

• Start with verbs for actions
• Avoid "should", "would", "could"
• Skip unnecessary context

Structure

For feature documentation:

Copy## Feature Name

Brief description (1 sentence).

### Usage

Code example or command

### Parameters/Options

- `param` - Description

For architectural updates to CLAUDE.md:

Copy## Section Name

Key points only:
- Fact 1
- Fact 2

Instructions

1. Identify the change: What was added, modified, or needs documentation?

2. Choose location: Use the decision tree above

3. Read existing docs: Check current content to maintain consistency

4. Update concisely:

   • Add new sections or update existing ones
   • Remove outdated information
   • Keep formatting consistent
   • One sentence when one sentence suffices

5. Verify accuracy: Ensure technical details match implementation

Examples

Adding New API Endpoint

Location: src/README.md (update API Endpoints section)

Copy### GET /api/users
Get all users.

**Response:**
\`\`\`json
[
  { "id": 1, "name": "User 1" }
]
\`\`\`

Documenting New Environment Variable

Location: src/README.md (update Setup section) or CLAUDE.md (if workspace-level)

Copy- `RATE_LIMIT` - Max requests per minute (default: 60)

Adding Development Command

Location: CLAUDE.md (update Development Commands section)

Copy### API (`src/backend/`):
- `yarn validate` - Run linting and type checking

What NOT to Document

• Obvious code behavior
• Implementation details better suited for code comments
• Temporary fixes or TODOs
• Information that duplicates existing docs