code-documenter

Code Documenter

Overview

Analyzes source code to generate accurate, context-aware documentation at multiple levels: inline comments for complex logic, function/class docstrings, module-level overviews, architecture documents, and onboarding guides. Understands control flow, data transformations, side effects, and cross-module dependencies.

Instructions

When asked to document code:

1. Determine the documentation level needed:

   • Inline: Function/method docstrings, JSDoc, Python docstrings, Go doc comments
   • Module: README or header comment explaining the module's purpose and exports
   • Architecture: High-level document showing how modules interact, data flows, key design decisions
   • Onboarding: Getting-started guide for new team members

2. For function/method documentation, extract:

   • Purpose: What does this function do? (one sentence)
   • Parameters: name, type, description, default values, constraints
   • Return value: type, description, possible values
   • Side effects: database writes, API calls, file I/O, state mutations, cache invalidation
   • Exceptions/errors: what can go wrong, when, and what error types
   • Example usage: realistic call with realistic data

3. For complex logic, add inline comments explaining:

   • WHY, not WHAT — explain the reasoning, not the obvious operation
   • Business rules embedded in conditionals
   • Performance-critical sections and why they're written a certain way
   • Workarounds with links to issues/bugs if available in git history
   • Non-obvious algorithm choices

4. For architecture documentation:

   • Map module dependencies (imports/requires graph)
   • Identify entry points (API handlers, CLI commands, event listeners)
   • Trace key data flows through the system (e.g., "user signup" flow)
   • Document configuration and environment variables
   • List external service dependencies (databases, APIs, queues)
   • Note design patterns used (repository pattern, event sourcing, CQRS, etc.)