How to Document AI-Generated Code for Future Maintenance

Apr 4, 2026

Notebook with documentation and planning notes

The Problem

I spent three months vibe coding with Cursor and Claude. My app worked. It had authentication, a dashboard, real-time notifications, everything I needed. Then I took a two-week break.

When I came back, I couldn’t understand my own code.

Session 1 (Month 0):  "Add authentication"
                       Claude generates 15 files
                       Everything works

Session 50 (Month 2): "Fix the notification bug"
                       Claude patches something in auth middleware
                       I don't know why it worked

Session 100 (Month 3): "Add a new feature"
                        I try to understand the codebase
                        I find 47 files with no comments
                        Functions I don't recognize
                        Logic I can't trace

Me: "Claude, explain this function"
Claude: "I don't have context from 3 months ago"

The real cost of vibe coding isn’t the subscription fee. It’s the documentation debt that compounds every session. I found a Reddit thread where developers shared the same frustration, and the solutions they found.

Why This Happens

AI coding tools generate code fast. They don’t generate documentation. Every session adds functions, files, and logic without explaining why they exist or how they connect.

Day 1:   10 functions, 0 comments    → Understandable
Day 30:  100 functions, 5 comments   → Getting confusing
Day 60:  300 functions, 10 comments  → Hard to navigate
Day 90:  500 functions, 15 comments  → Impossible to understand

The Reddit thread called this out directly: “Keep changelogs. Document EVERYTHING. I’m not a dev, but I’m not scared of my app because I understand how to apply documentation and project management principles.”

The key insight: You need to build documentation practices into your workflow from day one, not as an afterthought.

The Solution: Four Documentation Strategies

1. Changelogs

I started keeping a CHANGELOG.md that tracks every meaningful change. This creates a chronological record of what happened and why.

## [2026-04-04] - User Authentication Refactor

### Added
- JWT token refresh mechanism
- Rate limiting on login endpoint

### Changed
- Password hashing switched to Argon2 from bcrypt
- Session timeout reduced from 30 days to 7 days

### Why
Previous auth was vulnerable to timing attacks.
Claude suggested Argon2 for better security.

### Files Affected
- src/auth/handler.go
- src/middleware/auth.go
- src/config/auth.go

The “Why” section is critical. Without it, I can’t understand the reasoning behind changes months later. The “Files Affected” section helps trace impact when debugging.

2. Claude.md Files

The Reddit thread recommended a specific pattern for Claude.md:

“For every function and code element add a brief comment about what the code does, and where it connects. If something changes, update the comment.”

I added this instruction to my Claude.md:

# Project Documentation

## Code Comments Policy
For every function and code element add a brief comment about:
- What the code does
- Where it connects in the system
- Any dependencies or side effects

If something changes, update the comment immediately.

This creates a “code graph” - a map of how everything connects. Both humans and AI can trace dependencies without guessing.

3. Intent Files

The most valuable tip from Reddit: write the intent down before prompting.

“What fixed this for me: writing the intent down before prompting. Not a full spec, just a simple intent.md that captures what this feature should do and why, plus any decisions I made that the AI should know about.”

Before asking Claude to generate code, I write an intent.md:

# Intent: User Dashboard Feature

## What this feature should do
Display a real-time dashboard showing user activity metrics,
including login frequency, feature usage, and error rates.

## Why
Users requested better visibility into account activity.
Helps identify suspicious behavior and usage patterns.

## Key Decisions
- Use WebSocket for real-time updates (not polling)
- Cache metrics for 5 minutes to reduce database load
- Display only last 30 days by default

## Constraints
- Must work on mobile (responsive design)
- Maximum 3 second load time
- Accessible to screen readers

This file serves two purposes. First, it helps me clarify my thinking before generating code. Second, it becomes documentation that explains why the feature exists.

4. Inline Comments

Generated code needs comments that explain connections, not just functionality. I follow this pattern:

// Authentication middleware - validates JWT tokens
// Called by: All protected routes in src/routes/
// Depends on: src/utils/jwt.ts for token verification
// Modifies: Sets req.user with decoded token payload
export async function authMiddleware(req, res, next) {
  // Extract token from Authorization header
  // Format: "Bearer <token>"
  const token = req.headers.authorization?.split(' ')[1];

  if (!token) {
    // No token = unauthenticated request
    // Don't throw error, just set user to null
    req.user = null;
    return next();
  }

  // Verify token and attach user to request
  // Throws if token is expired or malformed
  req.user = await verifyToken(token);
  next();
}

The “Called by”, “Depends on”, and “Modifies” lines create a traceable graph. When something breaks, I can follow the connections to understand impact.

What This Changes

WITHOUT DOCUMENTATION:
─────────────────────────────────────────────────────────────
Month 3: Return to project
  → Open random file
  → See function with no name context
  → Search for where it's used
  → Find 15 references
  → Can't tell which is the main usage
  → Claude has no context either
  → Spend 3 hours understanding one function

WITH DOCUMENTATION:
─────────────────────────────────────────────────────────────
Month 3: Return to project
  → Open CHANGELOG.md
  → See chronology of changes
  → Open function
  → Read comment: "Called by: routes/auth.ts, Depends on: jwt.ts"
  → Open intent.md for the feature
  → Understand in 15 minutes
  → Claude reads same documentation
  → Can suggest changes with full context

The time investment is small upfront but massive in returns:

Time to write intent.md:        5 minutes before prompting
Time to add inline comments:    10 seconds per function
Time to update CHANGELOG:       2 minutes after changes

Time saved at month 3:          3 hours per debugging session
Number of debugging sessions:   20+
Total time saved:               60+ hours

Break-even: After first debugging session

Common Mistakes

Mistake	Why It Fails	Fix
No documentation at all	You won’t remember what you did	Build documentation into every session
Over-documenting	Comments become noise	Explain “why” and connections, not “what”
Documentation as afterthought	10x harder to reconstruct later	Write intent.md before prompting
Inconsistent formats	Hard to parse and maintain	Use templates for changelog, intent, comments
Not updating docs	Stale docs are misleading	Update comments immediately when code changes

The biggest mistake: assuming code is self-documenting. Generated code is never self-documenting because it lacks the context of why it was created and how it fits into the larger system.

My Workflow Now

1. Write intent.md (what, why, decisions)
2. Prompt Claude with intent.md reference
3. Review generated code
4. Add inline comments (connections, dependencies)
5. Update CHANGELOG.md (what, why, files)
6. Update Claude.md if new pattern established
7. Commit with documentation included

This takes extra time upfront. But at month 3, when I need to debug or extend a feature, I have the context I need. The Reddit commenter was right: “tokens now for traceability forever.”

Final Words + More Resources

My intention with this article was to help others share my knowledge and experience. If you want to contact me, you can contact by email: Email me

Here are also the most important links from this article along with some further resources that will help you in this scope:

👨‍💻 Reddit: The real cost of vibe coding isn't the subscription

Oh, and if you found these resources useful, don’t forget to support me by starring the repo on GitHub!