Your First Week with Spec Coding · Agentic Spec Coding Academy

Your First Week with Spec Coding

You've heard about spec coding. Maybe you saw someone ship a feature in an hour that would've taken you a week. Maybe you're drowning in backlog and can't keep up.

Here's what you need to know to get started.

What Spec Coding Actually Is:

Stop writing code line by line. Start writing specifications.

The workflow:

You define WHAT you want (the spec)
AI figures out HOW to build it (the code)

You become the architect. AI becomes the builder.

Why This Works

The old way:

You: Think about the feature
You: Write the code
You: Write tests
You: Debug
You: Review
You: Ship

The spec coding way:

You: Think about the feature (write a clear spec)
AI: Writes the code, tests, and handles implementation
You: Review and merge

You do the high-value thinking. AI does the repetitive implementation.

The Three Core Documents

1. PRD (Product Requirements Document)

Defines what you're building and why.

Must include:

Problem you're solving
Who it's for
What success looks like
What you're NOT building

Example:

Problem: Users can't reset their password

Target: Existing users who forgot their login

Must-have: Email-based reset flow

Success: User can reset password in under 2 minutes

Out of scope: SMS reset, social login recovery

2. User Stories

Break features into specific, testable pieces.

Format: "As a [user type], I want to [action] so that [benefit]"

Example: "As a logged-out user, I want to request a password reset email so that I can regain access to my account"

3. Acceptance Criteria

How you know the story is done.

Format: Given [context], when [action], then [result]

Example:

Given I'm on the login page
When I click "Forgot Password" and enter my email
Then I receive a reset link within 5 minutes

Your First Spec Coding Project

Pick something small. A single feature or component. Not your entire app.

Good first projects:

Contact form with validation
User profile page
Simple API endpoint
Dashboard component

Follow these steps:

Step 1: Write the PRD (15 minutes)

What problem does this solve?
Who is it for?
What are the 3-5 must-have requirements?

Step 2: Break it into stories (15 minutes)

List 3-5 user stories
Write acceptance criteria for each

Step 3: Feed to AI agent (5 minutes)

Use SAM, Cursor, or Claude Code
Paste your spec
Let it generate

Step 4: Review the code (20 minutes)

Does it meet your acceptance criteria?
Any security issues?
Is it maintainable?

Step 5: Iterate if needed

Give specific feedback: "The validation doesn't check for email format"
Not vague feedback: "This doesn't look right"

Common Mistakes (And How to Fix Them)

Mistake 1: Vague specs ❌ "Build a login system" ✅ "Build email/password login with password strength validation, 'remember me' option, and account lockout after 5 failed attempts"

Mistake 2: Skipping acceptance criteria Without clear criteria, you can't verify the AI did it right.

Mistake 3: Not reviewing the code AI is good, not perfect. Always review for security, edge cases, and alignment with your spec.

Mistake 4: Trying to spec your entire app at once Start small. One feature. One epic. Build the muscle memory.

Spec Coding vs. Vibe Coding

Vibe coding: "Hey AI, make me a todo app" → iterate until it works

When vibe coding works: