TL;DR
A PRD builder prompt for vibe coding turns a rough product idea into a structured Product Requirements Document before an AI coding agent starts building. It gives tools like ChatGPT Projects, Replit, Lovable, Cursor, Bolt, and Claude Code the context they need: goals, non-goals, user flows, acceptance criteria, risks, and open questions. The prompt below is my version 16 PRD Builder, hardened through real AI builds, agent misfires, and the very glamorous experience of wasting credits on preventable nonsense. Use it for serious products. Skip it for tiny demos.
Vibe coding is fast.
That is the best part. Seeing your product assemble itself in front of your eyes is thrilling, full of promise and a bit intoxicating.
Kind of like margaritas.
No wonder we want to skip ahead to that part.
But!
Before you touch a single line of code, you need these three steps. Skip them, and you’re signing up for wasted credits and lost time:
A Product Requirements Document - blueprint
Rules for AI - guardrails
Context files
Today, I’m going to walk you through the first one.
What’s Inside
Why vibe coding without a PRD gets expensive. What a Product Requirements Document should contain. How my PRD Builder Prompt works. When to use it, when it is overkill, and how it connects to the bigger shift from vibe coding to spec-driven development.
Hey, I’m Karo Zieminski 🤗
AI Product Manager and builder.
I write Product with Attitude, an AI newsletter for thousands of subscribers developing critical AI literacy the only way it sticks: through practice.
We don’t just use AI. We build workflows, automations, and products with it, while studying how AI itself is built, positioned, and woven into our work.
If you’re new here, welcome! Here’s what you might have missed:
Why Bother?
I know. It sounds boring.
But hear me out: specs are how we turn AI experiments into products worth keeping. Fifteen minutes with this prompt can be the difference between building something brilliant—or brilliantly useless.
Speed without specs wastes credits.
That is the whole argument.
When we give an AI coding agent a vague idea, it fills in the blanks. Sometimes those blanks are harmless. Sometimes they become the database schema, the onboarding flow, the pricing logic, and the feature nobody asked for.
What A PRD Is
A Product Requirements Document, or PRD, is the blueprint for a product. It explains what we are building, why it matters, who it is for, what is in scope, what is out of scope, and how we will know the thing is done.
It outlines:
What you’re building
Why it matters
Who it’s for
How you’ll know it’s done
It takes the messy soup of user needs, business goals, and technical constraints and turns it into one neat little document.
In traditional product teams, PMs write PRDs.
In vibe coding, that PM is you.
What Should A PRD Contain?
Whole books have been written about PRDs, and there are countless ways to create a “proper” one - but at the very minimum, a PRD should cover these areas:
There are plenty of paid tools out there that promise to generate a PRD for you, but this prompt gives you the same clarity and structure, without the price tag.