PRDs

What Is a PRD for Vibe Coding?

A PRD is a short brief that tells an AI coding agent what to build and what to leave out. Here is what belongs in one and what does not.

Last updated 5 min read
Sebastian Volkis, founder of CodeSpring

Written by Sebastian VolkisFounder of CodeSpring

A PRD for vibe coding is a short written brief that tells an AI coding agent what one feature must do, who it is for, and what is deliberately out of scope. PRD stands for product requirements document, and in this context it is written to be read by the agent, not filed away for a stakeholder.

It exists to turn an instruction into a piece of work that can be reviewed. Without one you are comparing what the agent built against what you meant. With one you are comparing it against something you wrote down before the code existed.

What belongs in a useful PRD

Start with the outcome, not the implementation. Say where in the product the feature is used and what the person using it is trying to get done, then describe the behaviour.

A good test while you write: if somebody with no context on your app had to build this feature, what would they need to know? Anything you would have to explain out loud belongs in the document.

  • The user, and the problem the feature solves for them
  • The expected behaviour, including the empty, loading and error states
  • The data it reads and the data it creates
  • What is deliberately excluded from this version
  • How you will know it works, in terms you can check

Front end, back end and database are separate documents

One feature usually needs three different kinds of answer: what the screen does, what the server does, and what gets stored. Mixing them into one document makes each of them vaguer.

CodeSpring generates them as separate PRDs off a feature, so you can hand an agent only the part it needs for the task in front of it. The PRD documentation walks through generating each type from a feature on the map.

The PRD bridge in CodeSpring, offering a front end, back end or database requirements document for one feature.

Keep the first version specific

A PRD should cover one complete outcome, not every variation of an idea. Specific scope is what makes the work finishable and the result checkable.

Write down the edge cases that matter now. Put the later ideas somewhere else, in a note or a second document, rather than letting them widen the request you are about to hand over.

Be equally clear about what you are not building. An explicit exclusion is the cheapest instruction you can give an agent, and it is the one most often left out.

When to write the PRD, and when it goes stale

Write the requirements when you are close to building the feature, not months ahead. A PRD describes a system that keeps changing around it, so one written early is usually wrong by the time anyone reads it.

The map is the durable artefact. The PRD is the working document you generate from it when the feature reaches the top of the list, and regenerate when the feature genuinely changes shape.

A generated front end PRD in CodeSpring, with its version tag and the sections an agent reads before it writes any code.

Turn one PRD into ordered tasks

Once the requirement is clear, split it into tasks that can be reviewed on their own. Each task needs a clear start, a clear finish and enough context that somebody could pick it up cold, which in practice includes you, next week.

That sequence is the bridge between a product decision and a coding session. CodeSpring turns a feature and its PRDs into a numbered Kanban task list that stays attached to the map it came from.

If you have not mapped the app yet, start with how to plan an app before you start AI coding. The PRD is the second step, not the first.

Keep reading

More guides on planning an AI build