What is an AI PRD, and what does 'PRD' mean in AI coding tools? #
An AI PRD is a product requirements document for a product whose core behavior comes from a model: it adds evaluation criteria, guardrails, model and data decisions, and failure modes to the traditional PRD. Separately, when developers say 'PRD' in AI coding tools, they usually mean a short requirements file (such as PRD.md) written for a coding agent to build from; the term is the same, the document is much smaller.
- AI PRD, in product work: the PRD variant for probabilistic products, where 'correct' is a distribution and acceptance criteria become evals
- PRD in AI coding, in engineering work: a compact brief a coding agent or assistant uses as its source of truth for what to build
- Both share the core of any PRD: the problem, the users, the scope and the definition of done
- An AI PRD adds sections a traditional PRD lacks: eval sets, quality thresholds, guardrails, fallback behaviour, model selection and drift monitoring
- A PRD.md for an agent adds constraints an engineer would take for granted: stack, conventions, files to touch and not to touch, how to verify
- Neither replaces discovery: a sharp problem statement and product concept still come first
This guide covers the first meaning in depth, the PRD for AI products, and returns to the second, writing a PRD that an AI agent can build from, in the question on writing a PRD for an AI agent. For the traditional PRD, start with the PRD guide.












