Building & Product

How do I write a spec or PRD that an AI coding agent like Claude Code can build from?

Write a short spec the agent can check its own work against, not a long PRD. 1) State the outcome: who uses it, the job it does, and what done looks like as things you can test. 2) List the must-haves, what it must not do or touch, and what is out of scope for now. 3) Name the stack, the data it stores and the screens or commands, briefly. 4) If you have not thought it through, let the agent interview you: Anthropic's own advice is to ask Claude Code to interview you until it could write the spec, save it as SPEC.md, then build from it in a fresh session. 5) Have it split the spec into small tasks, do one at a time, and review each against SPEC.md. Keep standing project rules (build and test commands, conventions) in CLAUDE.md or AGENTS.md, not in the spec. GitHub's Spec Kit and Kiro's specs turn the same flow into requirements, a plan and a task list.

On the AI map, 29 October 2026 Coding agents App builders

Go deeper

7 resources.

🛠 Tool

GitHub's open-source toolkit for spec-driven development: a constitution, then specify, plan and tasks commands you run inside your coding agent.

Spec Kit

GitHub 2026

Open github.com →
🧭 Guide

Shows the three files a working spec splits into: requirements with acceptance criteria, a design doc, and a task list you track.

Specs (Kiro docs)

Kiro (AWS) 2026

Open kiro.dev →
🧭 Guide

The open format for a README written for coding agents: setup and test commands and code style, read by Codex, Copilot and others.

AGENTS.md

AGENTS.md 2026

Open agents.md →

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The same ground, over in Build the product, our Starting Up track.

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