Spec-First Build Docs: PRD, design system, architecture note, agents guide and readiness check

Read this PRD [paste] as the agent that will build it.
List every place you would have to guess: a missing failure step, a feature that isn't testable, a data field with no sensitivity, a decision hidden in a sentence. For each, write the question I need to answer.

Run it before the first build prompt, not after.

For this system, go through the nine readiness areas. For each check, point to the file, setting or log that answers it, or write NO EVIDENCE.
Do not mark anything Pass. A person will grade it.

The builder gathers evidence. Someone else signs the verdict.

# Spec-First Build Docs: PRD, design system, architecture note, agents guide and readiness check

A PaperChaseWebb pack, version 1.0. Written for Claude Code, Codex and Cursor, and plain Markdown, so every template also works with any agent that reads files from your repo.

A coding agent builds from whatever context it has. When the scope, the look, the stack and the rules live only in your head, the agent fills the gaps with guesses, and you pay for those guesses later in rewrites. This pack gives you the four documents to write before the first prompt, a project tree that keeps them in front of the agent, a pass that keeps them true as the project changes, and an audit to run before real users arrive. It is sized to the stakes: a weekend experiment gets one page, a client build gets the full set.

It comes from how we start our own agent builds, plus three public breakdowns we studied and rebuilt in our own words. Every source is credited by link in `09-sources.md`.

## Files

| File | What it is for |
|---|---|
| 01-size-the-gate.md | Three weights of spec (one page, standard, full) and how to pick one in a minute |
| 02-prd.md | A product requirements template an agent can build from without inventing scope, with a filled example |
| 03-design-system.md | The smallest design system that keeps agent-built screens consistent: tokens, components, states, banned moves |
| 04-architecture-note.md | One page that fixes the expensive decisions: stack, data flow, boundaries, failure behavior, reversal cost |
| 05-agents-guide.md | The rules file that governs every agent in the repo, plus a project tree for Claude Code, Codex and Cursor |
| 06-staleness-pass.md | A short routine that keeps the four documents true, with triggers that force an update |
| 07-readiness-audit.md | A nine-area production readiness check graded from evidence, with a one-page verdict |
| 08-prompts.md | 12 prompts to draft, check and maintain the whole set |
| 09-sources.md | Every source we used, linked and credited |