Read: docs/PRD.md, docs/research/VERDICT.md, docs/SCREENS.md, and all files in wireframes/

You are a Senior Software Architect. This is a pre-implementation phase only. Do not write any feature code.

━━━ OUTPUT 1: STACK DECISION (docs/STACK.md) ━━━

Recommend a tech stack. Justify every choice in exactly one sentence. Default to boring, proven technology. Resist novelty.

Consider: complexity of the PRD, offline requirements, team size (assume solo unless stated), performance needs, and deployment simplicity.

Structure:

• Frontend framework + why
• Styling approach + why
• Backend approach (or "none needed" if client-only) + why
• Database (or "none needed") + why
• Auth approach + why
• Hosting recommendation + why
• Unit test runner + why
• E2E test runner (Playwright — always Playwright) + why

━━━ OUTPUT 2: DATA MODEL (docs/DATA_MODEL.md) ━━━

List every entity the product manages. For each entity:

• Fields, types, constraints
• Relationships to other entities
• Which screen(s) display or modify this entity

Keep it simple. Normalise only what needs normalising.

━━━ OUTPUT 3: CLAUDE.md (project root) ━━━

This is the most important file you will write. It persists across every future session. Write it carefully.

---

CLAUDE.md

What We Are Building

[One paragraph from PRD vision]

Stack

[From STACK.md — 6-8 bullet points]

Project Structure

[Folder tree with one-line description of each folder's purpose]

Commands

npm run dev — start development server npm run build — production build npm run test — run unit + integration tests npm run test:e2e — run Playwright E2E suite npm run test:visual — run visual regression tests npm run coverage — coverage report npm run lint — ESLint + TypeScript check

Non-Negotiable Rules

1. Every feature must have unit + integration + E2E tests before it is considered complete. No exceptions. No "I'll add tests later."
2. Playwright tests use ONLY semantic locators: getByRole(), getByLabel(), getByText(), getByTestId() Never CSS class selectors. Never XPath.
3. The test suite only grows. Tests are never deleted — only updated.
4. Every bug fix ships with a regression test that first reproduces the bug.
5. Visual snapshots are the design truth. Unintentional visual changes are treated as regressions.
6. A feature with a quality score below 85 is not done.

Coding Conventions

[Language-specific: naming, file organisation, import order, etc.]

Definition of Done Checklist

[ ] Feature works per acceptance criteria in PRD [ ] Unit tests written and passing (≥80% line coverage) [ ] Integration tests written and passing [ ] Playwright E2E test covers happy path + at least 2 edge cases [ ] Visual regression snapshot created or updated [ ] No TypeScript errors (if applicable) [ ] No lint errors [ ] QA quality score ≥ 85

Known Patterns

[Document any architectural patterns chosen, e.g.: "Use Repository pattern for all data access" "All API calls go through src/lib/api.ts — never fetch() directly in components"]

━━━ OUTPUT 4: MCP CONFIG (.mcp.json) ━━━

Create .mcp.json at project root with Playwright MCP configured for interactive browser testing. This is REQUIRED for /test-ui and /qa-run:

{ "mcpServers": { "playwright": { "command": "npx", "args": [ "@playwright/mcp@latest", "--caps", "screenshot,pdf,testing" ] } } }

The "testing" cap enables: browser_generate_playwright_test, browser_generate_locator, browser_verify_text_visible, browser_verify_element_visible, browser_verify_value.

The "screenshot" cap enables: browser_take_screenshot for visual verification.

If the project needs GitHub integration, add: { "github": { "command": "npx", "args": ["-y", "@modelcontextprotocol/server-github"], "env": { "GITHUB_PERSONAL_ACCESS_TOKEN": "YOUR_TOKEN" } } }

━━━ OUTPUT 5: PROJECT SCAFFOLD ━━━

Execute:

1. Create all folders per the structure in CLAUDE.md
2. Initialise package.json / equivalent
3. Install all dependencies
4. Configure: ESLint, Prettier, TypeScript (if applicable)
5. Configure Vitest (or chosen unit runner) with coverage reporting
6. Configure Playwright with:
   • Default project (Chromium, 1280x720)
   • Mobile project (375x667, mobile emulation)
   • Visual project (for snapshot tests)
7. Create .mcp.json with Playwright MCP (see OUTPUT 4)
8. Create .github/workflows/qa.yml (CI pipeline)
9. Create qa/browser-tests/ directory for Playwright MCP test artifacts
10. Write a single smoke test: "dev server starts and returns 200"
11. Run the smoke test. Confirm it passes.

When complete, say: "Architecture complete. CLAUDE.md written. Project scaffolded. Playwright MCP configured. Smoke test passing. Ready to build features — run /build [feature-name] using the P0 features from the PRD, in order."