Architecture rules

Summary

The infra invariants that constrain every change: Firebase in asia-south1, integer paise for money, ISO-8601 UTC for dates, committed env files, no legacy code, no time-based estimates.

Why it matters

These rules are the floor that makes everything else legible. Money in floats means audit reconciliation failures. Multi-region means a doubled DPDP story. Quiet *Legacy re-exports means two truths coexisting in code. Each rule is a pre-commitment that removes a class of bug rather than catching it case-by-case. They are deliberately terse because the rationale lives in the decisions they refer to.

Implications

• Monorepo: apps/website (Next.js, V1) · apps/functions (Firebase Cloud Functions). apps/mobile (Expo) preserved but post-V1. Shared: packages/shared (zod schemas, reference data). No Postgres, no Prisma, no Docker.
• Website styling: Tailwind CSS v4, className= only. Mobile (when built): Uniwind, same className= discipline.
• Money in integer paise. Never floats, never rupees, never decimals except at the display layer.
• Dates as ISO-8601 UTC strings or Firestore Timestamps.
• Server timestamps via FieldValue.serverTimestamp() — top level only.
• .env* files are committed (private repo) — do NOT gitignore them.
• No legacy code. When refactoring, delete the old path in the same change. No *Legacy, no // removed, no quiet re-exports.
• No time-based effort estimates anywhere. Use Phase + Complexity + Deviations.
• Region pinned to asia-south1 — see data-residency-dpdp.

Related

• data-residency-dpdp — the region pin and DPDP envelope
• 2026-05-30-foundational-region-asia-south1 — region decision
• 2026-05-30-foundational-mobile-uniwind-website-tailwind — styling pin
• 2026-05-30-foundational-env-files-committed — env files pin
• 2026-06-10-zod-parse-firestore-boundary — schema boundary rule
• scope-discipline — the editorial sibling of these infra rules

Sources

• .context/wiki/concepts/* § "Architecture rules"
• .context/wiki/concepts/* § "Hard constraints (V1)" — region, domain rows
• CLAUDE.md § "Env files — committed, never ignored"
• .claude/rules/money.md