# 05 — Master Build Checklist

Working checklist; tick as we go. Ordered roughly by phase. Details live in the other docs.

## Foundations (Phase 0)
- [ ] Product name + branding decided (D1)
- [ ] Tech stack locked after spikes (D2)
- [ ] Sync approach locked: buy (PowerSync/ElectricSQL) vs custom outbox (D3)
- [ ] GSP vendor chosen for e-Invoice/e-Way (D4)
- [ ] Pricing tiers & edition feature matrix signed off (D5)
- [ ] Sync spike passes pulled-cable test
- [ ] Hardware spike: ESC/POS print, drawer kick, scanner, scale — from chosen shell
- [ ] Billing engine v0 reproduces 100 real Classic bills to the paisa
- [ ] Oracle schema mapped; 3 real datasets exported and audited
- [ ] Billing screen prototype tested with 3 real cashiers (timed)
- [ ] Repo, CI, environments (dev/stage/prod), code review rules, error tracking

## Data model & platform
- [ ] Tenant → stores → counters → users model with RLS
- [ ] Item master (HSN, GST dated rates, MRP, multi-unit, barcodes, batch/expiry)
- [ ] Party master (GSTIN validation, credit limits)
- [ ] Document model: append-only bills/notes with client UUIDs, per-counter series
- [ ] Audit log: append-only, before/after, synced, unpurgeable
- [ ] Outbox/inbox sync tables + background worker + idempotency
- [ ] Licensing service: plans → feature flags → signed license token
- [ ] Auto-update channel with staged rollout + rollback
- [ ] Encrypted cloud backup of store DBs + restore drill actually performed
- [ ] Telemetry + crash reporting (PII-free)

## POS (Phase 1)
- [ ] Billing screen: scan box, lines, totals, hold/resume, one-key cash close
- [ ] Fuzzy item search < 150 ms on 50k SKUs
- [ ] Payments: cash, card (record), UPI static QR, khata, split
- [ ] Returns/exchange + credit notes
- [ ] Thermal + A4/A5 printing, print profiles, reprint
- [ ] Shift open/close, denomination count, day-end report
- [ ] Supervisor PIN gates (void, discount cap, price override)
- [ ] Power-cut recovery: reopen mid-bill intact
- [ ] Offline soak test: 48h no internet, then clean sync
- [ ] Keyboard map + "Classic keys" preset

## Back office (Phase 1–2)
- [ ] Item/party CRUD + Excel import/export
- [ ] Purchase entry with price/MRP update prompts + label print queue
- [ ] Stock views, adjustments, valuation
- [ ] Ledgers, outstanding, ageing
- [ ] Core reports + GST invoice formats, HSN summary
- [ ] Users/roles/permission matrix + audit browser
- [ ] Dashboard with sync-health per store

## Compliance (Phase 2)
- [ ] GSTR-1 / GSTR-3B JSON exports
- [ ] e-Invoice IRN queue (offline-tolerant) via GSP
- [ ] e-Way bill generation
- [ ] Tally export (masters + vouchers)
- [ ] FY close + lock dates
- [ ] Audit-trail compliance review (MCA) for company clients

## Engagement & polish (Phase 2)
- [ ] WhatsApp e-bill + khata reminders + UPI collect links
- [ ] UPI dynamic QR + webhook auto-confirm
- [ ] Schemes/offers engine (golden tests)
- [ ] Multi-counter + Store Hub LAN sync
- [ ] Weighing-scale barcode support
- [ ] Hindi + one regional language UI
- [ ] Onboarding wizard: GSTIN → store → import → first bill < 15 min

## Differentiators (Phase 3)
- [ ] Purchase Inbox: email-in + upload + parse (AI) → draft → review UI → post
- [ ] Item-matching memory (supplier name ⇄ our SKU)
- [ ] GSTR-2B reconciliation
- [ ] Owner app v1 (sales live, alerts, approvals)
- [ ] Stock-take mobile scanning
- [ ] Loyalty + redemption at counter
- [ ] Dashboards + scheduled WhatsApp/email digests

## Migration & GTM (continuous)
- [ ] Classic → Next migration tool with verification report
- [ ] Parallel-run playbook + cutover checklist
- [ ] 5 pilot stores migrated and billing daily
- [ ] Dealer kit: install, train, migrate, support scripts
- [ ] Pricing/upgrade offers for Classic base
- [ ] Support runbook + sync diagnostics dashboard for the support team

## Scale-out (Phase 4)
- [ ] HO console, central pricing, transfers with e-Way
- [ ] Consolidated multi-store GST + reporting
- [ ] API access for Enterprise
- [ ] Android POS evaluation
- [ ] Classic sunset plan (>80% migrated first)