Omnifiscal
We built Omnifiscal end to end: a fiscal operating system for Mexico that consolidates into one platform what the market had scattered across five products that don't talk to each other. We designed a Fastify + Prisma backend on PostgreSQL with 38 business modules and ~287 endpoints, modeling the country's real fiscal complexity (all 5 CFDI 4.0 types, IEPS, state-by-state ISH, withholdings, payroll with batch stamping, SAT bulk download, and multi-company accounting) across a 58-entity schema. On top we shipped a native iOS app of 290 Swift files and ~141 views, offline-first with sync and conflict resolution, that captures expenses by photographing the receipt with on-device Apple Intelligence, at no per-scan cost and with no data leaving the phone. We built it secure by design: CSD/FIEL certificates live encrypted, stamping is centralized in the backend, and every operation is audited. The proof is that it has been in production since February 2026, with live monetization via subscriptions and payments.
Category
Fiscal
Stack
Swift (iOS nativo), TypeScript, PostgreSQL
The problem
In Mexico, electronic invoicing (the SAT's CFDI 4.0) is mandatory, but the existing tools force a trade-off: enterprise systems (Contpaqi, Aspel, SAP) are expensive, heavy, locally installed and have no real mobile apps; web services only do basic invoicing with no payroll or finance; and QuickBooks Mexico doesn't understand the country's tax complexity (IEPS, ISH, multiple withholdings, tax regimes). The accountant ends up hand-stitching five products that don't talk to each other. The problem isn't in any one system, it's between them.
What we built
- —Full CFDI 4.0 invoicing across all 5 document types (Income, Expense, Payment, Payroll, Transfer) with the end-to-end flow: draft, SAT validation, stamping via a PAC, PDF/XML, and cancellation with the SAT's 4 reason codes including substitution.
- —A real Mexican tax engine, not just 16% VAT: 0% rate, exempt, VAT and income-tax withholdings, IEPS and ISH (state-by-state lodging tax), each product tied to SAT catalog codes.
- —Electronic payroll with employees (CURP, NSS, employer registry, CLABE), weekly/biweekly/monthly periods, automatic deduction calculation, and batch stamping of an entire period in a single operation.
- —GPS time clock in the iOS app that records clock-in/out with coordinates, plus attendance history and reports.
- —SAT bulk download via FIEL/CSD: request the package, poll for status, download and parse the XMLs into the database, so accountants see the full fiscal picture without chasing invoices by hand.
- —Multi-company accounting: one account manages dozens of companies, each with its own RFC, CSD/FIEL certificates, stamp balance, folios, and collaborator team with roles.
- —A unified data model (Equipo) that treats customers, suppliers, employees, and collaborators as a single entity, so the same RFC can be a customer of one company and a supplier of another without duplication.
- —Financial management: multi-currency bank accounts, transactions, atomic inter-account transfers, reconciliation against invoices, projected cash flow, and collections with overdue tracking.
- —On-device receipt OCR with Apple Intelligence on iOS: photograph the receipt and extract issuer RFC, name, total, date, and a suggested category, with no per-scan cost and no data leaving the device.
- —Native offline-first iOS app with SwiftData and a conflict-resolving sync engine, Apple Sign In and TOTP 2FA, and a built-in invoice PDF generator.
Results
Backend live in production and staging since February 2, 2026 (green API with 6+ weeks of healthy uptime).
38 business modules in the backend (auth, companies, payroll, invoicing, collections, SAT bulk download, finance, projects, sync, and more).
A 58-model Prisma data schema on PostgreSQL.
An iOS app of 290 Swift files and ~141 views across 26 UI modules, ~95% wired to the backend.
Documented ~287 versioned REST endpoints.
Live business model: 6 stamp packages ($19 to $899 MXN) and 3 subscription tiers ($299/$499/$799 MXN/mo) integrated with subscriptions and payments.