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● Live in productionSparks Business — Inventory, Sales & GST Invoicing Platform
Multi-tenant inventory, sales and GST-invoicing SaaS for Indian trading businesses
Visit Live Site49 data models
Installable PWA
Health-gated CI/CD
Overview
Sparks Business is a multi-tenant platform built by eSparks IT Solutions to run inventory, purchases, sales and GST invoicing from one system. It pairs a NestJS 11 API with an installable Next.js 15 PWA, backed by PostgreSQL 17 through Prisma 6 across 49 data models. Every query is scoped to its tenant through an AsyncLocalStorage-driven Prisma client extension, and an append-only audit table is enforced at the database level — even a direct update or delete against it is rejected by a trigger. GST math (CGST/SGST/IGST splitting, GSTIN validation) runs on decimal.js for exact, rounding-free results, and a real Tally XML importer lets a business bring in existing ledgers, vouchers and stock items instead of starting over. Redis and BullMQ handle background email and document generation, S3-compatible object storage holds product images, invoice PDFs and backups, and Microsoft Graph sends transactional email. Deploys are health-gated, so a broken build never reaches production.
Running a trading business across Tally, Excel and WhatsApp doesn't scale.
Stock and sales live in different files.
Purchases go into one register, sales into another, and GST gets computed by hand or bolted on at month-end — with no single view of what's actually in stock or who owes what.
GST math is easy to get wrong.
Manually splitting CGST, SGST and IGST, tracking which invoice used which rate, and reconciling rounding differences eats hours every filing cycle.
Migrating off Tally feels like starting over.
Years of ledgers, vouchers and stock history sit in an export file nobody wants to re-type.
A trading business doesn't need five tools and a spreadsheet. It needs one system that already knows what's in stock, what's owed, and what tax applies.
Why it matters
The outcomes that actually move the needle
One system for buy, stock, sell and invoice.
Purchases update stock, sales generate GST-correct invoices, and payments reconcile against real dues — no manual re-entry between tools.
GST computed to the paisa, automatically.
CGST/SGST/IGST split, GSTIN checksum validation, and exact decimal math remove the manual tax-calculation risk.
Bring your Tally history with you.
A real XML import reads existing ledgers, vouchers and stock items instead of asking you to start from zero.
Your data stays yours, and stays safe.
Tenant isolation is enforced at the database, not just trusted to the app — and backups run encrypted to a destination you choose.
Works like an app, even offline.
Install it to your home screen; a dedicated offline view keeps you working when the connection doesn't.
Every action is on the record.
An append-only audit log — even a database update attempt against it is rejected — gives you a trustworthy trail.
Key Capabilities
What we designed, built and shipped
Tenant isolation enforced at the database, not just the app layer
GST-correct invoicing with exact decimal math (CGST/SGST/IGST)
Real Tally XML import for ledgers, vouchers and stock items
Append-only audit log — a DB trigger rejects update/delete against it
Technology Stack
Every choice made for a reason — not just what's trendy
| Layer | Technology | Why |
|---|---|---|
| API | NestJS 11 (modular monolith) | Testable, structured service boundaries without microservice overhead |
| Web | Next.js 15 — installable PWA | Works like a native app, offline-aware |
| Database | PostgreSQL 17 + Prisma 6 | Relational integrity across 49 real domain models |
| Cache & queues | Redis + BullMQ | Background email and PDF generation, off the request path |
| Auth | Argon2id + rotating opaque refresh tokens | OWASP-baseline password hashing; stolen tokens can't be replayed |
| Tax engine | decimal.js | Exact GST math, no floating-point rounding drift |
| Object storage | S3-compatible API (AWS SDK) | Product images, invoice PDFs and backups |
| Microsoft Graph | Transactional email for invitations, resets and CA sharing | |
| Security | Helmet + rate limiting | Security headers and abuse protection on every endpoint |
| CI/CD | GitHub Actions, health-gated deploy | A broken build never reaches production |
Architecture
How every tenant stays isolated
One database, enforced boundaries — every request is scoped to its business before a single row is touched.
Every request resolves its tenant into AsyncLocalStorage, and a Prisma client extension applies that scope automatically — no query can accidentally cross a tenant boundary. Background jobs, object storage and transactional email all run through real, verified integrations: Redis/BullMQ, S3-compatible storage, and Microsoft Graph.
How it works
From sign-up to your first GST invoice
1
Set up your business
Add your GSTIN, locations and opening stock.
2
Add products & parties
Products, customers and suppliers — or import them straight from a Tally export.
3
Record purchases
Stock updates automatically as goods come in.
4
Sell and invoice
Sales orders become GST-correct invoices in one flow.
5
Track, report, back up
Reports show GST, stock and dues; backups run to your chosen destination.
Deployment
How it runs
Fully managed, single environment.
We run it on our own infrastructure — Docker Compose behind a health-gated deploy pipeline, so a broken build never reaches production.
Integrations
- S3-compatible object storage — product images, invoice PDFs and backups
- Google Drive & OneDrive — alternate encrypted backup destinations
- Microsoft Graph — transactional email for invitations, resets and CA sharing
- Tally XML import — bring ledgers, vouchers and stock items from an existing Tally export
See it running with real business data.
We'll walk you through inventory, sales, GST and reporting on a live tenant — on a call. No commitment, no sales script.
Complete feature guide
Everything the platform does
Sparks Business is a multi-tenant inventory, purchase, sales, GST and invoicing platform for stock-driven businesses. Buy, stock, sell, invoice and stay on top of tax — one system, real GST math. Here is everything the platform does.
Operations
Run the whole trading cycle
Buy, stock, sell, invoice and get paid — one system, real GST math, not a spreadsheet.
Products & inventory
- Product catalogue. Products, variants and categories with HSN/SAC codes.
- Multi-location stock. Stock transfers between locations, with adjustments and a full movement history.
- Weighted-average costing. Inventory value calculated on weighted-average cost, not guesswork.
Purchases & sales
- Purchase orders. Record purchases and receive stock straight into inventory.
- Sales & invoicing. Sales orders turn into GST-correct invoices in one flow.
- Customers & suppliers. A full party ledger for every customer and supplier.
- Tally XML import. Bring ledgers, vouchers and stock items across from an existing Tally export.
GST & tax
- CGST / SGST / IGST engine. Automatic inter-state vs. intra-state split, computed to the paisa.
- GSTIN validation. Checksum-validated GSTIN on every party.
- Exact money math. Decimal arithmetic throughout — no floating-point rounding drift.
Payments & dues
- Payment allocation. Payments apply against specific invoices, so dues are always accurate.
- Outstanding reports. See exactly which customers owe what, at a glance.
Reports & exports
- Sales, purchase & GST reports. Output and input GST, inventory movement, and profit — built in.
- CSV export. Take any report out to a spreadsheet.
Platform & security
Built for real businesses, not a demo
Tenant isolation enforced at the database, not just the app — plus real backup and disaster recovery.
Multi-tenancy
- Isolated by design. Every tenant-owned table is enforced through a Prisma extension — an unscoped query throws rather than risk leaking data.
- Database-level guarantees. Partial unique indexes and check constraints back up the application layer.
Access control
- Role-based permissions. Eight system roles across a granular permission catalogue.
- Invitations. Add teammates by email invitation, not shared logins.
Audit & accountability
- Append-only audit log. Audit rows are enforced immutable at the database level — even an update attempt is rejected.
Backup & recovery
- Three backup destinations. S3-compatible storage, Google Drive or OneDrive — your choice.
- Encrypted backups. Every backup is encrypted before it leaves the server.
- Tested restore path. Restore is a real, tested flow — not a one-way export.
Installable PWA
- Works like an app. Install to your home screen — no app store required.
- Offline-aware. A dedicated offline view keeps the app usable without a connection.
- Quick actions. Jump straight to New Sale or Stock from a home-screen shortcut.
Security & privacy
- Passwords hashed with Argon2id, tuned to OWASP's baseline parameters.
- Refresh tokens are opaque, stored only as hashes, and rotate on every use.
- Reusing a revoked refresh token immediately revokes every session in that family.
- Rate limiting on every endpoint — tighter still on login.
- Security headers enforced on every response.
- Every tenant-owned table is guarded by both the application layer and database constraints.
- Backups are encrypted before they leave the server.
Reliability
- Hundreds of automated tests run in CI before every deploy.
- Deploys are health-gated — the pipeline polls the live health endpoint before declaring success.
- Background jobs (email, PDF generation) run through a real queue, not inline in the request.
- Manual, tag-triggered deploys — a broken main branch can never auto-deploy to production.
See it in action
This product is live in production — explore it for yourself.
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