$ cd ../projects

thos@portfolio:~$ cd ~/projects/kotisthos && cat README.md

── Kotisthos ──

personal project · April 22, 2026

[Next.js] [TypeScript] [Zustand] [TanStack Query] [shadcn/ui] [Zod]

Kotisthos

Multi-tenant SaaS platform that automates dues tracking for families, associations, classes, and professional teams — configurable contribution rules, real-time payments, zero paperwork.

Why Kotisthos exists

Group dues are usually tracked in a shared spreadsheet: someone forgets to update it, partial payments break the math, and chasing late payers becomes a part-time job. Kotisthos replaces the spreadsheet with rules that generate their own periods, statuses that update themselves, and receipts that issue themselves — so the only manual act left is recording a payment.

How it works

  1. Create your group — a Super Admin sets up the organization and assigns an administrator
  2. Add members — CSV import or manual entry; credentials are generated automatically
  3. Define the rules — amount, frequency (monthly, weekly, or quarterly), due day; periods are generated up to 12 months ahead
  4. Track in real time — recovery rate, top late payers, and upcoming deadlines at a glance

Every payment is recorded against its period — full, partial, or in advance across multiple periods — and all dependent statuses recalculate instantly. A nightly cron job closes the loop by flipping overdue unpaid periods to late automatically, so nobody has to remember to do it.

Statuses that speak for themselves

Each contribution carries one precise, color-coded status:

StatusMeaningSet by
PaidPeriod fully coveredInstant recalculation
PartialSome of the amount receivedInstant recalculation
AdvanceCovers future periods tooInstant recalculation
PendingDue date not yet reachedRule generation
LatePast due and unpaidNightly cron

Three roles, three isolated spaces

CapabilitySuper AdminAdminMember
Manage groups & subscription plans✓
Assign admins, block/unblock groups✓
Platform-wide metrics dashboard✓
Manage members & contribution rules✓
Record payments, issue PDF receipts✓
Recovery dashboard, CSV/Excel exports✓
View own dues, history & alerts✓
Anonymous aggregate view of the group✓

Tenants are hermetically isolated: no data crosses from one group to another, and each role sees exactly its own slice.

Traction and outputs

The product landing reports 240+ active groups, 4 800+ members managed, and a 97% satisfaction rate. Every payment can emit a PDF receipt, and any admin can export the full payment history to CSV or Excel in one click.

Tech Stack

  • Next.js 16
  • TypeScript
  • Zustand (state management)
  • TanStack Query (data fetching)
  • Axios
  • shadcn/ui
  • Zod (validation)