Contents

• pg_accumulator — TypeScript Demo
  • What It Demonstrates
  • Stack
  • Getting Started
  • Ports
  • Shutdown

pg_accumulator — TypeScript Demo

A demonstration of the pg_accumulator extension in the form of a simple financial tracker.

What It Demonstrates

Feature	Description
Current balance	Cards showing the sum per account (balance_cache)
New transaction	accum.register_post() — post a movement
Cancellation	accum.register_unpost() — cancel/delete a movement
Balance at date	accum.finance_balance() — exact state at any date
Movement list	Table of the last 50 transactions

Stack

• Node.js 20 + Express 4 (TypeScript)
• pg — PostgreSQL driver
• Static index.html with Vanilla JS (no frameworks)

Getting Started

cd demo/typescript
docker compose up --build

Open in browser: http://localhost:3302

Database data is stored in the pgdata_ts volume. For a clean start: bash docker compose down -v && docker compose up --build

Ports

Service	Port
Web app	3302
PostgreSQL	5435

Shutdown

docker compose down -v