IO Saga — Real-Time CS2 Skin Economy

What it is

IO Saga is a live economy platform built around Counter-Strike 2 skins. Users browse items priced by real market data, buy instantly, and receive them through automated Steam trade offers — no manual handling, no waiting on a human to accept.

Architecture

The backend is Node.js + Express with a raw PostgreSQL layer (no ORM — explicit SQL keeps the trade-critical queries auditable). Redis handles sessions, rate limiting, and hot price caches. Socket.io pushes live price movement and trade status to the client in real time.

The Steam layer is the hard part. A pool of steam-user bots manages authenticated sessions with steam-totp token generation, and steam-tradeoffer-manager handles the full offer lifecycle: proposal → sent → awaiting confirmation → accepted → completed. Mobile confirmations are automated through the Steam confirmation protocol, with retry logic and error recovery for every state transition a trade can get stuck in.

The data side

Prices don't come from Valve — they come from the secondary market. A continuous ingestion pipeline (see the Market Price Pipeline) feeds Buff163 market data into Postgres, and the platform recalculates item values, trends, and spread signals on every ingest. That's what makes instant buy/sell pricing possible without taking on inventory risk.

What I own

Everything: schema design, trade engine, bot infrastructure, real-time layer, UI, deployment, and monitoring. The interesting engineering problems here are all distributed-systems problems — idempotent trade settlement, crash recovery mid-confirmation, and keeping three independent sources of price truth consistent under failure.