Trading & bots · March 2026

Ultra-fast CS skins auto-buy bot — Playwright, WS

A tool for live sale-feed monitoring and accelerated CS-skin purchasing on the skinport.com marketplace. The bot receives a real-time stream of new listings over WebSocket, instantly filters them against user rules, and drives a matching item to the payment page in ~2 seconds. Final confirmation (entering the CVC) always stays with the user — there is no automatic payment.

What was built:

Live Sale Feed monitoring over a binary protocol (Socket.IO + msgpack) with auto-reconnect
In-memory O(1) filter engine: matching by skin name, float (wear) range, pattern ID and max price in sub-milliseconds
Optimized purchase flow (~2.2s E2E): fast navigation (domcontentloaded ~437ms), SPA Add to Cart click (~87ms), direct checkout (~769ms), stop before CVC entry
Session management: persistent Chromium profile (Playwright), encrypted cookie storage, automatic CSRF token refresh (TTL 5 min)
Rate limiting: 500ms minimum interval, post-purchase cooldown, exponential backoff on 429/503 (up to 60s)
REST + WebSocket API (Fastify): module state, rule CRUD, purchase log, manual E2E purchase test
React + Vite + TailwindCSS web panel: status, live feed, rule editor, purchase history

Stack: Node.js 20, TypeScript, Fastify, Socket.IO, msgpack, undici, Playwright (Chromium), pino, React, Vite, TailwindCSS, Vitest.

Role: end-to-end design and development of the bot (backend, browser automation, real-time, UI).

Project screens

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