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Sell Sync

Invite-only SaaS for game-account resellers that syncs inventory and auto-generates listings across 4 games and 6+ marketplaces, with a browser extension for one-click account linking.

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Sell Sync

Overview

SellSync is a production, invite-only platform (sellsync.space) that centralizes inventory, listing, and order management for game-account resellers across Valorant, Call of Duty, Fortnite, and PUBG Mobile, publishing to six marketplaces: Eldorado, GameBoost, PlayHub, U7Buy, Racoon, and SkyCoach. A companion Chrome extension, SellSync Linker, automates the account-linking OAuth flow so sellers never have to copy-paste tokens by hand. An asynchronous background pipeline (Redis + RQ) handles inventory sync and image generation, cutting API response times by 85%.

4 Titles

Games Supported

6+ Platforms

Marketplace Sync

-85%

API Response Time

One-Click

Account Linking

How it came together

Challenge

Each game and marketplace has its own inventory shape and listing template, and Riot/Epic's OAuth flows don't return tokens the same way: Valorant hands one back in a redirect URL, Fortnite renders it as JSON on the landing page. Linking an account originally meant a seller manually opening the provider's login, copying a token or code, and pasting it back into the dashboard, a slow and error-prone process at scale, on top of needing to keep listing templates and pricing in sync across marketplaces without overselling.

Solution

I structured the Flask backend around a per-game service module (Valorant, Call of Duty, Fortnite, PUBG Mobile), each with its own importer and per-marketplace ad-generator behind a common interface, so adding a new game or marketplace doesn't touch the others. To remove the manual copy-paste step, I built SellSync Linker, a Chrome extension whose background service worker watches for each provider's specific OAuth callback shape and hands the result straight to the open dashboard tab via a scoped CustomEvent, with optional auto-fill login and 2FA handling, and messaging locked to sellsync.space so no other site can talk to it. Redis + RQ workers handle listing sync and OpenCV/Pillow-based image generation asynchronously, Supabase stores accounts with encrypted credentials, and CSV/GameBoost bulk import lets sellers onboard existing inventory in one pass.

Outcome

SellSync now runs as an invite-only production platform at sellsync.space, syncing 4 games across 6+ marketplaces with bulk CSV/GameBoost import, an 85% reduction in API response times, and one-click account linking via the browser extension in place of the old manual token copy-paste flow.

Technical Stack

Next.jsFlaskSupabaseRedisRQOpenCVApexChartsChrome ExtensionOAuth

Tags

#Next.js#Flask#Supabase#Python#Chrome Extension

Visual Showcase

Dashboard Overview

Centralized dashboard showing linked accounts and stats.

Dashboard Overview
Valorant Management
Import Accounts
Inventory Analysis
Asset Visualization
Account Listing
Platform Configuration
Game Settings
Performance Analytics
User Management
System Logs
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Key Features

One-Click Account Linking

A companion Chrome extension captures the Riot/Epic OAuth result automatically and hands it to the dashboard, no more copying tokens by hand.

Multi-Game, Multi-Marketplace

Valorant, Call of Duty, Fortnite, and PUBG Mobile accounts synced and listed across Eldorado, GameBoost, PlayHub, U7Buy, Racoon, and SkyCoach.

Bulk Account Import

Onboard existing inventory in one pass via a CSV template or a direct pull from a GameBoost seller account.

Advanced Inventory Analytics

Deep extraction and visualization of account assets, including skins, ranks, and rarity distribution.

Dynamic Marketing Pipeline

Automated asset generation engine using OpenCV and Pillow to create high-converting, per-marketplace listing images at scale.