Harmonia | Flutter Music Streaming App With NestJS Backend and Next.js Admin Panel

Harmonia | Flutter Music Streaming App with NestJS Backend and Next.js Admin Panel
Launch your own music streaming service on Android and iOS – three complete projects in one package

Harmonia is a complete, production-ready music streaming platform. Listeners get a polished Flutter app for Android and iOS with background playback, synced lyrics, offline downloads, Chromecast and Android Auto. You get a secure NestJS + PostgreSQL backend and a Next.js admin panel to run the catalogue, the home feed, Premium subscriptions, ads and push notifications.

All three projects ship as full source code in one download. Nothing is delivered separately.

Important – Third-Party Services and Possible Costs

Harmonia is a self-hosted package. You receive the full source code for all three projects, with no licence keys and no subscription payable to us.

Some features connect to third-party services. Those services are not included in this purchase. Each one is billed to you directly by its provider, under that provider’s own terms and pricing.

Please note: buyers are responsible for any and all fees charged by external services. This includes hosting, developer accounts, app store commissions, storage and any usage beyond a provider’s free tier. None of these fees are part of the item price, and none of them are collected by us.

• Hosting (required): a VPS or cloud server with Node.js 20+ and PostgreSQL 14+ for the backend and admin panel. Billed by your hosting provider.
• Firebase – your own project (required): Authentication for app sign-in and Cloud Messaging for push notifications (firebase_core, firebase_auth, firebase_messaging in the app; firebase-admin in the backend). You create and maintain your own Firebase project and accept Google’s Firebase Terms of Service. The free Spark plan covers typical usage; usage-based beyond it, billed by Google. The package contains placeholder Firebase files only.
• Cloudflare R2 (required): stores audio files, cover art and images uploaded from the admin panel. Includes a free tier; usage-based beyond it, billed by Cloudflare.
• Google Play Developer account (required to publish on Android): USD 25 one-time, paid to Google.
• Apple Developer Program (only to publish on iOS): USD 99 per year, paid to Apple.
• Payments – Google Play Billing (optional): the only payment method included. Premium subscriptions are sold through Google Play, which takes a commission on every sale, typically 15-30%. The backend verifies purchases and renewals with the Google Play Developer API (googleapis), which requires your own Google Cloud service-account credentials.
• Not included – Apple In-App Purchase, Stripe, PayPal and other payment gateways: this version has no checkout integration for them. Adding one is your own development work.
• Facebook Login – your own Facebook App ID (optional): Facebook sign-in (flutter_facebook_auth / Facebook SDK) requires you to register your own app at Meta for Developers and use your own App ID and client token, under Meta’s Platform Terms. Free. No Facebook App ID is included.
• FFmpeg (required for stream qualities, free): installed on your own server with its package manager (for example sudo apt install ffmpeg). It is not bundled with the package.
• Advertising – Google AdMob (optional): free to join and integrate; you earn revenue with your own AdMob account. You are responsible for following AdMob and Google ad network policies and for any costs related to your account or traffic. Only Google’s official test ad IDs are included.
• Expiring audio links – Cloudflare Workers (optional): the included worker script signs audio URLs. Includes a free tier; usage-based beyond it.
• Music licensing (required for real content): you must hold the rights, or a licence, for every track you publish. The demo uses Creative Commons music for demonstration only; no music is included in the package.

The item price covers the source code and documentation only. To go live you need hosting, your own Firebase project, a Cloudflare R2 bucket, and a Google Play (and optionally Apple) developer account; for Premium, your own Google Cloud service account; for Facebook sign-in, your own Facebook App ID. Every service marked optional can be left out; the platform runs without it, with the matching feature switched off. Third-party pricing is outside our control and may change, so please check each provider’s current rates before you buy. We support our own code, but we cannot support, waive or refund any third-party fees or account approvals.