The Stellar-powered beat marketplace where producers get paid instantly.

Crate is a peer-to-peer marketplace for music producers to sell sample licenses on-chain. Upload a beat, set your price, and earn on every sale and resale — instantly, with no intermediary. Buyers get a tamper-proof on-chain license. Collaborators split royalties automatically at the contract layer.

Streaming platforms pay producers fractions of a cent per play, months after the fact. Beat marketplaces take cuts of 30–50% and hold payouts for 30–90 days. When a track gets sampled, the original producer rarely sees a royalty at all.

Soroban contracts change the economics. Revenue splits happen in the same transaction as the purchase — zero delay, zero platform cut beyond a transparent basis-points fee. Resale royalties are enforced by the contract, not by a platform's goodwill.

Producer uploads a beat → IPFS stores the audio → contract stores metadata + price
  ↓
Buyer selects a license tier (Basic / Premium / Exclusive)
  ↓
purchase_license: platform fee split, producer cut paid out, collaborator shares distributed
  ↓
On-chain license record created — buyer can prove ownership
  ↓
Buyer lists for resale → buy_resale: producer gets resale royalty, platform fee, seller gets remainder
  ↓
Producer calls withdraw_earnings → accumulated earnings transfer to wallet

Every payment is atomic. If a split fails, the entire purchase reverts. No partial pays, no accounting debt.

Single Rust/WASM contract deployed on Stellar Testnet. Handles the full marketplace lifecycle.

License tiers: Basic · Premium · Exclusive — each with independent pricing set by the producer at upload time.

Collaborator splits: up to a configurable maximum collaborators per sample, shares expressed in basis points. The contract validates that shares sum correctly and distributes them atomically on every purchase.

Resale royalties: producers specify a resale royalty percentage at upload. Every secondary sale enforces it at the contract layer — no off-chain trust required.

┌─────────────────────────────────────────────────────────────────┐
│                      crate-frontend                             │
│   React 18 + Tailwind + Freighter / EVM wallet                 │
│                                                                 │
│  Marketplace      Producer Dashboard    Upload                  │
│  ├ SearchBar      ├ RevenueChart        ├ IPFS upload           │
│  ├ FilterPanel    ├ WithdrawalHistory   ├ Collaborator config   │
│  ├ SampleCard     ├ BeatPerformance     └ Price per tier        │
│  ├ SalesFeed      └ StatsCard                                   │
│  └ CrossChainPaymentModal (CCTP)                                │
└───────────────────────────┬─────────────────────────────────────┘
                            │ REST + WebSocket
                            ▼
┌─────────────────────────────────────────────────────────────────┐
│                      crate-backend                              │
│   Express · TypeScript · PostgreSQL · Redis                     │
│                                                                 │
│  /samples      CRUD + IPFS proxy                                │
│  /royalties    split calculations + payout records              │
│  /analytics    per-sample stats and platform aggregates         │
│  /moderation   content review queue                             │
│  /webhooks     outbound event dispatch                          │
│  /ws           WebSocket server — real-time sales feed          │
│                                                                 │
│  Soroban event indexer → decodes contract events → Postgres     │
│  Reconciliation worker  → aligns on-chain state with DB         │
│  Redis cache layer      → cache-aside on samples + analytics    │
└───────────────────────────┬─────────────────────────────────────┘
                            │ Soroban RPC
                            ▼
┌─────────────────────────────────────────────────────────────────┐
│                  Stellar Testnet / Soroban                      │
│                                                                 │
│              crate_marketplace contract                         │
│   upload · purchase · resale · withdraw · collaborator splits   │
└─────────────────────────────────────────────────────────────────┘

The backend is built for production: a PostgreSQL database for off-chain state, a Soroban event indexer that decodes contract events and writes them to relational tables, a reconciliation worker that periodically checks on-chain state against the database and flags drift, and a Redis cache layer with cache-aside reads and targeted invalidation on writes.

WebSocket support streams real-time sale events to connected frontends — the SalesFeed component on the marketplace page receives them without polling.

The IPFS proxy avoids exposing the pinning service credentials to the client. Audio uploads go client → backend → IPFS; the CID returned is what gets written to the contract.

The marketplace supports full-text search with keyboard shortcut activation and autocomplete, a filter panel (genre, BPM range, license tier, price) with URL-serialised state for shareable links, and pagination. Sample cards show a 30-second preview player.

The producer dashboard shows accumulated on-chain earnings from get_earnings, a revenue chart over time from the backend analytics endpoint, per-beat performance stats, and a withdrawal history. Withdrawal calls withdraw_earnings directly on the contract via Freighter.

Multi-wallet support handles both Freighter (Stellar native) and EVM wallets. Cross-chain payment via Circle's CCTP lets buyers on EVM chains pay in USDC without bridging manually.

The Expo app covers the producer workflow on mobile: a Discover feed of recent uploads, an Earnings screen with live balance from the contract, an Upload tab for submitting beats from the device, and a beat preview player using expo-av. Haptic feedback on purchase confirmation. Safe area insets handled correctly on notch devices.

• Freighter browser extension
• Stellar Testnet account funded via Friendbot
• Node.js 20+, Rust + cargo, PostgreSQL, Redis (optional — gracefully disabled)

# Contracts
cd crate-contracts
cargo test
stellar contract build

# Backend
cd crate-backend
cp .env.example .env       # fill in RPC URL, contract ID, Postgres, IPFS creds
npm install && npm run dev

# Frontend
cd crate-frontend
cp .env.example .env
npm install && npm run dev

# Mobile
cd crate-mobile
cp .env.example .env
npx expo start

Contracts: upload with collaborators, purchase across all three license tiers, revenue split arithmetic, resale flow with royalty enforcement, collaborator empty check, zero-share validation, comprehensive collaborator revenue-split matrix.

Backend: sample repository CRUD, royalty split calculations, payout records, reconciliation worker logic, moderation queue, Soroban event decoder, IPFS service, auth middleware, route-level timeout handling — across 10 test files.

MIT · Built on Stellar and Soroban