Crate · Contracts

Soroban smart contracts — the trustless core of the Crate beat marketplace.

Overview · Functions · Architecture · Deploy · Testing

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Currently Building

Feature	Status	Branch
Core marketplace contract	✅ Done	main
Three license tiers (Lease/Premium/Exclusive)	✅ Done	main
90/10 revenue split with XLM token transfer	✅ Done	main
Collaborator revenue split (basis points)	🔄 In Progress	feat/collab-splits
Dispute resolution for exclusive purchases	📋 Planned	—
Mainnet deployment	📋 Planned	—

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Overview

The crate_marketplace contract is the source of truth for every beat sale on Crate. It handles payments, licensing, and revenue splits — without any intermediary.

No escrow service. No payment processor. No chargebacks. The contract enforces every rule at the protocol level.

"A producer selling a $20 beat on Ethereum loses $5+ in gas. On Crate, the contract takes $2. The producer keeps $18."

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Deployed Contract

Network	Address
Stellar Testnet	CA7DGEWWS3VH5J2I4I7FFEB5UHK2MJSYWDKDQKXQM7GDNLI2IRATDTLG
Stellar Mainnet	Coming soon

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Contract Functions

Write

Function	Auth	Description
__constructor(platform_fee, platform_address)	—	Initialize with fee (basis points) and platform wallet
upload_sample(uploader, title, ipfs_cid, lease_price, premium_price, exclusive_price, genre, bpm)	uploader	List a beat with all three tier prices
purchase_license(buyer, sample_id, token_address, tier)	buyer	Buy a license — XLM transfers immediately, 90/10 split
withdraw_earnings(producer, token_address)	producer	Pull accumulated balance to wallet
delist_sample(uploader, sample_id)	uploader	Remove listing — fails if any license sold

Read

Function	Returns	Description
get_sample(sample_id)	SampleData	Full metadata + prices + sale count + exclusivity
get_earnings(address)	i128	Withdrawable balance in stroops
get_stats()	(u32, i128)	Total samples listed + total XLM volume

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Architecture

Producer calls upload_sample()
         │
         ▼
┌───────────────────────────────────────────┐
│           crate_marketplace               │
│                                           │
│  SampleData {                             │
│    id, uploader, title, ipfs_cid          │
│    lease_price, premium_price             │
│    exclusive_price, genre, bpm            │
│    is_exclusive, total_sales              │
│  }                                        │
│                                           │
│  purchase_license(buyer, id, token, tier) │
│    ├─ 90% ──▶ producer earnings ledger    │
│    └─ 10% ──▶ platform address (instant)  │
│                                           │
│  withdraw_earnings(producer, token)       │
│    └─ pull balance ──▶ producer wallet    │
└───────────────────────────────────────────┘
              Soroban / Stellar

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Data Structure

pub struct SampleData {
    pub id:              u32,
    pub uploader:        Address,
    pub title:           String,
    pub ipfs_cid:        String,    // IPFS content hash
    pub lease_price:     i128,      // stroops
    pub premium_price:   i128,
    pub exclusive_price: i128,
    pub genre:           String,
    pub bpm:             u32,       // validated: 40–300
    pub is_exclusive:    bool,      // true = sold exclusively, delisted
    pub total_sales:     u32,
}

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License Tiers

Tier	Value	What the buyer gets
0 — Lease	lease_price	Non-exclusive, limited commercial, 100k streams
1 — Premium	premium_price	Commercial, unlimited streams, radio rights
2 — Exclusive	exclusive_price	Full ownership transfer, beat delisted forever

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Prerequisites

# Rust toolchain
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
rustup target add wasm32-unknown-unknown

# Stellar CLI
cargo install --locked stellar-cli

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Build & Test

# Build WASM
make build

# Run tests
make test

# Optimize WASM size (~40% smaller)
make optimize

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Deploy

# Deploy contract to testnet
make deploy

# Initialize (one-time)
stellar contract invoke \
  --id YOUR_CONTRACT_ID \
  --source YOUR_ACCOUNT \
  --network testnet \
  -- __constructor \
  --platform_fee 1000 \
  --platform_address YOUR_PLATFORM_ADDRESS

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Testing

Tests live in contracts/crate_marketplace/src/test.rs and cover:

• upload_sample — metadata stored, counter incremented
• purchase_license — XLM split verification (90/10 arithmetic)
• withdraw_earnings — pull pattern, double-withdraw prevention
• exclusive purchase — beat auto-delisted after tier-2 sale
• get_stats — volume accumulation

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Contributing

# Fork → clone → branch
git checkout -b feat/your-feature

# Make changes, run tests
cargo test

# Open a PR

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Ecosystem

Repo	Description
crate-frontend	React 18 + TypeScript web app
crate-backend	Node.js API, IPFS proxy, analytics
crate-mobile	React Native mobile app

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License

MIT — see LICENSE

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_{Built on Stellar · Soroban · Open Source}