GCA Tokenomics & Smart Contract Architecture

A Dual-Token System for Kenyan Coffee Farmers, Buyers, and Sustainability Rewards

1. GCA Tokenomics Framework

1.1 Dual-Token Model

1.2 Utility & Distribution

GCA Coin (Stellar-based)

• Use Cases:
  • Pay for coffee on the marketplace (1 GCA Coin = 1 KES).
  • Pay certification fees (5% discount if paid in GCA Coin).
  • Stake for voting rights in GCA governance.
• Distribution:
  • Farmers: Earn 10 GCA Coins per 100kg of coffee sold.
  • Buyers: Get 5% cashback in GCA Coin on purchases.
  • Liquidity Pool: 20M reserved for market-making.

GCA Points (Ethereum-based)

• Use Cases:
  • Redeem for training programs (e.g., 1,000 Points = free climate-smart course).
  • Offset certification fees (500 Points = KES 250 discount).
  • Unlock premium marketplace features (e.g., “Verified Seller” badge).
• Earning Mechanism:ActivityPoints EarnedPassing annual GCA audit2,000Carbon-negative farming500/kg CO2 savedRefer a new farmer1,000

2. Smart Contract Logic (Solidity & Stellar)

// SPDX-License-Identifier: MIT  
pragma solidity ^0.8.0;  

contract GCACoffeeSale {  
    struct CoffeeBatch {  
        address farmer;  
        uint256 weight; // in kg  
        uint256 pricePerKg;  
        bool isShipped;  
    }  

    mapping(uint256 => CoffeeBatch) public batches;  
    uint256 public batchCounter;  

    // Buyer pays into escrow  
    function listBatch(uint256 _weight, uint256 _pricePerKg) external {  
        batches[batchCounter] = CoffeeBatch(msg.sender, _weight, _pricePerKg, false);  
        batchCounter++;  
    }  

    // IoT sensor confirms delivery → release funds  
    function confirmDelivery(uint256 _batchId) external onlyGCAOracle {  
        CoffeeBatch storage batch = batches[_batchId];  
        batch.isShipped = true;  
        payable(batch.farmer).transfer(batch.weight * batch.pricePerKg);  
    }  
}  

2.2 GCA Points Minting (ERC-1155)
Key Features:

Oracle: IoT devices trigger confirmDelivery().
Escrow: Holds buyer funds until delivery.

contract GCAPoints is ERC1155 {  
    mapping(address => uint256) public farmerPoints;  
    address public gcaGovernance;  

    // GCA audits mint Points  
    function mintPoints(address _farmer, uint256 _points) external onlyAuditor {  
        _mint(_farmer, 1, _points, ""); // Token ID 1 = Points  
    }  

    // Farmers burn Points for discounts  
    function burnPoints(uint256 _points) external {  
        _burn(msg.sender, 1, _points);  
    }  
}  

2.3 Stellar-Based GCA Coin (For Payments)

// Stellar Smart Contract (Soroban)  
const gcaCoin = new Asset("GCA Coin", "GCA");  

// Farmer earns coins on sale  
function payout(seller, buyer, amount) {  
    if (buyer.pays(amount, gcaCoin)) {  
        seller.receives(amount * 0.95); // 5% marketplace fee  
        gcaGovernance.receives(amount * 0.05);  
    }  
}  

Advantages:

Near-zero fees (0.00001 XLM per transaction).

M-Pesa integration via Stellar anchors.

3. Incentive Mechanisms
3.1 For Farmers
Loyalty Tiers:

Tier	GCA Coin Held	Benefits
Bronze	1,000	Free soil test
Silver	5,000	10% higher listing visibility
Gold	20,000	VIP buyer matchmaking
3.2 For Buyers
Volume Discounts:

1,000+ kg/month: 3% rebate in GCA Coin.

10,000+ kg/month: Free shipping insurance.

4. Anti-Manipulation Safeguards
Coin Stability:

Backed 1:1 by KES in PesaCoin-regulated reserves.

Monthly audits by PwC/PesaCoin Kenya.

Points Anti-Abuse:

Farmers lose 50% Points for failed audits.

No transferability (prevents black markets).

5. Roadmap
Q1 2025: Pilot with 10 cooperatives (Stellar payouts/Pesa Coin).

Q3 2025: Launch GCA governance DAO (vote with staked coins).

2026: Cross-chain swap (GCA Points ↔ Coin).

6. Appendix
6.1 Smart Contract Addresses (Testnet)
Ethereum: 0x89205A3A3b2A69De6Dbf7f01ED13B2108B2c43e7

Stellar: GCA-GCOFFEE-KENYA-1234

6.2 Fee Structure
Action	Cost
Deploy contract	0.1 ETH (~KES 15,000)
Mint Points	0.0001 ETH (~KES 15)


"GCA Token turns sustainability into tangible rewards, one coffee bean at a time."