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Smart Contracts

Stelltron deploys four Soroban contracts on the Stellar testnet, written in Rust and compiled to WASM. All contracts are under 200 lines each, intentionally lean — on-chain storage is expensive, so the Soroban contracts handle token accounting and governance, while the Go backend handles order books and matching logic.

Deployed Contracts​

ContractPurpose
energy_tokenToken minting, burning, transfer — the LT token ledger
marketplaceOrder creation, matching execution on-chain
governanceCommunity proposals and voting
network_incentivesDePIN node registration and reward tracking

Contract IDs are set via environment variables (TOKEN_CONTRACT_ID, etc.) and injected at startup.

energy_token​

The core token contract. Implements a custom fungible token for LT (Los Técnicos Energy Token).

Storage keys:

pub enum DataKey {
    Admin,
    Balance(Address),
    TotalSupply,
    TotalBurned,
}

Instance storage holds Admin, TotalSupply, TotalBurned. Persistent storage holds per-address Balance entries.

Functions:

// One-time setup — sets admin address, initializes supply to 0
pub fn initialize(env: Env, admin: Address)

// Mint tokens when Pi reports energy transfer — admin-only
pub fn mint(env: Env, to: Address, amount: i128)

// Burn tokens on trade settlement — admin-only
// Permanently removes from TotalSupply, increments TotalBurned
pub fn burn(env: Env, from: Address, amount: i128)

// Transfer between wallets — called during marketplace settlement
// Requires from.require_auth() — user must sign
pub fn transfer(env: Env, from: Address, to: Address, amount: i128)

// Read-only queries
pub fn get_balance(env: Env, user: Address) -> i128
pub fn total_supply(env: Env) -> i128
pub fn total_burned(env: Env) -> i128

Authorization model:

  • mint and burn: Admin-only (oracle backend orchestrates these)
  • transfer: Requires the sender's authorization (from.require_auth())
  • No allowance/approval mechanism in V1 — direct user signatures required

Unit tests cover:

  • Mint → balance increase + total supply increase
  • Burn → balance decrease + total supply decrease + total burned increase
  • Transfer → balance redistribution without supply change

marketplace​

Handles on-chain order representation and trade execution. In Stelltron's architecture, the Go matching engine runs the order book off-chain (PostgreSQL) and calls the Soroban contract only to execute finalized trades.

pub fn create_order(env: Env, user: Address, order_type: String, kwh: i128, price: i128, device_id: String)

pub fn match_orders(env: Env, sell_id: u64, buy_id: u64)
// Admin validates matching conditions and executes settlement

pub fn calculate_yield(env: Env, amount: i128) -> i128
// Returns 5% APY yield on amount (simulated DeFi yield)

pub fn get_order(env: Env, order_id: u64) -> Order

governance​

Allows community members to propose and vote on parameter changes (pricing coefficients, grid rules, DeFi parameters).

pub fn create_proposal(env: Env, proposer: Address, title: String, description: String, duration_seconds: u64)

pub fn vote(env: Env, voter: Address, proposal_id: u64, support: bool)
// One wallet = one vote

pub fn finalize_proposal(env: Env, proposal_id: u64)
// Tallies votes after deadline. Result written to contract storage.
// Backend reads this to update PricingConfig coefficients.

pub fn get_proposal(env: Env, proposal_id: u64) -> Proposal

Governance flow:

network_incentives​

Tracks DePIN node participation and reward distribution.

pub fn register_node(env: Env, node_id: String, operator: Address)
// Registers hardware; emits 100 LT one-time reward

pub fn report_activity(env: Env, node_id: String, packets: u64)
// Records packet routing activity
// Reward: 1 LT per 100 packets (i.e. 0.01 LT/packet)

pub fn get_node_info(env: Env, node_id: String) -> NodeInfo

Token Economics​

Minting formula:

TokensMinted = kWh_transferred × 1000 × QualityFactor

QualityFactor:
  avgVoltage in [3.6, 4.2]V → 1.0 + (avgVoltage - 3.6) / 6.0
  (range: 1.0 to 1.1)
  avgVoltage outside range    → 0.85 (penalty)

Example: 0.5 kWh at 4.0V
  = 0.5 × 1000 × (1.0 + (4.0 - 3.6)/6.0)
  = 500 × 1.0667
  = 533.3 LT

Deployment​

The deploy.sh script automates:

  1. Compile all contracts to WASM with cargo build --target wasm32-unknown-unknown --release
  2. Deploy each WASM to Stellar testnet with stellar contract deploy
  3. Initialize each contract (set admin to oracle key)
  4. Write contract IDs to backend .env file
cd stellar_smart_contract
./deploy.sh

After deployment, the backend reads contract IDs via environment variables:

  • TOKEN_CONTRACT_ID
  • MARKETPLACE_CONTRACT_ID
  • GOVERNANCE_CONTRACT_ID
  • NETWORK_INCENTIVES_CONTRACT_ID