Smart Contracts

The ETF network supports ink! smart contracts via Substrate’s pallet-contracts.

Chain Extension and ETF Environment

The ETF Network uses a custom chain extension to allow smart contracts to check if a slot is in the future or in the past. The chain extension allows you to check if a block has been authored in a given slot, which is very useful in cases where it is important to know if data can be decrypted. The custom environment can be configured in ink! smart contracts to call the chain extension exposed by the ETF network runtime.

See the auction orchestrator for an example.

ETF Environment setup

1. Add the dependency to your contract

etf-chain-extension = { version = "0.1.0, default-features = false, features = ["ink-as-dependency"] }

2. Configure the environment in your contract

#![allow(unused)]
fn main() {
use etf_chain_extension::ext::EtfEnvironment;
#[ink::contract(env = EtfEnvironment)]
mod your_smart_contract {
    use crate::EtfEnvironment;
    ...
}
}

3. Query the runtime to check if a block has been authored in the slot.

#![allow(unused)]
fn main() {
self.env()
    .extension()
    .check_slot(deadline)
}