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Chapter 15 / 15

Deploy to Sepolia

Install, compile, deploy, verify — end-to-end in four commands.

This chapter walks through a complete deployment of a Covenant contract to the Sepolia Ethereum testnet using covenant-cli. You will need: a funded Sepolia wallet, a Sepolia RPC endpoint (Alchemy or Infura), and an Etherscan API key for verification.

Step 1 — install covenant-cli
# Requires Rust 1.78+ (rustup.rs)
cargo install covenant-cli

# Verify
covenant --version
# covenant-cli 0.7.0
counter.cov — contract to deploy
record Counter {
    count: u64;
    owner: address;

    action increment() only(self.owner) {
        self.count += 1;
    }

    action reset() only(self.owner) {
        self.count = 0;
    }

    view get() -> u64 {
        return self.count;
    }
}
Step 2 — compile to EVM bytecode
covenant build counter.cov --target-chain evm --out build/

# Output:
#   build/Counter.bin          — deployment bytecode
#   build/Counter.abi.json     — ABI
#   build/Counter.metadata.json
Step 3 — set environment variables
export SEPOLIA_RPC="https://eth-sepolia.g.alchemy.com/v2/"
export PRIVATE_KEY="0x..."          # funded Sepolia wallet
export ETHERSCAN_KEY=""   # from etherscan.io/myapikey
Step 4 — deploy
covenant deploy build/Counter.bin \
    --abi build/Counter.abi.json \
    --network sepolia \
    --rpc $SEPOLIA_RPC \
    --key $PRIVATE_KEY

# Output:
#   Deploying Counter to sepolia...
#   Transaction: 0xabc...
#   Confirmed in block 5834201
#   Contract address: 0x1234...56789
Step 5 — verify on Etherscan
covenant verify 0x1234...56789 \
    --source counter.cov \
    --network sepolia \
    --etherscan-key $ETHERSCAN_KEY

# Output:
#   Submitting source to Etherscan...
#   Verification successful.
#   https://sepolia.etherscan.io/address/0x1234...56789#code
Step 6 — interact via CLI
# Call a view
covenant call 0x1234...56789 get \
    --network sepolia --rpc $SEPOLIA_RPC
# Returns: 0

# Send a transaction
covenant send 0x1234...56789 increment \
    --network sepolia --rpc $SEPOLIA_RPC --key $PRIVATE_KEY
# Transaction mined: 0xdef...

covenant call 0x1234...56789 get \
    --network sepolia --rpc $SEPOLIA_RPC
# Returns: 1

Annotations

covenant buildcompiles .cov source to EVM deployment bytecode and generates the ABI JSON.
covenant deploysends the deployment transaction and waits for confirmation. Outputs the contract address.
covenant verifysubmits the source and compiler metadata to Etherscan's verification API.
GasCovenant bytecode is typically 10–30% smaller than equivalent Solidity due to IR-level optimizations. This translates to lower deployment gas.

Key takeaways