Deterministic Address in Soroban

with Soroban, the Smart Contract Platform on Stellar we can know what the address of an smart contract will be, when we deploy the contract using a Deployer contract or Factory contract.

In fact, from after soroban-sdk version 20.0.0-rc2 we can use the deployed_address method for a DeployerWithAddress struct. For more information please check the documentation here: https://docs.rs/soroban-sdk/20.0.0-rc2/soroban_sdk/deploy/struct.DeployerWithAddress.html#method.deployed_address

We can calculate the contract address like this:

pub fn calculate_address(
    env: Env, 
    deployer: Address,
    salt: BytesN<32>,
) -> Address {

    let deployer_with_address = env.deployer().with_address(deployer.clone(), salt);

    // Calculate deterministic address:
    // This function can be called at anytime, before or after the contract is deployed, because contract addresses are deterministic.
    // https://docs.rs/soroban-sdk/20.0.0-rc2/soroban_sdk/deploy/struct.DeployerWithAddress.html#method.deployed_address
    let deterministic_address = deployer_with_address.deployed_address();
    deterministic_address
}

---

I wrote a playground repo available here: https://github.com/paltalabs/deterministic-address-soroban

Where we answer the following questions:

1. Same WASM, different salt ✅

Can a deployer deploy 2 contracts with same WASM and different salt?

Answer: ✅ Yes!

Check test_deploy_from_contract_twice_same_wasm_different_salt

2. Same WASM, same salt ❌

Can a deployer deploys 2 contracts with same WASM and same salt?

Answer: ❌ No!

Check test_deploy_from_contract_twice_same_wasm_same_salt_should_panic

3. Different WASM, same salt ❌

Can a deployer deploys 2 different contracts (different WASM) with same salt?

Answer: ❌ No!

Check test_deploy_from_contract_different_wasm_same_salt_should_panic

This proves that in fact the contract addresses does not depend on the WASM, but on the combination of address & salt

4. Two deployers, same WASM, same salt ✅

Can one deployer deploys a (wasm/salt) and another deployer deploys the same (wasm/salt)?

Answer: ✅ Yes!

Check test_deploy_from_two_contract_deployers_same_wasm_same_salt

They have indeed different contract addreess, because, again, the contract address depends on the combination of address&salt.!!

5. Calculate a deterministic address

Can we calculate the address of a contract only knowing the address of the factory that will (or that already did) deploy the contract and the salt used (or to be used)?

Answer: ✅ Yes!

Check test_calculate_address

After soroban-sdk = { version = "20.0.0-rc2" }, we can use the deployed_address method for a DeployerWithAddress struct. For more information please check the documentation here: https://docs.rs/soroban-sdk/20.0.0-rc2/soroban_sdk/deploy/struct.DeployerWithAddress.html#method.deployed_address