Smart contracts

Deploy a smart contract

CosmPy offers the possibility to easily deploy smart contracts using the LedgerContract object. For this, you will need the path to where the contract is stored (in this case simple.wasm), a LedgerClient and a Wallet .

The example below shows how to achieve this:

from cosmpy.aerial.contract import LedgerContract
 
PATH = "contracts/simple/simple.wasm"
 
contract = LedgerContract(PATH, ledger_client)
contract.deploy({}, wallet)

Interact with smart contracts

We can now start interacting with any smart contract in different ways by executing one of the following operations.

Retrieve contract address

After deployment, you can obtain the address of the deployed contract on the network using the address method in the following way:

print(f"Contract deployed at: {contract.address}")

Query contract's state variables

We can also query the values of the contract's state variables using the query method and provide a dictionary specifying the query information:

result = contract.query({"get": {"owner": wallet}})
print("Initial state:", result)

Set contract's state variables

We can update the contract's state variables by using the execute method and by providing a dictionary specifying the update wanted. Use the wait_to_complete() method to wait for the execution to finish.

The following code sets the state variable value to foobar:

contract.execute({"set": {"value": "foobar"}}, wallet).wait_to_complete()

Once you set a state variable to its updated value, you can query it again to confirm such changes took place effectively. Considering the example above, we can check if changes were set correctly in the following way:

result = contract.query({"get": {"owner": wallet)}})
print("State after set:", result)

Clear state variables

We can clear the contract's state variables using the execute method in the following way:

contract.execute({"clear": {}}, wallet).wait_to_complete()

Then, we can check if the operation was correctly executed by running what follows:

result = contract.query({"get": {"owner": wallet}})
print("State after clear:", result)