MultiversX SDK-Py Smart Contracts

This skill covers ABI loading, deployments, calls, and queries.

ABI Loading

from multiversx_sdk import Abi
from pathlib import Path

# Load from file
abi = Abi.load("contract.abi.json")

Smart Contract Controller

# Create controller with loaded ABI
controller = entrypoint.create_smart_contract_controller(abi=abi)

Deployment

bytecode = Path("contract.wasm").read_bytes()

tx = controller.create_transaction_for_deploy(
    sender=account,
    nonce=account.get_nonce_then_increment(),
    bytecode=bytecode,
    gas_limit=60000000,
    arguments=[42]  # Typed automatically via ABI
)

tx_hash = entrypoint.send_transaction(tx)
parsed_outcome = controller.await_completed_deploy(tx_hash)
contract_address = parsed_outcome[0].contract_address

Contract Calls

# Call endpoint
tx = controller.create_transaction_for_execute(
    sender=account,
    nonce=account.get_nonce_then_increment(),
    contract=contract_address,
    function="add",
    arguments=[10],
    gas_limit=5000000
)

# Call with token transfer (Transfer & Execute)
tx = controller.create_transaction_for_execute(
    sender=account,
    nonce=account.get_nonce_then_increment(),
    contract=contract_address,
    function="deposit",
    gas_limit=10000000,
    native_amount=1000000000000000000
)

VM Queries

Read-only calls to the contract state.

# Using controller (parsed output)
result = controller.query_contract(
    contract=contract_address,
    function="getSum",
    arguments=[]
)
print(result[0])  # Typed output

Without ABI (Manual Typing)

If ABI is not available, use manual type hinting (less recommended).

from multiversx_sdk import SmartContractTransactionsFactory

factory = entrypoint.create_smart_contract_transactions_factory()

tx = factory.create_transaction_for_execute(
    sender=account.address,
    contract=contract_address,
    function="add",
    gas_limit=5000000,
    arguments=[42]  # Basic types inferred
)

Upgrades

new_bytecode = Path("contract_v2.wasm").read_bytes()

tx = controller.create_transaction_for_upgrade(
    sender=account,
    nonce=account.get_nonce_then_increment(),
    contract=contract_address,
    bytecode=new_bytecode,
    gas_limit=60000000,
    arguments=[]
)

Best Practices

1. Always use ABI: Ensures correct argument encoding/decoding
2. Query for reads: Free (no gas), instant response
3. Wait for completion: Use controller methods to get parsed results
4. Gas limit: Ensure enough gas for computation + storage