Quickstart#

Using FullNodeClient#

A Client is a facade for interacting with Starknet. FullNodeClient is a client which interacts with a Starknet full nodes like Pathfinder, Papyrus or Juno. It supports read and write operations, like querying the blockchain state or adding new transactions.

from starknet_py.net.full_node_client import FullNodeClient

node_url = "https://your.node.url"
full_node_client = FullNodeClient(node_url=node_url)

call_result = await full_node_client.get_block(block_number=1)

The default interface is asynchronous. Although it is the recommended way of using starknet.py, you can also use a synchronous version. It might be helpful to play with Starknet directly in python interpreter.

node_url = "https://your.node.url"
full_node_client = FullNodeClient(node_url=node_url)
call_result = full_node_client.get_block_sync(block_number=1)

You can check out all of the FullNodeClient’s methods here: FullNodeClient.

Using GatewayClient#

Warning

Gateway / Feeder Gateway API will become deprecated in the future. As a result, GatewayClient won’t work and will eventually be removed. Consider migrating to FullNodeClient.

GatewayClient will make requests directly to Starknet sequencer through gateway or feeder_gateway endpoints. It can be used to either query the blockchain state or add new transactions. It requires information about used network:

from starknet_py.net.gateway_client import GatewayClient
from starknet_py.net.networks import MAINNET, TESTNET

# Use testnet for playing with Starknet
testnet_client = GatewayClient(TESTNET)
# or
testnet_client = GatewayClient("testnet")

mainnet_client = GatewayClient(MAINNET)
# or
mainnet_client = GatewayClient("mainnet")

# Local network
local_network_client = GatewayClient("http://localhost:5000")

call_result = await testnet_client.get_block(
    "0x495c670c53e4e76d08292524299de3ba078348d861dd7b2c7cc4933dbc27943"
)

It also has async/sync interface:

synchronous_testnet_client = GatewayClient(TESTNET)
call_result = synchronous_testnet_client.get_block_sync(
    "0x495c670c53e4e76d08292524299de3ba078348d861dd7b2c7cc4933dbc27943"
)

You can check out all of the GatewayClient’s methods here: GatewayClient.

Creating Account#

Account is the default implementation of BaseAccount interface. It supports an account contract which proxies the calls to other contracts on Starknet.

Account can be created in two ways:

  • By constructor (address, key_pair and net must be known).

  • By static method Account.deploy_account

There are some examples how to do it:

from starknet_py.net.account.account import Account
from starknet_py.net.full_node_client import FullNodeClient
from starknet_py.net.models.chains import StarknetChainId
from starknet_py.net.signer.stark_curve_signer import KeyPair

# Creates an instance of account which is already deployed
# Account using transaction version=1 (has __validate__ function)
client = FullNodeClient(node_url="your.node.url")
account = Account(
    client=client,
    address="0x4321",
    key_pair=KeyPair(private_key=654, public_key=321),
    chain=StarknetChainId.TESTNET,
)

# There is another way of creating key_pair
key_pair = KeyPair.from_private_key(key=123)
# or
key_pair = KeyPair.from_private_key(key="0x123")

# Instead of providing key_pair it is possible to specify a signer
signer = StarkCurveSigner("0x1234", key_pair, StarknetChainId.TESTNET)

account = Account(client=client, address="0x1234", signer=signer)

Using Account#

Example usage:

from starknet_py.contract import Contract

# Declare and deploy an example contract which implements a simple k-v store.
declare_result = await Contract.declare(
    account=account, compiled_contract=map_compiled_contract, max_fee=MAX_FEE
)
await declare_result.wait_for_acceptance()
deploy_result = await declare_result.deploy(max_fee=MAX_FEE)
# Wait until deployment transaction is accepted
await deploy_result.wait_for_acceptance()

# Get deployed contract
map_contract = deploy_result.deployed_contract
k, v = 13, 4324
# Adds a transaction to mutate the state of k-v store. The call goes through account proxy, because we've used
# Account to create the contract object
await (
    await map_contract.functions["put"].invoke(k, v, max_fee=int(1e16))
).wait_for_acceptance()

# Retrieves the value, which is equal to 4324 in this case
(resp,) = await map_contract.functions["get"].call(k)

# There is a possibility of invoking the multicall

# Creates a list of prepared function calls
calls = [
    map_contract.functions["put"].prepare(key=10, value=20),
    map_contract.functions["put"].prepare(key=30, value=40),
]

# Executes only one transaction with prepared calls
transaction_response = await account.execute(calls=calls, max_fee=int(1e16))
await account.client.wait_for_tx(transaction_response.transaction_hash)

Using Contract#

Contract makes interacting with contracts deployed on Starknet much easier:

from starknet_py.contract import Contract

contract_address = (
    "0x01336fa7c870a7403aced14dda865b75f29113230ed84e3a661f7af70fe83e7b"
)
key = 1234

# Create contract from contract's address - Contract will download contract's ABI to know its interface.
contract = await Contract.from_address(address=contract_address, provider=account)

# If the ABI is known, create the contract directly (this is the preferred way).
contract = Contract(
    address=contract_address,
    abi=abi,
    provider=account,
)

# All exposed functions are available at contract.functions.
# Here we invoke a function, creating a new transaction.
invocation = await contract.functions["put"].invoke(key, 7, max_fee=int(1e16))

# Invocation returns InvokeResult object. It exposes a helper for waiting until transaction is accepted.
await invocation.wait_for_acceptance()

# Calling contract's function doesn't create a new transaction, you get the function's result.
(saved,) = await contract.functions["get"].call(key)
# saved = 7 now

Note

To check if invoke succeeds use wait_for_acceptance on InvokeResult and get its status.

Although asynchronous API is recommended, you can also use Contract’s synchronous API:

from starknet_py.contract import Contract

contract_address = (
    "0x01336fa7c870a7403aced14dda865b75f29113230ed84e3a661f7af70fe83e7b"
)

key = 1234
contract = Contract.from_address_sync(address=contract_address, provider=account)

invocation = contract.functions["put"].invoke_sync(key, 7, max_fee=int(1e16))
invocation.wait_for_acceptance_sync()

(saved,) = contract.functions["get"].call_sync(key)  # 7

Note

Contract automatically serializes values to Cairo calldata. This includes adding array lengths automatically. See more info in Serialization.