SubxtClient

A client for interacting with a Substrate-based blockchain.

This class provides methods to interact with the blockchain, including fetching storage entries, constants, events, making runtime API calls, and submitting transactions.

Class Methods

SubxtClient.new() -> SubxtClient

Create a new SubxtClient instance asynchronously.

Returns:

• SubxtClient: A new client connected to the default network.

Raises:

• RuntimeError: If the client fails to connect.

Example:

import asyncio
from subxtpy import SubxtClient

async def main():
    client = await SubxtClient.new()
    # Use the client for further operations

asyncio.run(main())

Instance Methods

storage(pallet_name: str, entry_name: str, key: list) -> Any

Fetch a storage entry from the blockchain asynchronously.

Parameters:

• pallet_name (str): The name of the pallet.
• entry_name (str): The name of the storage entry.
• key (list): A list of keys for the storage entry.

Returns:

• Any: The value of the storage entry.

Raises:

• RuntimeError: If fetching the storage entry fails.
• ValueError: If the storage entry is not found.

Example:

import asyncio
from subxtpy import SubxtClient

async def main():
    client = await SubxtClient.new()
    balance = await client.storage("Balances", "FreeBalance", [account_id])
    print(f"Balance: {balance}")

asyncio.run(main())

constant(pallet_name: str, constant_name: str) -> Any

Fetch a constant value from the blockchain asynchronously.

Parameters:

• pallet_name (str): The name of the pallet.
• constant_name (str): The name of the constant.

Returns:

• Any: The value of the constant.

Raises:

• RuntimeError: If fetching the constant fails.

Example:

import asyncio
from subxtpy import SubxtClient

async def main():
    client = await SubxtClient.new()
    existential_deposit = await client.constant("Balances", "ExistentialDeposit")
    print(f"Existential Deposit: {existential_deposit}")

asyncio.run(main())

events() -> list

Fetch events from the blockchain asynchronously.

Returns:

• list: A list of events, where each event is a dictionary containing pallet, variant, and fields.

Raises:

• RuntimeError: If fetching events fails.

Example:

import asyncio
from subxtpy import SubxtClient

async def main():
    client = await SubxtClient.new()
    events = await client.events()
    for event in events:
        print(event)

asyncio.run(main())

runtime_api_call(pallet_name: str, entry_name: str, key: list) -> Any

Perform a runtime API call to the blockchain asynchronously.

Parameters:

• pallet_name (str): The name of the pallet.
• entry_name (str): The name of the runtime API function.
• key (list): A list of arguments for the runtime API call.

Returns:

• Any: The result of the runtime API call.

Raises:

• RuntimeError: If the runtime API call fails.

Example:

import asyncio
from subxtpy import SubxtClient

async def main():
    client = await SubxtClient.new()
    result = await client.runtime_api_call("SomePallet", "someFunction", [arg1, arg2])
    print(f"Result: {result}")

asyncio.run(main())

storage_iter(pallet_name: str, entry_name: str, key: bytes) -> StorageIterator

Iterate over storage entries from the blockchain asynchronously.

Parameters:

• pallet_name (str): The name of the pallet.
• entry_name (str): The name of the storage entry.
• key (bytes): The prefix key for iteration.

Returns:

• StorageIterator: An asynchronous iterator over storage key-value pairs.

Raises:

• RuntimeError: If the iteration fails.

Example:

import asyncio
from subxtpy import SubxtClient

async def main():
    client = await SubxtClient.new()
    iterator = await client.storage_iter("System", "Account", b"")
    async for item in iterator:
        print(item)

asyncio.run(main())

sign_and_submit(from: Keypair, pallet_name: str, entry_name: str, payload: list) -> str

Sign and submit a transaction to the blockchain asynchronously.

Parameters:

• from (Keypair): The keypair to sign the transaction.
• pallet_name (str): The name of the pallet.
• entry_name (str): The name of the extrinsic.
• payload (list): A list of arguments for the extrinsic.

Returns:

• str: The transaction hash as a hexadecimal string.

Raises:

• RuntimeError: If signing or submitting the transaction fails.

Example:

import asyncio
from subxtpy import SubxtClient, Keypair

async def main():
    client = await SubxtClient.new()
    keypair = Keypair.from_secret_key("your_64_character_hex_secret_key")
    tx_hash = await client.sign_and_submit(keypair, "Balances", "transfer", [dest_account_id, amount])
    print(f"Transaction Hash: {tx_hash}")

asyncio.run(main())

subscribe_new_blocks() -> BlockSubscription

Subscribe to new blocks on the blockchain asynchronously.

Returns:

• BlockSubscription: An asynchronous iterator that yields blocks as they are finalized.

Raises:

• RuntimeError: If the subscription fails.

Example:

import asyncio
from subxtpy import SubxtClient

async def main():
    client = await SubxtClient.new()
    subscription = await client.subscribe_new_blocks()
    async for block in subscription:
        print(block)

asyncio.run(main())