Python

Python has a strong toolchain for the Avalanche C-Chain. Use web3.py for general scripting and application code — balance checks, transaction submission, data pipelines — and eth-brownie when you want a full smart-contract development workflow with compilation, testing, and deployment. Together they cover everything from a quick one-off script that reads an AVAX balance to a production service indexing C-Chain activity at chain ID 43114.

web3.py version 6 and later offers both a synchronous and an async interface against the C-Chain. Synchronous code is simplest for scripts; for concurrent workloads, use AsyncWeb3 together with an async-compatible provider so many Avalanche calls can be in flight at once without blocking the event loop.

Web3.py

web3.py is the official, full-featured Python library for EVM chains and exposes the complete C-Chain API surface. Install it with pip install web3, then connect with Web3(Web3.HTTPProvider('https://avalanche.therpc.io/YOUR_API_KEY')). From that client you read AVAX balances, fetch the current gas price, build and sign transactions, and submit them to the Avalanche C-Chain.

1from web3 import Web3
2from eth_account import Account
3import json
4 
5# Initialize web3
6web3 = Web3(Web3.HTTPProvider('https://avalanche.therpc.io/YOUR_API_KEY'))
7 
8# Get balance
9def get_balance(address):
10    balance_wei = web3.eth.get_balance(address)
11    balance_eth = web3.from_wei(balance_wei, 'ether')
12    return balance_eth
13 
14# Send transaction
15def send_transaction(private_key, to_address, value_eth):
16    account = Account.from_key(private_key)
17    transaction = {
18        'nonce': web3.eth.get_transaction_count(account.address),
19        'to': to_address,
20        'value': web3.to_wei(value_eth, 'ether'),
21        'gas': 21000,
22        'gasPrice': web3.eth.gas_price
23    }
24    signed_txn = account.sign_transaction(transaction)
25    tx_hash = web3.eth.send_raw_transaction(signed_txn.rawTransaction)
26    return web3.eth.wait_for_transaction_receipt(tx_hash)

• GitHub: https://github.com/ethereum/web3.py
• Docs: https://web3py.readthedocs.io/
• Key features: full Avalanche C-Chain API coverage, synchronous and async interfaces, type hints, a pluggable middleware stack, and ENS resolution

Eth-brownie

eth-brownie is a Python framework built around the smart-contract lifecycle on EVM chains like the Avalanche C-Chain: compiling Solidity, writing pytest-style tests against a local fork, and deploying to the network. Install it with pip install eth-brownie, then configure an Avalanche C-Chain network entry pointing at https://avalanche.therpc.io/YOUR_API_KEY to deploy and interact with your contracts.

1from brownie import *
2 
3# Deploy contract
4def deploy_contract():
5    account = accounts[0]
6    return MyContract.deploy({'from': account})
7 
8# Interact with contract
9def interact_with_contract(contract_address):
10    contract = MyContract.at(contract_address)
11    return contract.myFunction({'from': accounts[0]})
12 
13# Test contract
14def test_contract(Contract):
15    account = accounts[0]
16    contract = account.deploy(Contract)
17    assert contract.myFunction() == expected_value

• GitHub: https://github.com/eth-brownie/brownie
• Docs: https://eth-brownie.readthedocs.io/
• Key features: a contract testing framework, deployment management, an interactive console for live C-Chain interaction, network configuration for Avalanche, and a Python REPL

Async Support

For concurrent workloads against the C-Chain, web3.py's async interface centers on AsyncWeb3, which lets you fan out many calls — fetching a batch of blocks or balances — without blocking. It needs an async-compatible provider and runs inside an asyncio event loop, so wrap your coroutines and drive them with asyncio.run. This is where Avalanche's fast finality pays off: parallel awaited requests resolve in quick succession.

1from web3.auto import w3
2import asyncio
3 
4async def get_latest_blocks(count):
5    latest = await w3.eth.get_block_number()
6    blocks = []
7    for i in range(count):
8        block = await w3.eth.get_block(latest - i)
9        blocks.append(block)
10    return blocks
11 
12# Usage
13blocks = asyncio.run(get_latest_blocks(10))

Type Hints

web3.py ships comprehensive type stubs, so you can annotate your C-Chain code with TxParams, Wei, and Address from web3.types. Those annotations give you IDE autocompletion and let mypy catch type mistakes — passing a plain int where Wei is expected, or a malformed Address — statically, before any transaction reaches the Avalanche endpoint.

1from web3.types import TxParams, Wei, Address
2from typing import Optional
3 
4def prepare_transaction(
5    to: Address,
6    value: Wei,
7    gas_price: Optional[Wei] = None
8) -> TxParams:
9    return {
10        'to': to,
11        'value': value,
12        'gasPrice': gas_price or web3.eth.gas_price
13    }