Why do I get the error "Method eth_maxPriorityFeePerGas not supported" when I try to run Web3py with Ganache?

Question

Running Web3.py with Ganache-cli returns this error:

Method eth_maxPriorityFeePerGas not supported.

However this does work when working with a test-network like Ropsten directly without Ganache-cli.

Running this code in following a tutorial:

from solcx import compile_standard, install_solc
import json
from web3 import Web3
import os
from dotenv import load_dotenv

load_dotenv()

with open("./SimpleStorage.sol", "r") as file:
    simple_storage_file = file.read()

install_solc("0.6.0")

compiled_sol = compile_standard(
    {
        "language": "Solidity",
        "sources": {"SimpleStorage.sol": {"content": simple_storage_file}},
        "settings": {
            "outputSelection": {
                "*": {"*": ["abi", "metadata", "evm.bytecode", "evm.sourceMap"]}
            }
        },
    },
    solc_version="0.6.0",
)

with open("compiled_code.json", "w") as file:
    json.dump(compiled_sol, file)

bytecode = compiled_sol["contracts"]["SimpleStorage.sol"]["SimpleStorage"]["evm"][
    "bytecode"
]["object"]

abi = compiled_sol["contracts"]["SimpleStorage.sol"]["SimpleStorage"]["abi"]

w3 = Web3(Web3.HTTPProvider("HTTP://127.0.0.1:7545"))
chain_id = 1337
my_address = "0x3d5CDfCea81141d7C839938095912F594b566Ab8"
private_key = os.getenv("private_key")

SimpleStorage = w3.eth.contract(abi=abi, bytecode=bytecode)

nonce = w3.eth.getTransactionCount(my_address)

transaction = SimpleStorage.constructor().buildTransaction(
    {"chainId": chain_id, "from": my_address, "nonce": nonce}
)

signed_txn = w3.eth.account.sign_transaction(transaction, private_key=private_key)

tx_hash = w3.eth.send_raw_transaction(signed_txn.rawTransaction)

I get this error in the terminal:

Traceback (most recent call last):
  File "C:\Users\Axceus\Desktop\demos\web3_py_simple_storage\deploy.py", line 54, in <module>
    transaction = SimpleStorage.constructor().buildTransaction(
  File "C:\Users\Axceus\AppData\Local\Programs\Python\Python310\lib\site-packages\eth_utils\decorators.py", line 18, in _wrapper
    return self.method(obj, *args, **kwargs)
  File "C:\Users\Axceus\AppData\Local\Programs\Python\Python310\lib\site-packages\web3\contract.py", line 684, in buildTransaction
    return fill_transaction_defaults(self.web3, built_transaction)
  File "cytoolz/functoolz.pyx", line 250, in cytoolz.functoolz.curry.__call__
    return self.func(*args, **kwargs)
  File "C:\Users\Axceus\AppData\Local\Programs\Python\Python310\lib\site-packages\web3\_utils\transactions.py", line 121, in fill_transaction_defaults
    default_val = default_getter(web3, transaction)
  File "C:\Users\Axceus\AppData\Local\Programs\Python\Python310\lib\site-packages\web3\_utils\transactions.py", line 71, in <lambda>
    web3.eth.max_priority_fee + (2 * web3.eth.get_block('latest')['baseFeePerGas'])
  File "C:\Users\Axceus\AppData\Local\Programs\Python\Python310\lib\site-packages\web3\eth.py", line 549, in max_priority_fee
    return self._max_priority_fee()
  File "C:\Users\Axceus\AppData\Local\Programs\Python\Python310\lib\site-packages\web3\module.py", line 57, in caller
    result = w3.manager.request_blocking(method_str,
  File "C:\Users\Axceus\AppData\Local\Programs\Python\Python310\lib\site-packages\web3\manager.py", line 198, in request_blocking
    return self.formatted_response(response,
  File "C:\Users\Axceus\AppData\Local\Programs\Python\Python310\lib\site-packages\web3\manager.py", line 171, in formatted_response
    raise ValueError(response["error"])
ValueError: {'message': 'Method eth_maxPriorityFeePerGas not supported.', 'code': -32000, 'data': {'stack': 'Error: Method eth_maxPriorityFeePerGas not supported.\n    at GethApiDouble.handleRequest (C:\\Program Files\\WindowsApps\\GanacheUI_2.5.4.0_x64__5dg5pnz03psnj\\app\\resources\\static\\node\\node_modules\\ganache-core\\lib\\subproviders\\geth_api_double.js:70:16)\n    at next (C:\\Program Files\\WindowsApps\\GanacheUI_2.5.4.0_x64__5dg5pnz03psnj\\app\\resources\\static\\node\\node_modules\\ganache-core\\node_modules\\web3-provider-engine\\index.js:136:18)\n    at GethDefaults.handleRequest (C:\\Program Files\\WindowsApps\\GanacheUI_2.5.4.0_x64__5dg5pnz03psnj\\app\\resources\\static\\node\\node_modules\\ganache-core\\lib\\subproviders\\gethdefaults.js:15:12)\n    at next (C:\\Program Files\\WindowsApps\\GanacheUI_2.5.4.0_x64__5dg5pnz03psnj\\app\\resources\\static\\node\\node_modules\\ganache-core\\node_modules\\web3-provider-engine\\index.js:136:18)\n    at SubscriptionSubprovider.FilterSubprovider.handleRequest (C:\\Program Files\\WindowsApps\\GanacheUI_2.5.4.0_x64__5dg5pnz03psnj\\app\\resources\\static\\node\\node_modules\\ganache-core\\node_modules\\web3-provider-engine\\subproviders\\filters.js:89:7)\n    at SubscriptionSubprovider.handleRequest (C:\\Program Files\\WindowsApps\\GanacheUI_2.5.4.0_x64__5dg5pnz03psnj\\app\\resources\\static\\node\\node_modules\\ganache-core\\node_modules\\web3-provider-engine\\subproviders\\subscriptions.js:137:49)\n    at next (C:\\Program Files\\WindowsApps\\GanacheUI_2.5.4.0_x64__5dg5pnz03psnj\\app\\resources\\static\\node\\node_modules\\ganache-core\\node_modules\\web3-provider-engine\\index.js:136:18)\n    at DelayedBlockFilter.handleRequest (C:\\Program Files\\WindowsApps\\GanacheUI_2.5.4.0_x64__5dg5pnz03psnj\\app\\resources\\static\\node\\node_modules\\ganache-core\\lib\\subproviders\\delayedblockfilter.js:31:3)\n    at next (C:\\Program Files\\WindowsApps\\GanacheUI_2.5.4.0_x64__5dg5pnz03psnj\\app\\resources\\static\\node\\node_modules\\ganache-core\\node_modules\\web3-provider-engine\\index.js:136:18)\n    at RequestFunnel.handleRequest (C:\\Program Files\\WindowsApps\\GanacheUI_2.5.4.0_x64__5dg5pnz03psnj\\app\\resources\\static\\node\\node_modules\\ganache-core\\lib\\subproviders\\requestfunnel.js:32:12)\n    at next (C:\\Program Files\\WindowsApps\\GanacheUI_2.5.4.0_x64__5dg5pnz03psnj\\app\\resources\\static\\node\\node_modules\\ganache-core\\node_modules\\web3-provider-engine\\index.js:136:18)\n    at Web3ProviderEngine._handleAsync (C:\\Program Files\\WindowsApps\\GanacheUI_2.5.4.0_x64__5dg5pnz03psnj\\app\\resources\\static\\node\\node_modules\\ganache-core\\node_modules\\web3-provider-engine\\index.js:123:3)\n    at Timeout._onTimeout (C:\\Program Files\\WindowsApps\\GanacheUI_2.5.4.0_x64__5dg5pnz03psnj\\app\\resources\\static\\node\\node_modules\\ganache-core\\node_modules\\web3-provider-engine\\index.js:107:12)\n    at listOnTimeout (internal/timers.js:531:17)\n    at processTimers (internal/timers.js:475:7)', 'name': 'Error'}}

Lanneret

Use the latest Ganache instead of Ganache-cli: npm install --global ganache. You might need to uninstall the old version with: npm uninstall --global ganache-cli ganache-core – Palpitation

Answer 1

Please use this to send your transaction:

 transaction = SimpleStorage.constructor().buildTransaction( {
    "gasPrice": w3.eth.gas_price, 
    "chainId": chain_id, 
    "from": my_address, 
    "nonce": nonce, 
}

Sharitasharity

Answer 2

By default, web3py will try to create an EIP-1559 transaction. To do so, it will try to fetch the estimated priority fee.

The current stable version of Ganache (6.x) does not support EIP-1559 related functionality, so the RPC call fails. Adding the gas price argument to the transaction will make web3py send a "legacy transaction" (i.e. pre EIP-1559), so it will not try to query the priority fee and simply hard-code the gas price.

From Ganache 7.x (in beta at the time of writing), EIP-1559 transactions will be supported, so the default behavior of web3py will work too.

Leolaleoline

Answer 3

from solcx import compile_standard, install_solc
from web3 import Web3
import json

with open("simpleStorage.sol", "r") as f:
    simple_storage_file = f.read()


# install version of compiler
install_solc("0.6.0")

compiled_sol = compile_standard(
    {
        "language": "Solidity",
        "sources": {"simpleStorage.sol": {"content": simple_storage_file}},
        "settings": {
            "outputSelection": {
                "*": {
                    "*": ["abi", "metadata", "evm.bytecode", "evm.sourceMap"]
                }
            }
        }
    },
    solc_version = "0.6.0"
)

# print(compiled_sol)



# save the json to file
with open("compile_code.json", "w") as f:
    json.dump(compiled_sol, f)


# get bytecode for deployment
bytecode = compiled_sol["contracts"]["simpleStorage.sol"]["SimpleStorage"]["evm"]["bytecode"]["object"]

# get ABI
abi = compiled_sol["contracts"]["simpleStorage.sol"]["SimpleStorage"]["abi"]


# connect to ganache

# setup RPC SERVER / HTTP provider
w3 = Web3(Web3.HTTPProvider("http://127.0.0.1:7545"))
chain_id = 1337
my_address = "address here"
private_key = "private key here"


SimpleStorage = w3.eth.contract(abi=abi, bytecode=bytecode)
# print(SimpleStorage)

# nonce >> Number only used once in a cryptographic communication
nonce = w3.eth.getTransactionCount(my_address)
# print(nonce)


transaction = SimpleStorage.constructor().buildTransaction({
    "gasPrice": w3.eth.gas_price, "chainId": chain_id, "from": my_address, "nonce": nonce
})
print(transaction)

Cumbersome

Answer 4

_{Migrating OP's solution from the question into an answer:}

SOLUTION:

 transaction = SimpleStorage.constructor().buildTransaction( {
    "gasPrice": w3.eth.gas_price, 
    "chainId": chain_id, 
    "from": my_address, 
    "nonce": nonce, 
}

Amii

Answer 5

I've tried to follow Daniel's suggestion but I couldn't install ganache-cli 7.x on my computer for somewhat reason. So I downgrade web3 version to 5.24.0 and it works.

Stagnant

This does not provide an answer to the question. Once you have sufficient reputation you will be able to comment on any post; instead, provide answers that don't require clarification from the asker. - From Review – Knack