ValueError: Method eth_maxPriorityFeePerGas not supported, web3.py with ganache

Question

I'm running the following code with web3.py :

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

And I am running into the following error:

Traceback (most recent call last):
  File "/Users/patrick/code/web3_py_simple_storage/deploy.py", line 64, in <module>
    transaction = SimpleStorage.constructor().buildTransaction(
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/eth_utils/decorators.py", line 18, in _wrapper
    return self.method(obj, *args, **kwargs)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/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__
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/web3/_utils/transactions.py", line 121, in fill_transaction_defaults
    default_val = default_getter(web3, transaction)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/web3/_utils/transactions.py", line 71, in <lambda>
    web3.eth.max_priority_fee + (2 * web3.eth.get_block('latest')['baseFeePerGas'])
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/web3/eth.py", line 549, in max_priority_fee
    return self._max_priority_fee()
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/web3/module.py", line 57, in caller
    result = w3.manager.request_blocking(method_str,
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/web3/manager.py", line 198, in request_blocking
    return self.formatted_response(response,
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/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 (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/lib/subproviders/geth_api_double.js:70:16)\n    at next (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/node_modules/web3-provider-engine/index.js:136:18)\n    at GethDefaults.handleRequest (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/lib/subproviders/gethdefaults.js:15:12)\n    at next (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/node_modules/web3-provider-engine/index.js:136:18)\n    at SubscriptionSubprovider.FilterSubprovider.handleRequest (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/node_modules/web3-provider-engine/subproviders/filters.js:89:7)\n    at SubscriptionSubprovider.handleRequest (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/node_modules/web3-provider-engine/subproviders/subscriptions.js:137:49)\n    at next (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/node_modules/web3-provider-engine/index.js:136:18)\n    at DelayedBlockFilter.handleRequest (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/lib/subproviders/delayedblockfilter.js:31:3)\n    at next (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/node_modules/web3-provider-engine/index.js:136:18)\n    at RequestFunnel.handleRequest (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/lib/subproviders/requestfunnel.js:32:12)\n    at next (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/node_modules/web3-provider-engine/index.js:136:18)\n    at Web3ProviderEngine._handleAsync (/Applications/Ganache.app/Contents/Resources/static/node/node_modules/ganache-core/node_modules/web3-provider-engine/index.js:123:3)\n    at Timeout._onTimeout (/Applications/Ganache.app/Contents/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'}}

How do I fix this?

Answer 1

This is an issue from a new edition of web3.py.

You need to add gasPrice to your transaction, like so:

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

This is due to EIP1559 changing, and web3.py updating for the change.