How to access Uniswap on Polygon network?

[roya12]

Hello, newbie here. I'm trying to use this package to access Uniswap on Polygon network. I changed the provider to a free matic RPC (provided by Maticvigil) and provided the relevant token addresses on the Matic network, but the script returns an error. How do I access the swaps information on Uniswap's Polygon chain (Or other chains like BNB / Fantom / Xdai / etc.)? Thanks!

from uniswap import Uniswap

address = ""          # or None if you're not going to make transactions
private_key = ""  # or None if you're not going to make transactions
version = 3                       # specify which version of Uniswap to use
provider = "https://rpc-mainnet.maticvigil.com/v1/<maticvigil-key>"    # can also be set through the environment variable `PROVIDER`

uniswap = Uniswap(address=address, private_key=private_key, version=version, provider=provider)

# MATIC Some token addresses we'll be using later in this guide
matic = "0x0000000000000000000000000000000000001010"
dai = "0x8f3Cf7ad23Cd3CaDbD9735AFf958023239c6A063"

print (uniswap.get_price_input(matic, dai, 10**18))

[liquid-8]

Please, post the error message. From what I see, this snippet should work correctly.

[roya12]

Hello, I have attached the error message below (I'm running on Windows with Python 3.9.10). Thank you.

D:\py-projects\uniswap>py uniswap-2.py
No fee set, assuming 0.3%
Traceback (most recent call last):
  File "D:\py-projects\uniswap\uniswap-2.py", line 14, in <module>
    uniswap.get_price_input(matic, dai, 10**18)
  File "C:\Python39\lib\site-packages\uniswap\uniswap.py", line 198, in get_price_input
    return self._get_token_token_input_price(token0, token1, qty, fee, route)
  File "C:\Python39\lib\site-packages\uniswap\uniswap.py", line 296, in _get_token_token_input_price
    price = self.quoter.functions.quoteExactInputSingle(
  File "C:\Python39\lib\site-packages\web3\contract.py", line 957, in call
    return call_contract_function(
  File "C:\Python39\lib\site-packages\web3\contract.py", line 1501, in call_contract_function
    return_data = web3.eth.call(
  File "C:\Python39\lib\site-packages\web3\module.py", line 57, in caller
    result = w3.manager.request_blocking(method_str,
  File "C:\Python39\lib\site-packages\web3\manager.py", line 198, in request_blocking
    return self.formatted_response(response,
  File "C:\Python39\lib\site-packages\web3\manager.py", line 170, in formatted_response
    apply_error_formatters(error_formatters, response)
  File "C:\Python39\lib\site-packages\web3\manager.py", line 70, in apply_error_formatters
    formatted_resp = pipe(response, error_formatters)
  File "cytoolz/functoolz.pyx", line 667, in cytoolz.functoolz.pipe
    return c_pipe(data, funcs)
  File "cytoolz/functoolz.pyx", line 642, in cytoolz.functoolz.c_pipe
    data = func(data)
  File "C:\Python39\lib\site-packages\web3\_utils\method_formatters.py", line 580, in raise_solidity_error_on_revert
    raise ContractLogicError('execution reverted')
web3.exceptions.ContractLogicError: execution reverted

[liquid-8]

I'm not sure if they have a 0.3% pool there, try fee=500 in constructor params like
uniswap = Uniswap(address=address, private_key=private_key, version=version, provider=provider, fee=500)

[roya12]

Tried, however, it seems that 'fee' is not part of the params in the Uniswap class

Traceback (most recent call last):
  File "d:\py-projects\uniswap\uniswap-2-matic.py", line 9, in <module>
    uniswap = Uniswap(address=address, private_key=private_key, version=version, provider=provider, fee=500) 
TypeError: __init__() got an unexpected keyword argument 'fee'

classuniswap.Uniswap(address: Optional[Union[Address, ChecksumAddress, str]], private_key: Optional[str], provider: Optional[str] = None, web3: Optional[web3.main.Web3] = None, version: int = 1, default_slippage: float = 0.01, use_estimate_gas: bool = True, factory_contract_addr: Optional[str] = None, router_contract_addr: Optional[str] = None)

[ErikBjare]

I think @liquid-8 was a bit too quick there.

The fee argument is on the get_price_input/output methods: http://uniswap-python.com/api.html#uniswap.Uniswap.get_price_input

If you configure logging correctly, it should emit a warning that fee was implicitly set to 3000 (0.3%).

[roya12]

Sure, I have tried changing to the following:

print (uniswap.get_price_input(matic, dai, 10**18, fee=500))

However, the script indicates an error in that line:

Traceback (most recent call last):
  File "d:\py-projects\uniswap\uniswap-2-matic.py", line 14, in <module>
    print (uniswap.get_price_input(matic, dai, 10**18, fee=500))
  File "C:\Python39\lib\site-packages\uniswap\uniswap.py", line 198, in get_price_input
    return self._get_token_token_input_price(token0, token1, qty, fee, route)
  File "C:\Python39\lib\site-packages\uniswap\uniswap.py", line 296, in _get_token_token_input_price
    price = self.quoter.functions.quoteExactInputSingle(
  File "C:\Python39\lib\site-packages\web3\contract.py", line 957, in call
    return call_contract_function(
  File "C:\Python39\lib\site-packages\web3\contract.py", line 1501, in call_contract_function
    return_data = web3.eth.call(
  File "C:\Python39\lib\site-packages\web3\module.py", line 57, in caller
    result = w3.manager.request_blocking(method_str,
  File "C:\Python39\lib\site-packages\web3\manager.py", line 198, in request_blocking
    return self.formatted_response(response,
  File "C:\Python39\lib\site-packages\web3\manager.py", line 170, in formatted_response
    apply_error_formatters(error_formatters, response)
  File "C:\Python39\lib\site-packages\web3\manager.py", line 70, in apply_error_formatters
    formatted_resp = pipe(response, error_formatters)
  File "cytoolz/functoolz.pyx", line 667, in cytoolz.functoolz.pipe
    return c_pipe(data, funcs)
  File "cytoolz/functoolz.pyx", line 642, in cytoolz.functoolz.c_pipe
    data = func(data)
  File "C:\Python39\lib\site-packages\web3\_utils\method_formatters.py", line 580, in raise_solidity_error_on_revert
    raise ContractLogicError('execution reverted')
web3.exceptions.ContractLogicError: execution reverted