I'm new to Logic Apps. What I would like to achieve is to sign and send raw transactions to Ethereum network using Logic Apps service. Currently, what I have done is to transfer ERC20 tokens from the token contract itself in Logic Apps.
What I would like to achieve is to transfer tokens from account to account which is the transfer from the method the ERC20 protocol.
How can I do that in Logic Apps? In my opinion, it's required the sender to sign the raw transaction message.
While I am not familiar with ERC20, since you seem to be using web3py, I believe you can offload the signing to an Python Azure Function which you can invoke from within a Logic App.
As for signing a transaction, looks like this is covered in the web3py docs.
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I'm building a DeFi application on Ethereum, and I would like to implement the Deposit function. Everything works fine between ETH and a ERC20 token that I built, but I would like to add some tokens like aToken for AAVE or cTokens for Compound that the user will receive after a Deposit call.
So the question is: is it possible to add a function in my smart contract to create multiple tokens without creating a smart contract for each of them? If not, I have to create a different contract for each token I want to add in my app or there is a best method to do it?
Yes this is possible. You can transfer the tokens to the user's address after the Compound Protocol mint operation. This can be made generic using the ERC-20 transfer interface. Be sure to account the amounts users are due and beware of the reentrancy vulnerability.
I'm developing a new dapp and I'm wondering with current Ethereum state of network, which are correct parameters to send along with web3, i.e.
myconytact.methods.myfunction(<params>).send({from:address,?????})
my problem is gas, gas limit and so on. I should use estimateGas? and the put gas:gas in the object passed in send()?
Generally, you never need to put in gas or gas limit, as those are set by the user in his or her wallet when confirming the transaction.
I am wondering if there are any services or websites that will automatically monitor an Ethereum wallet and when a transaction occurs with it (either in or out) it calls a specified web hook?
Defender Sentinel from Openzeppelin monitors function calls and events on contracts and can trigger webhooks, emails, slack ect.
It doesn't seem to work on non-contract addresses though.
https://docs.openzeppelin.com/defender/sentinel
Alchemy Notify seems to be able to do that with non-contract addresses.
https://docs.alchemy.com/alchemy/guides/using-notify
Can NFT's be used as a mean of authentication? The scenario is a user buys an NFT (ERC721) now he visits the site that uses this Token for authentication, so am guessing the web3.js on the site checks the users wallet if he has the token in wallet then can access the site....but what about server side calls...the server can check the ledger to see who owns the token, but how can it know if the person making the call is the owner..address can be spoofed so sending it with call is out of question. Also the case if users sells his token now a new user owns it
Am thinking something like digital signature but how to get the owners public key and is requiring users to sign messages a hassle...am noob to solidity what do I know but SO requires me to try to answer my question before asking for an answer also some code a requirement for every posts
pragma solidity ^0.4.22;contract helloWorld {
function renderHelloWorld () public pure returns (string) {
return 'helloWorld';
}
}
Checking that the viewer has an address that owns the token is not enough. You would need to confirm that the viewer controls the address by asking them to sign a message.
One system like this is called MetaKey.
If you want to coordinate sessions with a backend, you need to do additional work because the NFT could be transferred. You would need to revoke the session key when the NFT is transferred, which requires that you monitor the blockchain for transfer events.
I don't recommend building sign in infrastructure around an NFTs though. It will be extremely difficult or impossible to avoid security flaws. Better to authenticate people using a wallet signature. There are many tutorials online for building this flow, for example here.
Everyone can create ethereum token by solidity codes but don't know how can this token integrate as payment gateway in ecommerce website.
For real project . This token need frontend web wallet /android wallet and integration to every website as payment.
Plz suggest me .how can find this way.
What need more to study.
Token is not a payment gateway. If i understand your question correctly, you are asking, how can you interact with a token that you have created through Solidity from frontend. One use case would be how people can use the token that you have created to purchase some item. For this the users should already be holding the tokens. This can be bought from an ICO or from an exchange. Basically there's a couple of functions in ERC20 token i.e., approve() and transfer() that will approve apps like exchanges to perform transactions on behalf of the owner of the token. Once the users have those tokens they can purchase items from it. Again, you have to write the logic how and what you expect users to do.
ERC20 Token is works likes Currency.And solidity is a programming language. which we used for write the smart contract. if you want to invoke your function then you need to create wallet account ,after that you can do transaction using with web3js. you can get ether for testing purpose from faucet.Basically these are functions in ERC20 token i.e., approve() and transfer() that will perform transactions
I don't suggest using ERC20 tokens as payment method.
Ethereum network is not fast enough,you need 30 confirmations to make sure you received the token, some times the delay can be 1 day
Cost is high, when you transfer token ,usually you have a smart contract, it costs lots of gas
Ether price is not stable, it drops 90% of value from Jan 2018 to Dec 2018. it will be hard for estore to maintain profit.
However if you still want to do that, yes, you can create your own gateway using tokens as your accepted currency.