my wallet metamask account has been hacked, all my BNB is gone. But I still have NFT locking. around 2000$ there I'm trying to deposit on BNB trying to revoke all the coins that exist. and wished I could transfer my funds to pay the gas fee but the funds "automatically" moved to another wallet looks like the hacker has installed a bot on my metmask wallet Do you have any other solution? I have complete data Please help me
What if I want to programmatically send money to an address? Without manually interacting with metamask? For example, I have an application where the user can claim some money after performing an action. How would the application send the money to that user address ?
Two ways: 1. You can write a script that sends money from wallet (in Node.js or any other programming language) 2. You can prepare smart contract that acts as a vault. Inside the logic of the contract you can whitelist somebody to claim their funds.
Thanks Artur for the great tutorial. I would like to ask, if I am selling my token (a smart contract) to the buyer and I need to verify the amount of payment is enough for the tokens, how can I do that? In my smart contract, I have a function that verifies the payment amount (and all the logic). But how can we combine the payment transaction (sent by the buyer) AND call that function at the same time ? Thank you a lot
sir can u explain how to handle logout in metamask. (my problem is even after clearing the local storage when logout but still metamask is not locked) ?
@@ArturChmaro and what if i want to use it to pay subscription of something so I can't put the amount of Ethereum by myself how can I calculate it according to the current price of Ethereum
Thanks for a great question. Both libraries basically do the same thing. Migrating shouldn't be hard because usually you just do the setup for provider/signer and calling smart contracts or sign transactions. I personally prefer ethers over web3 because: - ethers has clearer syntax (for me at least) - ~3x smaller than web3 - better abstraction over wallet and signer - more friendly maintainer - better docs (still not perfect though) Here is a cheatsheet with differences between web3 and ethers: github.com/adrianmcli/web3-vs-ethers
Thanks for the video! In case I want to build a marketplace, how can I prevent attacker to change the value on "debug mode" and send different amount? I can't do it on server unless they send me their private key (which is not something I want)
That's a regular React.js project. All you have to do is build it using "build" command (included in the package.json) and then you would get "dist" folder with a package of HTML/CSS/js files ready to be deployed. Just upload this files to your HTTP server via FTP and you are done. You can also use tools like netlify/vercel/firebase that can host it for you.
@@ArturChmaro Unfortunately, it is not clear how to make the "build" command to get the files for uploading to the hosting. Please tell us more for beginners, or better record a video. Thanks for the dialogue!
@@hector-j1v8c if you are using npm as a package manager do "npm rub build " for react to get your build ready . If it is yarn you are using as a package manager then do "yarn build " to get your build running. when the build is ready, get your build file (dist) and upload it to your HTTP sever.
Sure, however than you have to interact with ERC20 smart contracts (standard for most of tokens). Then instead of moving ether you are just moving ERC20 coins.
Hello, thank you and you're the best lifesaver I would love to ask for some suggestion on how to do with minting and on the whitelist part, revealing that stuff. I am currenctly working on a start up company and I'm still overwhelmed on this ethereum and other crypto stuffs. thank you
Great video! How can you prevent people from trying to pay with test coins just like you do in the test environment and only allow them to submit payments from the official blockchain? In the metamask account?
You don't have to do much about it. Testnet & mainnet addresses are different, so it's impossible to call testnet by mistake. Secondly you control the provider object inside your dapp and you can force (or check) there to which network metamask user is connected.
do you know some payment gateway where the client pays normally by credit/debit card and I(owner of the store) receive automatically money converted to cryptocurrencie?
Haven't used any service like that. I can only recommend something similar: ramp.network/ This service allows user to quickly swap regular currencies (EUR/USD/GBP/PLN and other fiats) to any crypto. The process is straightforward and can be used via a special widget (without leaving your app)
Hello Sir, at the final of this video when I try to show the trasaction id by putting the (setTxs([tx]) line of code I get this error: Error: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports. Any help please? Thanks a lot
how would you determine after the await signer.sendTransaction if the Eth sent is Ethereum Mainnet or Ropsten Test Network ethereum? as i would like to log in my database that a real transaction has been sent? also can you get a receipt for when the transaction has officially mined and reach your account?
After issuing a transaction you can store txHash, pass it to the backend and double-check whether the funds were sent on the mainnet. You may also check how much confirmation did transaction get on-chain
@@ArturChmaro So i can't just do something like if tx.network !== "mainnet". {. deny transaction- no real funds paid? }. and i have to do some sort of api request to eth scan? is that correct ?
Hello Artur! It's awesome lesson. There is 1 question left: is it possible to generate 2 signatures from 2 different keys and combine their transaction into 1? So one of them will pay gas for both.
@@ArturChmaro Thanks! I can see that contracts can pay fees on their behalf. But what about user A pays for user B to send as combined transaction into a contract?
🎁 Web3 Starter for JS Devs (free email course): @t
Super materiał! IMO niedługo będzie "boom" na dapps/blochain developers! Czekam na kolejny materiał! Pozdrawiam
Artur, więcej takich poradników blockchain-related! Złoto.
Będzie dużo, don't worry :) Mój angielski chyba aż tak nie przeszkadza w odbiorze, bo sporo ludzi korzysta z tych materiałów
my wallet metamask account has been hacked, all my BNB is gone.
But I still have NFT locking. around 2000$ there
I'm trying to deposit on BNB trying to revoke all the coins that exist. and wished I could transfer my funds to pay the gas fee but
the funds "automatically" moved to another wallet
looks like the hacker has installed a bot on my metmask wallet
Do you have any other solution?
I have complete data
Please help me
Love you brother for making this great tutorial. I hope you will keep providing us Web3.0 , solidity or react good content in english
Will do my best! Thanks for kind words buddy :)
What if I want to programmatically send money to an address? Without manually interacting with metamask?
For example, I have an application where the user can claim some money after performing an action. How would the application send the money to that user address ?
Two ways:
1. You can write a script that sends money from wallet (in Node.js or any other programming language)
2. You can prepare smart contract that acts as a vault. Inside the logic of the contract you can whitelist somebody to claim their funds.
Hello, how do I make the payment through a imported token
Thanks Artur for the great tutorial. I would like to ask, if I am selling my token (a smart contract) to the buyer and I need to verify the amount of payment is enough for the tokens, how can I do that?
In my smart contract, I have a function that verifies the payment amount (and all the logic). But how can we combine the payment transaction (sent by the buyer) AND call that function at the same time ?
Thank you a lot
Excellent English!
Is it possible buy tokens nft by code? There is any video on your channel about this?
how can we send different tokens from same method for example what if I want to make transaction through stable coins
sir can u explain how to handle logout in metamask. (my problem is even after clearing the local storage when logout but still metamask is not locked) ?
is there a way to automate it?
does it work with other currencies or just eht
Best demonstration
Hey,do you have video about staking smart conract,thanke you
Got one video about NFT staking. Check my channel videos ;)
Very nice and useful video!
Glad it was helpful!
Hi I want to do the same to transfer SepoliaETH to a recipient address, do I need to change something in the code? thanks!
Everything remains the same. Just make sure that provider is configured for Sepolia ;)
hey thank you for this video, Artur
Happy to help Riaz!
Don't we need any type of token or anything to send transactions?
Yes, you need to cover gas fees
@@ArturChmaro no i mean like authentication token type thing
@@ArturChmaro and what if i want to use it to pay subscription of something so I can't put the amount of Ethereum by myself how can I calculate it according to the current price of Ethereum
Great video
Hey Artur. Great video! What's the advantage of ethers over web3? Should I convince my team to move into ethers from web3? Is it a challenge?
Thanks for a great question. Both libraries basically do the same thing. Migrating shouldn't be hard because usually you just do the setup for provider/signer and calling smart contracts or sign transactions. I personally prefer ethers over web3 because:
- ethers has clearer syntax (for me at least)
- ~3x smaller than web3
- better abstraction over wallet and signer
- more friendly maintainer
- better docs (still not perfect though)
Here is a cheatsheet with differences between web3 and ethers: github.com/adrianmcli/web3-vs-ethers
@@ArturChmaro Thanks!
Isn't web3 going to be deprecated?
@@papitomyking dunno tbh, still a lot of folks uses it 🤷♂️
great question Artur
Thanks for the video! In case I want to build a marketplace, how can I prevent attacker to change the value on "debug mode" and send different amount? I can't do it on server unless they send me their private key (which is not something I want)
Contract may validate amount sent along with transaction. If funds are not enough contract will revert the transaction.
As it is on the site, nothing comes out to run. In index.html there is no link to .js files and package.json. What files should be on the hosting?
That's a regular React.js project. All you have to do is build it using "build" command (included in the package.json) and then you would get "dist" folder with a package of HTML/CSS/js files ready to be deployed. Just upload this files to your HTTP server via FTP and you are done.
You can also use tools like netlify/vercel/firebase that can host it for you.
@@ArturChmaro Unfortunately, it is not clear how to make the "build" command to get the files for uploading to the hosting. Please tell us more for beginners, or better record a video. Thanks for the dialogue!
@@hector-j1v8c if you are using npm as a package manager do "npm rub build " for react to get your build ready . If it is yarn you are using as a package manager then do "yarn build " to get your build running. when the build is ready, get your build file (dist) and upload it to your HTTP sever.
I was wondering if it's possible to use BSC with this and send custom tokens?
Sure, however than you have to interact with ERC20 smart contracts (standard for most of tokens). Then instead of moving ether you are just moving ERC20 coins.
Great video. How do I get the web3 starter for JS devs email course
Here bit.ly/web3starter 😊
@@ArturChmaro Done. Thank you
Hello, thank you and you're the best lifesaver
I would love to ask for some suggestion on how to do with minting and on the whitelist part, revealing that stuff.
I am currenctly working on a start up company and I'm still overwhelmed on this ethereum and other crypto stuffs. thank you
also would love to learn about smart contracts and other technical term and how to code them. thank you !
life save count : 3. thanks man
Great video! How can you prevent people from trying to pay with test coins just like you do in the test environment and only allow them to submit payments from the official blockchain? In the metamask account?
You don't have to do much about it. Testnet & mainnet addresses are different, so it's impossible to call testnet by mistake. Secondly you control the provider object inside your dapp and you can force (or check) there to which network metamask user is connected.
how can I specify the network that I want the TX to be with?
Force provider network on UI side :) or just check it before actually asking for a transaction
if I want to send usdc , what I want to change
Different flow. You need to call erc20 (usdc) contract. I guess I have to record another video...
do you know some payment gateway where the client pays normally by credit/debit card and I(owner of the store) receive automatically money converted to cryptocurrencie?
Haven't used any service like that. I can only recommend something similar: ramp.network/ This service allows user to quickly swap regular currencies (EUR/USD/GBP/PLN and other fiats) to any crypto. The process is straightforward and can be used via a special widget (without leaving your app)
Hello Sir, at the final of this video when I try to show the trasaction id by putting the (setTxs([tx]) line of code I get this error: Error: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports.
Any help please? Thanks a lot
Hello Mohamed! Please check the live version of this code. It works :) codesandbox.io/s/react-eth-metamask-7vuy7
how would you determine after the await signer.sendTransaction if the Eth sent is Ethereum Mainnet or Ropsten Test Network ethereum? as i would like to log in my database that a real transaction has been sent? also can you get a receipt for when the transaction has officially mined and reach your account?
After issuing a transaction you can store txHash, pass it to the backend and double-check whether the funds were sent on the mainnet. You may also check how much confirmation did transaction get on-chain
@@ArturChmaro So i can't just do something like if tx.network !== "mainnet". {. deny transaction- no real funds paid? }. and i have to do some sort of api request to eth scan? is that correct ?
Is it possible with smart chain instead of ethereum?
Of course, however then native coin is BNB, not ETH :)
@@ArturChmaro there is an API to Smart chain to? I'm Brazilian beginner developer. In Brazil, there is no information about that.
How to display wallet balance ?
Use getBalance function from ethers: provider.getBalance("your_addr")
Can you do this for angular?
No plans for it as I have no Angular experience 😅
sir pls teach us how to write ether " transfer code in Solidity " and Front end in React js
i'd like to see the code in git hub\
Hello Artur! It's awesome lesson. There is 1 question left: is it possible to generate 2 signatures from 2 different keys and combine their transaction into 1? So one of them will pay gas for both.
You can pay gas for other addresses transaction. Google for "ethereum gas stations". I'm using Biconomy in my projects for exactly it.
@@ArturChmaro Thanks! I can see that contracts can pay fees on their behalf. But what about user A pays for user B to send as combined transaction into a contract?
great video
Thanks!
thank u
You're welcome!
How secure is this
It's secure :) Wallet app is responsible for signing the transaction. Private key never leave it.
@@ArturChmaro thanks bro