[Blockchain knowledge] I bought the last Travelloggers with 10,000 yuan | Blockchain browser

Travelloggers

Traveloggers is an NFT issued by Matters, a creative forum. If you are still unclear about what NFT is, you can refer to my previous article - "Understanding what NFT is and its application in one article" .

Traveloggers introduced him on the official website as follows: "Traveloggers are 1500 NFT digital avatars issued by Matters Lab. It is an interactive and scalable social co-creation NFT. Having this identity will open up the most radical in the Matters universe. Experiment permission. Each Travelloggers avatar hides a unique Logbook (logbook), only the owner can add a record to it once.”

All in all, it can be imagined that each NFT is a character living in Matters, and the owner can help the character write his own story on the blockchain, and write anything, which will become part of this NFT! Someday in the future he is traded into another person's wallet, and the stories written by these former holders will live on.

Since I founded Technology Essay in November this year, I have also posted several articles on Matters, but when I saw this cool NFT, I had already missed the previous waves of airdrops, but I wanted to start watching it. Which one to buy, I immediately found out that Travelloggers number 1500 has no owner, since I can't be the first, then I will be the last! So it's better to act immediately. I immediately bought some ether from the exchange and bought it directly.

This #1500 is not very pleasing! It's basically a bearded stinky eggplant with a fat pumpkin on its head~ but the more I look at it, the more cute I think it is.

The topic is too far away. Although the price of Travellogger on OpenSea is 0.06 ETH, the actual transaction action will need to be on the blockchain, so an additional transaction fee will be required, which we call gas fee, and the transaction fee of Ethereum As everyone knows, it is expensive, and here is my transaction record at that time:

Value: 0.06 Ether is the money spent on the purchase, Transaction Fee: 0.0257 Ether is the transaction fee, you read that right, so I spent about 0.0857 ETH in total, which is the transaction price of $264.17 + handling fee at the moment of purchase 113.43 USD = 377.6 USD, which is more than 10,000 Taiwan dollars. The transaction fee is 42%. You say which idiot would buy 100 yuan for 142 yuan, is it stupid? But there is no way, this is the Ethereum Noble Chain!

Where did this historical data map come from? How to check?

Just as we need to know how to use a web browser if we want to browse the Internet, there is also a tool that we must understand in the blockchain and currency circles, that is, the blockchain browser. The blockchain browser may be a very unfamiliar thing to those who are just beginning to study the blockchain, so this article will teach how to use the blockchain browser by the way. Learning this trick can make us in the encrypted world One of the secrets to survival! For example, if you are not in a hurry to trade and want to save a little handling fee, you can check the current gas fee through the blockchain browser. If the gas fee in the last few blocks is particularly low, then now may be a good opportunity for transaction transfer.

What is a blockchain browser

Any different blockchain has the ability to "record assets", that is to say, when we want to transfer assets, we must record a sum of money from who to whom (From who, To to whom, Value how many assets to pass), and pay a transaction fee.

It is said that the blockchain is one block after another linked together and stored on the Internet. If you want to check whether we have just sent a transaction request, whether the current account has been on the chain, or whether I have already received the money. Yes, but I want to go back and look at the historical transfer records. How to query the asset data like these recorded on the blockchain? You need to go through a blockchain browser.

Using a blockchain browser has one thing in common with using a normal web browser, that is, you can enter whatever keywords you want to query! The blockchain browser can help us better understand how these transfer actions interact with the blockchain, wallets and smart contracts, because all the data on the chain is open and transparent in the blockchain browser, except that you can query your own In addition to wallets and historical transaction records, we can analyze these data, and there may be opportunities to discover something early and reduce the chance of encountering risks. The process of using a blockchain browser is like finding information on Google browsers. No fee is required.

Basically, each blockchain will have its own blockchain browser for everyone to query. For example, the browser of the Ethereum main chain is called Etherscan , the browser of Binance Smart Chain is called BSCscan , etc. If you want to search the blockchain Browser, but if you don’t know how to search Google keywords, the more mindless way to search is to add “Scan” to the chain or the main currency issued on that chain. For example, to find the Bitcoin blockchain browser, just Query " BTC scan ", if you want to see your NFT transaction records on Polygon, you can find it by querying " MATIC scan " or " Polygon scan "! (MATIC is the token that needs to be paid for transactions on Polygon!)

In use, as long as you give it any wallet address, they can immediately look up all historical transaction records, total balance, and how many tokens there are in the wallet address, and can also query the smart contract deployment code and smart contract call history. records, asset value of smart contracts, etc.

Speaking of this, you will find that as long as you know the wallet address of the other party, anyone can see how much money he has, when he has done transactions, and what NFTs he currently has. The world, on the contrary, is completely open and transparent! Cool!

All blockchain browsers are similar in appearance. If you use one of them, you will basically use the other, and the functions are similar, so we will take Ethereum's Etherscan as an example. After reading this article, you should be able to use all the browsers. Basic functions of different blockchain browsers.

How to use Etherscan?

Etherscan is a blockchain browser on Ethereum. We don't need to do any login actions (register or connect to a wallet) to use Etherscan directly, so here we should pay more attention to the possibility of fraudulent groups creating a page that is very similar The phishing website usually requires you to enter the wallet private key or any privacy to start using it, so remember to check the website URL and be vigilant before using it. Do not provide your private key and mnemonic at will. Failure to do so will result in loss of assets.

We can view all public data on Ethereum including transactions, smart contracts, addresses, etc. on it, and we can also search for historical related transaction activities through the hash function of transactions. If you want to use Etherscan to query the wallet balance, then you will The wallet address is required; if you want to query historical transactions, you will need the ID (TxID) of the transaction number; if you want to query the decentralized application (DApp), you will need the contract address. Depending on the keywords you query, the information you can see will be different, but most of them will include information such as block time, address, and amount.

1. Etherscan's page

You can directly connect to Etherscan here , and after entering it is its home page, which looks like this.

On the home page, we can see a lot of data, which can let us immediately understand the details of the current Ethereum main chain, such as ETH's quotation (ETHER PRICE), ETH's total market value (MARKET CAP), and the total number of transactions (TRANSACTIONS) , mining difficulty (DIFFICULTY), average gas fee/on-chain transfer fee (MED GAS PRICE), recently produced blocks and transaction records (Latest Blocks, Transactions) and other functions.

2. Query wallet balance, historical transactions, and smart contract records through Etherscan

No matter on the home page or any other page, there is always a search box at the top. This is where we can fill in the wallet address, smart contract address, ID records of historical transactions, block height and other information to search, so if If you want to check your wallet balance or the NFT you own, then you can open your wallet, copy and paste your address into the search box, remember that what you want to paste is the "wallet address", never put the private key Or fill in the mnemonic, which will be a bit awkward.

Examples of wallet balance and historical transaction records

Let's play with a query that should be quite interesting as an example. Let's check the wallets that mint Travelloggers NFT and see how much money they make after sending an NFT !

The wallet address is "0xdB9fdaB72D71c998e3EebCf1096704e03C3cDaE5", after entering, you can see the wallet balance and past transaction records (lazy link) :

From Overview, we learned that there are 6.35 ethers in this wallet at the moment of writing the article. If converted into US dollars, the market value is more than 24,000 US dollars. But this does not mean the money they make, because there must be a sum of money to support the handling fees generated in the process of minting and airdropping NFTs, and the subsequent sales will start to make profits. If you are really interested, If you know how much Travelloggers earn, you can calculate it yourself, but I think the higher probability at this stage should still be losing money~

Open the drop-down menu in the Token column, and you can see which currencies are still in the wallet. Taking this wallet as an example, we know that there are still 755 Travelloggers in the wallet at the moment of the screenshot. It seems that there is still some distance from the sale. , it's better to act immediately, if you want, you can choose only what you like and buy it~

In the bottom block, you can see all the past records. As long as you have created, called smart contracts, minted NFT, and imported and remitted money, it will be recorded. Analytics can see that Etherscan has integrated various wallet data into Some charts, these charts make it easier for us to quickly grasp the records of the wallet.

Smart contract query example

Here we check OpenSea, the largest NFT secondary trading market, and try it out. Its contract address is "0x7Be8076f4EA4A4AD08075C2508e481d6C946D12b". After entering, you can see OpenSea's Etherscan page (lazy link) :

A smart contract is like a vending machine on the blockchain. We put money into it, tell it what function to perform, and it will do it for us. On OpenSea's blockchain browser, in addition to Apart from the recent transactions, I think the most important function is the "Contract" with a green tick next to the bottom block.

The code behind the vending machine is built. This Contract contains the code of the smart contract address of OpenSea. As long as it is on the chain, anyone can study whether there are loopholes in it anytime, anywhere. If you want to borrow it It is also feasible to use the code to develop the new smart contracts we want.

In an open and transparent blockchain world, all the code on the chain is also open and transparent and cannot be changed, which means that we do not have to be afraid that this vending machine will suddenly change the rules when we invest money, causing money The problem of suddenly being eaten after investing in it occurs.

3. Check the Gas Fee through Etherscan

On the homepage, directly click the number under "MED GAS PRICE" (eg 97 Gwei) to enter the fuel fee inquiry page.

If you stay on this page for a long time, you will find that the gas fee is fluctuating, and this gas fee can be used as a reference for our transaction. If the current average fee is relatively high, it means that more people are transferring money now, maybe You can wait a while before transferring money. If you are going to use a more complicated smart contract, just waiting like this will probably save dozens of dollars on Ethereum.

You can mention the "Estimated Cost of Transfers & Interactions" field a little. There are three things below that can be used as the current rate indicator:

The first one is ERC20 Transfer. When we usually transfer money between wallets and wallets or exchanges and wallets, we look at the fuel cost of this ERC20. Taking this picture as an example, we can probably know that it takes about 24.11 to transfer money. US dollars to complete the transfer.
The second and third are Uniswap, which is a decentralized exchange. I will write an article to introduce decentralized exchanges when I have the opportunity in the future, but you can use it as a reference indicator for measuring gas costs. .

So what if I want to know how much is the transaction fee for NFT on OpenSea?

The contract address of OpenSea is "0x7Be8076f4EA4A4AD08075C2508e481d6C946D12b", you can search directly according to the method of how to query the address mentioned above, or click to scroll down on the fuel fee page, and click on it when you see OpenSea, so that you can enter the address page of OpenSea. Then click the link starting with 0x under "Txn Hash" to enter each transaction record. These transactions are the most recent transactions. If you look at the "Transaction Fee" of a few transactions, you can probably get the current transfer fee. .

4. The mysterious function of Etherscan

In addition to querying these on-chain records, Etherscan has some other functions. For example, you can see the airdrop plans of some newly issued tokens in the airdrop list ; look at the word cloud of recent keyword searches on Etherscan; If you are interested in these functions, such as the application directory related list , etc., you can study more, maybe you will find treasures.

They also have APIs for program developers to use. If the programs to be developed need to capture data on Etherscan, the official development documents of the API are linked here . I think related development applications such as stocks and bank exchange rates have been rotten. Now, if you want to do some side projects, start with the blockchain browser and do some own analysis. It should be easier to have pretty good problems. Maybe you can find new profit opportunities.

Finally, thank you for taking the time out of your busy schedule to read my articles. If you still like these content, I hope to get your follow-up and support. You are also welcome to click this link to find me on other platforms .

See you next time o((>ω< ))o~

Original link ITechNote technology essay