When using various Dapps (such as Uniswap, AAVE), users will need to connect a wallet to interact with the Dapp. When pressing Connect Wallet, a list of wallets currently available for the Dapp will appear, and in Among the options of these wallets, there is usually one option that will be the protagonist of our article today - Metamask.
Metamask was released in 2016, just in time for the bull market in the currency circle in 2017, and officially established its leading position in the industry at that time. In addition to being used as a Google plug-in, Metamask also launched a mobile version in 2019, supporting Android and iOS systems.
What is Metamask?
Metamask is a cryptocurrency wallet launched by ConsenSys and is currently the most used cryptocurrency wallet in the cryptocurrency industry. Metamask can be installed as a plug-in on Chrome, Firefox, Brave, Edge and other browsers. It has many functions and is very convenient to use.
The main functions of Metamask are:
Buy tokens
Store tokens
Send tokens
Interact with Dapps
Give an example of interacting with a Dapp:
We want to exchange USDC for ETH. At this time, we can go to the decentralized trading platform Uniswap to exchange. At this time, we must first connect to the Metamask wallet and authorize Metamask to use the USDC tokens in your wallet, so that Uniswap can send your USDC Go to the trading pool and exchange it for ETH for you.
Therefore, the Metamask wallet is an indispensable accessory for the use of many Dapps.
Is Metamask safe?
Metamask itself has high security. So far, there has been no large-scale asset loss crisis. As long as the private key and mnemonic phrase of the wallet are kept well, no one can move the cryptocurrency in the wallet. But two points must be noted:
Storage of private keys and mnemonics
Authorization when interacting with Dapp
Storage of private keys and mnemonics
When registering Metamask at the beginning, the private key and mnemonic phrase of the wallet will be given to the user, and they will not appear again, so they need to be kept well, and it is recommended to use paper rather than electronic means. Store it in a certain way, such as computer notepad, screenshots, etc., to prevent it from being leaked if the computer is infected.
Authorization when interacting with Dapp
Since Metamask is often used to interact with Dapps, it is necessary to authorize some permissions for Dapps to use during interaction. Many hackers will start from this process. Improper authorization may cause the loss of crypto assets in the wallet, so when using it, Must pay more attention.
Is Metamask a scam?
Metamsk itself is not a scam. As mentioned in the above introduction, it is a very practical and convenient cryptocurrency wallet. However, because of its popularity, many unscrupulous people will use various methods to steal private keys and mnemonics. words, for example:
Fake Metamask wallet
fishing link
Fake customer service notification
These are common fraud techniques, and Metamsk does not have customer service to contact users. Therefore, we must pay more attention during use and do not accidentally leak our private keys and mnemonic phrases to avoid asset losses.
Metamask installation tutorial
Add extensions
First, we enter the Metamask extension function of Google Chrome and click to add to Chrome.
Pin Metamask
After downloading, you can pin Metamask here to display it in the extended function for easy use later. Next click to get started.
If you already have a Metamask wallet, you can enter the wallet through the mnemonic vocabulary here. If not, click "Create Wallet".
A video will pop up next to tell you:
The mnemonic phrase (also called Secret Recovory Phrase) is your "account + password or Master Key". So if someone has your Master Key, he can transfer your money, so never let others know your mnemonic phrase.
For example, if you change computers and want to transfer money to your wallet, you need to use a mnemonic phrase. So be sure to write down the mnemonic phrase. Even Metamask officials won’t know what your mnemonic phrase is.
Here we write down the mnemonic phrase. We recommend writing it down on paper and keeping it properly to reduce any risk of leakage.
Go to the next page and arrange the mnemonics in the order just now. After completion, a new wallet will be successfully added!
Metamask allows you to send tokens to others, see your own address, add different tokens, and receive tokens sent by others. Reminder: Be sure to confirm whether the address is complete. If any letter is missing, the assets will disappear!
After talking about wallets, let’s talk about how to add new tokens.
How to add new tokens in Metamask
As we walk around the currency circle, we will collect a variety of tokens, so we also need to learn how to add new tokens. Go to Metamask and select "Add Token".
There will be two situations at this time: Situation 1: You can directly search for tokens. Larger tokens such as USDC can be added by searching.
Situation 2: If the token you want to add cannot be found in the search bar, you need to select "Custom Token" and add the token manually. Each token has an issuance address, just like the location of a factory. We only need to enter the token contract address to add the token we want.
After entering the settings, you need to provide the "Token Contract Address", "Token Code", and "Decimal Point Accuracy". I can directly search for tokens on token websites such as CoinMarketCap or CoinGecko, and you can see them on the website. Information about the token you want to add.
Taking CRV Token as an example, there is a contract address in the middle of the web page and a Metamask symbol next to it. There are two ways to add it. One is to directly click on the Metamask symbol to add the token to the Metamask wallet.
The other is to manually copy the address in the red box and paste it into the "Contract Address" in the custom token.
Note: On Ethereum, all tokens share a wallet. That is, if you want to transfer various ERC20 tokens to Metamask, you must use the same wallet address, which is the string of addresses under Account.
The above is the tutorial on how to add new tokens. It should be noted that different blockchain networks will have different token addresses. Therefore, for example, if I want to use USDC on Binance Chain, I need to add a token again. currency. Don’t be nervous if you don’t see the balance after sending the transaction. It’s possible that you forgot to add the token to your wallet.
Next we actually send the transaction once.
Metamask Send Transaction
Suppose we want to transfer ETH from Metamask to Binance.
Step 1: First log in to Binance’s website. Since what we want to transfer is spot, we click on Binance’s spot wallet, search for ETH and click to recharge.
Step 2: On the right, you can see three options "ERC20", "BEP20" and "BEP2", which represent the Ethereum chain, Binance Smart Chain, and Binance Chain respectively. These three chains are different networks. About the block We will introduce the chain network in "Different Blockchain Networks". Because we are currently using the Ethereum network, we choose the ERC20 transfer address and copy the address.
Step 3: Click to send
Step 4: Paste the Binance ETH address in the address field and enter the amount to be sent.
Note that in the transaction waste fields below, there are "Slow", "Average" and "Fast", which respectively represent the transaction time required for different Gas Fees. The higher the handling fee that users pay, the faster the transaction speed will be. In the following chapters, we will introduce how to set the Gas Fee parameters. Here we choose average first.
Step 5: After sending, we click on the transaction record to see the transaction just sent.
Step 6: Confirm that the ETH just sent has been received on Binance
Next, let’s imagine a situation where we are grabbing a limited amount of NFT, but if the transaction is completed too slowly, we won’t be able to grab it; or if I suddenly find that I sent the wrong address, what should I do?
In fact, although transactions on the blockchain cannot be tampered with, if the sent transaction has not been processed, there is still time to "accelerate" or "cancel" it.
Metamask transaction acceleration and cancellation
It's easy to do this on Metamask, where there are options to choose from. For example, if I submit a transaction, but the gas price submitted is very low, I will find that the transaction has not been processed for a long time. At this point, I have a few options:
Maintain the status quo and wait until the gas price of the network drops and the miners are willing to process my gas prcie transaction.
Click Speed Up to let me increase the gas fee for submission so that the transaction is processed faster.
Or to cancel, just click Cancel on Metamask.
Gas Fee is the handling fee charged by the miners. You can think of it as the handling fee charged by the bank to the user. On the blockchain, the amount of the handling fee will depend on the complexity of the transaction or operation. For example, if you just want to transfer assets from address A to address B, the handling fee will be cheaper. But if I want to exchange my assets for B tokens, deposit them into C vault, and then transfer them to D application, the handling fee will be more expensive. And the gas fee for a transaction does not depend on the transaction amount, so the handling fees for $100 and $1,000 will be the same.
Here we first try to click "Send" to send a transfer and then select the "Advanced Options" for transaction fees.
In the picture above, we can see two parameters, one is "Gas price" and the other is "Gas upper limit".
Gas price: The price of a single gas, such as how much a liter of gasoline costs. This can be set by the user. For example, if the gas price is too expensive now and I want to wait until the gas price drops to 25 yuan before refueling, then I will set the gas price to 25 yuan. Or if you are in a hurry and want to make a transaction quickly, then I will set the gas price a little higher, so that you will not have to wait for a long time due to traffic jams.
Small reminder: On Ethereum, Gas Price fluctuates quite a lot. Sometimes it is very expensive, sometimes it is relatively cheap. Before trading, you can go to Etherscan to see what the recommended Gas Price is.
In the "Ethereum Gas Tracker" field, you can see that there are three prices: "Low", "Average", and "High", which represent the approximate transaction time required for different Gas Prices. For example, if Average 19 gwei means I set the Gas Price to 19, I need to wait about two and a half minutes.
Going back to the previous picture, in addition to Gas Price, there is another parameter called "Gas Limit". The Gas limit is a parameter that cannot be adjusted. You can imagine that the "gas limit" is the number of liters of gasoline you need to add. For example, a 100-kilometer trip from point A to point B requires at least 4 liters of gasoline. To save money, I changed it to 2 liters, which would cause the car to be directly on the road. Anchorage, the same thing will happen on the blockchain. If the gas limit is lowered, the transaction may fail.
As for the final amount of gas consumed, it is actually paid, that is, it will deduct how much it is actually used. The Gas Limit is just to set an upper limit first.
After learning the settings of Metamask transactions, let’s talk about what different blockchain networks are. If you transfer the wrong network assets, your network assets will disappear!
After entering Metamask, look at the network in the upper right corner. The default is "Ethereum Main Network".
Why the Ethereum main network?
We can think of different networks as different countries, and Ethereum is now the most mainstream country and the country where the most applications and developers are located. Each different country, such as Bitcoin, Ethereum, AVAX, Binance Smart Chain, Polygon, Solana, etc., each of the above names represents an independent blockchain network, and each network has its own Different rules. Just like every different country has its own laws and currencies, tokens from different countries cannot be transferred to each other.
For example, ETH tokens cannot be transferred to Solana's address, just like Taiwan dollars cannot be transferred directly to the address of a US dollar account. So if we want to use the Binance Smart Chain network, we need "Custom RPC" to set up the Binance Smart Chain network. Let’s talk about how to customize RPC. Here we take the Binance Smart Chain network as an example.
BSC Binance Smart Chain Network Settings Tutorial
First, after we click on Custom RPC, we will enter the settings page, and then fill in the content according to the network information. Below is information about the Binance Smart Chain network.
Network Name: Smart Chain
New RPC URL: https://bsc-dataseed.binance.org/
ChainID (smart chain ID): 56
Symbol: BNB
Block Explorer URL: https://bscscan.com
After filling in, click Save and you will see the Smart Chain network you just added!
If you want to set up other public chains such as Bitcoin, Solana, AVAX Avalanche Protocol, or the recently popular Polygon, you need to find their parameter setting network separately.
Metamask summary
Finally, do you still remember that there is a blockchain browser option when "setting up the network"?
The blockchain browser is like a ledger on different networks, where we can see or search every transaction record, assets at different addresses, or the addresses of each token and smart contract.
We click on the upper right corner of Metamask and select "Browse on Etherscan".
After clicking, you will enter the Etherscan page.
Here we can see all the records about this account in great detail.
Including: all owned assets, past transaction records, payee and object of each transaction, etc., even NFT. Etherscan can only see records on Ethereum. If you want to see Binance Smart Chain, you need to switch to the BSC network and select "Browse in Explorer" on Metamask.
After you learn to use Metmask, you can basically roam freely in the DeFi world. However, one thing to remember is that the blockchain gives users full control over their property, but with greater power comes greater responsibility. If the private key is lost, the asset will disappear forever along with the private key. It is rumored that there are about 20% of Bitcoins have been lost forever due to lost private keys.
So the above is the teaching about Metamask this time. If you have any questions, you are welcome to join the Sangbi community. If you have any topics you want to see, please leave a message and tell us!
This article introduces Metamask Little Fox Wallet, registration, transaction deposit, fraud, and Metamask tutorial. It first appeared in Zombit.