This post explains how to manage the list of tokens displayed by Metamask. It also reveals one quick trick for discovering if there are tokens that you own but did not even know about.
Your Metamask wallet doesn't actually hold tokens. Instead it displays a list of token types from the currently specified network along with the quantity of that token that you hold. So when "adding" or "hiding" tokens in metamask that really just means changing the visibility of that type of token in your wallet. The quantity of tokens held for a given type of token will never be changed just by changing the token's visibility and therefore every operation in this post is totally safe and cannot lead to a loss of tokens. The only way you can go wrong is if you manage to add a garbage token that does not actually represent the asset that you think that it does and then you use some other dapp outside of the wallet to trade something of value for the garbage token. We will want to be careful not to do that!
Adding a Token
Metamask doesn't list many tokens be default. Fortunately adding more types of tokens is usually quite easy. For the sake of safety I suggest always starting with simple name matching and only proceed to the advanced methods if this doesn't work and if you are confident about the token in question.
Let's say that the LINK token is not visible in Metamask and you want to add it. The "Add Token" button is shown below your token list. You may have to scroll down to see it. Select it to get a window that has "Search" as the default tab and a textbox to "Search Tokens", Type "LINK" into this field and you will see a number of tokens that include this word in their name. The Chainlink Token is probably at the top. Select is and hit "Next". After that another window appears asking you to verify this selection. Select the "Add Tokens" button and then we are done. LINK is now visible in your token list in Metamask.
If the search doesn't reveal the token that you are looking for, then you will need to use the "Custom Token" tab of the Add Tokens window. To make this option work you need to track down the ERC-20 smart contract address for the token that you want to add. When you find it and make sure that it is from a reputable source, paste it into the "Token Contract Address" field. If the correct token name appears in gray in the "Token Symbol" field then you can select "Next" and complete the process of adding the token.
Hiding a Token
This is the opposite of adding a token. Select the token you want to hide as if you were going to perform a send transaction. Instead of sending, select the 3 dots in the upper right hand corner to reveal a menu that includes the Hide option. Select Hide and confirm to complete the process. Once hidden, a token can be added back to the token list by using the "Add Token" process as discussed above in the usual manner.
Now for the trick. If a DeFi app or a person sends you a new token that is not on your Metamask token list, then there is a very quick, easy and accurate way to track down the ERC-20 contract address for that new token. Simply visit an explorer for your current network using your address. On Polygon you can copy your Metamask address (which begins with "0x") and paste it after the final slash of this url:
Visit that URL and you will see detailed information about the history and disposition of your interactions with the Polygon network. You can select the "Tokens" tab to see a list of the tokens that you current hold. Each token also has its' respective contract type and address. If it is an ERC-20 contract, then you can copy that address into the "Token Contract Address" field of the "Custom Token" tab in the "Add Token" window making the "Add Token" process a snap.
You may also discover tokens that you didn't even know that you owned. Projects have been known to airdrop tokens to wide varieties of network users. While it is highly unlikely that any tokens that you discover in this way have any value, you will never know unless you take a look.
That is it for my quick dive into Metamask. There is more to say about it but first we need to start transacting in earnest. That will start happening in my next article covering Quickswap which is the leading decentralized exchange (DEX) on Polygon.
Also note that I now have the Binance Smart Chain set up in Metamask and I started doing some trading and looking around on that network as well. Therefore this series of articles will include BSC dapps sooner rather than later to go along with my dive into the Polygon network.
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