The DefaultAccountState
extension provides the option to have all new Token
Accounts to be frozen by default. With this configuration, Token Accounts must
first be thawed (unfrozen) by the Freeze Authority of the mint before they
become usable. This feature grants token creators the ability to have greater
control over token distribution by limiting who can hold the tokens.
In this guide, we'll walk through an example of using Solana Playground. Here is the final script.
Getting Started
Start by opening this Solana Playground link with the following starter code.
If it is your first time using Solana Playground, you'll first need to create a Playground Wallet and fund the wallet with devnet SOL.
If you do not have a Playground wallet, you may see a type error within the
editor on all declarations of pg.wallet.publicKey
. This type error will clear
after you create a Playground wallet.
To get devnet SOL, run the solana airdrop
command in the Playground's
terminal, or visit this devnet faucet.
Once you've created and funded the Playground wallet, click the "Run" button to run the starter code.
Add Dependencies
Let's start by setting up our script. We'll be using the @solana/web3.js
and
@solana/spl-token
libraries.
Replace the starter code with the following:
Mint Setup
First, let's define the properties of the Mint Account we'll be creating in the following step.
Next, let's determine the size of the new Mint Account and calculate the minimum lamports needed for rent exemption.
With Token Extensions, the size of the Mint Account will vary based on the extensions enabled.
Build Instructions
Next, let's build the set of instructions to:
- Create a new account
- Initialize the
DefaultAccountState
extension - Initialize the remaining Mint Account data
First, build the instruction to invoke the System Program to create an account and assign ownership to the Token Extensions Program.
Next, build the instruction to initialize the DefaultAccountState
extension
for the Mint Account.
Lastly, build the instruction to initialize the rest of the Mint Account data. This is the same as with the original Token Program.
Send Transaction
Next, let's add the instructions to a new transaction and send it to the
network. This will create a Mint Account with the DefaultAccountState
extension enabled.
Run the script by clicking the Run
button. You can then inspect the
transaction on the SolanaFM.
Default Frozen Token Account
When a Token Account is created, it will be frozen by default. As a result, any transactions interacting with the Token Account will fail.
In the default frozen state, users are unable to hold or interact with tokens from the mint until the Freeze Authority thaws (unfreezes) the Token Account.
For instance, minting tokens to the new Token Account will fail.
Run the script by clicking the Run
button. You can then inspect the error in
the Playground terminal. You should see a message similar to the following:
Unfreeze (Thaw) Token Account
A Token Account can be unfrozen using the thawAccount
instruction in the same
way as with the original Token program.
The instruction to thaw the Token Account can be added to more complex transactions, requiring users to perform certain actions to unfreeze their Token Account.
Update Default State
The token creator can choose to relax the initial restriction by using the
updateDefaultAccountState
instruction by passing in the new account state to
set on created accounts.
Run the script by clicking the Run
button. You can then inspect the
transaction on the SolanaFM.
Conclusion
The DefaultAccountState
extension introduces a valuable tool for token
creators to have enhanced control of their token. This feature allows for
controlled token distribution, enabling mechanisms like mandatory KYC
verification for token holders.