04_spl_tokens.md

🛹 SPL Tokens

tl; dr

• SPL tokens are all non-native tokens on the Solana blockchain (fungible or non-fungible).

• The Token Program has instructions for creating and interacting with SPL tokens:

  • Token Mints are accounts holding data about a specific token (but not the tokens).
  • Token Accounts are used to hold tokens of a particular token mint.
  • They both require allocating rent in SOL.

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Getting started with spl-token-cli

• Install with:

cargo install spl-token-cli

• Alternatively, you could use the JavaScript's library spl-token.

---

Creating a SPL Token

spl-token create-token

• The address of the token will be printed out.

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Getting the Token's Supply

spl-token supply <TOKEN ADDRESS>

• To interact with any created token, we must create an account to store the token amount in our wallet.

• If we create a token without an account, the above command will return 0.

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Creating an Account

• A Token Account holds tokens of a specific mint and owner:

spl-token create-account <TOKEN ADDRESS>

• This command will print the address of the account created for the token, representing the wallet (account) holding the tokens in your wallet.

• If using JavaScript's @solana/spl-token:

const tokenAccount = await createAccount(
  connection,
  payer,
  mint,
  owner,
  keypair
);

---

Checking the Balance of an Account

spl-token balance <TOKEN ADDRESS>

• This command will print 0 if you haven't minted any tokens to that wallet.

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Minting Tokens

• Minting tokens is the process of issuing new tokens into circulation (by increasing the supply of the token and depositing the newly minted tokens into a token account).

• A Token Mint is the account that holds data about a specific token:

spl-token mint <TOKEN ADDRESS> <NUMBER OF TOKENS TO BE MINTED>

• If using JavaScript's @solana/spl-token, this would create a new account and initialize a new mint together:

const tokenMint = await createMint(
  connection,
  payer,
  mintAuthority,
  freezeAuthority,
  decimal
);

---

Transferring Tokens

• Token transfers require both the sender and receiver to have token accounts for the mint of the tokens being transferred:

spl-token transfer <TOKEN ADDRESS> <NUMBER OF TOKENS TO BE MINTED> <RECIPIENT ADDRESS>

• If using JavaScript's @solana/spl-token:

const transactionSignature = await transfer(
  connection,
  payer,
  source,
  destination,
  owner,
  amount
)

• If the recipient is new (has no account), you can add --fund-recipient, as it's a requirement to deposit enough SOL for rent exemption when initializing a new account (getMinimumBalanceForRentExemptMint on @solana/spl-token)

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Approving or Revoking Delegate

• The process of authorizing another account to transfer or burn tokens from a token account.
  • The authority over the token account remains with the original owner.
  • The maximum amount of tokens a delegate may transfer or burn is specified at the time the owner of the token account approves the delegate.

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Resources

• Create Tokens With The Token Program, by soldev
• SPL Tokens on Solana, by Ackee Blockchain Security