docs(token 2022): guide for permanent delegate extension (#21)

* docs(token 2022): guide for permanent delegate extension

* docs(token 2022): add missing section

* Add Solana Playground

* Revision and print SolanaFM links

* proofread

* refactor: changed dir

* refactor: editorial changes

---------

Co-authored-by: John <[email protected]>
Co-authored-by: nickfrosty <[email protected]>

content/guides/token-extensions/permanent-delegate.md

@@ -0,0 +1,349 @@
+---
+date: Dec 06, 2023
+seoTitle: "Token Extensions: Permanent Delegate"
+title: How to use the Permanent Delegate extension
+description:
+  "Token Extensions allow you to specify a permanent account delegate for a mint
+  with unlimited delegate privileges over any account associated with that mint,
+  including burning or transferring any amount of tokens."
+keywords:
+  - token 2022
+  - token extensions
+  - token program
+difficulty: beginner
+tags:
+  - token 2022
+  - token extensions
+---
+
+The `PermanentDelegate` extension allows for a designated Permanent Delegate for
+a Mint Account. This permanent delegate has unrestricted delegate privileges
+over all Token Accounts for that mint, enabling them to burn or transfer tokens
+without limitation.
+
+In this guide, we'll walk through an example of creating a token with the
+Permanent Delegate using Solana Playground. Here is the
+[final script](https://beta.solpg.io/6570a56bfb53fa325bfd0c4b) that this guide
+will walkthrough.
+
+## Understanding the Implications
+
+This is a very powerful feature, and its implications have to be clearly stated
+for both users and app developers.
+
+<Callout type="warning">
+The Permanent Delegate is effectively a global owner of all Token Accounts for
+the mint. Due to the unlimited powers of the Permanent Delegate, if the
+delegate's keys are compromised, an attacker will have complete control over all
+Token Accounts for that mint.
+</Callout>
+
+## Getting Started
+
+Start by opening this Solana Playground
+[link](https://beta.solpg.io/656e19acfb53fa325bfd0c46) with the following
+starter code.
+
+```javascript
+// Client
+console.log("My address:", pg.wallet.publicKey.toString());
+const balance = await pg.connection.getBalance(pg.wallet.publicKey);
+console.log(`My balance: ${balance / web3.LAMPORTS_PER_SOL} SOL`);
+```
+
+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.
+
+To get devnet SOL, run the `solana airdrop` command in the Playground's
+terminal, or visit this [devnet faucet](https://faucet.solana.com/).
+
+```
+solana airdrop 5
+```
+
+Once you've created and funded the Playground wallet, click the "Run" button to
+run the starter code.
+
+## Add Dependencies
+
+Lets 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:
+
+```javascript
+import {
+  Connection,
+  Keypair,
+  SystemProgram,
+  Transaction,
+  clusterApiUrl,
+  sendAndConfirmTransaction,
+} from "@solana/web3.js";
+import {
+  ExtensionType,
+  TOKEN_2022_PROGRAM_ID,
+  createInitializePermanentDelegateInstruction,
+  createInitializeMintInstruction,
+  getMintLen,
+  createAccount,
+  mintTo,
+  transferChecked,
+  burnChecked,
+} from "@solana/spl-token";
+
+// Playground wallet
+const payer = pg.wallet.keypair;
+
+// Connection to devnet cluster
+const connection = new Connection(clusterApiUrl("devnet"), "confirmed");
+
+// Transaction signature returned from sent transaction
+let transactionSignature: string;
+```
+
+## Mint Setup
+
+First, lets define the properties of the Mint Account we'll be creating in the
+following step.
+
+```javascript
+// Generate new keypair for Mint Account
+const mintKeypair = Keypair.generate();
+// Address for Mint Account
+const mint = mintKeypair.publicKey;
+// Decimals for Mint Account
+const decimals = 2;
+// Authority that can mint new tokens
+const mintAuthority = pg.wallet.publicKey;
+// Authority that can transfer or burn from any token account
+const permanentDelegate = pg.wallet.publicKey;
+```
+
+Next, lets determine the size of the new Mint Account and calculate the minimum
+lamports needed for rent exemption.
+
+```javascript
+// Size of Mint Account with extension
+const mintLen = getMintLen([ExtensionType.PermanentDelegate]);
+// Minimum lamports required for Mint Account
+const lamports = await connection.getMinimumBalanceForRentExemption(mintLen);
+```
+
+With Token Extensions, the size of the Mint Account will vary based on the
+extensions enabled.
+
+## Build Instructions
+
+We will need to build a set of instructions to:
+
+- Create a new account
+- Initialize the `PermanentDelegate` 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.
+
+```javascript
+// Instruction to invoke System Program to create new account
+const createAccountInstruction = SystemProgram.createAccount({
+  fromPubkey: payer.publicKey, // Account that will transfer lamports to created account
+  newAccountPubkey: mint, // Address of the account to create
+  space: mintLen, // Amount of bytes to allocate to the created account
+  lamports, // Amount of lamports transferred to created account
+  programId: TOKEN_2022_PROGRAM_ID, // Program assigned as owner of created account
+});
+```
+
+Next, build the instruction to initialize the `PermanentDelegate` extension for
+the Mint Account.
+
+```javascript
+// Instruction to initialize the MintCloseAuthority Extension
+const initializeMintCloseAuthorityInstruction =
+  createInitializePermanentDelegateInstruction(
+    mint, // Mint Account address
+    permanentDelegate, // Designated Permanent Delegate
+    TOKEN_2022_PROGRAM_ID, // Token Extension Program ID
+  );
+```
+
+Lastly, build the instruction to initialize the rest of the Mint Account data.
+This is the same as with the original Token Program.
+
+```javascript
+// Instruction to initialize Mint Account data
+const initializeMintInstruction = createInitializeMintInstruction(
+  mint, // Mint Account Address
+  decimals, // Decimals of Mint
+  mintAuthority, // Designated Mint Authority
+  null, // Optional Freeze Authority
+  TOKEN_2022_PROGRAM_ID, // Token Extension Program ID
+);
+```
+
+## Send Transaction
+
+Now add the instructions to a new transaction and send it to the network. This
+will create a Mint Account with the `PermanentDelegate` extension enabled.
+
+```javascript
+// Add instructions to new transaction
+const transaction = new Transaction().add(
+  createAccountInstruction,
+  initializeMintCloseAuthorityInstruction,
+  initializeMintInstruction,
+);
+
+// Send transaction
+transactionSignature = await sendAndConfirmTransaction(
+  connection,
+  transaction,
+  [payer, mintKeypair], // Signers
+);
+
+console.log(
+  "\nCreate Mint Account:",
+  `https://solana.fm/tx/${transactionSignature}?cluster=devnet-solana`,
+);
+```
+
+Run the script by clicking the `Run` button. You can then inspect the
+transaction on the SolanaFM.
+
+## Create Token Accounts
+
+Next, we will set up two Token Accounts to demonstrate the functionality of the
+Permanent Delegate.
+
+First, generate a random keypair and use it as the owner of a
+`sourceTokenAccount`.
+
+```javascript
+// Random keypair to use as owner of Token Account
+const randomKeypair = new Keypair();
+// Create Token Account for random keypair
+const sourceTokenAccount = await createAccount(
+  connection,
+  payer, // Payer to create Token Account
+  mint, // Mint Account address
+  randomKeypair.publicKey, // Token Account owner
+  undefined, // Optional keypair, default to Associated Token Account
+  undefined, // Confirmation options
+  TOKEN_2022_PROGRAM_ID, // Token Extension Program ID
+);
+```
+
+Next, create a `destinationTokenAccount` owned by the Playground wallet.
+
+```javascript
+// Create Token Account for Playground wallet
+const destinationTokenAccount = await createAccount(
+  connection,
+  payer, // Payer to create Token Account
+  mint, // Mint Account address
+  payer.publicKey, // Token Account owner
+  undefined, // Optional keypair, default to Associated Token Account
+  undefined, // Confirmation options
+  TOKEN_2022_PROGRAM_ID, // Token Extension Program ID
+);
+```
+
+Lastly, mint 2 tokens to the `sourceTokenAccount` to fund it.
+
+```javascript
+// Mint tokens to sourceTokenAccount
+transactionSignature = await mintTo(
+  connection,
+  payer, // Transaction fee payer
+  mint, // Mint Account address
+  sourceTokenAccount, // Mint to
+  mintAuthority, // Mint Authority address
+  200, // Amount
+  undefined, // Additional signers
+  undefined, // Confirmation options
+  TOKEN_2022_PROGRAM_ID, // Token Extension Program ID
+);
+
+console.log(
+  "\nMint Tokens:",
+  `https://solana.fm/tx/${transactionSignature}?cluster=devnet-solana`,
+);
+```
+
+## Transfer with Permanent Delegate
+
+Next, lets send a transaction to transfer 1 token from the `sourceTokenAccount`
+to the `destinationTokenAccount`. Remember, the `sourceTokenAccount` is owned by
+a randomly generated keypair.
+
+To transfer tokens using the Permanent Delegate, use the `transferChecked`
+instruction and specify the Permanent Delegate as the owner of the
+`sourceTokenAccount`.
+
+```javascript
+// Transfer tokens from source to destination
+transactionSignature = await transferChecked(
+  connection,
+  payer, // Transaction fee payer
+  sourceTokenAccount, // Transfer from
+  mint, // Mint Account address
+  destinationTokenAccount, // Transfer to
+  permanentDelegate, // Use Permanent Delegate as owner
+  100, // Amount
+  decimals, // Mint Account decimals
+  undefined, // Additional signers
+  undefined, // Confirmation options
+  TOKEN_2022_PROGRAM_ID, // Token Extension Program ID
+);
+
+console.log(
+  "\nTransfer Tokens:",
+  `https://solana.fm/tx/${transactionSignature}?cluster=devnet-solana`,
+);
+```
+
+## Burn with Permanent Delegate
+
+Lets also send a transaction to burn 1 token from the `sourceTokenAccount`.
+
+To burn tokens using the `Permanent Delegate`, use the `burnChecked` instruction
+and specify the Permanent Delegate as the owner of the `sourceTokenAccount`.
+
+```javascript
+// Burn tokens from token account
+transactionSignature = await burnChecked(
+  connection,
+  payer, // Transaction fee payer
+  sourceTokenAccount, // Burn from
+  mint, // Mint Account address
+  permanentDelegate, // Use Permanent Delegate as owner
+  100, // Amount
+  decimals, // Mint Account decimals
+  undefined, // Additional signers
+  undefined, // Confirmation options
+  TOKEN_2022_PROGRAM_ID, // Token Extension Program ID
+);
+
+console.log(
+  "\nBurn Tokens:",
+  `https://solana.fm/tx/${transactionSignature}?cluster=devnet-solana`,
+);
+```
+
+Run the script by clicking the `Run` button. You can then inspect the
+transactions on the SolanaFM.
+
+<Callout type="success">
+Note that both the transfer and burn transactions complete successfully,
+even though the transactions are not signed by the owner of the Token Account.
+</Callout>
+
+## Conclusion
+
+The `PermanentDelegate` extension is a powerful extension that enables
+developers to have much greater control over tokens they create, such as the
+ability to retrieve tokens that have been mistakenly transferred. While this
+extension offers greater flexibility, it's essential for users to be aware of
+the implications of holding tokens with this extension enabled, particularly the
+risks associated with compromised delegate keys.