> ## Documentation Index
> Fetch the complete documentation index at: https://docs.x0protocol.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Token Operations

> Manage the x0-USD token mint, transfer fees, and Token-2022 extensions using TokenClient.

## TokenClient

The `TokenClient` handles x0-USD mint initialization, fee configuration, and token operations using SPL Token-2022.

```typescript theme={null}
import { TokenClient, createTokenClient } from '@x0-protocol/sdk';

const tokenClient = createTokenClient(connection);
```

## Mint Initialization

### `buildInitializeMintInstruction(params, payer)`

Create a new x0-USD token mint with Token-2022 extensions:

```typescript theme={null}
import { Keypair } from '@solana/web3.js';

const mintKeypair = Keypair.generate();

const ix = tokenClient.buildInitializeMintInstruction(
  {
    mint: mintKeypair,
    mintAuthority: adminPubkey,
    decimals: 6,
    feeReceiver: treasuryPubkey,
    enableConfidential: true,
  },
  payerPubkey
);
```

This instruction initializes a mint with:

* **TransferFee** extension — 0.8% protocol fee
* **TransferHook** extension — x0-guard policy enforcement
* **ConfidentialTransfer** extension (optional) — ElGamal-encrypted balances

### `buildConfigureConfidentialInstruction(params, authority)`

Enable confidential transfers on an existing mint:

```typescript theme={null}
const ix = tokenClient.buildConfigureConfidentialInstruction(
  {
    mint: mintPubkey,
    autoApproveNewAccounts: true,
  },
  authorityPubkey
);
```

## Token Operations

### `buildMintTokensInstruction(params, authority)`

Mint new tokens (authority only):

```typescript theme={null}
const ix = tokenClient.buildMintTokensInstruction(
  {
    mint: mintPubkey,
    destination: recipientAta,
    amount: new BN(1_000_000_000), // 1000 tokens
  },
  mintAuthorityPubkey
);
```

### `buildDepositConfidentialInstruction(params, owner)`

Deposit public tokens into the confidential balance:

```typescript theme={null}
const ix = tokenClient.buildDepositConfidentialInstruction(
  {
    mint: mintPubkey,
    tokenAccount: ownerAta,
    amount: new BN(50_000_000),
  },
  ownerPubkey
);
```

## Fee Management

### `buildWithdrawFeesInstruction(mint, sourceAccounts, feeReceiver, authority)`

Withdraw accumulated transfer fees from token accounts:

```typescript theme={null}
const ix = tokenClient.buildWithdrawFeesInstruction(
  mintPubkey,
  [account1, account2, account3],
  treasuryPubkey,
  mintAuthorityPubkey
);
```

### `buildHarvestFeesInstruction(mint, authority, sourceAccounts)`

Harvest fees from multiple accounts in a single transaction.

## Fee Calculation

### `calculateTransferFee(amount)`

```typescript theme={null}
const fee = tokenClient.calculateTransferFee(new BN(1_000_000));
// fee = 8000 (0.8%)
```

### `calculateAmountAfterFee(amount)`

```typescript theme={null}
const net = tokenClient.calculateAmountAfterFee(new BN(1_000_000));
// net = 992000
```

## Token Account Helpers

### `getAssociatedTokenAddress(mint, owner)`

```typescript theme={null}
const ata = tokenClient.getAssociatedTokenAddress(mintPubkey, ownerPubkey);
```

### `buildCreateATAInstruction(mint, owner, payer)`

```typescript theme={null}
const ix = tokenClient.buildCreateATAInstruction(mintPubkey, ownerPubkey, payerPubkey);
```

## Mint Info

### `fetchMintInfo(mint)`

```typescript theme={null}
const info = await tokenClient.fetchMintInfo(mintPubkey);
```

**Returns:** `X0TokenMintInfo`

| Field                   | Type        | Description                                |
| ----------------------- | ----------- | ------------------------------------------ |
| `address`               | `PublicKey` | Mint address                               |
| `mintAuthority`         | `PublicKey` | Current mint authority                     |
| `supply`                | `BN`        | Total token supply                         |
| `decimals`              | `number`    | Token decimals (6)                         |
| `transferHookProgramId` | `PublicKey` | x0-guard program ID                        |
| `transferFeeBps`        | `number`    | Transfer fee in basis points               |
| `feeReceiver`           | `PublicKey` | Fee receiver account                       |
| `confidentialEnabled`   | `boolean`   | Whether confidential transfers are enabled |

## Factory

### `deriveExtraAccountMetasPda(mint)`

Derive the PDA for the TransferHook extra account metas:

```typescript theme={null}
const [metasPda, bump] = deriveExtraAccountMetasPda(mintPubkey);
```