Create READEM.md

Author: krishnaagrawal7508

tokens/transfer-hook-transfer-switch/anchor/READEM.md

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+# Transfer Hook Transfer Switch
+
+This Solana program implements a transfer hook that can be toggled on or off for 
+any token. It allows you to control whether transfers are allowed for a given wallet.
+
+## Features
+
+- **Initialize Transfer Control**: Set up a wallet with a default transfer status for a specified token mint.
+- **Toggle Transfer On/Off**: Enable or disable token transfers for specific token mints.
+- **Transfer Hook**: Enforces a transfer hook that checks the transfer status before allowing any token transfers.
+
+## Prerequisites
+
+- Rust and Cargo (for building the Solana program)
+- Solana CLI (for interacting with Solana network)
+- Anchor Framework (for Solana smart contract development)
+- `pnpm` (for managing JavaScript dependencies)
+- `solana-bankrun` for testing
+
+## Installation
+
+1. Clone the repository:
+   ```
+   git clone https://github.com/solana-developers/program-examples.git
+   cd program-examples/tokens/transfer-hook-transfer-switch/anchor
+   ```
+
+2. Install dependencies:
+   ```
+   pnpm install
+   ```
+
+## Building the Program
+
+To build the program, run:
+
+```
+anchor build
+```
+
+## Testing
+
+To run the test suite:
+
+```
+anchor test
+```
+
+## Program Structure
+
+The program consists of three main instructions:
+
+1. `initialize`: Creates and initializes the transfer switch account.
+2. `toggle_transfer`: Toggles the transfer switch on or off.
+3. `transfer_hook`: Checks if transfers are allowed before a token transfer.
+
+## Usage
+
+### Initializing the Transfer Switch
+
+```typescript
+await program.methods
+  .initialize()
+  .accounts({
+    walletState: walletStatePda,
+    owner: wallet.publicKey,
+    tokenMint: tokenMintPublicKey,
+    systemProgram: anchor.web3.SystemProgram.programId,
+  })
+  .rpc();
+```
+
+### Toggling the Transfer Switch
+
+```typescript
+await program.methods
+  .toggleTransferSwitch(tokenMintPublicKey)
+  .accounts({
+    walletState: walletStatePda,
+    owner: wallet.publicKey,
+  })
+  .rpc();
+```
+
+### Using the Transfer Hook
+
+```typescript
+await program.methods
+  .transferTokens(new anchor.BN(amount))
+  .accounts({
+    from: fromTokenAccount,
+    to: toTokenAccount,
+    senderState: senderWalletStatePda,
+    owner: ownerPublicKey,
+    authority: transferAuthority,
+    tokenProgram: anchor.utils.token.TOKEN_PROGRAM_ID,
+  })
+  .rpc();
+```
+
+## Account Structure
+
+The `TransferSwitch` account has the following structure:
+
+```rust
+pub struct WalletState {
+    pub owner: Pubkey, // The owner of the wallet
+    pub transfer_status: Vec<(Pubkey, bool)>, // List of token mints and their transfer status
+}
+```
+
+## Error Handling
+
+The program defines a custom error:
+
+```rust
+#[error_code]
+pub enum ErrorCode {
+    #[msg("Transfers are disabled for this wallet.")]
+    TransfersDisabled, // Triggered when transfers are disabled
+    #[msg("Token not initialized for transfer management.")]
+    TokenNotInitialized, // Triggered when a token mint has not been registered
+}
+
+```
+
+This error is thrown when a transfer is attempted while the transfer switch is disabled.
+
+## Security Considerations
+
+- The `authority` of the `TransferSwitch` account has the power to toggle transfers on and off. Ensure this authority is properly managed and secured.
+- This program does not implement any access control on who can transfer tokens. It only provides a global on/off switch for all transfers.