> ## Documentation Index
> Fetch the complete documentation index at: https://lightprotocol-migration.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Create Compressed Token Pools for Mint Accounts

> Complete guide to create and manage token pools for compressed tokens for SPL mints with `createTokenPool()`, troubleshooting and advanced configurations.

The `createTokenPool()` function registers an existing SPL mint with the compressed token program and creates a token pool PDA. `createTokenPool()` requires only `fee_payer` and has no mint authority constraint.

<Info>
  The token pool account itself requires rent, but individual compressed token accounts are rent-free.
</Info>

Before we create a token pool, we need an existing SPL mint account.

<CodeGroup>
  ```typescript function-create-token-pool.ts theme={null}
  // Creates token pool account for existing SPL mint
  const transactionSignature = await createTokenPool(
      rpc,
      payer,
      mint,
  );
  ```
</CodeGroup>

<Check>
  **Best Practice:** Each mint supports a maximum of 4 token pools total. During compression/decompression operations, token pools get write-locked. Use `addTokenPools()` to create additional pools that increase per-block write-lock capacity.
</Check>

## Full Code Example

### Prerequisites

Make sure you have dependencies and developer environment set up!

<Accordion title="Prerequisites & Setup">
  **Dependencies**

  Make sure you have dependencies and developer environment set up!

  **Prerequisites & Setup**

  #### Dependencies

  ```bash theme={null}
  npm install --save-dev typescript tsx @types/node && \
  npm install --save \
      @lightprotocol/stateless.js \
      @lightprotocol/compressed-token \
      @solana/web3.js \
      @solana/spl-token
  ```

  **Alternatives:**

  ```bash theme={null}
  yarn add --dev typescript tsx @types/node && \
  yarn add \
      @lightprotocol/stateless.js \
      @lightprotocol/compressed-token \
      @solana/web3.js \
      @solana/spl-token
  ```

  ```bash theme={null}
  pnpm add --save-dev typescript tsx @types/node && \
  pnpm add \
      @lightprotocol/stateless.js \
      @lightprotocol/compressed-token \
      @solana/web3.js \
      @solana/spl-token
  ```

  **Developer Environment**

  By default, this guide uses Localnet.

  ```bash theme={null}
  # Install the development CLI
  npm install @lightprotocol/zk-compression-cli
  ```

  ```bash theme={null}
  # Start a local test validator
  light test-validator

  ## ensure you have the Solana CLI accessible in your system PATH
  ```

  ```typescript theme={null}
  // createRpc() defaults to local test validator endpoints
  import {
    Rpc,
    createRpc,
  } from "@lightprotocol/stateless.js";

  const connection: Rpc = createRpc();

  async function main() {
    let slot = await connection.getSlot();
    console.log(slot);

    let health = await connection.getIndexerHealth(slot);
    console.log(health);
    // "Ok"
  }

  main();
  ```

  **Alternative: Using Devnet**

  Follow these steps to create an RPC Connection. Replace `<your_api_key>` with your API key before running.

  <Info>
    [Get your API key here](https://www.helius.dev/zk-compression), if you don't have one yet.
  </Info>

  ```typescript theme={null}
  import { createRpc } from "@lightprotocol/stateless.js";

  // Helius exposes Solana and Photon RPC endpoints through a single URL
  const RPC_ENDPOINT = "https://devnet.helius-rpc.com?api-key=<your_api_key>";
  const connection = createRpc(RPC_ENDPOINT, RPC_ENDPOINT, RPC_ENDPOINT);

  console.log("Connection created!");
  console.log("RPC Endpoint:", RPC_ENDPOINT);
  ```
</Accordion>

### Create Token Pool

Run this script to create token pools for an SPL mint!

```typescript create-token-pools.ts highlight={31-33, 43-45} lines expandable theme={null}
// 1. Setup funded payer and connect to local validator
// 2. Create SPL mint
// 3. Call createTokenPool() to register mint with compressed token program
// 4. Add additional pools to increase write-lock capacity (optional)

import { Keypair, PublicKey } from '@solana/web3.js';
import { createRpc } from '@lightprotocol/stateless.js';
import { createTokenPool, addTokenPools } from '@lightprotocol/compressed-token';
import { createMint } from '@solana/spl-token';

async function createTokenPools() {

    // Step 1: Setup funded payer and connect to local validator
    const rpc = createRpc(); // defaults to localhost:8899
    const payer = Keypair.generate();
    const airdropSignature = await rpc.requestAirdrop(payer.publicKey, 1000000000); // 1 SOL
    await rpc.confirmTransaction(airdropSignature);

    // Step 2: Create SPL mint
    const mint = await createMint(
        rpc,
        payer,
        payer.publicKey, // mint authority
        payer.publicKey, // freeze authority
        9
    );

    console.log("SPL mint created");
    console.log("Mint address:", mint.toBase58());

    // Step 3: Call createTokenPool() to register SPL mint with compressed token program
    // Creates token pool PDA (omnibus account) that holds SPL tokens for compressed tokens
    const poolTx = await createTokenPool(
        rpc,
        payer,
        mint // existing SPL mint to register
    );

    console.log("\nToken pool created!");
    console.log("SPL mint registered with compressed token program:", mint.toBase58());
    console.log("Pool transaction:", poolTx);

    // Step 4: Add up to 3 additional pools - increase write-lock capacity for higher throughput
    const additionalPoolsCount = 2;
    const additionalPoolsTx = await addTokenPools(
        rpc,
        payer,
        mint, // SPL mint with existing token pool
        additionalPoolsCount, // number of additional pools (max 3 more)
    );

    console.log(`\nAdded ${additionalPoolsCount} additional token pools!`);
    console.log("Additional pools transaction:", additionalPoolsTx);


    return {
        mint,
        poolTransaction: poolTx,
        additionalPoolsTransaction: additionalPoolsTx
    };
}

createTokenPools().catch(console.error);
```

### Troubleshooting

<AccordionGroup>
  <Accordion title="TokenPool not found">
    You're trying to access a token pool that doesn't exist.

    ```typescript theme={null}
    // Create the missing token pool
    const poolTx = await createTokenPool(rpc, payer, mint);
    console.log("Token pool created:", poolTx);
    ```
  </Accordion>
</AccordionGroup>

### Advanced Configuration

<AccordionGroup>
  <Accordion title="Batch Pool Creation">
    Create pools for multiple mints:

    ```typescript theme={null}
    const mints = [
        new PublicKey("MINT_1_ADDRESS"),
        new PublicKey("MINT_2_ADDRESS"),
        new PublicKey("MINT_3_ADDRESS"),
    ];

    for (const mint of mints) {
        try {
            const poolTx = await createTokenPool(rpc, payer, mint);
            console.log(`Pool created for ${mint.toBase58()}:`, poolTx);
        } catch (error) {
            console.log(`Failed for ${mint.toBase58()}:`, error.message);
        }
    }
    ```
  </Accordion>

  <Accordion title="Create Pool with Token-2022">
    Create token pools for Token-2022 mints:

    ```typescript theme={null}
    import { TOKEN_2022_PROGRAM_ID } from '@solana/spl-token';

    const poolTx = await createTokenPool(
        rpc,
        payer,
        mint, // Token-2022 mint
        undefined,
        TOKEN_2022_PROGRAM_ID,
    );
    ```
  </Accordion>
</AccordionGroup>

## Next Steps

Learn how to merge multiple compressed token accounts into one to simplify state management.