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

# Merge

> Merge PT and YT into the base asset

The `ixMergeToBase` method on the `Vault` class creates transaction instructions that merge PT and YT back into SY and then unwrap the SY into the base asset in a single atomic operation.

## Usage

```typescript theme={null}
import { Vault, LOCAL_ENV } from "@exponent-labs/exponent-sdk";
import { Connection, PublicKey, Transaction, sendAndConfirmTransaction } from "@solana/web3.js";

const connection = new Connection("https://api.mainnet-beta.solana.com");
const vault = await Vault.load(LOCAL_ENV, connection, vaultAddress);

const { ixs, setupIxs } = await vault.ixMergeToBase({
  owner: wallet.publicKey,
  amountPy: 1_000_000_000n,
});

const tx = new Transaction().add(...setupIxs, ...ixs);
const signature = await sendAndConfirmTransaction(connection, tx, [wallet]);
```

<Tip>
  This method returns both `setupIxs` (token account creation) and `ixs` (the merge + unwrap instructions, including any pre/post instructions from the flavor). Make sure to include both in your transaction.
</Tip>

## Required Parameters

| Parameter  | Type        | Description                   |
| ---------- | ----------- | ----------------------------- |
| `owner`    | `PublicKey` | The owner's wallet public key |
| `amountPy` | `bigint`    | Amount of PT and YT to merge  |

## Optional Parameters

| Parameter | Type        | Description                                            |
| --------- | ----------- | ------------------------------------------------------ |
| `ptSrc`   | `PublicKey` | Source PT token account. Defaults to owner's ATA       |
| `ytSrc`   | `PublicKey` | Source YT token account. Defaults to owner's ATA       |
| `syDst`   | `PublicKey` | Intermediate SY token account. Defaults to owner's ATA |
| `baseDst` | `PublicKey` | Destination base token account                         |

## Returns

Returns a `Promise<{ ixs: TransactionInstruction[]; setupIxs: TransactionInstruction[] }>`:

* `ixs` — The merge and unwrap instructions, including any flavor-specific pre/post instructions
* `setupIxs` — Setup instructions that create associated token accounts for SY, PT, and YT