> ## 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.

# Post Order

> Post a limit order to the orderbook

The `ixWrapperPostOffer` instruction posts a limit order to the Exponent orderbook.

## Usage

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

const { ix, setupIxs } = await orderbook.ixWrapperPostOffer({
  trader: wallet.publicKey,
  price: 4.5,
  amount: 1_000_000_000n,
  offerType: OfferType.SellYt,
  offerOption: offerOptions("FillOrKill", [false]),
  virtualOffer: false,
  expirySeconds: 3600,
  mintSy: syMintAddress,
});

// Build and send the transaction
const tx = new Transaction().add(...setupIxs, ix);
const signature = await sendAndConfirmTransaction(connection, tx, [wallet]);
```

## Required Parameters

| Parameter       | Type           | Description                                                        |
| --------------- | -------------- | ------------------------------------------------------------------ |
| `trader`        | `PublicKey`    | The trader's wallet public key                                     |
| `price`         | `number`       | The limit price for the offer in APY terms                         |
| `amount`        | `bigint`       | The amount to offer in lamports                                    |
| `offerType`     | `OfferType`    | The type of offer (`OfferType.BuyYt` / `OfferType.SellYt`)         |
| `offerOption`   | `OfferOptions` | Offer execution option via `offerOptions("FillOrKill", [boolean])` |
| `virtualOffer`  | `boolean`      | Whether this is a virtual offer                                    |
| `expirySeconds` | `number`       | Time until the offer expires (in seconds)                          |
| `mintSy`        | `PublicKey`    | The SY token mint address                                          |

## Optional Parameters

| Parameter         | Type        | Description                       |
| ----------------- | ----------- | --------------------------------- |
| `ptSrc`           | `PublicKey` | PT token source account           |
| `ytSrc`           | `PublicKey` | YT token source account           |
| `sySrc`           | `PublicKey` | SY token source account           |
| `tokenBaseTrader` | `PublicKey` | Base token account for the trader |

## Returns

Returns an object with:

* `ix` — The `TransactionInstruction` that posts the limit order
* `setupIxs` — An array of setup instructions to run before `ix`:
  * `setupIxs[0]` — Creates the PT associated token account (if needed)
  * `setupIxs[1]` — Creates the YT associated token account (if needed)
  * `setupIxs[2]` — Creates the SY associated token account (if needed)

<Tip>
  Use `offerOptions("FillOrKill", [true])` to require the order to be filled completely or not at all. Pass `false` to allow partial fills.
</Tip>

<Note>
  Offer expiry is capped at vault maturity — if `expirySeconds` exceeds the time remaining until maturity, the offer expires at maturity instead. After maturity, new offers are rejected.
</Note>