> ## 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 Offer

> Low-level instruction to post a limit order on the orderbook

# createPostOfferInstruction

Builds a raw instruction to post a limit order on the orderbook, allowing users to place buy or sell offers for YT tokens at a specified price.

## Usage

```typescript theme={null}
import { createPostOfferInstruction } from "@exponent-labs/exponent-sdk/client/orderbook";
import { PublicKey } from "@solana/web3.js";

const ix = createPostOfferInstruction(
  {
    trader: wallet.publicKey,
    orderbook: orderbookAddress,
    vault: vaultAddress,
    cpiAccountOrderbook: cpiAccountsOrderbook,
    yieldPosition: yieldPositionAddress,
    tokenEscrowYt: orderbookYtEscrow,
    tokenEscrowSy: orderbookSyEscrow,
    tokenEscrowPt: orderbookPtEscrow,
    tokenSyTrader: userSyTokenAccount,
    tokenYtTrader: userYtTokenAccount,
    tokenPtTrader: userPtTokenAccount,
    systemProgram: SYSTEM_PROGRAM_ID,
    syProgram: syProgramId,
    tokenProgram: TOKEN_2022_PROGRAM_ID,
    exponentCore: EXPONENT_CORE_PROGRAM_ID,
    addressLookupTable: vaultLookupTable,
    eventAuthority: eventAuthorityPda,
    program: EXPONENT_ORDERBOOK_PROGRAM_ID,
  },
  {
    priceApy: 5.25,
    amount: BigInt(1_000_000),
    offerTypeFlag: { sellYt: {} },
    virtualOffer: false,
    expirySeconds: 86400,
    options: { fillOrKill: [false] },
  }
);
```

## Accounts

| Name                  | Type        | Signer | Writable | Description                 |
| --------------------- | ----------- | ------ | -------- | --------------------------- |
| `trader`              | `PublicKey` | Yes    | No       | The user posting the offer  |
| `orderbook`           | `PublicKey` | No     | Yes      | Orderbook account           |
| `vault`               | `PublicKey` | No     | Yes      | Vault account               |
| `cpiAccountOrderbook` | `PublicKey` | No     | No       | CPI accounts orderbook      |
| `yieldPosition`       | `PublicKey` | No     | Yes      | Vault robot yield position  |
| `tokenEscrowYt`       | `PublicKey` | No     | Yes      | Orderbook YT escrow account |
| `tokenEscrowSy`       | `PublicKey` | No     | Yes      | Orderbook SY escrow account |
| `tokenEscrowPt`       | `PublicKey` | No     | Yes      | Orderbook PT escrow account |
| `tokenSyTrader`       | `PublicKey` | No     | Yes      | Trader SY token account     |
| `tokenYtTrader`       | `PublicKey` | No     | Yes      | Trader YT token account     |
| `tokenPtTrader`       | `PublicKey` | No     | Yes      | Trader PT token account     |
| `systemProgram`       | `PublicKey` | No     | No       | System program              |
| `syProgram`           | `PublicKey` | No     | No       | SY program                  |
| `tokenProgram`        | `PublicKey` | No     | No       | SPL Token 2022 program      |
| `exponentCore`        | `PublicKey` | No     | No       | Exponent Core program       |
| `addressLookupTable`  | `PublicKey` | No     | No       | Vault address lookup table  |
| `eventAuthority`      | `PublicKey` | No     | No       | Event authority PDA         |
| `program`             | `PublicKey` | No     | No       | Exponent Orderbook program  |

## Args

| Name            | Type           | Description                                        |
| --------------- | -------------- | -------------------------------------------------- |
| `priceApy`      | `number`       | Price in implied APY (f64)                         |
| `amount`        | `bigint`       | Amount of tokens to offer (in base units)          |
| `offerTypeFlag` | `OfferType`    | Type of offer: `{ sellYt: {} }` or `{ buyYt: {} }` |
| `virtualOffer`  | `boolean`      | Whether this is a virtual offer                    |
| `expirySeconds` | `number`       | Expiry time in seconds (u32)                       |
| `options`       | `OfferOptions` | Offer options: `{ fillOrKill: [boolean] }`         |

## Returns

`TransactionInstruction` — a transaction instruction ready to be added to a transaction.