> For the complete documentation index, see [llms.txt](https://orders-exchange.gitbook.io/orders/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://orders-exchange.gitbook.io/orders/orderbook-dex/technology-and-theory/ask-orders.md).

# Ask Orders

### 1. Maker creates ASK PSBT

Maker creates a partially-signed Bitcoin transaction (PSBT) for an ask order where the input is the BRC20 Ordinal UTXO and the output is the amount of Bitcoin they wish to exchange.

Maker should then sign the PSBT with a SIGHASH type of `SIGHASH_SINGLE | ANYONECANPAY`, and then publish the order to the exchange.

<figure><img src="https://3932846654-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FkOBpu4b0Qqu8MG54y1Zq%2Fuploads%2FhoF3DwtDrNGiUC8Cwj8Y%2Fimage.png?alt=media&amp;token=12ce1f5f-e747-4019-acd3-391192aabdaf" alt=""><figcaption><p>The ASK PSBT that the maker creates</p></figcaption></figure>

### 2. Exchange lists the order

The exchange lists the order created by the maker.

### 3. Taker completes the order

Taker accepts the order and builds a complete **BUY** PSBT based on the single-signed **ASK** PSBT. The transaction structure is as follows.

The Taker should then sign the **BUY** PSBT with a SIGHASH type of `SIGHASH_ALL`.

The Taker then broadcasts the transaction to the BTC network and reports to the exchange to update the order state.

<figure><img src="https://3932846654-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FkOBpu4b0Qqu8MG54y1Zq%2Fuploads%2FKjZj4gKZMYOzXP0dvQSJ%2Fimage.png?alt=media&amp;token=c9e063f9-3393-4b51-8059-b738a604b122" alt=""><figcaption><p>Taker completes the order</p></figcaption></figure>

### 4. The Exchange Checks the Status of the Order

The exchange checks whether the transaction has been successfully broadcast to the BTC network. Once confirmed, the exchange should mark the order status as completed and delist it.

{% hint style="success" %}
This process allows for secure, seamless, and trustless trading between parties with different types of assets.
{% endhint %}

{% content-ref url="/pages/CvdIHQIF1NPx6O5e3aXb" %}
[Technical flowchart for placing ASK orders](/orders/orderbook-dex/technology-and-theory/ask-orders/technical-flowchart-for-placing-ask-orders.md)
{% endcontent-ref %}