> For the complete documentation index, see [llms.txt](https://docs.jaspervault.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.jaspervault.io/development/architecture/option-offering-and-buying-flow.md).

# Option Offering and Buying Flow

1. **Seller Side**

Jasper Vault sellers lock BTC on the Bitcoin blockchain. The relayer continuously monitors the transaction logs on the Bitcoin network. When the relayer detects a transaction, Jasper nodes use EIP-712 to sign the locked BTC. The relayer submits these BTC transaction logs along with the Jasper signatures. These EIP-712 signatures are then submitted to the EVM chain, where they are verified. Finally, the EVM chain records the order information in a smart contract.

<figure><img src="/files/CdlfuDxuSP44i8QD6r7h" alt=""><figcaption></figcaption></figure>

2. **Buyer Side**

Jasper Vault buyers purchase sellers' orders and pay the premium on the EVM chain. The EVM chain records the order information. The relayer continuously monitors the EVM transaction logs, and the premium is sent to the sellers.

<figure><img src="/files/7i4OpVLoo6LORfTlYwGg" alt=""><figcaption></figcaption></figure>