> For the complete documentation index, see [llms.txt](https://chekin.gitbook.io/chekin-public-api/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://chekin.gitbook.io/chekin-public-api/faqs/guests-sdk.md).

# Guests SDK

* **PMS needs to know when all guests submitted the arrival form to disable this in the GP. Is this possible?**\
  \
  Guest SDK offers callback functions which let your system know (without API requests), when a guest is registered.\
  As well, Chekin have webhooks which inform that a new guest is registered.<br>
* **How clients use the guest data that is collected through arrival form?**\
  \
  Normally hosts need especially the data of lead guest to automate the invoice generation since in lot of countries they need data of lead guest for a proper invoice.\
  Also, there are depending on each country requirements some documents to be stored: one that is mandatory in almost all european countries is the guestbook, which we generated starting from guests data; also, in some countries after registration in police website you have to store the proof of registration.\
  In both case we store those documents. Chekin stores them in a apposite section called "Documents", this section can also be launched in your PMS through the Host SDK.<br>
* **There are statuses of the data submission? Hostaway could retrieve this to show if guest data was sent to authorities or not, correct?**\
  \
  Yes, you can connect our webhooks to be aware right after different events happen, and you can fetch the different statuses via API.