---
title: "Introduction to Client-Side API"
description: "Build direct integrations using booking confirmation data via URL parameters and JavaScript for Booking Pages and Booking Calendars."
url: "https://help.oncehub.com/developers/client-side-api/introduction"
---

## What is the OnceHub client-side API?

[Section titled “What is the OnceHub client-side API?”](#what-is-the-oncehub-client-side-api)

Our client-side API is a collection of advanced features that can be used to build direct integrations with third party applications, using booking confirmation data sent via URL parameters and JavaScript. It is suitable for developers or technically savvy users with scripting or programming knowledge. You can use the OnceHub client-side API to develop custom integrations with your own web applications, services, or data warehouse.

The client-side API is available for **Booking Calendars**, allowing you to integrate scheduling data seamlessly into your applications.

## Use Cases

[Section titled “Use Cases”](#use-cases)

### Redirecting booking confirmation data

[Section titled “Redirecting booking confirmation data”](#redirecting-booking-confirmation-data)

Using Automatic redirect, you can send booking confirmation data to the redirect page via URL parameters. This feature can be used to personalize the scheduling process by displaying a custom thank you message, or help you streamline your customer pipeline by enabling client-side integrations such as pre-populating a form, among other client-side API use cases.

### Collecting data from an embedded Booking Calendar

[Section titled “Collecting data from an embedded Booking Calendar”](#collecting-data-from-an-embedded-booking-calendar)

If you have published your Booking Calendar using Website embed, you can collect booking confirmation data from an embedded Booking Calendar by adding a JavaScript function to your embed code. Use cases include:

* Enriching your customer data repository with high-value personal information submitted at the time of booking
* Displaying a custom confirmation message inside the embedding frame or a pop-up
* Triggering custom analytics or tracking events
* Integrating with your own application workflows