# Input nodes

*Input* nodes require some form of input from your customers.

The following *Input* nodes are available:

* [**Contact Receiving** ](https://guides.clickatell.com/flow/user-facing-nodes/input-nodes/contact-receiving)- Request contact information from your customers and use the information as [variables ](https://guides.clickatell.com/flow/variable-management)in your workflow.
* [**OAuth Request**](https://guides.clickatell.com/flow/user-facing-nodes/input-nodes/oauth-request) - Allows you to authenticate your customers securely against your chosen identity provider (IDP).
* [**Request input**](https://guides.clickatell.com/flow/user-facing-nodes/input-nodes/menu-nodes-ask-for-input) - Ask customers to enter information (e.g., words, dates, numbers) that are saved as variables to be used later in the workflow.
* [**Send Form**](https://guides.clickatell.com/flow/user-facing-nodes/input-nodes/send-form) - Create rich, multipage interactive forms for customers to complete on their mobile devices. *(Apple Messages for Business only)*
* [**Time Picker** ](https://guides.clickatell.com/flow/user-facing-nodes/input-nodes/time-picker)- Allows a customer to select a slot from a list of available times, e.g., to make an appointment or schedule a delivery.  *(Apple Messages for Business only)*