> ## Documentation Index
> Fetch the complete documentation index at: https://studio.assembly.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# URL parameters

> Pass client and company data into automatic embeds using URL parameters.

You can add URL parameters to embeds in the **Manage URL Parameters** section when creating any app that is an automatic embed. This applies to embeds that accept URL parameters, such as the Forms app, which supports these parameters to auto-fill form fields.

To add URL parameters, click **Add parameter** to add a query parameter. Enter the parameter in the **URL parameter** input, and the value in the **Property** input.

For example, if you have a Jotform that supports pre-filled forms, you can add the required parameters to support pre-filled forms for your clients.

## Supported properties

**Clients**

* ID (Assembly UUID, used as a unique identifier for a client)
* Email
* Given (first) name
* Family (last) name

If you have custom fields for clients, these field types are also available as properties in the Clients section of the **Property** dropdown:

* Phone number
* Address
* URL
* Text
* Number
* Email

If you have renamed any of these field types, you'll see the name of your custom field displayed in the list.

<Note>
  Tags custom fields are not supported as properties for URL parameters.
</Note>

**Companies**

* ID (Assembly UUID, used as a unique identifier for a company)
* Name

If you have custom fields for companies, these field types are also available as properties in the Companies section of the **Property** dropdown:

* Phone number
* Address
* URL
* Text
* Number
* Email