--- title: "[Developer Hub guides] - Field Modifier Location" description: Field Modifier Location url: https://www.contentstack.com/docs/developers/developer-hub/field-modifier-location product: Contentstack doc_type: developer-hub-guide audience: - developers version: unknown last_updated: 2026-03-25 --- # [Developer Hub guides] - Field Modifier Location This page explains the Field Modifier UI location in Contentstack Developer Hub, including what it is, what it supports, and how to configure it for an app via the Developer Hub console. It is intended for developers building or configuring apps that extend entry fields, and should be used when setting up UI Locations and hosting for an app. ## Field Modifier Location The Field Modifier location is a type of UI location which extends the capabilities of the entry fields. With the Field Modifier UI location, you can create apps that add custom functionalities to entry fields, allowing content managers to do a lot more with their content. You can use Field Modifier across a variety of fields such as Text, JSON, Number, File, Reference etc. Try out this UI location through one of Contentstacks own implementations, like AI Assistant. To add the Field Modifier UI location to your app via the Developer Hub console, login to your Contentstack account and follow the steps given below: **Via the Developer Hub Console: **To add the Field Modifier UI location to your app via the Developer Hub console, login to your [Contentstack account](https://www.contentstack.com/login/) and follow the steps given below: - Click the **Developer Hub** icon in the left navigation panel. - Select an application for which you want to add the Field Modifier UI location. - Click the **UI Locations **tab. To set the **App URL**, click the **View Hosting **link. You will be redirected to the **Hosting **tab. - In the Hosting tab, you can select [Hosting with Launch](/docs/developers/developer-hub/app-hosting#hosting-with-launch) or [Custom Hosting](/docs/developers/developer-hub/app-hosting#custom-hosting) option. Select the **Custom Hosting **option to enter the hosted URL of your application. Click the **Save **button to save your hosting configuration. - Navigate to the **UI Locations **tab to configure the Field Modifier UI location. - Hover over the **Field Modifier** location, and click the **+ Add UI Location **button. - On the resulting **Configuration **page, set up the configurations for Field Modifier location by providing details such as **Name**, **Path**, **Allowed Field Types**, and **Description**. You can also enable the location by default using the **Enabled **toggle button.Properties that can be specified for this UI location: **Name (optional)**: Specifies the name of the UI location. This name will be displayed at the location after the app is installed. If not provided, the app name will be used. Ensure unique names for multiple configurations of the same location. - **Signed (optional)**: When enabled, Contentstack adds a JWT token to the initial HTTP request made for your app's first page. This token can be used to verify that the request originated from Contentstack. For more information, please refer to [Signed Locations](/docs/developers/developer-hub/securing-your-app/). - **Path (optional)**: Enables you to define the location relative to the base URL where the app is hosted. This is particularly useful when the developer intends the app to appear in multiple locations. - **Enabled (optional)**: Determines whether the location is visible after the app installation. If not specified, the location is enabled by default. Users can manage this option post-installation via the UI Locations tab on the app’s configuration screen. You can mark any UI location as **mandatory **using the **Required **toggle. If the toggle is enabled, the location becomes mandatory to your app users and cannot be disabled. Whereas, if the toggle is disabled, the UI location is available to use but not mandatory. **Additional Resource:** Refer to the [Marketplace App Manifest](/docs/developers/developer-hub/app-manifest) documentation for comprehensive details. - Finally, click the **Save **button to save the Field Modifier location’s configuration details.You will see the details of the configured UI location on the** UI Locations** tab in the **App Configuration** screen after installing the app and will have the option to enable or disable the non-required UI locations. Apps which have the Field Modifier location configured on different field types will be visible in the [entry](/docs/content-managers/author-content/about-entries) fields of the content type. Navigate to the entries page to view the app on the Field Modifier UI location. For example, the AI Assistant app can be viewed in the Field Modifier UI location as shown below: - **Additional Resources: **For more information, refer to the [AI Assistant](/docs/developers/marketplace-apps/ai-assistant) documentation. ## Common questions **Q: What is the Field Modifier location used for?** A: The Field Modifier location is a type of UI location which extends the capabilities of the entry fields. **Q: Which field types can use Field Modifier?** A: You can use Field Modifier across a variety of fields such as Text, JSON, Number, File, Reference etc. **Q: Where do I configure the Field Modifier UI location?** A: Configure it in the **UI Locations** tab for your application in the Developer Hub console. **Q: What does enabling “Signed” do?** A: When enabled, Contentstack adds a JWT token to the initial HTTP request made for your app's first page. This token can be used to verify that the request originated from Contentstack.