# Activity designer > Activity designer lets you preview the layout of your custom Integration Service activities as they will appear in UiPath® Studio. ## Overview Activity designer lets you preview the layout of your custom Integration Service activities as they will appear in UiPath® Studio. Its key features include: * Preview layout: preview the design of your custom activities and see how they will appear in Studio. You can visualize the setup and make necessary adjustments before deploying your connector. * Parameter settings: create and manage parameter fields, for more flexibility in customizing your activity. This includes input, output, in/out arguments, and properties that are used in your workflow. * Request and Response fields: add request and response fields. This helps you define the information required by the activity (request) and the information that will be returned by the activity (response). ## Input fields To configure a custom connector's resources, you use the **Parameters** tab to add fields specific to your request type. Activity designer retrieves all the parameter and fields from the **Parameters** or **Request fields** tabs and displays them under the **Input** section. The following image shows the resource's **Parameters** tab. Only one field is marked as required: Figure 1. Parameters with one required field ![docs image](https://dev-assets.cms.uipath.com/assets/images/integration-service/integration-service-docs-image-473287-aa278128.webp) Figure 2. Request fields with one required field The following image shows the resource's **Request fields** tab. Only one field is marked as required: ![docs image](https://dev-assets.cms.uipath.com/assets/images/integration-service/integration-service-docs-image-473291-12e047c0.webp) The following image shows the resource's **Activity designer** tab. The required parameter and request fields are displayed in the Preview window: ![docs image](https://dev-assets.cms.uipath.com/assets/images/integration-service/integration-service-docs-image-473295-7c837cbb.webp) ### Editing parameters Edit or delete parameters from the **Activity designer** tab by selecting the More options ![more options](https://dev-assets.cms.uipath.com/assets/images/integration-service/integration-service-docs-image-367213-45418e9f.svg) menu. Configure the placement of parameters and request fields by choosing a **Position** option: Primary, Secondary, or None. When you set a field as **Required**, its **Position** is automatically set to **Primary** and the field is displayed on the main section of the activity canvas. Change how the parameter is displayed in the Preview window (its **Display name** and **Description**) by selecting the Edit ![edit](https://dev-assets.cms.uipath.com/assets/images/integration-service/integration-service-edit-367221-7dd83cf0.svg) icon next to the parameter's name. ### Input parameter values In the **Activity designer** tab, you can specify a parameter or field's position on the activity canvas as **Primary**, **Secondary**, or **None**. Each option dictates the parameter's behavior and where it is displayed on the activity canvas. Alternatively, you can mark a field as **Required** to automatically set its position as Primary. * **Required**: The parameter or field requires a value to successfully execute the activity. The parameter is marked as required using the asterisk (*) symbol. This means it's always visible on the canvas and you must provide a value for it. ![docs image](https://dev-assets.cms.uipath.com/assets/images/integration-service/integration-service-docs-image-473300-0d65b07f.webp) * **Primary**: The parameter is displayed in the primary section of the activity. It may be left blank when using the activity in an automation. ![docs image](https://dev-assets.cms.uipath.com/assets/images/integration-service/integration-service-docs-image-473304-e012a7cb.webp) * **Secondary**: The parameter is hidden from the main canvas. It is displayed under the **Show additional options** section. These fields are optional and may be left blank. ![docs image](https://dev-assets.cms.uipath.com/assets/images/integration-service/integration-service-docs-image-473309-25dfde5e.webp) * **None**: The parameter is hidden from the activity. You must use the **Manage Properties** wizard to add it to the canvas. ### Ordering input parameters The order of input parameters dictates their location in the activity's Preview window. You can change the display order by using the icon located on the far left of each parameter to drag the list item up or down. ![docs image](https://dev-assets.cms.uipath.com/assets/images/integration-service/integration-service-docs-image-473316-fa950544.webp) ## Request fields Request fields allow you to populate the body of an HTTP request. Request fields are most often associated with `POST`, `PUT`, or `PATCH` requests (insert, upsert, or update record activities). ### Populating Request and Response fields There are two ways to populate the request and response fields. #### Option 1 (recommended): Using a properly formatted JSON. 1. Select a resource's **Send Request** button. 2. Add the JSON. 3. Make sure the **Overwrite fields on send request** option is enabled. 4. Select **Execute**. If the response is successful, the **Input** fields are populated with the JSON properties used for the request and the **Output** fields are populated based on the response. :::note If you use this method, make a request that is exhaustive of all the fields you want to use in your activity. ::: The following image shows an example payload for a `POST` request. Note that the **Overwrite fields on send request** field is enabled: ![docs image](https://dev-assets.cms.uipath.com/assets/images/integration-service/integration-service-docs-image-367664-06be90fc.webp) #### Option 2: Manually adding each request and response field from the **Activity designer** tab. 1. Navigate to the **Activity designer** tab. 2. In the **Input** tab, select the More options ![more options](https://dev-assets.cms.uipath.com/assets/images/integration-service/integration-service-docs-image-367213-45418e9f.svg) menu. 3. Select **Add request field**. 4. Add the details of the request field in a similar manner to adding a parameter. ![docs image](https://dev-assets.cms.uipath.com/assets/images/integration-service/integration-service-docs-image-473324-b29174d6.webp) 5. To add response fields, go to the **Output** tab and select the **Add response field** option. ![docs image](https://dev-assets.cms.uipath.com/assets/images/integration-service/integration-service-docs-image-473328-d90244ac.webp) ## Output fields The Output fields in **Activity designer** are pulled from the Response fields. The values can be populated by successfully making a call to the resource. ### Curated fields You can mark output fields as **Curated**. The field value is specifically extracted from the response object and can be assigned to a variable, making it easy to access and use in other activities when used in an automation. The following image shows how **Status**, the curated field, is directly displayed in the activity's **Output** section: ![docs image](https://dev-assets.cms.uipath.com/assets/images/integration-service/integration-service-docs-image-473335-b97ffb49.webp)