Proposed Pull Request Change

📄 Document Links

View on GitHub View on Microsoft Learn

--- title: Import an Azure Function App as an API titleSuffix: Azure API Management description: Learn how to import an Azure function app into Azure API Management as an API. services: api-management ms.service: azure-api-management ms.topic: how-to ms.date: 03/12/2026 ms.custom: sfi-image-nochange #customer intent: As an API developer, I want to import an Azure function app as an API in API Management. --- # Import an Azure function app as an API [!INCLUDE [api-management-availability-all-tiers](../../includes/api-management-availability-all-tiers.md)] Azure API Management supports importing Azure function apps as new APIs or appending them to existing APIs. The process automatically generates a host key in the Azure function app, which is then assigned to a named value in API Management. This article describes how to import an Azure function app as an API to Azure API Management and test the API. [!INCLUDE [api-management-workspace-availability](../../includes/api-management-workspace-availability.md)] In this article, you learn how to: > [!div class="checklist"] > * Import an Azure function app as an API > * Append an Azure function app to an API > * View the new function app host key and API Management named value > * Test the API in the Azure portal ## Prerequisites * Create an [Azure API Management instance](get-started-create-service-instance.md). * Make sure you have an Azure function app in your subscription. For more information, see [Getting started with Azure Functions](../azure-functions/functions-get-started.md). The function must have an HTTP trigger. The authorization level must be set to *Anonymous* or *Function*. > [!NOTE] > You can also use the API Management Extension for Visual Studio Code to import and manage your APIs. To get started, complete the [API Management Extension tutorial](visual-studio-code-tutorial.md). ## Import an Azure function app as a new API To create a new API from an Azure function app: 1. Navigate to your API Management service in the Azure portal. 1. In the sidebar menu, select **APIs** > **APIs**, and then select **+ Add API**. 1. Under **Create from Azure resource**, select the **Function App** tile: :::image type="content" source="./media/import-function-app-as-api/add-01.png" alt-text="Screenshot that shows the Function App tile in the Azure portal."::: 1. Select the **Browse** button: :::image type="content" source="./media/import-function-app-as-api/add-02.png" alt-text="Screenshot that highlights the Browse button." lightbox="./media/import-function-app-as-api/add-02.png"::: 1. Click the **Select** button under **Configure required settings** to choose from the list of available function apps: :::image type="content" source="./media/import-function-app-as-api/add-03.png" alt-text="Screenshot that shows the Select button." lightbox="./media/import-function-app-as-api/add-03.png"::: 1. Find the function app that you want to import functions from, select it, and then click **Select**: :::image type="content" source="./media/import-function-app-as-api/add-04.png" alt-text="Screenshot that shows a function app and the Select button." lightbox="./media/import-function-app-as-api/add-04.png"::: 1. Select the functions that you want to import and click **Select**. You can only import functions that have an HTTP trigger and an *Anonymous* or *Function* authorization level. :::image type="content" source="./media/import-function-app-as-api/add-05.png" alt-text="Screenshot that shows a function and the Select button." lightbox="./media/import-function-app-as-api/add-05.png"::: 1. Switch to the **Full** view and assign a **Product** to your new API. >[!NOTE] > *Products* are associations of one or more APIs that are offered to developers via the developer portal. First, developers must subscribe to a product to get access to the API. When they subscribe, they get a subscription key for any API in the product. If you created the API Management instance, you're an administrator and are subscribed to every product by default. > > In some pricing tiers, API Management instances come with two default sample products: > - **Starter** > - **Unlimited** 1. As needed, specify other settings. You can also specify settings later via the **Settings** tab. These settings are explained in the [Import and publish your first API](import-and-publish.md#import-and-publish-a-backend-api) tutorial. 1. Select **Create**. ## Append a function app to an existing API To append a function app to an existing API: 1. In your **Azure API Management** service instance, select **APIs** > **APIs** in the sidebar menu. 1. Choose an API that you want to import a function app to. Select the ellipsis (**...**) next to the API, and then select **Import**: :::image type="content" source="./media/import-function-app-as-api/append-function-api-1.png" alt-text="Screenshot that shows the Import menu option." lightbox="./media/import-function-app-as-api/append-function-api-1.png"::: 1. Select the **Function App** tile: :::image type="content" source="./media/import-function-app-as-api/append-function-api-2.png" alt-text="Screenshot that shows the Function App tile." lightbox="./media/import-function-app-as-api/append-function-api-2.png"::: 1. In the **Import from Function App window**, select **Browse**: :::image type="content" source="./media/import-function-app-as-api/append-function-api-3.png" alt-text="Screenshot that shows the Browse button." lightbox="./media/import-function-app-as-api/append-function-api-3.png"::: 1. Click the **Select** button under **Configure required settings** to choose from the list of available function apps: :::image type="content" source="./media/import-function-app-as-api/add-03.png" alt-text="Screenshot that shows the Function App section." lightbox="./media/import-function-app-as-api/add-03.png"::: 1. Find the function app you want to import functions from, select it, and then click **Select**: :::image type="content" source="./media/import-function-app-as-api/add-04.png" alt-text="Screenshot that shows the function app and the Select button." lightbox="./media/import-function-app-as-api/add-04.png"::: 1. Select the functions that you want to import, and then click **Select**: :::image type="content" source="./media/import-function-app-as-api/add-05.png" alt-text="Screenshot that shows the list of functions." lightbox="./media/import-function-app-as-api/add-05.png"::: 1. Select **Import**: :::image type="content" source="./media/import-function-app-as-api/append-function-api-4.png" alt-text="Screenshot that shows the Import button." lightbox="./media/import-function-app-as-api/append-function-api-4.png"::: ## Authorization When you import an Azure function app, these items are automatically generated: * A host key in the function app. The key is named `apim-<your API Management service instance name>`. * A named value in the API Management instance that has the name `<your Azure function app instance name>-key`. This value contains the host key. For APIs created after April 4, 2019, the host key is passed in HTTP requests from API Management to the function app in a header. Older APIs pass the host key as [a query parameter](../azure-functions/functions-bindings-http-webhook-trigger.md#api-key-authorization). You can change this behavior by using the `PATCH Backend` [REST API call](/rest/api/apimanagement/current-ga/backend/update#backendcredentialscontract) on the `Backend` entity that's associated with the function app. > [!WARNING] > Removing or changing either the Azure function app host key value or the API Management named value disables communication between the services. The values don't automatically sync. > > If you need to rotate the host key, be sure to also change the named value in API Management. ### Access a function app host key 1. Navigate to your Azure function app instance: :::image type="content" source="./media/import-function-app-as-api/keys-01.png" alt-text="Screenshot that shows a list of function app instances." lightbox="./media/import-function-app-as-api/keys-01.png"::: 1. In the **Functions** section of the sidebar menu, select **App keys**. Find the keys in the **Host keys** section: :::image type="content" source="./media/import-function-app-as-api/keys-02b.png" alt-text="Screenshot that shows App keys in the menu." lightbox="./media/import-function-app-as-api/keys-02b.png"::: ### Access the named value in API Management Navigate to your API Management instance and select **APIs** > **Named values** in the sidebar menu. The Azure function app key is stored there. :::image type="content" source="./media/import-function-app-as-api/api-named-value.png" alt-text="Screenshot that shows the location of the function app key." lightbox="./media/import-function-app-as-api/api-named-value.png"::: ## Test the new API in the Azure portal You can call operations directly from the Azure portal. Using the Azure portal is a convenient way to view and test the operations of an API. :::image type="content" source="./media/import-function-app-as-api/test-api.png" alt-text="Screenshot that shows the steps for testing an API." lightbox="./media/import-function-app-as-api/test-api.png"::: 1. Select the API that you created in the preceding section. 1. Select the **Test** tab. 1. Select the operation that you want to test. * The page displays fields for query parameters and headers. * One of the headers is `Ocp-Apim-Subscription-Key`. This header is for the product subscription key that's associated with the API. * If you created the API Management instance, you're an administrator, so the key is filled in automatically. 1. Select **Send**. When the test succeeds, the backend responds with **200 OK** and some data. [!INCLUDE [api-management-define-api-topics.md](../../includes/api-management-define-api-topics.md)]