Manage your function app

In Azure Functions, a function app provides the execution context for your individual functions. Function app behaviors apply to all functions hosted by a given function app. All functions in a function app must be of the same language.

Individual functions in a function app are deployed together and are scaled together. All functions in the same function app share resources, per instance, as the function app scales.

Connection strings, environment variables, and other application settings are defined separately for each function app. Any data that must be shared between function apps should be stored externally in a persisted store.

This article describes how to configure and manage your function apps.


Many configuration options can also be managed by using the Azure CLI.

Get started in the Azure portal

  1. To begin, go to the Azure portal and sign in to your Azure account. In the search bar at the top of the portal, enter the name of your function app and select it from the list.

  2. Under Settings in the left pane, select Configuration.

    Function app overview in the Azure portal

You can navigate to everything you need to manage your function app from the overview page, in particular the Application settings and Platform features.

Application settings

The Application settings tab maintains settings that are used by your function app. These settings are stored encrypted, and you must select Show values to see the values in the portal. You can also access application settings by using the Azure CLI.


To add a setting in the portal, select New application setting and add the new key-value pair.

Function app settings in the Azure portal.

Azure CLI

The az functionapp config appsettings list command returns the existing application settings, as in the following example:

az functionapp config appsettings list --name <FUNCTION_APP_NAME> \
--resource-group <RESOURCE_GROUP_NAME>

The az functionapp config appsettings set command adds or updates an application setting. The following example creates a setting with a key named CUSTOM_FUNCTION_APP_SETTING and a value of 12345:

az functionapp config appsettings set --name <FUNCTION_APP_NAME> \
--resource-group <RESOURCE_GROUP_NAME> \

Use application settings

The function app settings values can also be read in your code as environment variables. For more information, see the Environment variables section of these language-specific reference topics:

When you develop a function app locally, you must maintain local copies of these values in the local.settings.json project file. To learn more, see Local settings file.

Platform features

Function apps run in, and are maintained by, the Azure App Service platform. As such, your function apps have access to most of the features of Azure's core web hosting platform. The left pane is where you access the many features of the App Service platform that you can use in your function apps.


Not all App Service features are available when a function app runs on the Consumption hosting plan.

The rest of this article focuses on the following App Service features in the Azure portal that are useful for Functions:

For more information about how to work with App Service settings, see Configure Azure App Service Settings.

App Service editor

The App Service editor

The App Service editor is an advanced in-portal editor that you can use to modify JSON configuration files and code files alike. Choosing this option launches a separate browser tab with a basic editor. This enables you to integrate with the Git repository, run and debug code, and modify function app settings. This editor provides an enhanced development environment for your functions compared with the built-in function editor.

We recommend that you consider developing your functions on your local computer. When you develop locally and publish to Azure, your project files are read-only in the portal. To learn more, see Code and test Azure Functions locally.


Function app console

The in-portal console is an ideal developer tool when you prefer to interact with your function app from the command line. Common commands include directory and file creation and navigation, as well as executing batch files and scripts.

When developing locally, we recommend using the Azure Functions Core Tools and the Azure CLI.

Advanced tools (Kudu)

Configure Kudu

The advanced tools for App Service (also known as Kudu) provide access to advanced administrative features of your function app. From Kudu, you manage system information, app settings, environment variables, site extensions, HTTP headers, and server variables. You can also launch Kudu by browsing to the SCM endpoint for your function app, like https://<myfunctionapp>

Deployment Center

When you use a source control solution to develop and maintain your functions code, Deployment Center lets you build and deploy from source control. Your project is built and deployed to Azure when you make updates. For more information, see Deployment technologies in Azure Functions.

Cross-origin resource sharing

To prevent malicious code execution on the client, modern browsers block requests from web applications to resources running in a separate domain. Cross-origin resource sharing (CORS) lets an Access-Control-Allow-Origin header declare which origins are allowed to call endpoints on your function app.


When you configure the Allowed origins list for your function app, the Access-Control-Allow-Origin header is automatically added to all responses from HTTP endpoints in your function app.

Configure function app's CORS list

When the wildcard (*) is used, all other domains are ignored.

Use the az functionapp cors add command to add a domain to the allowed origins list. The following example adds the domain:

az functionapp cors add --name <FUNCTION_APP_NAME> \
--resource-group <RESOURCE_GROUP_NAME> \

Use the az functionapp cors show command to list the current allowed origins.


Configure authentication for a function app

When functions use an HTTP trigger, you can require calls to first be authenticated. App Service supports Azure Active Directory authentication and sign-in with social providers, such as Facebook, Microsoft, and Twitter. For details on configuring specific authentication providers, see Azure App Service authentication overview.

Next steps