Supported languages and runtimes in Azure Static Web Apps

Azure Static Web Apps features two different places where runtime and language versions are important, on the front end and for the API.

Runtime type	Description
Front end	The version responsible for running the website's build steps that build the front end application.
API	The version and runtime of Azure Functions used in your web application.

Front end

You can specify the version used to build the front end of your static web app. Configuring a non-default version is often only necessary if you need to target older versions.

You can specify the runtime version that builds the front end of your static web app in the package.json file in the engines section of the file.

{
  ...
  "engines": {
   "node": ">=14.0.0"
  }
}

API

The APIs in Azure Static Web Apps are supported by Azure Functions. Refer to the Azure Functions supported languages and runtimes for details.

The following versions are supported for managed functions in Static Web Apps. If your application requires a version not listed, considering bringing your own functions.

To configure the API language runtime version, set the apiRuntime property in the platform section to one of the following supported values.

Language runtime version	Operating system	Azure Functions version	apiRuntime value	End of support date
.NET Core 3.1	Windows	3.x	dotnet:3.1	December 3, 2022
.NET 6.0 in-process	Windows	4.x	dotnet:6.0	-
.NET 6.0 isolated	Windows	4.x	dotnet-isolated:6.0	-
.NET 7.0 isolated	Windows	4.x	dotnet-isolated:7.0	-
.NET 8.0 isolated	Windows	4.x	dotnet-isolated:8.0	-
Node.js 12.x	Linux	3.x	node:12	December 3, 2022
Node.js 14.x	Linux	4.x	node:14	-
Node.js 16.x	Linux	4.x	node:16	-
Node.js 18.x (public preview)	Linux	4.x	node:18	-
Python 3.8	Linux	4.x	python:3.8	-
Python 3.9	Linux	4.x	python:3.9	-
Python 3.10	Linux	4.x	python:3.10	-

.NET

To change the runtime version in a .NET app, change the TargetFramework value in the csproj file. While optional, if you set a apiRuntime value in the staticwebapp.config.json file, make sure the value matches what you define in the csproj file.

The following example demonstrates how to update the TargetFramework element for NET 8.0 as the API language runtime version in the csproj file.

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    ...
  </PropertyGroup>
...

Node.js

The following example configuration demonstrates how to use the apiRuntime property to select Node.js 16 as the API language runtime version in the staticwebapp.config.json file.

{
  ...
  "platform": {
    "apiRuntime": "node:16"
  }
  ...
}

Python

The following example configuration demonstrates how to use the apiRuntime property to select Python 3.8 as the API language runtime version in the staticwebapp.config.json file.

{
  ...
  "platform": {
    "apiRuntime": "python:3.8"
  }
  ...
}

Re-enabling proxies in v4.x

Azure Functions supports re-enabling proxies in v4.x. To enable proxy support in managed functions for your static web app, set SWA_ENABLE_PROXIES_MANAGED_FUNCTIONS to true in your application settings.

[!NOTE] While proxies are supported in v4.x, consider using Azure API Management integration with your managed function apps, so your app isn't reliant on proxies.

Deprecations

Note

Now that Azure Functions v3 is retired, Static Web Apps uses Azure Functions v4 for API runtime support for Python 3.8. Redeploy your app to enable this change. While not recommended, you can revert back to v3 by setting the environment variable USEV3_FOR_PYTHON38 to true.

The following runtimes are deprecated in Azure Static Web Apps. For more information about changing your runtime, see Specify API language runtime version in Azure Static Web Apps and Migrate apps from Azure Functions version 3.x to version 4.x.

• .NET Core 3.1
• Node.js 12.x