Configuration overview

The following different concepts apply to configuring a static web app.

Application configuration: Define rules in the staticwebapp.config.json file to control application behavior and features. Use this file to define route and security rules, custom headers, and networking settings.
Build configuration: Define settings that control the build process.
Application settings: Set application-level settings and environment variables that can be used by backend APIs.

Example scenarios

If you want to...	then...
Define routing rules	Create rules in the staticwebapp.config.json file
Set which branch triggers builds	Update the tracked branch name in the build configuration file
Define which security roles have access to a route	Secure routes with roles in the staticwebapp.config.json file
Set which HTML file is served if a route doesn't match an actual file	Define fallback route in the staticwebapp.config.json file
Set global headers for HTTP requests	Define global headers in the staticwebapp.config.json file
Define a custom build command	Set a custom build command value in the application configuration file
Set an environment variable for a frontend build	Define an environment variable in the build configuration file
Set an environment variable for an API	Set an application setting in the portal