What request hooks does Flask provide and when do they run?

Summary

before_request runs before each view (returning a response short-circuits), after_request receives and can modify the response, teardown_request/teardown_appcontext always run at the end (even on errors) for cleanup.

Longer Answer

Use before_request for auth checks and loading the current user into g; after_request for headers (CORS, security headers); teardown for closing resources. For WSGI-level middleware (e.g., ProxyFix), wrap app.wsgi_app.

Key Points

• before_request can short-circuit
• after_request modifies response
• Teardown always runs
• WSGI middleware via app.wsgi_app