python type_error ai_generated true

AttributeError: 'Starlette' object has no attribute 'add_middleware'

ID: python/starlette-attributeerror-starlette-app-has-no-attribute-add-middleware

Also available as: JSON · Markdown · 中文
80%Fix Rate
84%Confidence
0Evidence
2025-04-05First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.x active — — —

Root Cause

Trying to use add_middleware method on a Starlette instance, but the method is not available in older versions or incorrect object.

generic

中文

尝试在Starlette实例上使用add_middleware方法，但该方法在旧版本中不可用或对象错误。

Workarounds

  1. 90% success Use correct middleware registration syntax 
    app.add_middleware(MiddlewareClass)
  2. 85% success Check Starlette version and upgrade if needed 
    pip install --upgrade starlette

Dead Ends

Common approaches that don't work:

  1. Assuming Starlette has the same API as Flask 70% fail

    Starlette uses different middleware registration.

  2. Using add_middleware on a middleware class instead of app 80% fail

    Method exists on app, not middleware.