# AssertionError: 'response' parameter is not a valid response class

- **ID:** `python/fastapi-redirect-response-error`
- **Domain:** python
- **Category:** config_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

在 FastAPI 路由中使用了错误的 response 参数类型。

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.x | active | — | — |

## Workarounds

1. **** (100% success)
   ```
   @app.get('/item', response_model=Item)
async def get_item():
    return Item(name='test', price=10)
   ```

## Dead Ends

- **** — None 不是有效的响应类 (90% fail)
- **** — 会导致响应格式不正确 (70% fail)