python data_error ai_generated true

fastapi.exceptions.ResponseValidationError: 2 validation errors for UserResponse id value is not a valid integer (type=type_error.integer)

ID: python/fastapi-response-validation-error

Also available as: JSON · Markdown · 中文
80%Fix Rate
88%Confidence
0Evidence
2024-06-07First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
0.100.x active — — —
0.110.x active — — —

Root Cause

The view returns data that does not conform to the declared response_model (wrong types, missing fields, or extra nested structure).

generic

中文

视图返回的数据不符合声明的 response_model（类型错误、字段缺失或嵌套结构不匹配）。

Workarounds

  1. 95% success 
    Coerce in the view: `return UserResponse(id=int(user['id']), name=str(user['name']))` or use `.model_validate(user, from_attributes=True)`.
  2. 90% success 
    Set `model_config = ConfigDict(from_attributes=True)` on the Pydantic model and return ORM objects directly.

Dead Ends

Common approaches that don't work:

  1. 85% fail

    Still logs ResponseValidationError; clients get opaque failures.

  2. 75% fail

    Loses OpenAPI schema and silently returns wrong shapes.