SQLModel give fastapi incomplete pydantic model if generic is used in response_model.

[TrueRou]

First Check

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• I already read and followed all the tutorial in the docs and didn't find an answer.
• I already checked if it is not related to SQLModel but to Pydantic.
• I already checked if it is not related to SQLModel but to SQLAlchemy.

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Example Code

from typing import Generic, TypeVar

from fastapi import FastAPI
from sqlmodel import SQLModel

T = TypeVar("T")

app = FastAPI()


class User(SQLModel):
    name: str


class UserInternal(SQLModel):
    name: str
    hashed_password: str


class AppResponse(SQLModel, Generic[T]):
    data: T | None = None
    code: int = 200
    message: str = "success"


@app.get("/", response_model=AppResponse[User])
def get_user():
    db_user = UserInternal(name="John Doe", hashed_password="hashed_secret")
    return AppResponse(data=db_user)


if __name__ == "__main__":
    import uvicorn

    uvicorn.run(app, host="127.0.0.1", port=8001)

Description

Reproduce

• Create class User(SQLModel)
• Create class AppResponse[T](SQLModel)
• Route response_model=AppResponse[User]
• Wrong docs, and response with hashed_password

It seems that SQLModel won't give fastapi correct pydantic model if generic is used.
Make AppResponse extends from pydantic BaseModel can solve this problem, but SQLModel not.

Operating System

Windows

Operating System Details

No response

SQLModel Version

0.0.27

Python Version

Python 3.13.9

Additional Context

[YuriiMotov]

There is PR #1275 to fix this.

I checked, your code example works well on the branch of that PR