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

[TrueRou]

First Check

• I added a very descriptive title here.
• I used the GitHub search to find a similar question and didn't find it.
• I searched the SQLModel documentation, with the integrated search.
• I already searched in Google "How to X in SQLModel" and didn't find any information.
• 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.

Commit to Help

• I commit to help with one of those options 👆

Example Code

fromtypingimportGeneric, TypeVarfromfastapiimportFastAPIfromsqlmodelimportSQLModelT=TypeVar("T")
app=FastAPI()
classUser(SQLModel):
name: strclassUserInternal(SQLModel):
name: strhashed_password: strclassAppResponse(SQLModel, Generic[T]):
data: T|None=Nonecode: int=200message: str="success"@app.get("/", response_model=AppResponse[User])defget_user():
db_user=UserInternal(name="John Doe", hashed_password="hashed_secret")
returnAppResponse(data=db_user)
if__name__=="__main__":
importuvicornuvicorn.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

[TrueRou]

First Check

• I added a very descriptive title here.
• I used the GitHub search to find a similar question and didn't find it.
• I searched the SQLModel documentation, with the integrated search.
• I already searched in Google "How to X in SQLModel" and didn't find any information.
• 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.

Commit to Help

• I commit to help with one of those options 👆

Example Code

fromtypingimportGeneric, TypeVarfromfastapiimportFastAPIfromsqlmodelimportSQLModelT=TypeVar("T")
app=FastAPI()
classUser(SQLModel):
name: strclassUserInternal(SQLModel):
name: strhashed_password: strclassAppResponse(SQLModel, Generic[T]):
data: T|None=Nonecode: int=200message: str="success"@app.get("/", response_model=AppResponse[User])defget_user():
db_user=UserInternal(name="John Doe", hashed_password="hashed_secret")
returnAppResponse(data=db_user)
if__name__=="__main__":
importuvicornuvicorn.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

[TrueRou]

First Check

• I added a very descriptive title here.
• I used the GitHub search to find a similar question and didn't find it.
• I searched the SQLModel documentation, with the integrated search.
• I already searched in Google "How to X in SQLModel" and didn't find any information.
• 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.

Commit to Help

• I commit to help with one of those options 👆

Example Code

fromtypingimportGeneric, TypeVarfromfastapiimportFastAPIfromsqlmodelimportSQLModelT=TypeVar("T")
app=FastAPI()
classUser(SQLModel):
name: strclassUserInternal(SQLModel):
name: strhashed_password: strclassAppResponse(SQLModel, Generic[T]):
data: T|None=Nonecode: int=200message: str="success"@app.get("/", response_model=AppResponse[User])defget_user():
db_user=UserInternal(name="John Doe", hashed_password="hashed_secret")
returnAppResponse(data=db_user)
if__name__=="__main__":
importuvicornuvicorn.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

[TrueRou]

First Check

• I added a very descriptive title here.
• I used the GitHub search to find a similar question and didn't find it.
• I searched the SQLModel documentation, with the integrated search.
• I already searched in Google "How to X in SQLModel" and didn't find any information.
• 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.

Commit to Help

• I commit to help with one of those options 👆

Example Code

fromtypingimportGeneric, TypeVarfromfastapiimportFastAPIfromsqlmodelimportSQLModelT=TypeVar("T")
app=FastAPI()
classUser(SQLModel):
name: strclassUserInternal(SQLModel):
name: strhashed_password: strclassAppResponse(SQLModel, Generic[T]):
data: T|None=Nonecode: int=200message: str="success"@app.get("/", response_model=AppResponse[User])defget_user():
db_user=UserInternal(name="John Doe", hashed_password="hashed_secret")
returnAppResponse(data=db_user)
if__name__=="__main__":
importuvicornuvicorn.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

[TrueRou]

First Check

• I added a very descriptive title here.
• I used the GitHub search to find a similar question and didn't find it.
• I searched the SQLModel documentation, with the integrated search.
• I already searched in Google "How to X in SQLModel" and didn't find any information.
• 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.

Commit to Help

• I commit to help with one of those options 👆

Example Code

fromtypingimportGeneric, TypeVarfromfastapiimportFastAPIfromsqlmodelimportSQLModelT=TypeVar("T")
app=FastAPI()
classUser(SQLModel):
name: strclassUserInternal(SQLModel):
name: strhashed_password: strclassAppResponse(SQLModel, Generic[T]):
data: T|None=Nonecode: int=200message: str="success"@app.get("/", response_model=AppResponse[User])defget_user():
db_user=UserInternal(name="John Doe", hashed_password="hashed_secret")
returnAppResponse(data=db_user)
if__name__=="__main__":
importuvicornuvicorn.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

[TrueRou]

First Check

• I added a very descriptive title here.
• I used the GitHub search to find a similar question and didn't find it.
• I searched the SQLModel documentation, with the integrated search.
• I already searched in Google "How to X in SQLModel" and didn't find any information.
• 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.

Commit to Help

• I commit to help with one of those options 👆

Example Code

fromtypingimportGeneric, TypeVarfromfastapiimportFastAPIfromsqlmodelimportSQLModelT=TypeVar("T")
app=FastAPI()
classUser(SQLModel):
name: strclassUserInternal(SQLModel):
name: strhashed_password: strclassAppResponse(SQLModel, Generic[T]):
data: T|None=Nonecode: int=200message: str="success"@app.get("/", response_model=AppResponse[User])defget_user():
db_user=UserInternal(name="John Doe", hashed_password="hashed_secret")
returnAppResponse(data=db_user)
if__name__=="__main__":
importuvicornuvicorn.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

[TrueRou]

First Check

• I added a very descriptive title here.
• I used the GitHub search to find a similar question and didn't find it.
• I searched the SQLModel documentation, with the integrated search.
• I already searched in Google "How to X in SQLModel" and didn't find any information.
• 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.

Commit to Help

• I commit to help with one of those options 👆

Example Code

fromtypingimportGeneric, TypeVarfromfastapiimportFastAPIfromsqlmodelimportSQLModelT=TypeVar("T")
app=FastAPI()
classUser(SQLModel):
name: strclassUserInternal(SQLModel):
name: strhashed_password: strclassAppResponse(SQLModel, Generic[T]):
data: T|None=Nonecode: int=200message: str="success"@app.get("/", response_model=AppResponse[User])defget_user():
db_user=UserInternal(name="John Doe", hashed_password="hashed_secret")
returnAppResponse(data=db_user)
if__name__=="__main__":
importuvicornuvicorn.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

[TrueRou]

First Check

• I added a very descriptive title here.
• I used the GitHub search to find a similar question and didn't find it.
• I searched the SQLModel documentation, with the integrated search.
• I already searched in Google "How to X in SQLModel" and didn't find any information.
• 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.

Commit to Help

• I commit to help with one of those options 👆

Example Code

fromtypingimportGeneric, TypeVarfromfastapiimportFastAPIfromsqlmodelimportSQLModelT=TypeVar("T")
app=FastAPI()
classUser(SQLModel):
name: strclassUserInternal(SQLModel):
name: strhashed_password: strclassAppResponse(SQLModel, Generic[T]):
data: T|None=Nonecode: int=200message: str="success"@app.get("/", response_model=AppResponse[User])defget_user():
db_user=UserInternal(name="John Doe", hashed_password="hashed_secret")
returnAppResponse(data=db_user)
if__name__=="__main__":
importuvicornuvicorn.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