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 FastAPI documentation, with the integrated search.
• I already searched in Google "How to X in FastAPI" 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 FastAPI but to Pydantic.
• I already checked if it is not related to FastAPI but to Swagger UI.
• I already checked if it is not related to FastAPI but to ReDoc.

Commit to Help

• I commit to help with one of those options 👆

Example Code

import pytest
from fastapi import FastAPI
from starlette.testclient import TestClient


@pytest.fixture(name="client")
def get_client():
    app = FastAPI(separate_input_output_schemas=False)

    from pydantic import BaseModel, computed_field

    class Rectangle(BaseModel):
        width: int
        length: int

        @computed_field
        @property
        def area(self) -> int:
            return self.width * self.length

    @app.get("/")
    def read_root() -> Rectangle:
        return Rectangle(width=3, length=4)

    client = TestClient(app)
    return client


def test_get(client: TestClient):
    response = client.get("/openapi.json")
    data = response.json()

    rectangle_model = data["components"]["schemas"]["Rectangle"]["properties"]

    assert "area" in rectangle_model.keys()

Description

I expect that even with separate_input_output_schemas set to False the OpenAPI schema includes computed fields declared on a Pydantic model

Operating System

macOS

Operating System Details

No response

FastAPI Version

0.103.1

Pydantic Version

2.4.1

Python Version

3.8.16

Additional Context

I think it may come from here