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Example Code

from typing import Annotated

from pydantic import AfterValidator
from fastapi import FastAPI


app = FastAPI()

def validator(v):
    raise ValueError()

Ints = Annotated[list[int], AfterValidator(validator)]

@app.post("/")
def post(ints: Ints) -> None:
    return None

Description

If we run the code and send a request to the endpoint, e.g.

echo -n '[2,3,4]' | http POST http://localhost:8000

on version 0.115.9, we get a 422 but on 0.115.10 we get 200. Is this a bug?

Operating System

Linux

Operating System Details

No response

FastAPI Version

0.115.10

Pydantic Version

2.9.2, 2.10.6

Python Version

3.12

Additional Context

No response