Allow floats a 0 fractional part in JSON strict mode

Author: s3riusCreated Sep 12, 2026Updated Sep 17, 2026

Labelsfeature request

Initial Checks

I confirm that I'm using Pydantic V2

Description

Hello. According to the OpenAPI 3.1 spec, strict integer parsing should be relaxed.

Since there is no distinct JSON integer type, JSON Schema defines integers mathematically. This means that both 1 and 1.0 are equivalent, and are both considered to be integers.

So, to comply with the specification, we should accept values like 2.0 when the fractional part is 0 and treat them as integers even when strict=True is enabled.

Example Code

python

import pydantic


class MyModel(pydantic.BaseModel):
    value: int = pydantic.Field(strict=True)


print(MyModel.model_validate({'value': 2.0}))

Python, Pydantic & OS Version

pydantic version: 2.13.5
        pydantic-core version: 2.46.5
          pydantic-core build: profile=release pgo=false
               python version: 3.13.13 (main, Jun  2 2026, 22:27:49) [Clang 22.1.3 ]
                     platform: Linux-7.2.4-arch1-2-x86_64-with-glibc2.44
             related packages: typing_extensions-4.16.0 pydantic-extra-types-2.11.1 email-validator-2.3.0 pyright-1.1.409 pydantic-settings-2.15.0 mypy-2.3.1
                       commit: unknown

Source: pydantic/pydantic

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