get validation_alias in the model json schema instead of the field name

Question

I'm using Padantic v2, creating models, and then I provide the model_json_schema to other teams that need to make sure they provide all the required parameters.

Is there a way to get the validation_alias in the model_json_schema instead of the field name?

For example, this is my model:

from pydantic_settings import BaseSettings, SettingsConfigDict
from pydantic import Field, AliasPath

class Config(BaseSettings):
   model_config = SettingsConfigDict(validation_alias=lambda field_name: field_name.lower())
   a: int = Field(..., validation_alias=AliasPath("b", "c")) 

schema = Config.model_json_schema()

Current schema:

{
    "additionalProperties": false,
    "properties": {
        "a": {
            "title": "A",
            "type": "integer"
        }
    },
    "required": [
        "a"
    ],
    "title": "Config",
    "type": "object"
}

"a" does not exist in the source that I initialize the model with, For example, this is the source: {"b": {"c": 3}} On the other hand, I want to access "a" like this: model.a

and not model.b.c

This is the desired schema:

{
    "$defs": {
        "ConfigB": {
            "additionalProperties": false,
            "properties": {
                "c": {
                    "title": "C",
                    "type": "integer"
                }
            },
            "required": [
                "c"
            ],
            "title": "ConfigB",
            "type": "object"
        }
    },
    "additionalProperties": false,
    "properties": {
        "b": {
            "$ref": "#/$defs/ConfigB"
        }
    },
    "required": [
        "b"
    ],
    "title": "Config",
    "type": "object"
}

Thanks in advance

Answer 1

I used @computed_field instead of using validation_alias=AliasPath(...), like this:

from pydantic_settings import BaseSettings, SettingsConfigDict
from pydantic import Field, AliasPath

class BModel(BaseSettings):
    c: int

class Config(BaseSettings):
    model_config = SettingsConfigDict(validation_alias=lambda field_name: field_name.lower())
    b: BModel

    @computed_field
    @property
    def a(self) -> int:
       return self.b.c

schema = Config.model_json_schema()

schema

{
    "$defs": {
        "BModel": {
            "additionalProperties": false,
            "properties": {
                "c": {
                    "title": "C",
                    "type": "integer"
                }
            },
            "required": [
                "c"
            ],
            "title": "BModel",
            "type": "object"
        }
    },
    "additionalProperties": false,
    "properties": {
        "b": {
            "$ref": "#/$defs/BModel"
        }
    },
    "required": [
        "b"
    ],
    "title": "Config",
    "type": "object"
}