It would be cool to have an API to modify the RequestValidationError OpenAPI entry, and not only the exception_handler.

validation_error_definition = {
    "title": "ValidationError",
    "type": "object",
    "properties": {
        "loc": {
            "title": "Location",
            "type": "array",
            "items": {"anyOf": [{"type": "string"}, {"type": "integer"}]},
        },
        "input": {"title": "Input", "type": "any"},
        "url": {"title": "URL", "type": "string"},
        "msg": {"title": "Message", "type": "string"},
        "type": {"title": "Error Type", "type": "string"},
    },
    "required": ["loc", "msg", "type"],
}

This is what we need right? But this change would require changing a lot of tests.

from fastapi import FastAPI

app = FastAPI()

Your existing OpenAPI definitions

validation_error_definition = {...}
validation_error_response_definition = {...}

Add the existing definitions to the app

app.openapi_schema["components"]["schemas"]["ValidationError"] = validation_error_definition
app.openapi_schema["components"]["schemas"]["HTTPValidationError"] = validation_error_response_definition

Define the new definition for HTTPValidationError (modify as needed)

new_http_validation_error_definition = {
"title": "ModifiedHTTPValidationError",
"type": "object",
"properties": {
"detail": {
"title": "Detail",
"type": "array",
"items": {"$ref": "#/components/schemas/ValidationError"},
}
},
}

Update the OpenAPI entry

update_openapi_entry(app, new_http_validation_error_definition)

Your FastAPI routes and other configurations go here

using this code stay happy 👍