openapi-generators
Issue with client generation for FastApi version > 118
Describe the bug Pydantic V1 and V2 models co-existing is creating an issue with backwards compatibility. Please check the latest changes from fast api viz https://github.com/fastapi/fastapi/pull/14168 which create the models as xxxx-Input and xxxx-Output which is breaking the existing code.
Can you give me an example OpenAPI document that shows the issue? And what expected vs actual code is generated?
I have the same issue. This is a condensed example:
{
"openapi": "3.1.0",
"info": {
"title": "Test",
"version": "0.0.1"
},
"paths": {
"/endpoint": {
"post": {
"tags": [
"test"
],
"summary": "Test Endpoint",
"operationId": "test_endpoint",
"requestBody": {
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/MySchema-Input"
}
}
},
"required": true
},
"responses": {
"200": {
"description": "Successful Response",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/MySchema-Output"
}
}
}
}
}
}
}
},
"components": {
"schemas": {
"MySchema-Input": {
"properties": {
"id": {
"type": "string",
"format": "uuid",
"title": "Id"
},
"name": {
"type": "string",
"title": "Name"
}
},
"type": "object",
"required": [
"id"
],
"title": "MySchema"
},
"MySchema-Output": {
"properties": {
"id": {
"type": "string",
"format": "uuid",
"title": "Id"
},
"name": {
"type": "string",
"title": "Name"
}
},
"type": "object",
"required": [
"id",
"name"
],
"title": "MySchema"
}
}
}
}
Yields this output:
python -m openapi_python_client generate --meta=uv --overwrite --path failing.json chore ✭ ✖ ✱ ◼
Generating /Users/emil/Code/arbo-api-client/test-client
Warning(s) encountered while generating. Client was generated, but some pieces may be missing
WARNING parsing POST /endpoint within test.
Cannot parse response for status code 200 (Could not find reference in parsed models or enums), response will be omitted from generated client
Reference(ref='#/components/schemas/MySchema-Output')
Unable to parse schema /components/schemas/MySchema-Output
Unable to parse this part of your OpenAPI document: : Attempted to generate duplicate models with name "MySchema"
Schema(title='MySchema', multipleOf=None, maximum=None, exclusiveMaximum=None, minimum=None, exclusiveMinimum=None, maxLength=None, minLength=None, pattern=None, maxItems=None, minItems=None, uniqueItems=None, maxProperties=None, minProperties=None, required=['id', 'name'], enum=None, const=None, type=<DataType.OBJECT: 'object'>, allOf=[], oneOf=[], anyOf=[], schema_not=None, items=None, prefixItems=[], properties={'id': Schema(title='Id', multipleOf=None, maximum=None, exclusiveMaximum=None, minimum=None, exclusiveMinimum=None, maxLength=None, minLength=None, pattern=None, maxItems=None, minItems=None, uniqueItems=None, maxProperties=None, minProperties=None, required=None, enum=None, const=None, type=<DataType.STRING: 'string'>, allOf=[], oneOf=[], anyOf=[], schema_not=None, items=None, prefixItems=[], properties=None, additionalProperties=None, description=None, schema_format='uuid', default=None, nullable=False, discriminator=None, readOnly=None, writeOnly=None, xml=None, externalDocs=None, example=None, deprecated=None), 'name': Schema(title='Name', multipleOf=None, maximum=None, exclusiveMaximum=None, minimum=None, exclusiveMinimum=None, maxLength=None, minLength=None, pattern=None, maxItems=None, minItems=None, uniqueItems=None, maxProperties=None, minProperties=None, required=None, enum=None, const=None, type=<DataType.STRING: 'string'>, allOf=[], oneOf=[], anyOf=[], schema_not=None, items=None, prefixItems=[], properties=None, additionalProperties=None, description=None, schema_format=None, default=None, nullable=False, discriminator=None, readOnly=None, writeOnly=None, xml=None, externalDocs=None, example=None, deprecated=None)}, additionalProperties=None, description=None, schema_format=None, default=None, nullable=False, discriminator=None, readOnly=None, writeOnly=None, xml=None, externalDocs=None, example=None, deprecated=None)
The problem is that there are multiple schemas with the same title. There is a flag in FastAPI, separate_input_output_schemas, which is supposed to prevent this, but it doesn't seem to work anymore. It seems it doesn't correctly detect if it needs to split the schemas or not anymore - as far as I can see, our -Input and -Output variants are identical in actual usage under FastAPI 0.120. But then again, it evidently splits the schemas even when I tell it not to, so...
In any case, it would be nice if the api generator worked even in the presence of these split models, maybe there could be a config to take the model name from the schema id instead of the title or something?
One final note is that it doesn't seem to help to specify class_overrides in the config (gives the exact same output), I guess those aren't applied until later or something?
class_overrides:
MySchema-Output:
class_name: "MySchemaOutput"
module_name: my_schema_output
MySchema-Input:
class_name: "MySchemaInput"
module_name: my_schema_input
Actually, I missed that we had customized our openapi routes. the separate_input_output_schemas=False flag does seem to work if applied properly. 😅
It does not seem to work for us. Even with separate_input_output_schemas=False.
I'm trying to have a minimal reproducible one, but I haven't managed yet (would need to spend more time).
openapi-python-client will still need to fix this, as it seems it's there to last :-/
Actually, I missed that we had customized our openapi routes. the
separate_input_output_schemas=Falseflag does seem to work if applied properly. 😅
I was having the same issues with FastAPI > 118;
I tried:
With openapi-python-client 0.25.3
- FastAPI == 0.118.* - worked without this flag
- FastAPI == 0.121.0 - doesn't work without this flag
With openapi-python-client 0.27.1
- FastAPI == 0.121.0 - doesn't work without this flag
Hope that helps
