422 error but structure of data sent seems to be right

[Adib234]

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Go to /8000/docs and make a post request

Environment

• OS: [macOS]:
• FastAPI Version [e.g. 0.3.0]:

To know the FastAPI version use:

0.63.0

• Python version:
  3.9.4

Additional context

Hello everyone I'm getting a 422 error from using the OpenAPI docs and here's my models and my function header

class ImageProperty(BaseModel):
    text: str = Field(..., max_length=256)
    characteristics: str = Field(..., max_length=256)
    permissions: Optional[PermissionsEnum] = Field(PermissionsEnum.public)


class ImagesProperty(BaseModel):
    images: List[ImageProperty]


@router.post("/add/")
async def add_images(api_key: str, images_property: ImagesProperty, images_upload: List[UploadFile] = File(...)):

When I put the information into the interactive docs this is the curl request

curl -X 'POST' \
  'http://127.0.0.1:8000/add/?api_key=stringstring' \
  -H 'accept: application/json' \
  -H 'Content-Type: multipart/form-data' \
  -F 'images_property={
   "images":[
      {
         "text":"asdas",
         "characteristics":"asdfsd",
         "permissions":"public"
      }
   ]
}' \
  -F 'images_upload=@Screen Shot 2021-04-27 at 6.15.26 PM.png;type=image/png'

This is the response for the 422

{
  "detail": [
    {
      "loc": [
        "body",
        "images_property"
      ],
      "msg": "value is not a valid dict",
      "type": "type_error.dict"
    }
  ]
}

[Kludex]

https://fastapi.tiangolo.com/tutorial/request-forms-and-files/

[Adib234]

So I saw the docs and it suggested to use forms and files in the same request and this is what I've changed.

class ImageProperty(BaseModel):
    text: str = Field(..., max_length=256)
    characteristics: str = Field(..., max_length=256)
    permissions: Optional[PermissionsEnum] = Field(PermissionsEnum.public)


class ImagesProperty(BaseModel):
    api_key: str
    images: List[ImageProperty]


@router.post("/add/")
async def add_images(images_property: ImagesProperty = Form(...), images_upload: List[UploadFile] = File(...)):

Unfortunately I get the same error

[Adib234]

Are they also suggesting that I can't use a model in my request?

but you can't also declare Body fields that you expect to receive as JSON, as the request will have the body encoded using multipart/form-data instead of application/json.

[Adib234]

Okay yeah models are basically a request body so the quote above is what I suspected. I ended up just declaring all my properties in my model as lists of primitive values. This issue has been resolved. Thank you.

Final result, no more models in headers, just query params

async def add_images(api_key: str, t: List[str] = Query(..., alias="texts", title="Description for images"),
                     c: List[str] = Query(..., alias="characteristics",
                                          title="Tags for images"),
                     p: List[str] = Query(
                         'public', alias="permissions", title="Permissions of images"),
                     images_upload: List[UploadFile] = File(...)):

[tiangolo]

Thanks for the help here @Kludex ! 👏 🙇

Thanks for reporting back and closing the issue @Adib234 👍

Sorry for the long delay! 🙈 I wanted to personally address each issue/PR and they piled up through time, but now I'm checking each one in order.