Receiving 422 Error Flutter post request and Fastapi

Question

I am attempting to use flutter on the front to send json data to the backend. I am getting 422 errors which I understand are if the parameter is declared to be of the type of a Pydantic model, it will be interpreted in the request body.

So, following other stackoverflow posts and what I can gather from the docs I tried

Future<void> register() async {
    final uri = 'http://localhost:8000/register';
    final body = {
      "username": unController.text,
      "fullname": fullnameController.text,
      "email": emailController.text,
      "password": passwordController.text,
      "disabled": false,
    };
    var json_string = json.encode(body);
    print(json_string);
    var response;
    try {
      response = await http.post(
        Uri.parse(uri),
        body: json_string,
      );
    } catch (e) {
      print(e);
    }
    print(response);

My route signature looks like so.

class User(BaseModel):
    username: str
    fullname: str
    email: str
    hashed_password: Optional[str]
    disabled: bool
    password: Optional[str]

@authenticate.post('/register', response_model=User)
async def register_user(new_user: User):

I'm new to flutter and not sure why I am still receiving 422 status code. I keep running into this issue, but I'm unsure as how to proceed.

Answer 1

I have no clue which lang on code preview on bellow, but maybe you can be forgot add return JSON type of route. Because 422 error meaning error unprocessable entity. If i know which language you use, i can help you more specific method.

Maybe you need to add like return json.Encode(data) things.

Or you can set header "Content-Type": "application/json" :/