This is driving me nuts and I can’t figure out what the problem is. I have one project consisting of Web APIs and another project, the client, which calls them. Both projects are built using VS 2022, .net 8.

Below is my authentication function:

    [AllowAnonymous]
    [HttpPost("Authenticate")]
    public async Task<UserLoginResponse> Authenticate(string lr)
    {
        UserLoginResponse resp = new UserLoginResponse { Success = false, ResultMessage = string.Empty, UserToken = "" };
        UserSignIn usi = default;
        if (string.IsNullOrEmpty(lr))
        {
            resp.Success = false;
            resp.ResultCodes = LoginResponseCodes.UserNamePasswordRequired;
            resp.UserToken = string.Empty;
            return resp;
        }

        try
        {
            usi = JsonConvert.DeserializeObject<UserSignIn>(lr);
        }
        catch (Exception ex) 
        {
            resp.Success = false;
            resp.ResultCodes = LoginResponseCodes.UserNamePasswordRequired;
            resp.UserToken = string.Empty;
            return resp;
        }
        if (string.IsNullOrEmpty(usi.Email) || string.IsNullOrEmpty(usi.Password))
        {
            resp.Success = false;
            resp.ResultMessage = "Valid User Name (email)/Password Required";
        }
        else
        {
            //resp = await _userService.Authenticate(usi);
            //if(resp == null)
            //{
            //    resp = new UserLoginResponse { Success = false, ResultMessage = "NULL Error", UserToken = "" };
            //}
        }
        return resp;
    }

Below, is one of the many client variations I’ve tried, which all result in a StatusCode: 400, ReasonPhrase: ‘Bad Request’:

    [AllowAnonymous]
    [HttpPost("Authenticate")]
    public async Task<UserLoginResponse> Authenticate(string lr)
    {
        UserLoginResponse resp = new UserLoginResponse { Success = false, ResultMessage = string.Empty, UserToken = "" };
        UserSignIn usi = default;
        if (string.IsNullOrEmpty(lr))
        {
            resp.Success = false;
            resp.ResultCodes = LoginResponseCodes.UserNamePasswordRequired;
            resp.UserToken = string.Empty;
            return resp;
        }

        try
        {
            usi = JsonConvert.DeserializeObject<UserSignIn>(lr);
        }
        catch (Exception ex) 
        {
            resp.Success = false;
            resp.ResultCodes = LoginResponseCodes.UserNamePasswordRequired;
            resp.UserToken = string.Empty;
            return resp;
        }
        if (string.IsNullOrEmpty(usi.Email) || string.IsNullOrEmpty(usi.Password))
        {
            resp.Success = false;
            resp.ResultMessage = "Valid User Name (email)/Password Required";
        }
        else
        {
            //resp = await _userService.Authenticate(usi);
            //if(resp == null)
            //{
            //    resp = new UserLoginResponse { Success = false, ResultMessage = "NULL Error", UserToken = "" };
            //}
        }
        return resp;
    }

There are no errors produced anywhere, at least none I’ve been able to find.

If I test my API call using the Swagger Client, it works fine. It also works fine when I use the following javascript, within an html page.

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script>
    function CallWebApi() {
        var url = "https://localhost:7598/api/BlueUsers/Authenticate?lr=%7B%22Email%22%3A%22testemail%40gmail.com%22%2C%22Password%22%3A%22hjgtdsrsdes%22%7D";
        $.ajax({
            url: url,
            type: "POST",
            success: function (data) {
                console.log(data);
            },
            error: function (xhr, status, error) {
                console.log(xhr.responseText);
            }
        });
    }
    CallWebApi();

Could someone please help me with what I’m missing and/or doing incorrectly in my .net client?

Thank you