c# - HttpClient InternalServerError 500 - Works in postman, but not in code

Question

I'm trying to send GET requests to to the following API endpoints:

https://api.mediahound.com/1.3/search/all?PARAM_STRING
https://api.mediahound.com/1.3/graph/lookup?params=PARAMS_JSON

The first one works just fine with the following code (in both postman & c#):

var baseUri = new Uri("https://api.mediahound.com/1.3/search/all/");
using (var client = new HttpClient())
{
  var res = "";
  client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", _oAuth2.Token);
  Task task = Task.Run(async () => { res = await client.GetStringAsync(baseUri + searchInput + "?type=movie"); });
  task.Wait();
  .....
}

The second one I can't get to work and it gives me an InternalServerError response. It currently looks like this:

public async Task<ObservableCollection<Movie>> GetMoviesAsync(string id)
{
  var baseUri = new Uri("https://api.mediahound.com/1.3/graph/lookup?params=");
  using (var client = new HttpClient())
  {
    var param = "{\n\"ids\":\n[\"" + id +  "\"],\n\"components\":\n[\"primaryImage\",\n\"keyTraits\"]\n}";
    client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", _oAuth2.Token);
    var res = await client.GetAsync(baseUri + param);
    if(!res.IsSuccessStatusCode)
    {
      throw new Exception("HttpClient Error: " + res.StatusCode); //InternalServerError 500
    }
    var content = await res.Content.ReadAsStringAsync();
    .....
  }
}

Simply copy pasting the baseUri + param into postman, gives me the desired result, however I can't replicate that in the program no matter what I do, and I'm not sure how I should proceed with debugging the problem.

Anyone got some good ideas?

Answer 1

So I figured out the issue. Seems postman automatically escapes quotes etc. in the url, but c# doesn't. I solved the issue by adding Uri.EscapeUriString() on the param.