Develop Reference

Access a REST API with C#

I try to access to the REST API from NetExplorer. It works when I send a request with postman :
But It doesn't with my C# code :
var client = new RestClient("https://patrimoine-click.netexplorer.pro/api/auth");
var ReqAuth = new { user = "xxxxxxxxxxxxxxxxxx", password = "xxxxxxxxxxxxx" };
JsonResult result = new JsonResult(ReqAuth);
var request = new RestRequest(result.ToString(), Method.Post);
request.AddHeader("Accept", "application/json");
RestResponse response = await client.ExecuteAsync(request);
Here's the error message :
{"error":"Il n'existe aucune m\u00e9thode de l'API pouvant r\u00e9pondre \u00e0 votre appel."}
In english, there's no API method to resolve your call
If somebody can help me ...
Thanks

You are using the constructor of RestRequest wrong, the constructor does not take in the content (body) like that. Try using it with AddJsonBody like so:
var client = new RestClient("https://patrimoine-click.netexplorer.pro/api/auth");
var ReqAuth = new { user = "xxxxxxxxxxxxxxxxxx", password = "xxxxxxxxxxxxx" };
var request = new RestRequest();
request.Method = RestSharp.Method.Post;
request.AddJsonBody(ReqAuth);
request.AddHeader("Accept", "application/json");
RestResponse response = await client.ExecuteAsync(request);
Documentation: https://restsharp.dev/usage.html#request-body

How to get access token, refresh token in .NET Core (C#) without using SDK (Manually) in QuickBooks Online API?

I have created a simple console app in C#, I need to request access token without using SDK. I have managed to launch a URL to request code. I get code but trying to call the access_token endpoint is a challenge. I need help on how I can get access_token and refresh_token. Attached is the screenshot of codes having all the request details and the endpoint I used as follows.
Endpoint used: https://oauth.platform.intuit.com/oauth2/v1/tokens/bearer
Parameters: code,=[codeReceived] grant_type = authorization_code and redirect_uri = [RedirectUrl]
Headers:Authorization: Basic [Base64EncodedBytes], Accept: application/json, Host: oauth.platform.intuit.com, Content-Type: application/x-www-form-urlencoded
I have created a simple console app in C#, I need to request access token without using SDK. I have managed to launch a URL to request code. I get code but trying to call the access_token endpoint is a challenge. I need help on how I can get access_token and refresh_token. Attached is the screenshot of codes having all the request details and the endpoint I used as follows.
Posting
Endpoint used: https://oauth.platform.intuit.com/oauth2/v1/tokens/bearer
Parameters:[enter image description here][1]
code,=[codeReceived] grant_type = authorization_code and redirect_uri = [RedirectUrl]
Headers:
Authorization: Basic [Base64EncodedBytes], Accept: application/json, Host: oauth.platform.intuit.com, Content-Type: application/x-www-form-urlencoded
This is the Client Class I've created:
public class RestClient
{
public string ClientID;
public string ClientSecret;
public string RedirectUrl = "https://devices.pythonanywhere.com/";
public string Environment = "sandbox";
private async Task<string> GetAccessTokenAsync(string Url, string code, string ClientId, string ClientSecret)
{
var stringBytes = Encoding.UTF8.GetBytes($"{ClientId}:{ClientSecret}");
var encodedBytes = Convert.ToBase64String(stringBytes);
var uriBuilder = new UriBuilder(Url);
var query = HttpUtility.ParseQueryString(uriBuilder.Query);
query["grant_type"] = "authorization_code";
query["code"] = $"{code}";
query["redirect_uri"] = $"{RedirectUrl}";
uriBuilder.Query = query.ToString();
Url = uriBuilder.ToString();
var DecodedUrl = HttpUtility.UrlDecode(Url);
Console.WriteLine(encodedBytes);
HttpRequestMessage request = new(HttpMethod.Post, DecodedUrl);
request.Headers.Add("Accept", "application/json");
request.Headers.Add("Authorization", $"Basic {encodedBytes}");
request.Headers.Add("Host", "oauth.platform.intuit.com");
request.Content = new StringContent("application/x-www-form-urlencoded");
using HttpClient client = new();
using HttpResponseMessage response = await client.SendAsync(request);
var body = response.Content.ReadAsStringAsync();
return body.Result;
}
public string GetTokens(string Url, string code, string ClientId, string ClientSecret)
{
try
{
var response = GetAccessTokenAsync(Url, code, ClientId, ClientSecret).Result;
if (response.Length>0)
{
return "There is data";
}
return "No data";
}
catch (Exception ex)
{
return ex.Message;
}
}
}
and this here is where I'm calling it
class Program
{
static void Main(string[] args)
{
var client = new RestClient();
client.ClientID = "AB8EMz5arbI**************************************";
client.ClientSecret = "4y4vsz*********************************";
var OauthUrl = "https://oauth.platform.intuit.com/oauth2/v1/tokens/bearer";
var code = "AB11644908535RgJ**************************";
Console.WriteLine($"Response: {client.GetTokens(OauthUrl, code, client.ClientID, client.ClientSecret)}");
}
}

I was making a mistake in my C# code. Here is the working code that I used in GetAccessTokenAsync:
private async Task<string> GetAccessTokenAsync(string Url, string code, string ClientId, string ClientSecret)
{
var stringBytes = Encoding.UTF8.GetBytes($"{ClientId}:{ClientSecret}");
var encodedBytes = Convert.ToBase64String(stringBytes);
HttpRequestMessage request = new(HttpMethod.Post, Url);
request.Headers.TryAddWithoutValidation("Accept", "application/json");
request.Headers.TryAddWithoutValidation("Authorization", $"Basic {encodedBytes}");
var contentList = new List<string>();
contentList.Add("grant_type=authorization_code");
contentList.Add($"code={code}");
contentList.Add($"redirect_uri={RedirectUrl}");
request.Content = new StringContent(string.Join("&", contentList));
request.Content.Headers.ContentType = MediaTypeHeaderValue.Parse("application/x-www-form-urlencoded");
using HttpClient client = new();
using HttpResponseMessage response = await client.SendAsync(request);
var body = response.Content.ReadAsStringAsync();
return body.Result;
}

I hate reviving old threads, but your answer helped me a lot. I had to change it a little bit to accept the refresh token rather than authorization code and thought I would post it here. I banged my head around for quite some time trying to figure this out without any useful documentation that I could find on the matter. I hope it helps someone in the same way that your code has helped me. Thanks!
public async Task<string> RefreshAccessToken(string Url, string RefreshToken, string ClientId, string ClientSecret)
{
var stringBytes = Encoding.UTF8.GetBytes($"{ClientID}:{ClientSecret}");
var encodedBytes = Convert.ToBase64String(stringBytes);
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, Url);
request.Headers.TryAddWithoutValidation("Accept", "application/json");
request.Headers.TryAddWithoutValidation("Authorization", $"Basic {encodedBytes}");
var contentList = new List<string>();
contentList.Add("grant_type=refresh_token");
contentList.Add($"refresh_token={RefreshToken}");
request.Content = new StringContent(string.Join("&", contentList));
request.Content.Headers.ContentType = MediaTypeHeaderValue.Parse("application/x-www-form-urlencoded");
using (HttpClient client = new HttpClient())
{
using (HttpResponseMessage response = await client.SendAsync(request))
{
var body = response.Content.ReadAsStringAsync();
return body.Result;
}
}
}
Alternatively, I find that something like this works too. Using RestSharp..
public string RefreshAccessToken()
{
try
{
var stringBytes = Encoding.UTF8.GetBytes($"{strClientID}:{strClientSecret}");
var encodedBytes = Convert.ToBase64String(stringBytes);
var client = new RestClient("https://oauth.platform.intuit.com/oauth2/v1/tokens/bearer");
client.UseJson();
client.Timeout = -1;
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", $"Basic {encodedBytes}");
request.AddHeader("Content-Type", "application/x-www-form-urlencoded");
request.AddParameter("grant_type", "refresh_token");
request.AddParameter("refresh_token", CurrentRefreshToken);
IRestResponse response = client.Execute(request);
return response.Content;
}
catch (Exception ex)
{
WriteError("RefreshAccessToken() - " + ex.Message);
return ex.Message;
}
}

Why HttpClient uses an incorrect requestUri in post request?

When I use HttpClient class to send a POST request to an API URL, it modifies the URL that I've passed to it. For example, when I use the main API URL the RequestUri is incorrect and I receive the not found response. This problem happens when I use api word in the URL !!
Concept:
The Incorrect, modified URL:
Url: https://sandbox-api.alopeyk.com/api/v2/order
Request Url: https://sandbox-api.alopeyk.com
The Correct, and expected URL (This is the one I specify)
Url: https://google.com/api/v2/order
Request Url: https://google.com/api/v2/order
Code:
public async Task<CreateOrderResponse> CreateOrderAsync(CreateOrderRequest request)
{
var endPoint = EndPointFactory<CreateOrderResponse>.Build(HttpMethod.Post);
var jsonString = JsonConvert.SerializeObject(request);
var url = new Uri("https://sandbox-api.alopeyk.com");
var encodedFrom = new StringContent(jsonString);
var httpClient = endPoint.GetHttpClient(url);
var httpResponse = await httpClient.PostAsync("api/v2/orders", encodedFrom).ConfigureAwait(false);
// when use api it's https://sandbox-api.alopeyk.com it should be https://sandbox-api.alopeyk.com/api/v2/orders
// when use other host name for example it's correct
var requesturl = httpResponse.RequestMessage.RequestUri;
return await httpResponse.Content.ReadAsAsync<CreateOrderResponse>().ConfigureAwait(false);
}
// in the EndPoint class
public HttpClient GetHttpClient(Uri url)
{
return new Http.HttpClientFactory().GetOrCreate(Url, Headers);
}
If you want to see HttpClientFactory it's here.
The HttpClient have a problem with my main hostname that it's https://sandbox-api.alopeyk.com

Your Uri must end with a slash like this:
var url = new Uri("https://sandbox-api.alopeyk.com/");
That's a rather silly restriction of HttpClient.

Try this code:
HttpClient client = new HttpClient();
client.BaseAddress = new Uri("https://sandbox-api.alopeyk.com");
HttpResponseMessage response = client.PostAsync("api/v2/orders", new StringContent(jsonString, Encoding.UTF8, "text/json")).Result;
if (response.IsSuccessStatusCode)
{
// Parse the response body. Blocking!
var responseData = response.Content.ReadAsStringAsync().Result;
}

You can try with this code
HttpResponseMessage response = null;
using (var client = new HttpClient())
{
using (var request = new HttpRequestMessage(HttpMethod.Post,"https://sandbox-api.alopeyk.com/api/v2/orders"))
{
request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", /*token herer*/);
var data = new StringContent(JsonConvert.SerializeObject(request, Encoding.UTF8, "application/json"));
request.Content = data;
response = await client.SendAsync(request);
}
}

Error while sending POST request to API (Cannot send a body with this verb type)

I always get this error when I try to request the API.
Some details about the api : the method is POST and the parameters are correct, too (When I try it on postman, no issue)
Here is my code:
JavaScriptSerializer js = new JavaScriptSerializer();
using (WebClient client = new WebClient())
{
foreach (var ad in documents)
{
var doc = js.Serialize(ad);
var json = "{\"Message\":\"" + doc + "\"}";
var response =
client.UploadValues("apiUrl", new NameValueCollection()
{
{"json", json}
});
}
}
I read that UploadValues is POST by default. This code is called in a simple console app. Any idea why I get this error ?

Here is a working piece of code :
var doc = JsonConvert.SerializeObject(message);
var stringContent = new StringContent(
message,
UnicodeEncoding.UTF8,
"application/json");
HttpClient client = new HttpClient();
client.PostAsync("apiUrl", stringContent);

RestSharp post request - Body with x-www-form-urlencoded values

I am using postman and making an api post request where I am adding body with x-www-form-urlencoded key/values and it works fine in postman.
The issue arrises when I try it from c# using RestSharp package.
I have tried the following code below but not getting the response. I get "BadRequest" invalid_client error.
public class ClientConfig {
public string client_id { get; set; } = "value here";
public string grant_type { get; set; } = "value here";
public string client_secret { get; set; } = "value here";
public string scope { get; set; } = "value here";
public string response_type { get; set; } = "value here";
}
public void GetResponse() {
var client = new RestClient("api-url-here");
var req = new RestRequest("endpoint-here",Method.POST);
var config = new ClientConfig();//values to pass in request
req.AddHeader("Content-Type","application/x-www-form-urlencoded");
req.AddParameter("application/x-www-form-urlencoded",config,ParameterType.RequestBody);
var res = client.Execute(req);
return;
}
//Also tried this
req.AddParameter("client_id",config.client_id,"application/x-www-form-urlencoded",ParameterType.RequestBody);
req.AddParameter("grant_type",config.grant_type,"application/x-www-form-urlencoded",ParameterType.RequestBody);
req.AddParameter("client_secret",config.client_secret,"application/x-www-form-urlencoded",ParameterType.RequestBody);
req.AddParameter("scope",config.scope,ParameterType.RequestBody);
req.AddParameter("response_type",config.response_type,"application/x-www-form-urlencoded",ParameterType.RequestBody);
//tried this too
var client = new RestClient("url-here");
var req = new RestRequest("endpointhere",Method.POST);
var config = new ClientConfig();
req.AddBody(config);
var res = client.Execute(req);

this working for me, it was generator from postman
var token = new TokenValidation()
{
app_id = CloudConfigurationManager.GetSetting("appId"),
secret = CloudConfigurationManager.GetSetting("secret"),
grant_type = CloudConfigurationManager.GetSetting("grant_type"),
Username = CloudConfigurationManager.GetSetting("Username"),
Password = CloudConfigurationManager.GetSetting("Password"),
};
var client = new RestClient($"{xxx}{tokenEndPoint}");
var request = new RestRequest(Method.POST);
request.AddHeader("content-type", "application/x-www-form-urlencoded");
request.AddParameter("application/x-www-form-urlencoded", $"app_id={token.app_id}&secret={token.secret}&grant_type={token.grant_type}&Username={token.Username}&Password={token.Password}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
if (response.StatusCode != HttpStatusCode.OK)
{
Console.WriteLine("Access Token cannot obtain, process terminate");
return null;
}
var tokenResponse = JsonConvert.DeserializeObject<TokenValidationResponse>(response.Content);

I personally find this way to work better for me when sending Form-UrlEncoded data.
public void GetResponse() {
var client = new RestClient("api-url-here");
var req = new RestRequest("endpoint-here",Method.POST);
var config = new ClientConfig();//values to pass in request
// Content type is not required when adding parameters this way
// This will also automatically UrlEncode the values
req.AddParameter("client_id",config.client_id, ParameterType.GetOrPost);
req.AddParameter("grant_type",config.grant_type, ParameterType.GetOrPost);
req.AddParameter("client_secret",config.client_secret, ParameterType.GetOrPost);
req.AddParameter("scope",config.scope, ParameterType.GetOrPost);
req.AddParameter("response_type",config.response_type, ParameterType.GetOrPost);
var res = client.Execute(req);
return;
}
Details on this parameter type can be found here:
https://github.com/restsharp/RestSharp/wiki/ParameterTypes-for-RestRequest#getorpost

Personally, I found AddObject() method quite useful, and cleaner when you have so many parameters to add.
public void GetResponse() {
var client = new RestClient("api-url-here");
var req = new RestRequest("endpoint-here",Method.POST);
var config = new ClientConfig();//values to pass in request
req.AddHeader("Content-Type","application/x-www-form-urlencoded");
req.AddObject(config);
var res = client.Execute(req);
return res;
}

If it worked on postman, you can just press the code button on the right hand side. This will provide a working example in multiple languages. It is the button above the information icon. I would post a screenshot of it, but I don't have 10 reputation to do so.

i have found this good for my scenario , it is working perfect,
var client = new RestClient("https://test.salesforce.com/services/oauth2/token");
var request = new RestRequest(Method.POST);
request.AddHeader("content-type", "application/x-www-form-urlencoded");
request.AddParameter("application/x-www-form-urlencoded", "grant_type=password&client_id=3MVG9U_dUptXGpYKew7P.oPwrIsvowP_K4CsnkxHJIEOUJzW0XBUUY3o12bLDasjeIPGVobvBZo8TNFcCY6J3&client_secret=3189542819149073716&username=integraciones%40lamarina.com.mx.dev&password=2Password!4iwZvMQKVAwkYyJRy50JlAHk", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
Console.WriteLine("Response.StatusCode: " + response.StatusCode);
Console.WriteLine("Response.Content: " + response.Content);
Console.WriteLine("Response.ErrorMessage: " + response.ErrorMessage);
https://dotnetfiddle.net/J64FR5

in my case this is what worked
req.AddParameter("client_id", "unigen-corporation", ParameterType.HttpHeader);
req.AddParameter("grant_type", "client_credentials", ParameterType.GetOrPost);

If you've copied the code from the postman, try removing the following:
request.AlwaysMultipartFormData = true;
In my case after removing this line code worked.

var client1 = new RestClient(URI);
var request1 = new RestRequest(Method.POST);
request1.AddHeader("Content-Type", "application/x-www-form-urlencoded");
request1.AddParameter("client_id", "XX");
request1.AddParameter("client_secret", "XX");
request1.AddParameter("grant_type", "XX");
request1.AddParameter("role", "XX");
IRestResponse response1 = client1.Execute(request1);
System.Console.WriteLine(response1.Content);
Add parameters according to your needs. This work fine!

for my code, this works perfect.
// extention function for object->formed data body string
public static string toFormDataBodyString(this object src)
{
var res = new List<string>();
foreach (var key in src.GetType().GetProperties())
{
res.Add($"{key.Name}={src.GetType().GetProperty(key.Name)?.GetValue(src)}");
}
return string.Join("&", res);
}
//--------------------------------------
var data = new {
param1 = xxxx,
param2 = xxxx
}
var translateReq = new RestRequest("url_here")
.AddHeader("Content-Type", "application/x-www-form-urlencoded")
.AddParameter("application/x-www-form-urlencoded", data.toFormDataBodyString(), ParameterType.RequestBody);