Call external api with oauth 2.0 authentication using C# console app

Question

Code to call external api with OAuth 2.0 authentication

Sachin Singh · Answer

You can use this using System; using System.Net.Http; using System.Net.Http.Headers; using System.Threading.Tasks; class Program { static async Task Main() { // Replace these values with your actual OAuth 2.0 credentials string clientId = "your_client_id"; string clientSecret = "your_client_secret"; string accessToken = await GetAccessToken(clientId, clientSecret); if (!string.IsNullOrEmpty(accessToken)) { // Replace this URL with the API endpoint you want to call string apiUrl = "https://api.example.com/resource"; // Make the API request using the access token await CallApi(apiUrl, accessToken); } Console.ReadLine(); } static async Task GetAccessToken(string clientId, string clientSecret) { // Replace these values with the OAuth 2.0 token endpoint and required parameters string tokenEndpoint = "https://oauth.example.com/token"; string scope = "your_api_scope"; using (HttpClient client = new HttpClient()) { // Set the required headers for token endpoint authentication client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(System.Text.Encoding.ASCII.GetBytes($"{clientId}:{clientSecret}"))); // Set the parameters for token request var content = new FormUrlEncodedContent(new[] { new KeyValuePair ("grant_type", "client_credentials"), new KeyValuePair ("scope", scope) }); // Call the token endpoint to get the access token HttpResponseMessage response = await client.PostAsync(tokenEndpoint, content); if (response.IsSuccessStatusCode) { var responseContent = await response.Content.ReadAsStringAsync(); // Parse the JSON response to get the access token // Note: You may need to use a JSON parsing library here // For simplicity, we are assuming a simple JSON response format // Make sure to handle errors and parse the response appropriately in a production scenario return responseContent.Split('"')[3]; } else { Console.WriteLine($"Error getting access token: {response.StatusCode}"); return null; } } } static async Task CallApi(string apiUrl, string accessToken) { using (HttpClient client = new HttpClient()) { // Set the access token in the Authorization header client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", accessToken); // Make the API request HttpResponseMessage response = await client.GetAsync(apiUrl); if (response.IsSuccessStatusCode) { string apiResponse = await response.Content.ReadAsStringAsync(); Console.WriteLine($"API Response: {apiResponse}"); } else { Console.WriteLine($"Error calling API: {response.StatusCode}"); } } } }

Satyaprakash Samantaray · Answer

Hi, Please check http://tinyurl.com/yjyetf5z

Anandu G Nath · Answer

using System; using System.Net.Http; using System.Net.Http.Headers; using System.Threading.Tasks; namespace OAuth2APICallExample { class Program { static async Task Main(string[] args) { string apiUrl = "YOUR_API_ENDPOINT"; // Replace with your API endpoint string accessToken = "YOUR_ACCESS_TOKEN"; // Replace with your OAuth 2.0 access token using (HttpClient client = new HttpClient()) { client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", accessToken); HttpResponseMessage response = await client.GetAsync(apiUrl); if (response.IsSuccessStatusCode) { string responseData = await response.Content.ReadAsStringAsync(); Console.WriteLine("API call successful. Response:"); Console.WriteLine(responseData); } else { Console.WriteLine($"Failed to call API. Status code: {response.StatusCode}"); } } } } } Meghana M Check this code