How to generate a bearer token? (C#)

C# example

This tutorial is written in C# using the IdentityModel.Client library. Download the full C#.NET example project with helper library.

When do you need a bearer token?

You must obtain a bearer token before making any requests to the Platform APIs. The token is used to authenticate and authorize every API call under the OAuth 2.0 Client Credentials flow.

Tokens expire after a set period — your application should detect a 401 Unauthorized response and request a new token.

How to generate a bearer token (C#)

The following steps walk through obtaining an access token from the Platform Identity server using C#.

Libraries used:

• IdentityModel.Client
• Newtonsoft.Json
• System.Text

Step 1: Set the variable values

Set identityUrl, clientId, clientSecret, and scope to the appropriate values.

var identityUrl = "https://identity.example.com";
var clientId = "[Your_ClientId]";
var clientSecret = "[Your_ClientSecret]";
var scope = "platform_upload_api";

• identityUrl — the URL of the Platform Identity (token) server
• clientId and clientSecret — obtainable from the Platform web app
• scope — the API scope you want access to:
  • platform_upload_api for the Upload API
  • platform_processing_api for the Processing API

Step 2: Create an HTTP client

HttpClient client = new HttpClient();
client.BaseAddress = new Uri(identityUrl);

Step 3: Retrieve the OpenID Connect discovery document

var openIdDiscoveryDocument = client.GetDiscoveryDocumentAsync(identityUrl).GetAwaiter().GetResult();

This retrieves the Identity server's configuration, including the token endpoint URL.

Step 4: Build the token request

var request = new ClientCredentialsTokenRequest
{
    Address = openIdDiscoveryDocument.TokenEndpoint,
    ClientId = clientId,
    ClientSecret = clientSecret,
    Scope = scope
};

Step 5: Send the request and return the token

var tokenResponse = await client.RequestClientCredentialsTokenAsync(request);
if (tokenResponse != null)
{
    return tokenResponse.AccessToken;
}
else
{
    Console.WriteLine("Authentication failed");
    throw new Exception("Authentication failed");
}

Complete code

using IdentityModel.Client;
using Newtonsoft.Json;
using System.Text;

namespace Platform_API_Demo_Client
{
    public static class Identity
    {
        public static async void Run()
        {
            var identityUrl = "https://identity.example.com";
            var clientId = "[Your_ClientId]";
            var clientSecret = "[Your_ClientSecret]";

            var accessToken = await Authenticate(identityUrl, clientId, clientSecret, "platform_upload_api");
        }

        static async Task<string> Authenticate(string identityUrl, string clientId, string clientSecret, string scope)
        {
            HttpClient client = new HttpClient();
            client.BaseAddress = new Uri(identityUrl);

            var openIdDiscoveryDocument = client.GetDiscoveryDocumentAsync(identityUrl).GetAwaiter().GetResult();

            var request = new ClientCredentialsTokenRequest
            {
                Address = openIdDiscoveryDocument.TokenEndpoint,
                ClientId = clientId,
                ClientSecret = clientSecret,
                Scope = scope
            };

            var tokenResponse = await client.RequestClientCredentialsTokenAsync(request);
            if (tokenResponse != null)
            {
                return tokenResponse.AccessToken;
            }
            else
            {
                Console.WriteLine("Authentication failed");
                throw new Exception("Authentication failed");
            }
        }
    }
}