Keygen user and license creation example in C# (https://keygen.sh)

keygen.cs

using RestSharp;
using System;
using System.Collections.Generic;
using System.Text;

public class Example
{
  // This is your account ID or slug.
  //
  // Available at: https://app.keygen.sh/settings
  const string ACCOUNT_ID = "YOUR_ACCOUNT_ID_HERE";

  // This is the policy ID used when creating new licenses.
  //
  // Available at: https://app.keygen.sh/policies
  const string POLICY_ID = "YOUR_POLICY_ID_HERE";
  
  public static void Main()
  {
    var client = new RestClient(string.Format("https://api.keygen.sh/v1/accounts/{0}", ACCOUNT_ID));

    // You can request these from the user via a form, stdin, etc.
    var userDetails = new Dictionary<string, object> {
      { "firstName", "John" },
      { "lastName", "Doe" },
      { "email", "johndoe@example.com" },
      { "password", "secret" },
      { "metadata", new {
        /* … add *non-sensitive* payment details here e.g. a Stripe "token" */
        stripeToken = "STRIPE_TOKEN_HERE"
      }}
    };
    
    // Create the user
    var userResponse = CreateUser(client, userDetails);
    if (userResponse.ContainsKey("errors"))
    {
      Console.WriteLine("Failed to create user: {0}", userResponse["errors"]);
      // … user creation failed, handle errors
      return;
    }
    var user = (Dictionary<string, object>) userResponse["data"];

    // Authenticate the new user
    var tokenResponse = AuthenticateUser(client, (string) userDetails["email"], (string) userDetails["password"]);
    if (tokenResponse.ContainsKey("errors"))
    {
      Console.WriteLine("Failed to authenticate user: {0}", tokenResponse["errors"]);
      // … user authentication failed, handle errors
      return;
    }
    var token = (Dictionary<string, object>) tokenResponse["data"];
    var tokenAttrs = (Dictionary<string, object>) token["attributes"];
    var tokenStr = (string) tokenAttrs["token"];

    // Create a new license for the new user using the new token
    // to authenticate with Keygen's API
    var licenseResponse = CreateLicense(client, tokenStr, POLICY_ID, (string) user["id"]);
    if (licenseResponse.ContainsKey("errors"))
    {
      Console.WriteLine("Failed to create license: {0}", licenseResponse["errors"]);
      // … license creation failed, handle errors
      return;
    }
    var license = (Dictionary<string, object>) licenseResponse["data"];

    // Done and done! Next up, you could listen for the `license.created` webhook
    // event to handle billing your new user using a payment provider like Stripe.
    //
    // Read more at: https://keygen.sh/docs/using-webhooks

    Console.WriteLine(
      "Successfully created license {0} for user {1} using token {2}",
      (string) license["id"],
      (string) user["id"],
      tokenStr
    );
  }

  public static Dictionary<string, object> CreateUser(RestClient client, Dictionary<string, object> userDetails)
  {
    var request = new RestRequest("users", Method.POST);

    request.AddHeader("Content-Type", "application/vnd.api+json");
    request.AddHeader("Accept", "application/vnd.api+json");
    
    request.AddJsonBody(new {
      data = new {
        type = "users",
        attributes = new {
          firstName = (string) userDetails["firstName"],
          lastName = (string) userDetails["lastName"],
          email = (string) userDetails["email"],
          password = (string) userDetails["password"],
          metadata = userDetails["metadata"]
        }
      }
    });

    return client.Execute<Dictionary<string, object>>(request).Data;
  }

  public static Dictionary<string, object> AuthenticateUser(RestClient client, string userEmail, string userPassword)
  {
    var request = new RestRequest("tokens", Method.POST);
    var credentials = Convert.ToBase64String(
      Encoding.UTF8.GetBytes(string.Format("{0}:{1}", userEmail, userPassword))
    );

    request.AddHeader("Authorization", string.Format("Basic {0}", credentials));
    request.AddHeader("Accept", "application/vnd.api+json");

    return client.Execute<Dictionary<string, object>>(request).Data;
  }

  public static Dictionary<string, object> CreateLicense(RestClient client, string userToken, string policyId, string userId)
  {
    var request = new RestRequest("licenses", Method.POST);

    request.AddHeader("Authorization", string.Format("Bearer {0}", userToken));
    request.AddHeader("Content-Type", "application/vnd.api+json");
    request.AddHeader("Accept", "application/vnd.api+json");

    request.AddJsonBody(new {
      data = new {
        type = "licenses",
        relationships = new {
          policy = new {
            data = new { type = "policies", id = policyId }
          },
          user = new {
            data = new { type = "users", id = userId }
          }
        }
      }
    });

    return client.Execute<Dictionary<string, object>>(request).Data;
  }
}