Generating JWT for UIToolkit from c# backend

We’re integrating zoom into our platform using the VideoSDK and the UI Toolkit.
So far we are able to start sessions configuring the UIToolkit component in our react front-end as explained in the documentation. But we want to generate the configurtation/jwt in our c# back-end for obvious security reasons.

I’v reviewed this forum for information on how to accomplish that, and none of the examples works for us.

Is there an official resource on a c# implementation?

@ignacio.ortega ,

I have a working sample for Meeting SDK, you probably need to change the parameters a little

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.IdentityModel.Tokens;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.IdentityModel.Tokens.Jwt;
using System.IO;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Security.Claims;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
public static class meetingsdk

    public static Task MeetingSDK(HttpContext context)
        return Task.Run(async () =>

            string MSDK_CLIENT_ID = Environment.GetEnvironmentVariable("MSDK_CLIENT_ID");
            string MSDK_CLIENT_SECRET = Environment.GetEnvironmentVariable("MSDK_CLIENT_SECRET");

            var authorizationToken = context.Request.Query["code"].ToString();
            var currentDateOffset = DateTimeOffset.UtcNow;
            var epochTime = (int)currentDateOffset.ToUnixTimeSeconds();

            var epochTime48HoursLater = epochTime + 172800; // 172800 seconds = 2 days
            DateTime epochDateTimeExpiry = DateTimeOffset.FromUnixTimeSeconds(epochTime48HoursLater).UtcDateTime;

            var sdkSecret = MSDK_CLIENT_SECRET;
            var appKey = MSDK_CLIENT_ID;
            var data = new Dictionary
            { "appKey", appKey },
            { "iat", epochTime },
            { "exp", epochTime48HoursLater },
            { "tokenExp", epochTime48HoursLater },
            { "mn", 9898533313 },
            { "role", 1 }
            var meetingSdkKey = GenerateSignature(data, sdkSecret, epochDateTimeExpiry);

            await context.Response.WriteAsync(JsonConvert.SerializeObject(meetingSdkKey));

        static string GenerateSignature(Dictionary data, string secret, DateTime epochDateTimeExpiry)
            var claims = data.Select(kv => new Claim(kv.Key, kv.Value.ToString()));
            var identity = new ClaimsIdentity(claims, "Custom");
            //var handler = new JwtSecurityTokenHandler();
            //var securityToken = handler.CreateToken(new SecurityTokenDescriptor
            //    SigningCredentials = new SigningCredentials(new SymmetricSecurityKey(Encoding.UTF8.GetBytes(secret)), SecurityAlgorithms.HmacSha256),
            //    Subject = identity,
            //    Expires = epochDateTimeExpiry, 
            //    NotBefore= null
            //return handler.WriteToken(securityToken);
            // Create JWT token without setting the "nbf" claim
            var securityToken = new JwtSecurityToken(
                claims: identity.Claims,
                expires: epochDateTimeExpiry,
                signingCredentials: new SigningCredentials(new SymmetricSecurityKey(Encoding.UTF8.GetBytes(secret)), SecurityAlgorithms.HmacSha256),
                notBefore: null  // Exclude the "nbf" claim

            var handler = new JwtSecurityTokenHandler();
            return handler.WriteToken(securityToken);



Thank you! I’ll give it a try