C# JWT token invalid

I am having an issue with token, the error is invalid token.
Please help.

string key = "MY_Key";

                var securityKey = new Microsoft.IdentityModel.Tokens.SymmetricSecurityKey(Encoding.UTF8.GetBytes(key));
                var credentials = new Microsoft.IdentityModel.Tokens.SigningCredentials(securityKey, SecurityAlgorithms.HmacSha256);
                var header = new JwtHeader(credentials);
                var payload = new JwtPayload
                        { "iss", "my_API"},
                      { "iat", DateTimeOffset.Now.ToUnixTimeSeconds() },
                       { "exp", DateTimeOffset.Now.ToUnixTimeSeconds() + 1400 },
                var secToken = new JwtSecurityToken(header, payload);
                var handler = new JwtSecurityTokenHandler();

                var tokenString = handler.WriteToken(secToken);

                var token = handler.ReadJwtToken(tokenString);

                RestClient client = new RestClient();
                client.BaseUrl = new Uri("https://api.zoom.us/v2");
                RestRequest request = new RestRequest("/users", Method.GET);
                request.AddHeader("Authorization", "Bearer " + tokenString.ToString());
                request.AddHeader("User-Agent", "Zoom-api-Jwt-Request");
                request.AddHeader("Content-Type", "application/json");
                var response = client.Execute(request);

Hi @nvanderson,

Welcome to the Zoom Developer Forum. We are happy to help you.

  • If you are using the windows SDK, then there are two types of Authentications that you need to do within your implementation:
  1. SDK Authentication
  2. JWT Authentication

To do the SDK Authentication, you would need the SDK API key and secret. To get the SDK key and secret, please visit https://marketplace.zoom.us/docs/sdk/native-sdks/preface/sdk-keys-secrets. The SDK authentication is necessary for Zoom to allow you to use our SDKs.

JWT Authentication: If you need to do JWT authentication, please refer to the example mentioned here: https://github.com/zoom/zoom-sdk-windows/blob/45f58efe46cab9af80e2d9a7f24a1893e75a34c9/demo/sdk_demo_v2/zoomHmacSHA256.cpp. Even though this code is not written in C#, it is based on the same logic.
The JWT token enables you to use our APIs. To find a list of all our APIs, please visit: https://marketplace.zoom.us/docs/api-reference/introduction

I hope this helps.


Yes I followed the links, unfortunately they did not solve my problem.

@Michael_Purnell can you take a look here?

Hey @nvanderson,

Can you try hard coding the JWT token from your Zoom App Dashboard and see if the error goes away?

request.AddHeader("Authorization", "Bearer JWTTOKEN");

If it works, that would mean your JWT generation code is not working properly.


Yes, the hard-coded value works. I am trying to figure our what is wrong the token generation…?!:thinking:

Hey @nvanderson,

I am no expert in C#. You can try using one of the .net libraries here to generate the JWT.

Also check out this stack overflow question about how to generate a JWT in C#


Finally figure it out…:laughing:

1 Like

Happy to hear @nvanderson :slight_smile:

If you don’t mind, could you post the solution so if others have trouble they can see how you fixed it?


According to this https://marketplace.zoom.us/docs/guides/authorization/jwt/jwt-with-zoom
only 2 parameters are needed inside the playload.
{ “iss”: “API_KEY”,
“exp”: 1496091964000

However, 4 are needed
string s =null;
like this { aud = s, iss = Key, exp = secondsSinceEpoch, iat= NowsecondsSinceEpoch };

Thanks for posting this @nvanderson!

Hi Sr,

I was trying to reproduce the authorization process by testing with the JWT token and I got Unauthorized because an Invalid access token:

The token was taken from the test kwt on app info

Any help will be appreciatte.

Hey @jtuschman,

Please see my post here:


I did that but it did not work., even tho, I re-generated a new key and it did not work as well

1 Like

Did you include today’s date and token exp.date in Unix format?

Actually I’m testing with the JWT token that you provided me on my app JWT dashboard, this JWT token need to be necessary to know if the authorization is granted. And this one did not work either


1 Like

Actually I read another post:

where this issue is occurring since last days… so maybe is related to my concern, I’m just want to validate and check where it could be solved

Hey @jtuschman,

Yes, this is a caching issue, can you please try again tomorrow?


I’m using the JWT as provided by the Zoom page “credentials” for my Marketplace app.

I am trying the token using the Curl code as provided by the Zoom page at https://marketplace.zoom.us/docs/guides/auth/jwt :

curl --request GET \
  --url 'https://api.zoom.us/v2/users?status=active&page_size=30&page_number=1' \
  --header 'authorization: Bearer 39ug3j309t8unvmlmslmlkfw853u8' \
  --header 'content-type: application/json

(I simply replace “39ug3j309t8unvmlmslmlkfw853u8” with my JWT token as provided by the Zoom web page “credentials” for my app)

I receive the error message "Invalid access token."

Please help.

I think you need to include exp.date and todays date, so

4 total parameters are needed

string s =null;

like this { aud = s, iss = Key, exp = secondsSinceEpoch, iat= NowsecondsSinceEpoch };

Thanks - I’ll give it a go, and I really do appreciate your reply.

But I’m using the JWT as created by the Zoom page, so surely Zoom will include any params that Zoom requires? I’m not creating the JWT using my own code (yet).

If my own JWT code works, I’ll update you here.


  1. the Zoom page is giving me a bad JWT token, or…
  2. the Zoom API is incorrectly rejecting my JWT token