SystemAPI doesn't work in v4.3.0
Following this tutorial no longer works:
https://zitadel.com/docs/guides/integrate/zitadel-apis/access-zitadel-system-api
I tried all kinds of things.. but can't manage to use the AddCustomDomain API.. it always gives me this error:
ZITADEL Docs
This guide focuses on the ZITADEL System API. To access the other APIs (Admin, Auth, Management), please checkout this guide.
1 Reply
Hi @Aldraz, I'm an AI assistant for ZITADEL. While a team member reviews this question, I'll see if I can find relevant sources for your question.
Answer
 The 
AUTH-7fs1e error indicates an invalid token issue with System API authentication. Based on community reports, there are several common causes for this error:
Key troubleshooting steps:
1. Include the correct port in your JWT audience - The audience must match exactly what ZITADEL resolves to, including any port number (1)  . For example, if your ZITADEL instance runs on port 8080, use:
   
2. Verify your System API user configuration - Ensure your public key is properly loaded in the SystemAPIUsers configuration . The key should be base64-encoded and properly indented in your configuration.
3. Check JWT claims - Your JWT must include the correct iss, sub, aud, iat, and exp claims . The iss and sub should match your system user name.
4. Key format issues - If using zitadel-tools, you may need to generate your RSA key with the --traditional flag (2)  :
   
The error you're seeing is commonly reported when the JWT audience doesn't match the ZITADEL instance URL exactly, particularly when a port number is required but not included (1)  .
If you continue having issues after checking these items, please click the "Ask for help" button to tag a team member for further assistance.
To learn more, see the sources I considered:
[1] JWT auth fails when adding custom domain
[2] Zitadel Executing System API Call
Feel free to tag @Ask Inkeep with additional questions.