Hi Jamie,
We had success implanting basic authentication using out of the box constructs. Is this what you tried? https://docs.confluent.io/platform/current/security/authentication/http-basic-auth/overview.html We also implemented JWT but we did not have any success doing that out of the box. For that, we used a "proxy" to intercept and forward the requests from the proxy to the workers ---- On Tue, 22 Apr 2025 05:56:12 -0400 jamied...@aol.co.uk.INVALID wrote ---- Hi All, Has anyone managed to get a REST extension working with multiple connect instances / workers? Many Thanks, Jamie On Wednesday 16 April 2025 at 10:57:01 BST, Jamie <mailto:jamied...@aol.co.uk> wrote: Hi All, I'm trying to implement a custom REST extension for Kafka Connect that allows a token to be used for authentication. When I have a single instance of Kafka connect running in distributed mode (i.e. 1 worker) this works as expected. However, when I add another instance (another worker) I get an error when the worker that received the request has to forward it on to the group leader: Error IO error forwarding REST request: (org.apache.kafka.connect.runtime.rest.RestClient:143) java.util.concurrent.ExecutionException: org.eclipse.jetty.client.HttpResponseException: HTTP protocol violation: Authentication challenge without WWW-Authenticate header I noticed that someone also had the same issue with the basic authentication extension that comes as part of connect: https://stackoverflow.com/questions/60977591/kafkaconnect-rest-api-basic-authentication-issue. Has anyone been able to get either the basic authentication or another custom authentication extension working with Kafka connect when using more than one instance / worker? I'm using version 2.7.1 of Kafka and Kafka connect. Many Thanks, Jamie.