question NiFi WebSocket Headers in Support Questions

NiFi WebSocket Headers

jacektrocinski — Tue, 21 Apr 2026 07:45:30 GMT

I need to pass headers in order make a WebSocket connection.

How can I do this in NiFi?

Re: NiFi WebSocket Headers

ckumar — Tue, 17 Jan 2023 11:01:35 GMT

You can use InvokeHTTP processor wich provide options to handle Header

Thank you

Re: NiFi WebSocket Headers

jacektrocinski — Tue, 17 Jan 2023 12:00:08 GMT

@ckumar No, that won't work, I'm trying to invoke a WebSocket URL: wss://api.gemini.com/v1/order/events

InvokeHTTP can't create WebSocket connections.

Re: NiFi WebSocket Headers

ckumar — Tue, 17 Jan 2023 12:04:36 GMT

Ah my bad, for the WebSocket end point did you try ConnectWebSocket ?

Re: NiFi WebSocket Headers

jacektrocinski — Tue, 17 Jan 2023 12:15:15 GMT

@ckumar Yes, I am using ConnectWebSocket but how do I pass a custom header like X-GEMINI-APIKEY to the initial connection?

Re: NiFi WebSocket Headers

jacektrocinski — Tue, 17 Jan 2023 12:29:32 GMT

Here's the way to do it:

Connect GenerateFlowFile processor (with FF attributes) to ConnectWebSocket.

https://nifi.apache.org/docs/nifi-docs/components/org.apache.nifi/nifi-websocket-processors-nar/1.19.1/org.apache.nifi.processors.websocket.ConnectWebSocket/additionalDetails.html

Re: NiFi WebSocket Headers

ckumar — Tue, 17 Jan 2023 13:58:39 GMT

ConnectWebSocket does not read any details from Flow file attribute from an incoming flow file.

If you are a Cloudera customer, feel free to file a support ticket with us, we should be able to help you on this with a longer engagement.

Thank you

Re: NiFi WebSocket Headers

jacektrocinski — Wed, 18 Jan 2023 09:15:29 GMT

@ckumar That is incorrect, the ConnectWebSocket reads attributes from an incoming flow file.

It is also in the documentation that I posted:

https://nifi.apache.org/docs/nifi-docs/components/org.apache.nifi/nifi-websocket-processors-nar/1.19.1/org.apache.nifi.processors.websocket.ConnectWebSocket/additionalDetails.html

I contacted a Cloudera NiFi expert and he confirmed.

The solution I posted is correct.

Re: NiFi WebSocket Headers

ckumar — Wed, 18 Jan 2023 09:26:42 GMT

@jacektrocinski Yes, Sir, you are right, I put more focus on read attribute section of the document which has none but missed seeing Additional details.

Kudos!!