# DPC Streaming agent: Websocket getting HTTP 400

**URL:** <https://matillioncommunity.discourse.group/t/dpc-streaming-agent-websocket-getting-http-400/3416>\
**Category:** Maia\
**Tags:** maia\
**Created:** [September 15, 2025, 4:07pm UTC](https://matillioncommunity.discourse.group/t/dpc-streaming-agent-websocket-getting-http-400/3416 "2025-09-15T16:07:38Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![altinturk](https://sea2.discourse-cdn.com/flex002/user_avatar/matillioncommunity.discourse.group/altinturk/32/1193_2.png) [@altinturk](https://matillioncommunity.discourse.group/u/altinturk)\
**Post date:** [September 15, 2025, 4:07pm UTC](https://matillioncommunity.discourse.group/t/dpc-streaming-agent-websocket-getting-http-400/3416/1 "2025-09-15T16:07:38Z")

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Platform: Azure, DPC/Streaming.

State: Streaming agent is using the same container image, so we reused the terraform image agent for CDC with slight modifications. Container image started but not communicating with DPC.

Error:  
PlatformWebsocketConfiguration : Failed to send heartbeat

```auto
2025-09-15T09:51:33.400Z WARN 20 --- [parallel-1] m.n.a.p.w.PlatformWebsocketConfiguration : Failed to send heartbeat

java.util.concurrent.ExecutionException: jakarta.websocket.DeploymentException: The HTTP response from the server [400] did not permit the HTTP upgrade to WebSocket
	at java.base/java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:396) ~[na:na]
...

```

Reviewing updated ARM/ACI templates, I haven’t seen any websocket endpoint specified. Nor the “agent creation page” indicates a web socket url to be specified.  
is this PLATFORM\_WEBSOCKET\_ENDPOINT variable not used anymore?  
what’s causing http 400?

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<div class="post-metadata">

**Author:** ![altinturk](https://sea2.discourse-cdn.com/flex002/user_avatar/matillioncommunity.discourse.group/altinturk/32/1193_2.png) [@altinturk](https://matillioncommunity.discourse.group/u/altinturk)\
**Post date:** [September 17, 2025, 8:03am UTC](https://matillioncommunity.discourse.group/t/dpc-streaming-agent-websocket-getting-http-400/3416/2 "2025-09-17T08:03:18Z")

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well, problem solved: check your existing variables in the container group, and remove platform websocked endpoint (if you’re using an older template as i did).  
it’s running now, without that environment variable.