[Bug]: 404 on /api/v1/chat/completions

[Saboteur777]

Crust Version

2.1.0

Operating System

Linux

Area

Proxy

Bug Description

Trying to set up PhpStorm to use Crust as a proxy:

Connection works fine, as the model dropdowns are populated by the response from Crust.

Trying to use AI Assistant results in an error:

This is the stacktrace I got:

java.lang.IllegalStateException: Error from OpenAILLMClientExt API: 404 Not Found: Expected status code 200 but was 404
Body:

	at ai.koog.http.client.ktor.KtorKoogHttpClient$sse$1.invokeSuspend(KtorKoogHttpClient.kt:153)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:34)
	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:98)
	at com.intellij.openapi.application.impl.DispatchedRunnable.run(DispatchedRunnable.kt:42)
	at com.intellij.openapi.application.TransactionGuardImpl.runWithWritingAllowed(TransactionGuardImpl.java:239)
	at com.intellij.openapi.application.TransactionGuardImpl.access$100(TransactionGuardImpl.java:25)
	at com.intellij.openapi.application.TransactionGuardImpl$2.run(TransactionGuardImpl.java:221)
	at com.intellij.openapi.application.impl.NonBlockingFlushQueue.runNextEvent$lambda$1$1$0(NonBlockingFlushQueue.kt:334)
	at com.intellij.openapi.progress.impl.CoreProgressManager.computePrioritized(CoreProgressManager.java:901)
	at com.intellij.openapi.application.impl.NonBlockingFlushQueue.runNextEvent$lambda$1$1(NonBlockingFlushQueue.kt:333)
	at com.intellij.concurrency.ThreadContext.resetThreadContext(threadContext.kt:294)
	at com.intellij.openapi.application.impl.NonBlockingFlushQueue.runNextEvent$lambda$1(NonBlockingFlushQueue.kt:330)
	at com.intellij.platform.locking.impl.NestedLocksThreadingSupport.tryRunWriteIntentReadAction(NestedLocksThreadingSupport.kt:689)
	at com.intellij.openapi.application.impl.NonBlockingFlushQueue.runNextEvent(NonBlockingFlushQueue.kt:326)
	at com.intellij.openapi.application.impl.NonBlockingFlushQueue.flushNow(NonBlockingFlushQueue.kt:305)
	at com.intellij.openapi.application.impl.NonBlockingFlushQueue.FLUSH_NOW$lambda$0(NonBlockingFlushQueue.kt:167)
	at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:318)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:781)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:728)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:722)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:750)
	at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.kt:664)
	at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.kt:517)
	at com.intellij.ide.IdeEventQueue.dispatchEvent$lambda$0$0$0(IdeEventQueue.kt:333)
	at com.intellij.ide.IdeEventQueueKt.performActivity$lambda$1(IdeEventQueue.kt:1065)
	at com.intellij.openapi.application.TransactionGuardImpl.performActivity(TransactionGuardImpl.java:109)
	at com.intellij.ide.IdeEventQueueKt.performActivity(IdeEventQueue.kt:1065)
	at com.intellij.ide.IdeEventQueue.dispatchEvent$lambda$0(IdeEventQueue.kt:331)
	at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.kt:371)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:207)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
	at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:92)

The interesting here is the 404, which I found in the Crust logs:

09:59:04 [INFO] [proxy] POST /api/v1/chat/completions model=openai/gpt-5.2-codex → https://api.openai.com/api/v1/chat/completions status=404 duration=387.141886ms [stream-error]

It seems Crust routes these to https://api.openai.com/api/v1/chat/completions, but the correct URL is https://api.openai.com/v1/chat/completions (no /api/). I suspect this comes from the setup I did on PhpStorm, but omitting the /api/ part resulted in a failed connection.

I am not sure if this is IDEA product-related issue, so feel free to close it if unrelated.

Steps to Reproduce

1. Set up Crust in any IntelliJ IDEA product as OpenAI compatible provider.
2. Try to use AI Assistant.

Logs

09:59:04 [INFO] [proxy] POST /api/v1/chat/completions model=openai/gpt-5.2-codex → https://api.openai.com/api/v1/chat/completions status=404 duration=387.141886ms [stream-error]

[zhangchen-xu]

Hi!

Can you try using this endpoint: http:/[Your IP]:9090/v1 instead of http://[Your IP]:9090/api/v1 to see if this works? /v1 is our endpoint for openai-compatible LLMs. Thanks!

[Saboteur777]

In this case the connection fails:

An error message appears and the send button is disabled:

[cyyever]

I am investigating this issue.

[cyyever]

@Saboteur777 We have merged proper fixes into main. Check README for more info about PhpStorm . Welcome to reopen this issue if the fixes are incomplete.

[Saboteur777]

Thank you, but sadly now it doesn't work at all:

Logs seems to be good...:

23:52:35 [INFO] [proxy] GET /v1/models model= → https://openrouter.ai/v1/models status=200 duration=498.477334ms tokens=0/0 tools=0

...but in reality that's a 404:

[cyyever]

@Saboteur777 Hi, we have fixes for openroute on main branch. Can you try by building Crust docker using the main branch

docker build -t crust https://github.com/BakeLens/crust.git
docker run -p 9090:9090 crust --endpoint https://openrouter.ai/api

, and using the endpoint http://localhost:9090/v1?

[Saboteur777]

Thank you! The connection now works from the settings page, but the chat still errors out:

Failed to initialize ACP process. You're using a third-party AI provider.

To use Codex, set an OpenAI API key in "Settings | Tools | AI Assistant | Models and API keys", or disable the third-party provider (requires JetBrains AI or a ChatGPT account).

[cyyever]

The key issue is that PhpStorm's AI Chat requires an ACP agent (stdio), not an HTTP endpoint. Therefore, we have added ACP support. see the ACP setup guide (docs/acp.md) for step-by-step instructions on configuring Crust with PhpStorm and other ACP IDEs.