Exception during Client initialization: : Session $ID$ not found

[erokhins]

com.agentclientprotocol.protocol.AcpExpectedError: Session 019a25b1-615f-7310-8b93-f8f0d60ee988 not found
	at com.agentclientprotocol.protocol.ProtocolKt.acpFail(Protocol.kt:40)
	at com.agentclientprotocol.client.Client.getSessionOrThrow-0izbxq0(Client.kt:132)
	at com.agentclientprotocol.client.Client.access$getSessionOrThrow-0izbxq0(Client.kt:34)
	at com.agentclientprotocol.client.Client$2.invokeSuspend(Client.kt:48)
	at com.agentclientprotocol.client.Client$2.invoke(Client.kt)
	at com.agentclientprotocol.client.Client$2.invoke(Client.kt)
	at com.agentclientprotocol.client.Client$special$$inlined$setNotificationHandler$default$1.invokeSuspend(Protocol.extensions.kt:65)
	at com.agentclientprotocol.client.Client$special$$inlined$setNotificationHandler$default$1.invoke(Protocol.extensions.kt)

Related messages:

{"type":"com.agentclientprotocol.rpc.JsonRpcRequest","id":1,"method":"initialize","params":{"protocolVersion":1,"clientCapabilities":{"fs":{"readTextFile":true,"writeTextFile":true},"terminal":false}},"jsonrpc":"2.0"}
{"jsonrpc":"2.0","id":1,"result":{"protocolVersion":1,"agentCapabilities":{"loadSession":false,"promptCapabilities":{"image":true,"audio":false,"embeddedContext":true},"mcpCapabilities":{"http":false,"sse":false}},"authMethods":[{"id":"chatgpt","name":"Login with ChatGPT","description":"Use your ChatGPT login with Codex CLI (requires a paid ChatGPT subscription)"},{"id":"codex-api-key","name":"Use Codex API Key","description":"Requires setting the `CODEX_API_KEY` environment variable."},{"id":"openai-api-key","name":"Use OpenAI API Key","description":"Requires setting the `OPENAI_API_KEY` environment variable."}]}}
{"type":"com.agentclientprotocol.rpc.JsonRpcRequest","id":2,"method":"authenticate","params":{"methodId":"openai-api-key"},"jsonrpc":"2.0"}
{"jsonrpc":"2.0","id":2,"result":{}}
{"type":"com.agentclientprotocol.rpc.JsonRpcRequest","id":3,"method":"session/new","params":{"cwd":"/home/erokhins/IdeaProjects/Test","mcpServers":[]},"jsonrpc":"2.0"}
{"jsonrpc":"2.0","id":3,"result":{"sessionId":"019a25b1-615f-7310-8b93-f8f0d60ee988","modes":{"currentModeId":"read-only","availableModes":[{"id":"read-only","name":"Read Only","description":"Codex can read files and answer questions. Codex requires approval to make edits, run commands, or access network"},{"id":"auto","name":"Auto","description":"Codex can read files, make edits, and run commands in the workspace. Codex requires approval to work outside the workspace or access network"},{"id":"full-access","name":"Full Access","description":"Codex can read files, make edits, and run commands with network access, without approval. Exercise caution"}]},"models":{"currentModelId":"gpt-5-codex-medium","availableModels":[{"modelId":"gpt-5-codex-low","name":"gpt-5-codex low","description":"Fastest responses with limited reasoning"},{"modelId":"gpt-5-codex-medium","name":"gpt-5-codex medium","description":"Dynamically adjusts reasoning based on the task"},{"modelId":"gpt-5-codex-high","name":"gpt-5-codex high","description":"Maximizes reasoning depth for complex or ambiguous problems"},{"modelId":"gpt-5-minimal","name":"gpt-5 minimal","description":"Fastest responses with little reasoning"},{"modelId":"gpt-5-low","name":"gpt-5 low","description":"Balances speed with some reasoning; useful for straightforward queries and short explanations"},{"modelId":"gpt-5-medium","name":"gpt-5 medium","description":"Provides a solid balance of reasoning depth and latency for general-purpose tasks"},{"modelId":"gpt-5-high","name":"gpt-5 high","description":"Maximizes reasoning depth for complex or ambiguous problems"}]}}}
{"jsonrpc":"2.0","method":"session/update","params":{"sessionId":"019a25b1-615f-7310-8b93-f8f0d60ee988","update":{"sessionUpdate":"available_commands_update","availableCommands":[{"name":"review","description":"Review my current changes and find issues","input":{"hint":"optional custom review instructions"}},{"name":"review-branch","description":"Review the code changes against a specific branch","input":{"hint":"branch name"}},{"name":"review-commit","description":"Review the code changes introduced by a commit","input":{"hint":"commit sha"}},{"name":"init","description":"create an AGENTS.md file with instructions for Codex","input":null},{"name":"compact","description":"summarize conversation to prevent hitting the context limit","input":null},{"name":"logout","description":"logout of Codex","input":null}]}}}
{"type":"com.agentclientprotocol.rpc.JsonRpcRequest","id":4,"method":"session/set_mode","params":{"sessionId":"019a25b1-615f-7310-8b93-f8f0d60ee988","modeId":"auto"},"jsonrpc":"2.0"}
{"jsonrpc":"2.0","id":4,"result":{"meta":null}}
{"type":"com.agentclientprotocol.rpc.JsonRpcRequest","id":5,"method":"session/prompt","params":{"sessionId":"019a25b1-615f-7310-8b93-f8f0d60ee988","prompt":[{"type":"text","text":"Tell me about coroutines"},{"type":"resource_link","name":"Main.kt","uri":"/home/erokhins/IdeaProjects/Test/src/Main.kt"},{"type":"resource_link","name":"Main.kt","uri":"/home/erokhins/IdeaProjects/Test/src/Main.kt"}]},"jsonrpc":"2.0"}

[erokhins]

This exception happenning inside IDEA ACP support, curretly investigating is it a SDK problem or not

[erokhins]

So, the problem is indeed inside the SDK. Let's take a look at session initialization method:
Session is initialized inside the com.agentclientprotocol.client.Client#newSession and it is suspend function, that are running in some used-defined coroutine scope.
And requests are handled in the com.agentclientprotocol.protocol.Protocol#handleIncomingMessage and the requests are handled in the different coroutine scope:

requestsScope.launch {
    handleRequest(message)
}

So it is triggered in parallel with newSession => we have this exception.

[erokhins]

Still reproducing on 0.6.0