ConnectFailure occurs during the building C# code in Unity.

[And165KMT]

mcp calls script when the server is not accepting connections (such as during compilation), the process is interrupted. Is there a way to avoid it, such as by waiting?

Use VSCode Copilot Agent

Error Code
Failed to ensure server installation: Error: ConnectFailure (接続済みの呼び出し先が一定の時間を過ぎても正しく応答しなかったため、接続できませんでした。または接続済みのホストが応答しなかったため、確立された接続は失敗しました。

UnityEngine.Debug:LogError (object)
UnityMcpBridge.Editor.Helpers.ServerInstaller:EnsureServerInstalled () (at ./Library/PackageCache/com.justinpbarnett.unity-mcp@cbe9b3a2f0/Editor/Helpers/ServerInstaller.cs:48)
UnityMcpBridge.Editor.UnityMcpBridge:Start () (at ./Library/PackageCache/com.justinpbarnett.unity-mcp@cbe9b3a2f0/Editor/UnityMcpBridge.cs:63)
UnityMcpBridge.Editor.UnityMcpBridge:.cctor () (at ./Library/PackageCache/com.justinpbarnett.unity-mcp@cbe9b3a2f0/Editor/UnityMcpBridge.cs:53)
UnityEditor.EditorAssemblies:ProcessInitializeOnLoadAttributes (System.Type[])

[CoderGamester]

unfortunately no @And165KMT
Unity doesn't run any code while compiling.
This means the websocket will be closed and requires reconnection by the Node.JS server.

The Node.JS server is already waiting for reply for 10sec to allow cases where the Unity's main thread is on hold to then execute the code, but situations like compile block are not possible to solve with Unity in it's current form

[syntagmastudios]

Today im experiencing the Server being closed every 3 minutes resulting in having to close vcode and start again. Its happening when AI is modifiying a script.

[CoderGamester]

I see, that is a bad workflow to work on
Will look into improve it

[CoderGamester]

@syntagmastudios I just pushed a fix for this issue with version 1.0.1
Please check it out if it improves your workflow

[syntagmastudios]

Thanks I'll test this right away!

…

On Fri, Apr 25, 2025, 5:00 PM Miguel Tomas ***@***.***> wrote: *CoderGamester* left a comment (CoderGamester/mcp-unity#18) <#18 (comment)> @syntagmastudios <https://github.com/syntagmastudios> I just pushed a fix for this issue with version 1.0.1 Please check it out if it improves your workflow — Reply to this email directly, view it on GitHub <#18 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BK5U4VLISFE7FQM7LDSI25323I5XLAVCNFSM6AAAAAB3CD6XRSVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDQMZQGUZDAMZWGM> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[nowsprinting]

Hi @CoderGamester , I'm very excited about this feature!

I tried v1.0.1.
When I edited the code in IDE (Rider). Unity finishes building in the background, the bridge server still shows "Server Offline". It remained like this unless I moved focus to the Unity editor.
Of course, Can't connect from the MCP server.

When the build finished, the method with the [InitializeOnLoadMethod] attribute was called.
Can you restart the server at this point?

[CoderGamester]

@nowsprinting that is what is happening
the Unity websocket Server automatically restarts

Now, the Node.JS MCP server will automatically reconnect the websocket after invoking another prompt call

[CoderGamester]

#25 approved and merged
closing the issue