The result is very good!, and the speed is good too.The only thing I don’t fully understand is why MCP works like a CLI emulation. What I mean is that, in practice, the command relay\relay_win.exe is executed, not a real MCP server. So, effectively, this is already a CLI, not MCP.
Although CLI is even better than MCP.
One thing I would add is support for connecting additional agents not through API keys, but through browser-based authentication.Here is a good example of how such integrations are done with OpenAI: GitHub - AndreySkyFoxSidorov/UnityOpenAIConnector · GitHub
Here is what I got from comparing Unity MCP with the tools I’m currently using:
Direct = has a typed/direct command or MCP tool.
Via C# = possible through generic C# execution.
Partial = some coverage, but not complete or not first-choice.
It feels like no-one from the AI team is listening, but making the Unity AI MCP server subscription only seems like a step backwards. If it’s not costing you money to run it why are you charging me extra for it? Unity has already fallen far behind by not providing this until they were dragged kicking and screaming by the community and it’s clear whoever is making the decisions doesn’t see how this is going to affect Unity AI as a whole.
If MCP isn’t universally available on release then I’ll be uninstalling Unity AI and that’s it. I (and many others who aren’t willing to pay right now ) will be moving to a different solution like Coplay (or just letting AI do raw file editing) and Unity will have lost its chance to make a foothold or create a foundation that other solutions could build from. When I want to spend money on tokens I wont be going back to Unity AI, I’ll be spending it with Coplay or whatever other solution I end up using.
I have a Unity Industry subscription, and everything works well for me. But I also have a personal project where I help students build an indie game when I have free time.
The problem is that the guys are using the free version, and MCP throws an error for them. So for now, we had to stick with open-source connector versions.
For some reason when I use ask mode, it uses a crap ton of credits and a lot of time to answer a simple question. Both Plan and Agent use less and seem more accurate
Yes, it feels very strange for Unity as a company to make MCP paid.
I hope Unity separates MCP from AI tokens.
Right now, most software vendors are doing the opposite - they are adding free MCP support so they don’t fall behind in the software race.
There is also huge competition in the Unity MCP market. There are already around 10 decent MCP/CLI tools for Unity. If there are free, fully working alternatives, why wouldn’t people use them?
But overall, I like that Unity has started moving in this direction. That’s very good.
After you got everything set up, how long did you have to wait? I’m running into the same issue. It’s already been two hours since I finished setting everything up, so crazy!
Hey guys, considering you have so many agents supported, there is one that is widely used by a lot (more than some of the options provided) which is droid by factoryai https://docs.factory.ai/welcome its similar to claude code’s structure so it should be quite easy to integrate, it’s also been in the industry for a while so it’s not something that’ll go away overnight. https://x.com/FactoryAI
It’s hit and miss, it works, then it doesn’t, for seemingly no reason.
I waited about 20 minutes and restarted multiple times, every time I restarted unity I had to re allow the mcp.
Eventually, the stars aligned, and it started working, but it is not working again. I’m giving up.
Immediately after updating the package to 2.8, I got two errors from the package:
Library\PackageCache\com.unity.ai.assistant@667f49aff9c0\Modules\Unity.AI.Pbr\Srp\SrpUtilities.cs(8,13): error CS0103: The name ‘Generators’ does not exist in the current context
Library\PackageCache\com.unity.ai.assistant@667f49aff9c0\Modules\Unity.AI.Generators.IO\Utilities\MeshProcessorJob.cs(3,30): error CS0234: The type or namespace name ‘Srp’ does not exist in the namespace ‘Unity.AI.Generators.IO’ (are you missing an assembly reference?)
This is in a project that uses the built-in render pipeline. Clearing the console does not clear the errors; however, they go away after closing and re-opening the project.
Library\PackageCache\com.unity.ai.assistant@667f49aff9c0\Editor\Assistant\FunctionCalling\Permissions\SettingsPermissionsPolicyProvider.cs(101,53): error UAC0007: Assembly.Location returns "" in Unity as assemblies are loaded from stream. Use extension method 'Assembly.GetLoadedAssemblyPath()' instead.
and
Library\PackageCache\com.unity.ai.assistant@667f49aff9c0\Editor\Assistant\CodeAnalyze\DynamicAssemblyBuilder.cs(191,20): error UAC0020: System.Reflection.Assembly.Load(byte[]) loads assembly into non-Unity AssemblyLoadContext and is not supported. Use Unity API instead.
so in true me form, i uninstalled it and cancelled the free trial, if it cant be used its just rude the timer would count down
I think I’m going a bit mad. I’ve used package manager to install Unity AI. I can see it in Project Settings. I can see on dashboard it’s turned on. However
in project settings → AI->gateway I use dropdown to select Codex, but when move to another of this tab and go back it’s went back to Clude.
No AI shows up on my editor bar
I’ve enabled Assitant MCP exentions and Gateway
I’m on pro account for Unity and ChatGPT. I’m using Linux 6.3 LTS.
I think I’m missing something but don’t know what. Thanks
MCP seems to be broken in 2.8.0. I’m testing with Claude. MCP Server is enabled, I have most of the Tools enabled, integration is enabled for both Claude Code and Claude Desktop, and Claude shows as a connected client. However, every MCP request returns
{
“success”: false,
“error”: “Connection revoked. Go to Unity Editor > Project Settings > AI > Unity MCP to change approval.”
}
I’ve tried turning the bridge off and on but this doesn’t have any effect. I’m not sure what else to try.
EDIT: I reverted to 2.7.0-pre.3 and MCP works again.
