Unity plugin DLLs

Assets/Plugins/Core/*.dll (and *.deps.json) are not committed. Unity consumes them as local build output. Before touching the Editor, MCP, or any Unity-side asset/script, make sure those DLLs exist and are current, and that any Unity MCP instance you will call is this checkout.

When (mandatory)

Run this skill before the first Unity action in the session, whenever the task will:

• use Unity MCP (refresh_unity, manage_scene, manage_gameobject, read_console, execute_code, …)
• edit Assets/Scripts/, scenes, prefabs, UXML/USS, or ScriptableObjects
• run the unity-e2e-run skill
• otherwise need the Editor to compile against src/ types

Skip only when the work is purely src/ / docs / scripts and will not open or drive Unity.

Unattended issue automation with no Editor still runs this if the run will execute /dotnet-build Release for Unity-consumed types; it is cheap when up to date.

Steps

1. From the project root (no cd), run python scripts/unity/ensure_plugin_dlls.py (prefer .venv\Scripts\python.exe when that venv is present).
2. Read the command output:
   • UP_TO_DATE: — continue.
   • REBUILDING: / REBUILT: — continue. If Unity MCP will be used, pin this checkout first (next section), then refresh_unity and read_console(types=["error"]).
   • non-zero exit — read .tmp/dotnet-build.log (the script writes it) and stop. Do not start Unity work on missing/stale plugins.
3. Do not git add anything under Assets/Plugins/Core/ except newly authored *.dll.meta files for a brand-new plugin assembly. Never commit *.dll, *.pdb, *.deps.json, or *.xml from that folder.

Once per session: pin Unity MCP to this checkout

Do this once before the first Unity MCP tool or resource call in the session — including refresh_unity after a rebuild. Skip when MCP will not be used (DLL-only ensure, or unattended automation with no Editor).

Every GlobalStrategy clone and git worktree usually appears as instance name GlobalStrategy. Name is not identity. Drive only the Editor whose project root is this workspace.

1. Read mcpforunity://instances. If empty: interactive work stops and asks the user to open this checkout in Unity; unattended automation skips MCP as today.
2. For each instance: set_active_instance, then read the project path — prefer mcpforunity://project/info (assetsPath / project path if present), otherwise execute_code returning Application.dataPath. That identity probe is the only MCP call allowed before a match.
3. Unity project root is the parent of .../Assets. Compare it to this workspace root after normalizing separators and, on Windows, case. Keep the matching instance pinned.
4. If none match: stop. Report the connected path versus this workspace. Do not refresh_unity, edit scenes or assets, or otherwise interact. Ask the user to open this checkout in the Editor. Do not close or switch their other Editor for them.

After src/ edits

This skill does not replace the standing /dotnet-build Release requirement in .claude/rules/workflow.md. After changing src/, still Release-build (the ensure script will no-op if it already did). Still do not commit the DLLs.

Editor-side counterpart

Opening Unity also regenerates missing/stale DLLs via Assets/Scripts/Editor/PluginDlls/PluginDllRegenerator.cs. Do not wait on that instead of this skill — agents must ensure plugins before they start Editor work. Manual force: GS/Plugins/Regenerate Core DLLs.