Add a function to reload the domain

Closes #357

Author: msanatan

MCPForUnity/Editor/Tools/ReloadDomain.cs

@@ -0,0 +1,35 @@
+using System;
+using MCPForUnity.Editor.Helpers;
+using Newtonsoft.Json.Linq;
+using UnityEditor;
+
+namespace MCPForUnity.Editor.Tools
+{
+    /// <summary>
+    /// Handles domain reload operations to refresh Unity's script assemblies.
+    /// This is essential after creating or modifying scripts to make new types available.
+    /// </summary>
+    [McpForUnityTool("reload_domain")]
+    public static class ReloadDomain
+    {
+        /// <summary>
+        /// Main handler for domain reload command.
+        /// Triggers Unity to reload all script assemblies, which is necessary after
+        /// script changes before new components can be used.
+        /// </summary>
+        public static object HandleCommand(JObject @params)
+        {
+            try
+            {
+                McpLog.Info("[ReloadDomain] Requesting domain reload");
+                EditorUtility.RequestScriptReload();
+                return Response.Success("Domain reload requested. Unity will recompile scripts and refresh assemblies.");
+            }
+            catch (Exception ex)
+            {
+                McpLog.Error($"[ReloadDomain] Error requesting domain reload: {ex.Message}");
+                return Response.Error($"Failed to request domain reload: {ex.Message}");
+            }
+        }
+    }
+}

MCPForUnity/UnityMcpServer~/src/server.py

@@ -168,8 +168,10 @@ def _emit_startup():
 - `manage_gameobject`: Manages GameObjects in the scene.\n
 - `manage_script`: Manages C# script files.\n
 - `manage_asset`: Manages prefabs and assets.\n
-- `manage_shader`: Manages shaders.\n\n
-- Tips:\n
+- `manage_shader`: Manages shaders.\n
+- `reload_domain`: Triggers Unity domain reload to recompile scripts and refresh assemblies.\n\n
+Tips:\n
+- Always reload the domain after creating or modifying scripts before attempting to use them. Use `reload_domain` immediately after script changes, then check `read_console` for compile errors.\n
 - Create prefabs for reusable GameObjects.\n
 - Always include a camera and main light in your scenes.\n
 - Unless specified otherwise, paths are relative to the project's `Assets/` folder.\n

MCPForUnity/UnityMcpServer~/src/tools/reload_domain.py

@@ -0,0 +1,24 @@
+from fastmcp import Context
+from models import MCPResponse
+from registry import mcp_for_unity_tool
+from unity_connection import async_send_command_with_retry
+
+
+@mcp_for_unity_tool(
+    description="Trigger a Unity domain reload to recompile scripts and refresh assemblies. Essential after creating or modifying scripts before new components can be used."
+)
+async def reload_domain(ctx: Context) -> MCPResponse:
+    """
+    Request Unity to reload its domain (script assemblies).
+    This is necessary after:
+
+    - Creating new C# scripts
+    - Modifying existing scripts
+    - Before attempting to add new components to GameObjects
+
+    Returns immediately after triggering the reload request.
+    Unity will handle the actual recompilation asynchronously.
+    """
+    await ctx.info("Requesting Unity domain reload")
+    result = await async_send_command_with_retry("reload_domain", {})
+    return MCPResponse(**result) if isinstance(result, dict) else result

Server/server.py

@@ -168,8 +168,10 @@ def _emit_startup():
 - `manage_gameobject`: Manages GameObjects in the scene.\n
 - `manage_script`: Manages C# script files.\n
 - `manage_asset`: Manages prefabs and assets.\n
-- `manage_shader`: Manages shaders.\n\n
-- Tips:\n
+- `manage_shader`: Manages shaders.\n
+- `reload_domain`: Triggers Unity domain reload to recompile scripts and refresh assemblies.\n\n
+Tips:\n
+- Always reload the domain after creating or modifying scripts before attempting to use them. Use `reload_domain` immediately after script changes, then check `read_console` for compile errors.\n
 - Create prefabs for reusable GameObjects.\n
 - Always include a camera and main light in your scenes.\n
 - Unless specified otherwise, paths are relative to the project's `Assets/` folder.\n

Server/tools/reload_domain.py

@@ -0,0 +1,24 @@
+from fastmcp import Context
+from models import MCPResponse
+from registry import mcp_for_unity_tool
+from unity_connection import async_send_command_with_retry
+
+
+@mcp_for_unity_tool(
+    description="Trigger a Unity domain reload to recompile scripts and refresh assemblies. Essential after creating or modifying scripts before new components can be used."
+)
+async def reload_domain(ctx: Context) -> MCPResponse:
+    """
+    Request Unity to reload its domain (script assemblies).
+    This is necessary after:
+
+    - Creating new C# scripts
+    - Modifying existing scripts
+    - Before attempting to add new components to GameObjects
+
+    Returns immediately after triggering the reload request.
+    Unity will handle the actual recompilation asynchronously.
+    """
+    await ctx.info("Requesting Unity domain reload")
+    result = await async_send_command_with_retry("reload_domain", {})
+    return MCPResponse(**result) if isinstance(result, dict) else result