ArcGisProMcpSample/
+- ArcGisProBridgeAddIn/           # ArcGIS Pro Add-In project (in-process)
¦  +- Config.daml
¦  +- Module.cs
¦  +- ProBridgeService.cs          # Named Pipe server + command handler
¦  +- IpcModels.cs                 # IPC request/response DTOs
+- ArcGisMcpServer/                # MCP server project (.NET 8)
¦  +- Program.cs
¦  +- Tools/ProTools.cs            # MCP tool definitions (bridge client)
¦  +- Ipc/BridgeClient.cs          # Named Pipe client
¦  +- Ipc/IpcModels.cs             # Shared IPC DTOs
+- .mcp.json                       # MCP server manifest for VS Copilot

protected override bool Initialize()
{
    _service = new ProBridgeService("ArcGisProBridgePipe");
    _service.Start();
    return true; // initialization successful
}

protected override bool CanUnload()
{
    _service?.Dispose();
    return true;
}

case "pro.countFeatures":
{
    if (req.Args == null ||
        !req.Args.TryGetValue("layer", out string? layerName) ||
        string.IsNullOrWhiteSpace(layerName))
        return new(false, "arg 'layer' required", null);

    int count = await QueuedTask.Run(() =>
    {
        var fl = MapView.Active?.Map?.Layers
            .OfType()
            .FirstOrDefault(l => l.Name.Equals(layerName, StringComparison.OrdinalIgnoreCase));
        if (fl == null) return 0;
        using var fc = fl.GetFeatureClass();
        return (int)fc.GetCount();
    });

    return new(true, null, new { count });
}

await Host.CreateDefaultBuilder(args)
    .ConfigureServices(services =>
    {
        services.AddSingleton(new BridgeClient("ArcGisProBridgePipe"));
        services.AddMcpServer()
            .WithStdioServerTransport()
            .WithToolsFromAssembly(typeof(ProTools).Assembly);
    })
    .RunConsoleAsync();

[McpServerToolType]
public static class ProTools
{
    private static BridgeClient _client;
    public static void Configure(BridgeClient client) => _client = client;

    [McpServerTool(Title = "Count features in a layer", Name = "pro.countFeatures")]
    public static async Task CountFeatures(string layer)
    {
        var r = await _client.OpAsync("pro.countFeatures", new() { ["layer"] = layer });
        if (!r.Ok) throw new Exception(r.Error);
        var count = ((System.Text.Json.JsonElement)r.Data).GetProperty("count").GetInt32();
        return new { layer, count };
    }
}

{
  "servers": {
    "arcgis": {
      "type": "stdio",
      "command": "dotnet",
      "args": [
        "run",
        "--project",
        "McpServer/ArcGisMcpServer/ArcGisMcpServer.csproj"
      ]
    }
  }
}