Program.cs

using System.Runtime.InteropServices;
using Ardalis.GuardClauses;
using PolyType.SourceGenerator;
using SharpIDE.MsBuildHost;
using SharpIDE.MsBuildHost.Contracts;
using StreamJsonRpc;

var sdkVersion = args[0];
Guard.Against.NullOrWhiteSpace(sdkVersion);
var projectOrSlnDirectory = new DirectoryInfo(args[1]);
if (projectOrSlnDirectory.Exists is false) throw new DirectoryNotFoundException($"Project or sln directory '{projectOrSlnDirectory.FullName}' does not exist.");

SharpIdeMsbuildLocator.Register(sdkVersion, projectOrSlnDirectory.FullName);

if (args.Contains("--diag"))
{
	Console.WriteLine($"'{RuntimeInformation.FrameworkDescription}' Runtime, MSBuild from SDK: '{SharpIdeMsbuildLocator.ResolvedMsBuildSdkPath}'");
}

var inputStream = Console.OpenStandardInput();
var outputStream = Console.OpenStandardOutput();

var handler = new LengthHeaderMessageHandler(outputStream, inputStream, new NerdbankMessagePackFormatter { TypeShapeProvider = TypeShapeProvider_SharpIDE_MsBuildHost_Contracts.Default });
var rpc = new JsonRpc(handler);

rpc.AddLocalRpcTarget<IRpcBuildService>(new RpcBuildService(), null);

rpc.StartListening();

await rpc.Completion;