Visual Studio C# Dev Workflow

A local MCP workflow for AI-assisted C# development in Visual Studio. It combines a host-neutral .NET MCP server with a Visual Studio VSIX bridge backed by Roslyn and the Visual Studio debugger.

What it provides

• Workspace preparation for .sln and .slnx solutions.
• Compact source context, symbol navigation, references, call graphs, and impact analysis.
• Scoped diagnostics and build-failure triage designed to suppress unrelated solution noise.
• Repository-specific diagnostic noise can be configured in .csharp-workflow.json; project directory names are not embedded in the tool.
• Change review, related-test discovery, and focused verification planning.
• Preview-first rename, cleanup, Code Fix, and Fix All workflows.
• Debugger context and explicit debug controls.
• MCP resources for deferred evidence, reducing repeated output and model context usage.

The current MCP schema exposes 96 tools and 15 resource templates. Use get_csharp_workflow_capabilities for local task-based discovery and get_csharp_operation_status to reconcile interrupted operations without replaying them.

Architecture

Codex / Claude Code / DeepSeekHarness
                |
          MCP stdio server
                |
        named-pipe bridge
                |
       Visual Studio VSIX
                |
 Roslyn / Debugger / Output / Error List

The VSIX is the only component that accesses Visual Studio in-process APIs. Client integrations share the same MCP runtime and do not duplicate C# analysis logic.

Client support

Client	Status
Codex	Supported through the packaged plugin and workflow skill
DeepSeekHarness	Supported through a Cordis patch integration; see integrations/deepseek-harness/
Claude Code	MCP configuration is provided; clean-environment smoke testing is pending

The distribution zip carries one shared MCP runtime, one VSIX, and two host installers: Install-CodexPlugin.ps1 and Install-DshMcpServer.ps1.

See integrations/ for configuration templates and support levels.

Build and test

Requirements:

• Windows
• Visual Studio 2022 or later with C# development tools
• .NET 8 SDK

dotnet restore .\VisualStudio.CSharpNavigatorMcp.sln
dotnet build .\VisualStudio.CSharpNavigatorMcp.sln -c Release --no-restore
dotnet test .\tests\VisualStudio.CSharpNavigator.Server.Tests\VisualStudio.CSharpNavigator.Server.Tests.csproj -c Release --no-build --no-restore

Publish the host-neutral MCP runtime:

powershell -NoProfile -ExecutionPolicy Bypass -File .\scripts\Publish-McpServerRuntime.ps1 -Configuration Release

Generate a client configuration snippet without overwriting user settings:

powershell -NoProfile -ExecutionPolicy Bypass -File .\scripts\New-McpClientConfiguration.ps1 -ClientHost DeepSeekHarness -ServerExe <absolute-server-exe-path> -OutputPath .\visual-studio-csharp-navigator.cordis.patch.yml

Build the dual-host distribution zip:

powershell -NoProfile -ExecutionPolicy Bypass -File .\scripts\New-VisualStudioCSharpNavigatorDistribution.ps1 -Version 0.2.0

Workspace diagnostics configuration

Copy .csharp-workflow.example.json to .csharp-workflow.json at the repository root when a solution contains known noisy legacy or generated directories. Patterns are applied only to that workspace and are combined with the built-in generic bin, obj, generated, vendor, and package rules. Use noiseProfile=Off for a complete audit.

Safety model

Read-only task-level tools are preferred. Source mutations use preview/apply sessions with candidate identity, workspace version checks, and blockers. Debug controls and Visual Studio startup are explicit side effects. VSIX installation is never performed silently.

Documentation

• Agentic workflow architecture
• Multi-host distribution architecture
• Client integrations
• Contributing
• Security policy

License

Licensed under the Apache License 2.0.