VS MCP Server

Model Context Protocol (MCP) server for Visual Studio — Enables AI agents like Claude Code to control Visual Studio features including debugging, building, editing, and UI automation.

This is a beta release. Feedback and bug reports are welcome on GitHub Issues.

100% AI Generated — All code in this project was generated entirely by AI (Claude).

Features

VS MCP Server exposes 115 tools across the following categories:

Category	Tools	Description
General	7	Execute VS commands, get IDE status, view tool help, toggle focus guard, audit foreground transitions
Solution & Project	5	Open/close solutions, list/inspect projects
Build	6	Build solution/project, clean, rebuild, get build errors, switch configuration
Editor	7	Open/close/read/write/edit files, find in files
Edit Preview	4	Diff preview, approve/reject edits with VS diff viewer
Code Navigation	3	Go to definition, find references, go to implementation
Solution Explorer	6	Add/remove projects, files, and references
Debugger	13	Start/stop/restart, attach, stepping, call stack, locals, threads, evaluate, run without debugging
Breakpoints	4	Set/remove/list, enable/disable breakpoints
Output & Diagnostics	5	Read/write/clear output panes, error list, XAML binding errors
Console	3	Read console output, send input/keys, get console info for debugged apps
UI Automation	10	Capture screenshots, inspect UI trees, find/click/right-click/drag/invoke elements
Web	12	Browser automation via Chrome CDP and Firefox RDP — navigation, DOM, console, network, screenshots
Test	3	Discover, run, and view test results
NuGet	5	Search, install, update, remove NuGet packages
Advanced Debug	20	Watch, thread/process management, immediate window, registers, memory, parallel stacks

Tool Details

General

Tool	Description
execute_command	Execute a Visual Studio command by name
get_status	Get the current Visual Studio status including solution state, active document, and debugger mode
get_help	Get a categorized list of all available vs-mcp tools with descriptions
focus_guard_get	Get whether the focus guard is currently on
focus_guard_set	Turn the focus guard on or off — when on, MCP-driven builds, output writes, and debug launches do not steal foreground focus from the currently focused application, and VS is kept minimized across debug_start if it was already minimized
focus_guard_audit_read	Read recent foreground-window transitions from a bounded ring buffer — each entry names the process/window that gained (and lost) foreground, with timestamp and whether the guard was on. Use this to identify what actually stole focus.
focus_guard_audit_clear	Clear the buffered foreground-transition events so a subsequent audit read starts from a clean slate

Solution

Tool	Description
solution_open	Open a solution or project file in Visual Studio
solution_close	Close the current solution
solution_info	Get information about the currently open solution

Project

Tool	Description
project_list	List all projects in the current solution
project_info	Get detailed information about a specific project

Build

Tool	Description
build_solution	Build the entire solution (auto-stops debugger if active)
build_project	Build a specific project (auto-stops debugger if active)
clean	Clean the solution build output (auto-stops debugger if active)
rebuild	Clean and rebuild the entire solution (auto-stops debugger if active)
get_build_errors	Get the list of build errors and warnings from the Visual Studio Error List
build_configuration	Get or set the active solution build configuration and platform (e.g. Debug/Release, Any CPU/x64)

Editor

Tool	Description
file_open	Open a file in the Visual Studio editor
file_close	Close a file in the editor
file_read	Read the contents of a file with optional line range
file_write	Write content to a file, replacing its entire contents
file_edit	Edit a file by replacing a specific text occurrence with new text
get_active_document	Get information about the currently active document in the editor
find_in_files	Search for text in files within the solution

Edit Preview

Tool	Description
edit_preview	Show a diff preview of proposed changes in VS and create a pending edit for approval
edit_approve	Approve a pending edit and apply the changes to the file
edit_reject	Reject a pending edit and discard the changes
edit_list_pending	List all pending edit previews with their status

Code Navigation

Tool	Description
code_goto_definition	Navigate to the definition of a symbol at the specified position
code_find_references	Find all references of a symbol at the specified position
code_goto_implementation	Navigate to the implementation of an interface or abstract member

Solution Explorer

Tool	Description
solution_add_project	Add an existing project to the current solution
solution_remove_project	Remove a project from the current solution
project_add_file	Add an existing file to a project
project_remove_file	Remove a file from a project
project_add_reference	Add a project-to-project reference
project_remove_reference	Remove a reference from a project

Debugger

Tool	Description
debug_start	Start debugging the startup project (equivalent to F5)
debug_start_without_debugging	Start the startup project without the debugger attached (equivalent to Ctrl+F5)
debug_stop	Stop debugging the current session
debug_restart	Restart debugging the current session
debug_attach	Attach the debugger to a running process by name or PID
debug_break	Break (pause) the debugger at the current execution point
debug_continue	Continue (resume) execution after a breakpoint or break
debug_step	Step through code (direction: over, into, or out)
debug_get_callstack	Get the current call stack of the active thread
debug_get_locals	Get the local variables in the current stack frame
debug_get_threads	Get all threads in the current debug session
debug_get_mode	Get the current debugger mode (Design, Running, or Break)
debug_evaluate	Evaluate an expression in the current debug context (only works in break mode)

Breakpoint

Tool	Description
breakpoint_set	Set a breakpoint (location, conditional, hit count, or function breakpoint)
breakpoint_remove	Remove a breakpoint at a specific file and line
breakpoint_list	List all breakpoints in the current solution
breakpoint_enable	Enable or disable a breakpoint at a specific file and line

Output & Diagnostics

Tool	Description
output_write	Write text to a Visual Studio Output window pane
output_read	Read the content of a Visual Studio Output window pane (supports regex pattern filtering)
output_clear	Clear the content of a Visual Studio Output window pane
error_list_get	Get all items from the Visual Studio Error List window
diagnostics_binding_errors	Extract XAML/WPF binding errors from the Debug output pane

Console

Tool	Description
console_read	Read the console output buffer of a debugged console application
console_send	Send text input or special keys to the console of a debugged console application
console_get_info	Get console buffer size, cursor position, and window information of a debugged console application

UI Automation

Tool	Description
ui_capture_window	Capture a screenshot of the debugged application's main window (uses WGC for reliable capture even when occluded; works during debug break)
ui_capture_region	Capture a screenshot of a specific region of the debugged application's window
ui_snapshot	Capture a compact semantic snapshot (pruned UIA tree + screenshot + focus) in a single call; optimized for LLM-driven UI testing
ui_get_tree	Get the UI element tree of the debugged application's main window
ui_find_elements	Find UI elements matching specified criteria (supports exact/contains/regex match modes, hasPattern filter, and ancestorAutomationId scoping)
ui_get_element	Get detailed properties of a specific UI element by its AutomationId
ui_click	Click a UI element by AutomationId, Name, or screen coordinates
ui_double_click	Double-click a UI element by AutomationId, Name, or screen coordinates
ui_right_click	Right-click a UI element by AutomationId, Name, or screen coordinates
ui_drag	Perform a drag-and-drop operation from start coordinates to end coordinates
ui_set_value	Set the value of a UI element using ValuePattern
ui_invoke	Invoke the default action on a UI element using InvokePattern
ui_send_keys	Send keyboard input (shortcuts like ctrl+f, text typing) to the debugged application
ui_wait_for_element	Wait until a UI element reaches a given state (appears/disappears/enabled/focused) with a timeout
ui_wait_idle	Wait until the UI Automation tree stops changing for a quiet period (useful after triggering async UI updates)

Watch

Tool	Description
watch_add	Add a watch expression and return its current value (only works in break mode)
watch_remove	Remove a watch expression by value or index
watch_list	List all watch expressions with their current values

Thread

Tool	Description
thread_switch	Switch the active (current) thread by thread ID
thread_set_frozen	Freeze or thaw a thread
thread_get_callstack	Get the call stack of a specific thread by ID

Process

Tool	Description
process_list_debugged	List all processes currently being debugged
process_list_local	List local processes available for attaching the debugger
process_detach	Detach the debugger from a specific process
process_terminate	Terminate a process being debugged

Immediate

Tool	Description
immediate_execute	Execute an expression with side effects in the debugger context (like the Immediate Window)

Module

Tool	Description
module_list	List all loaded modules (DLLs/assemblies) in the current debug session

Register

Tool	Description
register_list	Get values of common CPU registers (works best in native or mixed-mode debugging)
register_get	Get the value of a specific CPU register by name

Exception

Tool	Description
exception_settings_get	Get exception break settings
exception_settings_set	Configure when to break on a specific exception type

Memory

Tool	Description
memory_read	Read memory bytes at an address expression or get a variable's memory representation

Parallel

Tool	Description
parallel_stacks	Get all threads' call stacks in a tree view, grouping threads that share common stack frames
parallel_watch	Evaluate the same expression on all threads and compare results
parallel_tasks_list	List TPL (Task Parallel Library) task information

Web

Tool	Description
web_connect	Connect to a browser for web debugging (Chrome/Edge via CDP, Firefox via RDP)
web_disconnect	Disconnect from the browser connection
web_status	Get the current browser connection status including console/network message counts
web_navigate	Navigate the browser to a URL
web_screenshot	Capture a screenshot of the current page
web_dom_get	Get the DOM tree of the current page with configurable depth
web_dom_query	Query DOM elements using a CSS selector
web_console	Manage browser console messages (enable/get/clear)
web_js_execute	Execute JavaScript in the browser page context
web_network	Manage network monitoring (enable/get/clear)
web_element_click	Click a DOM element found by CSS selector
web_element_set_value	Set the value of an input element found by CSS selector

Test

Tool	Description
test_discover	Discover all tests in the solution or a specific project
test_run	Run tests and get results with optional filtering by test name/category
test_results	Get detailed results from the last test run (or a specific TRX file)

NuGet

Tool	Description
nuget_list	List installed NuGet packages for a specific project
nuget_search	Search for NuGet packages on NuGet.org
nuget_install	Install a NuGet package into a project
nuget_update	Update a NuGet package to a specific version
nuget_uninstall	Remove a NuGet package from a project

Requirements

• Visual Studio 2019 (16.0 or later), Visual Studio 2022, or Visual Studio 2026 — Community, Professional, or Enterprise edition
• Windows
• .NET Framework 4.8
• .NET 8.0 Runtime (for the StdioProxy component)

Installation

1. Install the extension from Visual Studio Marketplace or download the .vsix file from Releases
2. Restart Visual Studio
3. The MCP server starts automatically when Visual Studio launches

Setup — Connecting with Claude Code

Note: %LOCALAPPDATA% is not recognized in bash. You must specify the full absolute path (e.g. C:\Users\<USERNAME>\AppData\Local\...).

Option A — CLI command:

claude mcp add vs-mcp -- "C:\Users\<USERNAME>\AppData\Local\VsMcp\bin\VsMcp.StdioProxy.exe"

Option B — Manual configuration (add to your MCP config JSON):

{
  "mcpServers": {
    "vs-mcp": {
      "command": "C:\\Users\\<USERNAME>\\AppData\\Local\\VsMcp\\bin\\VsMcp.StdioProxy.exe"
    }
  }
}

Architecture

The extension runs an HTTP-based MCP server inside Visual Studio. A lightweight StdioProxy bridges stdio-based MCP clients (like Claude Code) to the HTTP server, enabling seamless communication.

Claude Code  ──stdio──▶  StdioProxy  ──HTTP──▶  VS Extension
                          (relay)                (MCP server)

When Visual Studio is not running, the StdioProxy provides offline responses for basic protocol operations and returns cached tool definitions.

Multiple VS Instances

VS MCP Server supports multiple Visual Studio instances running simultaneously. Each VS instance registers itself via a port file (%LOCALAPPDATA%\VsMcp\server.<PID>.port) containing its HTTP port and the currently open solution path.

Instance Selection

StdioProxy selects which VS instance to connect to based on command-line arguments:

Argument	Behavior
(none)	Auto-detect — walks up from the current working directory to find .sln files and connects to the matching VS instance. Falls back to the most recently started VS instance if no .sln is found.
--sln <path>	Connects to the VS instance that has the specified solution open
--pid <pid>	Connects to the VS instance with the specified process ID

CWD-based Auto-Detection

When no --sln or --pid argument is provided, StdioProxy automatically discovers .sln files by walking up from the current working directory. This means that in most cases, no explicit configuration is needed — simply launching Claude Code from within a project directory is enough.

Scenario	Behavior
1 .sln found	Automatically connects to the VS instance with that solution
Multiple .sln found, 1 open in VS	Connects to the matching VS instance
Multiple .sln found, multiple open in VS	Connects to the closest match (nearest to CWD) and includes a hint in the initialize response
Multiple .sln found, none open in VS	Falls back to default behavior and includes a hint prompting the user to choose
No .sln found	Falls back to the most recently started VS instance

Configuration Examples

Single instance (auto-detect, no extra config needed):

claude mcp add vs-mcp -- "C:\Users\<USERNAME>\AppData\Local\VsMcp\bin\VsMcp.StdioProxy.exe"

Multiple instances (explicit solution-based — useful when CWD auto-detection is not sufficient):

{
  "mcpServers": {
    "vs-mcp-frontend": {
      "command": "C:\\Users\\<USERNAME>\\AppData\\Local\\VsMcp\\bin\\VsMcp.StdioProxy.exe",
      "args": ["--sln", "C:\\Projects\\Frontend\\Frontend.sln"]
    },
    "vs-mcp-backend": {
      "command": "C:\\Users\\<USERNAME>\\AppData\\Local\\VsMcp\\bin\\VsMcp.StdioProxy.exe",
      "args": ["--sln", "C:\\Projects\\Backend\\Backend.sln"]
    }
  }
}

Tool Filtering

Use the --tools argument to load only the tool categories you need. This reduces the number of tools exposed to the AI agent, which can improve token efficiency and response relevance.

Preset	Categories
core	General, Solution, Project, Build, Editor, EditPreview, Output, Navigation, NuGet, SolutionExplorer, Test
debug	Debugger, Breakpoint, Watch, Thread, Process, Immediate, Module, Register, Exception, Memory, Parallel, Diagnostics, Console
web	Web
ui	UI

Examples:

claude mcp add vs-mcp -- "C:\Users\<USERNAME>\AppData\Local\VsMcp\bin\VsMcp.StdioProxy.exe" --tools core,debug

{
  "mcpServers": {
    "vs-mcp": {
      "command": "C:\\Users\\<USERNAME>\\AppData\\Local\\VsMcp\\bin\\VsMcp.StdioProxy.exe",
      "args": ["--tools", "core,debug"]
    }
  }
}

You can also specify individual category names (e.g. --tools General,Build,Debugger). Omitting --tools loads all tools.

Reconnection

• If VS is restarted, StdioProxy automatically reconnects on the next tools/call request.
• Stale port files from crashed or closed VS instances are cleaned up automatically during discovery.

Showcase: hands-off AI-driven dogfood

With focus_guard_set enabled=true, an AI agent can drive a full build → debug → UI verification cycle in Visual Studio on one monitor while the developer keeps a fullscreen application (e.g. a game) running on another — no focus theft, no window flicker, no context switch.

Paired with jidodebugger — an upstream MCP server that sits above vs-mcp's desktop-app UIA layer and supersedes it with WPF-native automation (bridge injection into the debuggee, direct ICommand invocation, and ViewModel-property waits via wpf_bridge_inject / wpf_invoke_command / wpf_wait_for, on top of the raw UIA tools vs-mcp already provides) — the loop becomes: vs-mcp launches the debuggee under the focus guard, jidodebugger drives its UI over the same MCP session, and neither side has to touch the foreground.

Recorded end-to-end run against a WPF debuggee (6 tool calls, zero human interventions, zero foreground steals):

#	Tool	Result	What the guard did
1	debug_start (vs-mcp)	Debugging started	VS restore and debuggee launch both stayed background — the user's foreground app was never activated
2	wpf_bridge_inject (jidodebugger)	payload attached	—
3	wpf_invoke_command LoadCommand (jidodebugger)	fired=true, awaitedAsync=true	—
4	wpf_wait_for viewModel appears (jidodebugger)	matchCount=5 (~3.9 s)	—
5	wpf_invoke_command OpenMemberByKeyCommand (jidodebugger)	fired=true, awaitedAsync=true	—
6	wpf_wait_for propertyNotNull (jidodebugger)	matched	—

How it works under the hood, when the guard is on:

1. LockSetForegroundWindow denies foreign SetForegroundWindow calls during the debug-start window.
2. SPI_SETFOREGROUNDLOCKTIMEOUT is temporarily raised so the launched debuggee's own activation attempts are demoted to a taskbar flash.
3. If VS is minimized at the moment debug_start / debug_start_without_debugging / debug_restart is invoked, it is re-minimized (SW_SHOWMINNOACTIVE) whenever it tries to auto-restore during the lock window.

The setting is off by default, so opt-in via focus_guard_set before an autonomous session and turn it off again when you want normal VS focus behavior back.

Observability

When focus does slip through, you don't have to guess what took it. A background auditor (started automatically) records every foreground transition Windows fires — process name, window title, timestamp, and whether the guard was on. Call focus_guard_audit_read right after any perceived focus steal to see exactly which process / window pulled foreground and when, and focus_guard_audit_clear to reset the buffer before a new test scenario.

Bundled Claude Code Skills

The VS Extension ships a small set of Claude Code skills that complement the MCP tools. They are deployed automatically on extension startup to %USERPROFILE%\.claude\skills\, so Claude Code picks them up without manual setup.

Skill	Purpose
vs-ui-explore	Autonomous UI crawl of a VS debuggee — drives the app via ui_snapshot, ui_find_elements, and the ui_wait_* primitives, then reports crashes, error dialogs, unreachable screens, and disabled-but-expected states. Trigger it with prompts like "crawl the UI and report bugs".

Source files live under src/VsMcp.Extension/Skills/; edit them there and the extension will redeploy the updated copy on next launch (it compares file content and skips unchanged files).

Contributing

Pull Requests are not accepted.

For feature requests and bug reports, please use GitHub Issues.

License

MIT License