Claude Code for Visual Studio

Bring Claude Code into Visual Studio 2026. The claude CLI does the agent work. This extension is the IDE half of Claude Code's integration protocol: a native diff window with accept and reject, automatic selection and compiler-diagnostics context, a live debugger Claude can read and drive, Roslyn code navigation with decompile, and a test runner that catches failures under the debugger.

A fresh Claude session driving the Visual Studio debugger to find a bug that is invisible in the output, then opening the fix in the native diff.

Status: community project, not affiliated with Anthropic. Visual Studio 2026 only for now. Tested against claude 2.1.191.

Why

Claude Code ships first-class IDE integration for VS Code and JetBrains, but not Visual Studio. This extension implements that same integration protocol natively for VS, so the CLI drives a real Visual Studio diff window and reads your selection and build errors instead of you copy-pasting into a terminal.

The demand for this is on the Claude Code tracker. These requests ask for what the extension provides:

• Visual Studio support: #15942 for VS 2026, and #70516 for VS 2022+.
• A debugger Claude can use: #13865 for an interactive debug mode aimed at hard-to-reproduce runtime bugs, and #27110 to expose debugger state, the variables and call stack, to Claude.
• Reaching more IDEs, and stronger C#/.NET code intelligence: #1234 for IDEs beyond VS Code and JetBrains, and #16360 for the C# code intelligence our Roslyn navigation provides.

What you get

• Native diff with a single accept/reject gate - Claude's edits open in Visual Studio's diff viewer, and approving there is the only step (no duplicate y/n prompt in the terminal).
• Reject with feedback - reject an edit and tell Claude what to change, and it reconsiders with your note.
• Run wild (auto-accept) - a panel toggle that applies edits without opening the diff, for when you want to let it cook. Resets each session.
• Diagnostics sharing - Claude reads Visual Studio's compiler errors and warnings (C# and C++) and fixes them.
• Semantic code navigation - Claude asks Visual Studio's compiler (Roslyn) for the resolved meaning of your C# instead of grepping text: find-all-references, go-to-definition, find-implementations, and call/type hierarchies. These are the ground-truth answers text search gets wrong, like indirect and interface-dispatched references, the right overload, explicit interface implementations, and transitive callers for impact analysis. No debug session needed; it works whenever a C#/VB solution is loaded. Full reference: the semantic-navigation guide.
• Live debugger - while you are paused at a breakpoint, Claude sees your program's runtime state (call stack, variable values, threads) and, opt-in, can drive the debugger: continue, step, set breakpoints, break at the throw site of an exception, set a data breakpoint that breaks (or traces the full change history) the moment a value changes, attach to a running app (a hosted web service or desktop app, not just F5), and pause a hung process to untangle a deadlock by following the lock-ownership chain across threads to the exact cycle. Full reference: the debugger guide.
• Test integration - Claude discovers, runs, and debugs your unit tests through Visual Studio's Test Explorer engine: real per-test results (outcome, message, stack), re-run just the failures, and run a failing test under the debugger to stop at the fault, or hammer a flaky test until it fails and catch that iteration red-handed, paused inside the failure. Because it is the debugger's own session, a red test becomes a live investigation. Full reference: the testing guide.
• Selection context - Claude automatically knows the file and lines you are looking at.
• Claude in the IDE's own terminal - Launch opens claude inside Visual Studio's docked Terminal tool window (the same group as Developer PowerShell), already connected - it docks and tabs like any other VS terminal instead of floating over your desktop. An External console button keeps the standalone-window option. Full reference: the quality-of-life guide.
• Attach screenshots and files - the Windows CLI cannot take a pasted screenshot at all, so the panel is the paste point: Win+Shift+S, click Paste (or drop files from Explorer), and an @ reference lands directly in the CLI's input box with the real image attached. Every attachment shows an estimated token cost before you send, Excel/video/archives attach too (Claude gets the path and reaches for a script), and staged copies live in a gitignored .claude/attachments/. Full reference: the quality-of-life guide.
• Screen capture: Claude takes its own screenshots (opt-in) - two gated tools give Claude eyes: capture the debugged app's window, any window by title (the browser showing your site), the VS window, or the whole screen. Captures land in the attachment tray as visible chips with a token estimate, and the tool returns a path Claude reads with real vision - UI layouts, images, rendered pages, text in windows that are not files. Off by default behind an Allow screen capture toggle; every capture is logged. Full reference: the vision guide.
• Notifications - an in-IDE heads-up when Claude finishes responding or needs your input (a permission prompt, or it went idle waiting for you): a notification bar in Visual Studio, plus a taskbar flash when VS is in the background. For working in another window while it cooks. A panel toggle mutes it. Full reference: the quality-of-life guide.
• Live panel - a dockable Claude Code panel: connection status, edit decisions, and token usage with estimated cost (latest call vs cumulative session).

A closer look

A native diff with one approval step

Claude's edits open in Visual Studio's own diff viewer, and approving there is the only step. There is no second yes/no prompt in the terminal. You can reject an edit and leave a note, and Claude reconsiders with your feedback.

A debugger Claude can drive

While you are paused at a breakpoint, Claude reads your program's runtime state and, with driving turned on, steps and sets breakpoints to corner a bug. The clip at the top is a scoring function that returns the wrong total. Claude stopped inside the loop, stepped through the rounds, and watched a counter that should reset but did not. It kept a running trace of what it saw at each round:

It has grown past stepping. Claude can attach to a program that is already running, break at the throw site of an exception instead of the catch that swallows it, and pause a hung process to walk a deadlock back to the exact cycle. Full tool list in the debugger guide.

Break when a value changes

Point Claude at a field and it stops the moment that field is written, or traces every value the field takes, in order. It can watch conditionally and on several fields at once. Visual Studio's own UI can set this, but there is no automation API for it, so the extension arms it through a bundled debug-engine component.

The full data-breakpoint reference is in the debugger guide.

Catch a failing test, even the flaky ones

Claude discovers, runs, and debugs your tests through Visual Studio's Test Explorer engine, with real per-test results. The test tools sit on top of the debugger, so Claude can launch one failing test and stop at the throw with the exception and locals in view, or loop a flaky test until the failing run happens and leave you paused inside it.

Full tool list and the worked flow are in the testing guide.

Read code the way the compiler does

This gives Claude Visual Studio's resolved model of your C# (Roslyn): find-all-references, go-to-definition, find-implementations, and call and type hierarchies, resolved through interfaces, overrides, and overloads. It also reads the decompiled body of a method inside a referenced DLL, which searching your repo cannot do.

Details are in the semantic-navigation guide.

Claude in the IDE's own terminal

claude runs inside Visual Studio's docked Terminal tool window - the same terminal group as Developer PowerShell - instead of a separate console floating over your desktop. Under the hood this is VS 2026's own terminal engine, reached through an undocumented service, so the launch is guarded: any failure or stall falls back to the classic external console automatically. Prefer the standalone window anyway (a second monitor, or a session that survives closing VS)? The External console button next to Launch does exactly that. Details and known quirks: the quality-of-life guide.

Attach a screenshot, or any file

Pasting a screenshot into the Claude Code CLI on Windows silently does nothing (a long-open upstream gap), and a screenshot is not a file you can drag. The panel closes that gap: take the capture, click Paste (or drop files from Explorer), and the extension stages it and pushes an @ reference straight into the CLI's input box - the same protocol message the official VS Code plugin uses, verified to deliver the actual pixels, not just a path.

Every attachment shows an estimated token cost before you send: a tight screenshot crop costs a fraction of a full screen, and a 2 MB JSON log announcing ≈212k tokens is your cue to ask Claude to Grep it instead of reading it whole. Formats Claude cannot read directly (Excel, video, archives) still attach - the chip is labeled, Claude gets the path, and it reaches for a script or tool on its own. Files already in your workspace are referenced in place; everything else is copied into a gitignored .claude/attachments/.

Claude takes its own screenshots

With the Allow screen capture toggle on, Claude stops asking you for screenshots and takes its own: the debugged app's window, any window by title (the browser running your site), or the screen. Asked only "in one of my monitors I have an image, a notepad, and a documentation file - screen grab that and tell me what you see", it captured the desktop once (≈922 tokens) and read all three: the sunflower photo described, the Notepad numbers transcribed digit-for-digit, the visible .NET 11 doc bullets summarized.

Every capture is staged as a visible chip in the attachment tray and logged in the activity feed, so what Claude saw is never invisible to you. The full story is in the vision guide.

A live panel

A dockable Claude Code panel shows connection status, edit decisions, and token usage with an estimated cost. It also holds the three safety toggles (apply edits without the diff, allow Claude to drive the debugger, and allow screen capture), all off by default and all reset each session, plus a Notify toggle (on by default) that mutes the finished/needs-input notifications.

Requirements

• Visual Studio 2026.
• The Claude Code CLI, installed and authenticated. See the Claude Code docs. This extension makes no model calls and does no agent work itself, so it needs the CLI.
• Tested against claude 2.1.191.

Install

• From here: click Download or Install, or in Visual Studio open Extensions > Manage Extensions and search for Claude Code for Visual Studio.
• Sideload: download the .vsix from GitHub Releases and double-click it.

Quickstart

1. Open your project or solution in Visual Studio 2026.
2. Open the Claude Code panel (View > Other Windows > Claude Code) and click Launch Claude Code. It is also on the Tools menu.
3. claude opens in Visual Studio's docked Terminal window, already connected to the IDE, so you do not need /ide. The panel pill turns green and reads Connected. (Want a standalone window instead? Click External console.)
4. Ask Claude to make a change. Its edit opens as a diff, and you click Accept, Reject, or Reject with feedback.

Diagnostics need a loaded project, not a loose file in Open-Folder mode, for the compiler to analyze it.

To let Claude debug: set a breakpoint, tick Allow Claude to drive debugger in the panel, start debugging, then ask it to investigate. Reading runtime state works without the toggle. The toggle only gates driving execution.

How it works

This is a protocol bridge, not a re-implementation of the agent. On Launch it starts a localhost WebSocket server, launches claude already connected to the IDE, and implements the IDE tools the CLI drives (the diff, diagnostics, and selection updates). A small PreToolUse hook routes proposed edits through the Visual Studio diff, so approving there is the only gate. Debugger access, the test runner, and semantic navigation are exposed as extra MCP servers (vs-debug carries the debugger and the test tools, since they compose; vs-semantic carries Roslyn) the CLI reaches through a tiny stdio shim. The CLI does all agent work, and the extension never makes model calls.

Privacy and security

• The bridge binds to 127.0.0.1 only and validates an auth token from a lockfile on every connection. The token is never logged.
• The extension makes no network calls and no LLM calls of its own. All AI work is the claude CLI, under your own authentication.
• On Launch, it writes a few helper scripts into your workspace's .claude/ folder and merges hook entries into .claude/settings.json, preserving existing content: the edit-gate hook, a token-usage reporter, a break-state hook, a needs-input notification hook, and a stdio shim for the vs-debug and vs-semantic MCP servers (registered in your workspace .mcp.json).
• Token cost is an estimate from hardcoded per-tier prices, shown only when you click Show est. cost.
• Attachments you paste or drop are staged in your workspace's .claude/attachments/ (screenshots become PNGs there; out-of-workspace files are copied in). The folder carries its own * gitignore so nothing lands in your repo, staged copies are pruned after 7 days, and files already inside the workspace are referenced in place, never copied or deleted.

Limitations and known issues

• Visual Studio 2026 only for now. A VS 2022 backfill is planned if there is demand.
• The integration protocol is undocumented and version-fragile, so a claude update could change it. Known-good: 2.1.191.
• Diagnostics need a loaded project. The Error List and Roslyn will not analyze loose files.
• Semantic navigation is C#/VB and needs a loaded project. It reads the Roslyn workspace, so it sees the solution open in Visual Studio, and it does not cover C++ navigation.
• Debugger features target managed (.NET) code. Reading runtime state is always on, and driving execution is opt-in. Native and C++ runtime inspection is not covered.
• Test integration is for managed (.NET) test projects and needs a loaded solution. Coverage works, profiling is deferred, and the debug and flaky-catch tools are opt-in behind the debugger-drive toggle.
• Token stats refresh on edits, so a chat-only turn may not update them right away.
• Cost figures are estimates, not billing.
• Attachments: images read directly must be PNG/JPEG/GIF/WebP under 5 MB (bigger ones attach with a downscale note; BMPs are transcoded). Excel, video, archives and other binaries attach as paths for Claude's tools rather than direct reads. Attachment token figures are estimates.
• Screen capture is opt-in per session and cannot capture minimized windows (the tool asks for a restore). Windows that block PrintWindow fall back to a screen-region copy, which includes anything overlapping them.

Troubleshooting

• Panel says "Waiting for CLI": click Launch Claude Code, or run /ide in a claude terminal and pick Visual Studio.
• The debugger, test, or semantic tools are missing: the panel warns when the vs-debug and vs-semantic servers did not load for a session. Relaunch Claude from the panel and approve the project MCP servers if the CLI prompts.
• New files land in the wrong folder: launch from the extension, which pins the working directory to your workspace, or run claude from inside the repo.
• getDiagnostics returns nothing: open the code as a project and confirm the error appears in the Error List.
• claude opened in a separate console instead of the docked terminal: the native terminal path failed or timed out and fell back (by design - the reason is in Output > Claude Code). Everything still works.
• The Claude Code terminal tab turned into Developer PowerShell after restarting VS: expected - VS restores terminal tabs with the default shell, and the old session's port would be stale anyway. Close the leftover tab and click Launch Claude Code again.
• An attachment chip didn't show up in the CLI's input box: the CLI drops the reference if it was mid-turn when you attached. Click the chip in the panel to send it again; chips staged before Claude connects send themselves on connect.
• Filing a bug: include the Output > Claude Code pane contents and your claude --version.

Source, full documentation, and issue tracker: github.com/firish/claude_code_vs.

MIT © 2026 Rishi Gulati. Not affiliated with Anthropic. "Claude" and "Claude Code" are trademarks of Anthropic, used here only to describe interoperability.