LSP Bridge for VS Code

Experimental — this extension is under active development and may change significantly.

A VS Code extension that gives Claude Code access to VS Code's language intelligence — hover info, go-to-definition, references, completions, diagnostics, and more — over a local LSP bridge.

Why

Claude Code runs in the terminal and has no direct access to VS Code's language server features. This extension bridges that gap by exposing VS Code's language server providers through a Unix domain socket. When the bridge is running, Claude Code can query the same type information, diagnostics, and navigation data that you see in the editor.

Other approaches — such as MCP servers that wrap LSP — suffer from significant token overhead. Every MCP tool definition is injected into the system prompt (roughly 550–1,400 tokens per tool), and each tool-call response is serialized into the conversation history where it is re-processed on every subsequent turn. An MCP LSP server exposing even a handful of operations can add thousands of tokens of schema overhead per session before any real work begins.

This extension avoids that cost entirely. It integrates as a native LSP server plugin, so Claude Code handles language-server operations through its built-in LSP support rather than through MCP tool calls. Diagnostics flow automatically after every file edit without an explicit tool invocation, and active queries like hover or go-to-definition use Claude Code's internal LSP handling with no per-server schema overhead. The result is the most straightforward and token-efficient way to give LLM agents access to VS Code's language intelligence.

Supported Language Features

Feature	LSP Method
Hover	`textDocument/hover`
Go to Definition	`textDocument/definition`
Go to Type Def	`textDocument/typeDefinition`
Go to Implementation	`textDocument/implementation`
Find References	`textDocument/references`
Completions	`textDocument/completion`
Document Symbols	`textDocument/documentSymbol`
Workspace Symbols	`workspace/symbol`
Rename	`textDocument/rename`
Diagnostics	`textDocument/publishDiagnostics`

Requirements

VS Code 1.85.0 or later
macOS or Linux (Windows is not currently supported but could be added if requested)

Usage

Open a workspace in VS Code.
Run LSP Bridge: Select Languages to choose which languages to expose.
Run LSP Bridge: Generate Local Claude Plugin to create the plugin directory.
Run LSP Bridge: Start Server from the Command Palette (Cmd+Shift+P).

Loading the Plugin

The Generate Local Claude Plugin command (step 3) creates a plugin directory at .claude/plugins/vscode-lsp-bridge/ inside your workspace. This is not a marketplace plugin, so Claude Code does not discover it automatically — you need to load it explicitly:

claude --plugin-dir .claude/plugins/vscode-lsp-bridge

To avoid typing this every time, you can add it as a shell alias or use a project-level script.

Commands

All commands are available from the Command Palette (Cmd+Shift+P):

Command	Description
LSP Bridge: Start Server	Start the bridge server for the current workspace
LSP Bridge: Stop Server	Stop the running bridge server
LSP Bridge: Select Languages	Pick which installed language extensions to expose through the bridge
LSP Bridge: Generate Local Claude Plugin	Regenerate the Claude plugin directory (`.claude/plugins/vscode-lsp-bridge/`) without restarting the server

Auto-start

To start the bridge automatically when VS Code opens, enable the setting:

{
  "lspBridge.autoStart": true
}

How It Works

The extension listens on a Unix domain socket with a deterministic path derived from the workspace folder. A proxy script connects Claude Code to the socket using the socket transport mode. The extension generates a Claude Code plugin directory (.claude/plugins/vscode-lsp-bridge/) containing the proxy and .lsp.json configuration, which is then loaded via --plugin-dir.

License

MIT

LSP Bridge

Shillem Volpato