TypeScript LSP

TypeScript LSP is a native Claude Code plugin that provides full code intelligence support for TypeScript and JavaScript projects. Through the Language Server Protocol, Claude can understand your code the same way a professional IDE does.

Features

Feature	Description
Go to Definition	Quickly locate where a function, variable, or type is defined
Find References	Find all usages of a symbol throughout the project
Diagnostics	Real-time type errors and syntax issues
Hover	Get type signatures and documentation comments
Code Completion	Intelligent code completion suggestions

Supported File Types

TypeScript LSP supports the following file extensions:

Extension	Language
`.ts`	TypeScript
`.tsx`	TypeScript React (JSX)
`.js`	JavaScript
`.jsx`	JavaScript React (JSX)
`.mts`	TypeScript ES Module
`.cts`	TypeScript CommonJS Module
`.mjs`	JavaScript ES Module
`.cjs`	JavaScript CommonJS Module

Installation

Install the Language Server

First, install the TypeScript language server and TypeScript compiler globally:

npm install -g typescript-language-server typescript

yarn global add typescript-language-server typescript

pnpm add -g typescript-language-server typescript

Verify the Installation

After installation, verify that the language server is available:

typescript-language-server --version
tsc --version

If both commands output version numbers, the installation was successful.

Install the Claude Code Plugin

Install the TypeScript LSP plugin inside Claude Code:

# Option 1: Via the plugin marketplace (recommended)
/plugin
# Select the Discover tab, search for "typescript-lsp", and install
 
# Option 2: Install directly from GitHub
/plugin install boostvolt/claude-code-lsps:typescript-lsp

Restart Claude Code

After installation, restart Claude Code to load the plugin:

# Exit the current session
/exit
 
# Restart
claude

TypeScript LSP is a native Claude Code plugin — no VS Code or other IDE required. You can use the full code intelligence feature set in a pure terminal environment.

Plugin Configuration Details

The core configuration for the TypeScript LSP plugin looks like this:

{
  "typescript": {
    "command": "typescript-language-server",
    "args": ["--stdio"],
    "extensionToLanguage": {
      ".ts": "typescript",
      ".tsx": "typescriptreact",
      ".js": "javascript",
      ".jsx": "javascriptreact",
      ".mts": "typescript",
      ".cts": "typescript",
      ".mjs": "javascript",
      ".cjs": "javascript"
    }
  }
}

Configuration Reference

Field	Value	Description
`command`	`typescript-language-server`	The language server executable
`args`	`["--stdio"]`	Communicate via standard input/output
`extensionToLanguage`	Extension map	Maps file extensions to language identifiers

Usage Examples

Once installed, Claude automatically uses LSP features when working with TypeScript/JavaScript code.

Go to Definition

When you ask Claude to find where a function or variable is defined, it can pinpoint it precisely:

User: Where is getUserById defined?

Claude: (uses LSP go-to-definition)
getUserById is defined in src/services/user.ts:42

Find References

Find all places in the project where a symbol is used:

User: Find everywhere AuthContext is used

Claude: (uses LSP find-references)
AuthContext is used in the following locations:
- src/components/Login.tsx:15
- src/components/Header.tsx:8
- src/pages/Dashboard.tsx:23
- src/hooks/useAuth.ts:5

Real-Time Error Checking

Claude sees type errors immediately after editing code:

User: Help me fix the errors in this TypeScript file

Claude: (gets diagnostics via LSP)
Found the following type errors:
1. Line 15: Type 'string' is not assignable to type 'number'
2. Line 23: Property 'name' does not exist on type 'User'

Advanced Configuration

Custom tsconfig Settings

If you need to pass specific TypeScript configuration, use initializationOptions:

{
  "typescript": {
    "command": "typescript-language-server",
    "args": ["--stdio"],
    "initializationOptions": {
      "preferences": {
        "includeCompletionsForModuleExports": true,
        "includeCompletionsWithInsertText": true
      }
    },
    "extensionToLanguage": {
      ".ts": "typescript",
      ".tsx": "typescriptreact"
    }
  }
}

Enabling Debug Logs

When troubleshooting, enable verbose logging:

{
  "typescript": {
    "command": "typescript-language-server",
    "args": ["--stdio"],
    "loggingConfig": {
      "args": ["--log-level", "4"],
      "env": {
        "TSS_LOG": "-level verbose -file ${CLAUDE_PLUGIN_LSP_LOG_FILE}"
      }
    },
    "extensionToLanguage": {
      ".ts": "typescript"
    }
  }
}

Then start Claude Code with the --enable-lsp-logging flag:

claude --enable-lsp-logging

Log files are saved to ~/.claude/debug/.

Troubleshooting

”Executable not found in $PATH”

Cause: typescript-language-server is not installed or is not on your system PATH.

Solution:

Confirm the global installation:

npm install -g typescript-language-server typescript

Check that npm’s global directory is on your PATH:

npm config get prefix
# Make sure <output>/bin is in your PATH

For macOS/Linux, you may need to add the following to ~/.bashrc or ~/.zshrc:

export PATH="$(npm config get prefix)/bin:$PATH"

“No LSP server available for file type: .ts”

Cause: The plugin is not correctly installed or configured.