MCP configuration reference

This article provides a reference for the MCP server configuration file format, related commands, and settings in VS Code. For information about adding and managing MCP servers, see Add and manage MCP servers.

Configuration file

MCP server configuration is stored in the mcp.json JSON file. This file can be in your workspace (.vscode/mcp.json) or in your user profile. VS Code provides IntelliSense for the configuration file.

Configuration structure

The configuration file has two main sections:

• "servers": {}: an object that maps server names to their configurations. Each key is the server name, and the value is the server configuration object. Depending on the server type, different fields are required.

• "inputs": []: an optional array of input variable definitions for sensitive information like API keys.

You can use predefined variables in the server configuration, for example to refer to the workspace folder (${workspaceFolder}).

Standard I/O (stdio) servers

Use this configuration for servers that communicate through standard input and output streams. This is the most common type for locally-run MCP servers.

{
  "servers": {
    "memory": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-memory"]
    }
  }
}

HTTP and Server-Sent Events (SSE) servers

Use this configuration for servers that communicate over HTTP. VS Code first tries the HTTP Stream transport and falls back to SSE if HTTP is not supported.

In addition to servers available over the network, VS Code can connect to MCP servers listening for HTTP traffic on Unix sockets or Windows named pipes by specifying the socket or pipe path in the form unix:///path/to/server.sock or pipe:///pipe/named-pipe on Windows. You can specify subpaths by using a URL fragment, such as unix:///tmp/server.sock#/mcp/subpath.

{
  "servers": {
    "context7": {
      "type": "http",
      "url": "https://mcp.context7.com/mcp"
    }
  }
}

Input variables for sensitive data

Input variables let you define placeholders for configuration values, avoiding the need to hardcode sensitive information like API keys or passwords directly in the server configuration.

When you reference an input variable using ${input:variable-id}, VS Code prompts you for the value when the server starts for the first time. The value is then securely stored for subsequent use. Learn more about input variables in VS Code.

Input variable properties:

{
  "inputs": [
    {
      "type": "promptString",
      "id": "perplexity-key",
      "description": "Perplexity API Key",
      "password": true
    }
  ],
  "servers": {
    "perplexity": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "server-perplexity-ask"],
      "env": {
        "PERPLEXITY_API_KEY": "${input:perplexity-key}"
      }
    }
  }
}

Development mode

You can enable development mode for MCP servers by adding a dev key to the server configuration. This is an object with two properties:

• watch: A file glob pattern to watch for file changes that restarts the MCP server.
• debug: Enables you to set up a debugger with the MCP server. Currently, VS Code supports debugging Node.js and Python MCP servers.

Learn more about MCP development mode in the MCP Dev Guide.

Server naming conventions

When defining MCP servers, follow these naming conventions for the server name:

• Use camelCase for the server name, such as "uiTesting" or "githubIntegration"
• Avoid using whitespace or special characters
• Use a unique name for each server to avoid conflicts
• Use a descriptive name that reflects the server's functionality or brand, such as "github" or "database"

Commands

The following table lists the MCP-related commands available in the Command Palette (⇧⌘P (Windows, Linux Ctrl+Shift+P)).

Settings

For a full list of VS Code AI settings, see the AI Settings Reference. The following settings are specific to MCP servers.

Related resources

• Add and manage MCP servers
• Model Context Protocol Documentation
• MCP Dev Guide