C# Language Features MCP server

Bifrost is a VSCode extension that provides a Model Context Protocol (MCP) server, connecting AI coding assistants with VSCode's powerful development tools. It gives AI tools access to code navigation, analysis, and manipulation capabilities through a standardized interface, enhancing AI-assisted coding experiences with VSCode's language intelligence.

Installation

Prerequisites

• Visual Studio Code version 1.96.0 or higher
• Appropriate language extensions for your specific development needs (e.g., C# extension for C# files)

Installing the Extension

1. Open Visual Studio Code
2. Navigate to the Extensions view (click the Extensions icon in the Activity Bar or press Ctrl+Shift+X)
3. Search for "Bifrost MCP"
4. Click "Install" to install the extension
5. Open your project in VS Code

Usage

The extension automatically starts an MCP server when activated, making VSCode's language features available to AI assistants.

Server Configuration

By default, the MCP server runs on port 8008 with the following endpoints:

• SSE endpoint: http://localhost:8008/sse
• Message endpoint: http://localhost:8008/message

Available Commands

The extension provides several commands that can be accessed via the Command Palette (Ctrl+Shift+P):

• Bifrost MCP: Start Server - Manually start the MCP server on the default port (8008)
• Bifrost MCP: Start Server on port - Start the MCP server on a custom port
• Bifrost MCP: Stop Server - Stop the running MCP server
• Bifrost MCP: Open Debug Panel - Open a debug panel to test available tools

Connecting with AI Assistants

To use Bifrost with an AI assistant that supports the MCP protocol:

1. Ensure the Bifrost server is running
2. Configure your AI assistant to connect to the appropriate endpoints
3. Use the assistant as normal - it will now have access to VSCode's language intelligence

Available Tools

Bifrost exposes numerous VSCode language features, including:

• find_usages: Find all references to a symbol
• go_to_definition: Navigate to symbol definitions
• find_implementations: Find implementations of interfaces/abstract methods
• get_hover_info: View documentation and type information
• get_document_symbols: Get structured outline of document symbols
• get_completions: Access context-aware code completions
• get_signature_help: Get function parameter information
• get_rename_locations: Find safe locations for renaming
• get_code_actions: Access refactoring options and quick fixes
• get_semantic_tokens: Get enhanced syntax highlighting data
• get_workspace_symbols: Search for symbols across your workspace

Example Tool Usage

Finding References

{
  "name": "find_usages",
  "arguments": {
    "textDocument": {
      "uri": "file:///path/to/your/file"
    },
    "position": {
      "line": 10,
      "character": 15
    },
    "context": {
      "includeDeclaration": true
    }
  }
}

Searching for Workspace Symbols

{
  "name": "get_workspace_symbols",
  "arguments": {
    "query": "MyClass"
  }
}

Troubleshooting

If you encounter issues with Bifrost:

• Ensure you have installed the appropriate language extensions for your project
• Verify that your project has loaded correctly in VSCode
• Check that port 8008 (or your custom port) is available on your system
• Examine the VSCode output panel for any error messages
• Try restarting the server using the "Bifrost MCP: Stop Server" and "Bifrost MCP: Start Server" commands

How to install this MCP server

For Claude Code

To add this MCP server to Claude Code, run this command in your terminal:

claude mcp add-json "bifrost-mcp" '{"command":"code","args":["--install-extension","ConnorHallman.bifrost-mcp"]}'

See the official Claude Code MCP documentation for more details.

For Cursor

There are two ways to add an MCP server to Cursor. The most common way is to add the server globally in the ~/.cursor/mcp.json file so that it is available in all of your projects.

If you only need the server in a single project, you can add it to the project instead by creating or adding it to the .cursor/mcp.json file.

Adding an MCP server to Cursor globally

To add a global MCP server go to Cursor Settings > Tools & Integrations and click "New MCP Server".

When you click that button the ~/.cursor/mcp.json file will be opened and you can add your server like this:

{
    "mcpServers": {
        "bifrost-mcp": {
            "command": "code",
            "args": [
                "--install-extension",
                "ConnorHallman.bifrost-mcp"
            ]
        }
    }
}

Adding an MCP server to a project

To add an MCP server to a project you can create a new .cursor/mcp.json file or add it to the existing one. This will look exactly the same as the global MCP server example above.

How to use the MCP server

Once the server is installed, you might need to head back to Settings > MCP and click the refresh button.

The Cursor agent will then be able to see the available tools the added MCP server has available and will call them when it needs to.

You can also explicitly ask the agent to use the tool by mentioning the tool name and describing what the function does.

For Claude Desktop

To add this MCP server to Claude Desktop:

1. Find your configuration file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

2. Add this to your configuration file:

{
    "mcpServers": {
        "bifrost-mcp": {
            "command": "code",
            "args": [
                "--install-extension",
                "ConnorHallman.bifrost-mcp"
            ]
        }
    }
}

3. Restart Claude Desktop for the changes to take effect