Setting up the MCP server

The server is started by the client as a child process. It is therefore enough to put the path to the executable into the client’s configuration — no service, no port, no sign-in.

Build it first

dotnet publish src/Invoiceflair.Mcp/Invoiceflair.Mcp.csproj -c Release -o <target folder>

Claude Desktop

The file claude_desktop_config.json — on Windows %APPDATA%\Claude\, on macOS ~/Library/Application Support/Claude/:

{
  "mcpServers": {
    "invoiceflair": {
      "command": "C:\\Programme\\Invoiceflair MCP\\Invoiceflair.Mcp.exe",
      "env": {
        "INVOICEFLAIR_MCP_ROOT": "C:\\Rechnungen",
        "INVOICEFLAIR_MCP_OUTPUT": "C:\\Rechnungen\\_ergebnisse"
      }
    }
  }
}

VS Code

The file .vscode/mcp.json in the workspace:

{
  "servers": {
    "invoiceflair": {
      "type": "stdio",
      "command": "C:\\Programme\\Invoiceflair MCP\\Invoiceflair.Mcp.exe"
    }
  }
}

Claude Code

The file .mcp.json in the project folder — the same shape as for VS Code.

macOS

Instead of the .exe, the executable without an extension:

/Applications/Invoiceflair MCP/Invoiceflair.Mcp

Checking that it runs

Invoiceflair.Mcp.exe --help

This prints the list of switches along with the values currently in effect — and therefore also tells you whether your env block arrived.