Cadenza.Mcp

Cadenza.Mcp

Cadenza.Mcp is the MCP-server variant of the Cadenza SDK family — a single-file scripting MSBuild SDK that wraps the official ModelContextProtocol C# SDK (maintained jointly by Anthropic and Microsoft).

Quick start

Create a server.cs file:

#!/usr/bin/env dotnet run
#:sdk [email protected]

Tool("read_file", "Read a UTF-8 text file from disk",
    (string path) => ReadText(path));

Tool("list_files", "List files matching a glob pattern",
    (string pattern) => Glob(pattern).ToArray());

await Run();

Run iteratively:

dotnet run server.cs

Register with Claude Desktop (or another MCP client) by adding to its config:

{
  "mcpServers": {
    "cadenza-files": {
      "command": "dotnet",
      "args": ["run", "/absolute/path/to/server.cs"]
    }
  }
}

Publish as a self-contained single binary:

dotnet publish server.cs -r linux-x64 -c Release

Important: stdout is owned by the protocol

Stdio MCP servers carry JSON-RPC over stdout, so the System.Console bare names (WriteLine, Write, ReadLine) are intentionally not part of the Cadenza.Mcp Tier 1 surface. Writing to stdout from user code corrupts the protocol stream and disconnects the client. Use the Log.* helpers for diagnostics — they route through ILogger to stderr.

See the project repository for the full specification, security boundary notes, and additional samples.