The MCP Language Server is an MCP server that runs and exposes a Language Server Protocol interface to language model clients (LLMs). It enables MCP-enabled clients to navigate codebases with semantic tooling such as get definition, references, rename, and diagnostics via standard LSP features. The project borrows ideas from gopls to handle LSP communication and communicates over stdio, with arguments after -- forwarded to the language server and environment variables passed through. It supports integrating a variety of language servers (e.g., gopls, rust-analyzer, pyright-langserver, typescript-language-server, clangd) through the --lsp flag, enabling multi-language support for MCP contexts. The tooling exposes actions like definition, references, diagnostics, hover, rename_symbol, and edit_file, and includes a snapshot-based integration test suite that runs on mock workspaces across languages. This setup is designed for beta usage, easy local development, and integration with editors and Claude-like clients that host MCP-enabled language services.