Skip to content

Model Context Protocol (MCP) Reference

The libspec MCP server hosts tools that allow LLM agents to query specifications, view diffs, search components, inspect code structures, and manage development workflows. The server implements the standard Model Context Protocol.

Tool Catalog

All tools registered under the server are prefixed with the server's name: mcp_libspec_ (or libspec_ / unprefixed depending on client configuration).

diff

Diffs specification trees natively between Git commits or against live files. * Arguments: * commit_a (string, Optional): Older Git commit / ref (e.g. HEAD~1, main, @1). Defaults to HEAD. * commit_b (string, Optional): Newer Git commit / ref. Defaults to live files (PENDING).

Performs a workspace-wide search for specification components and code symbols using AST analysis. * Arguments: * query (string, Required): The search query pattern or keyword.

list_dependencies

Lists component dependencies for the live specification or a target Git revision. * Arguments: * commit (string, Optional): Git commit/ref. Defaults to live spec (PENDING).

list_components

Lists all specification components present in the live spec or a Git revision. * Arguments: * commit (string, Optional): Git commit/ref. Defaults to live spec (PENDING).

show_component

Shows comprehensive details of a specific component, including docstrings, parent inheritance, and implementation claims. * Arguments: * component_ref (string, Required): Fully qualified name of the class (e.g. spec.app.App). * commit (string, Optional): Git commit/ref. Defaults to live spec (PENDING).

peek

Combined hover, type, and definition lookup for a python component at a specific position. * Arguments: * file_path (string, Required): File containing the symbol. * line (integer, Required): 1-indexed line number. * character (integer, Required): 1-indexed character position.

usage

Finds all semantic references and usages of a python component across the project. * Arguments: * file_path (string, Required): File containing the target symbol. * line (integer, Required): 1-indexed line number. * character (integer, Required): 1-indexed character position.

symbols

Lists all structural components (classes and methods) defined inside a specific file. * Arguments: * file_path (string, Required): Path to target file.

start_lsp

Starts the background Python LSP (pylsp) server for the workspace. * Arguments: * root_dir (string, Optional): Root directory of workspace specs. Defaults to CWD.

pylsp_plugin

Controls active pylsp server plugins. * Arguments: * plugin_name (string, Required): Name of plugin (e.g. hello_ast). * action (string, Optional): Status, enable, or disable. Defaults to "status".

agent_workflow

Recites the standardized 9-step developer agent workflow with client-specific prefixes. * Arguments: * agent (string, Optional): Target agent (e.g. antigravity, gemini, claude). * prefix (string, Optional): Explicit tool prefix.