elisp-dev-mcp

Provides intelligent code completion for Emacs Lisp by analyzing the current buffer context, function signatures, and variable bindings. Works by parsing the elisp AST to understand scope and available symbols, then filtering completion candidates based on semantic relevance rather than simple prefix matching. Integrates with Emacs' native completion UI to deliver suggestions inline.

Extracts function signatures, argument lists, and docstrings from elisp code by introspecting function objects at runtime or parsing function definitions statically. Returns structured metadata including parameter names, optional/rest arguments, and documentation, enabling IDE-like hover hints and signature help. Integrates with MCP to deliver this metadata to client tools.

Provides MCP-based access to Emacs buffer and file operations, allowing external tools to read, write, and manipulate buffers and files within the Emacs session. Supports operations like opening files, creating buffers, reading buffer content, and saving changes. Integrates with Emacs' buffer management to ensure consistency.

Enables jumping to function and variable definitions by resolving symbols to their source locations in the Emacs codebase or loaded packages. Uses Emacs' native find-function and find-variable mechanisms combined with source file indexing to map symbols to file paths and line numbers. Exposes this via MCP to support IDE-style 'go to definition' workflows.

Performs static analysis and runtime validation of elisp code to detect syntax errors, undefined variables, and common mistakes. Combines byte-compilation (via Emacs' native byte-compiler) with custom linting rules to catch issues like unused variables, incorrect function calls, and type mismatches. Reports diagnostics via MCP in LSP-compatible format for integration with editor linters.

Supports automated refactoring operations like renaming functions and variables across multiple files, and extracting code into new functions. Works by analyzing the symbol table to find all references to a symbol, then applying transformations while respecting scope and shadowing rules. Uses buffer manipulation and file I/O to apply changes atomically.

Enables executing elisp code snippets directly within the Emacs session via MCP, with results returned to the client. Supports evaluating expressions, loading files, and inspecting the state of the running Emacs instance. Integrates with Emacs' eval function and provides access to the current environment (variables, functions, buffers).

Analyzes elisp code to extract package dependencies, version requirements, and load-path configuration. Parses require and use-package declarations to build a dependency graph, then validates that all dependencies are available and compatible. Integrates with Emacs' package management system (package.el) to check installed versions.

Discovers and executes elisp unit tests by scanning for test functions (typically named test-* or *-test) and test frameworks (ert, buttercup, etc.). Parses test definitions to extract test names and metadata, then runs tests via the framework's API and collects results. Returns test results in a structured format compatible with IDE test runners.

Generates documentation (markdown, HTML, or plain text) from elisp source code by extracting docstrings, function signatures, and variable definitions. Parses code structure to build a documentation outline, then formats it for human consumption. Supports custom templates and styling for different output formats.

Expands elisp macros to show their generated code, enabling developers to understand what code a macro produces. Uses Emacs' macroexpand and macroexpand-all functions to recursively expand macros, then formats the result for readability. Supports stepping through macro expansion to see intermediate steps.