Basilisp nREPL Bridge

GitHub
Basilisp nREPL MCP Bridge

This project provides a bridge between Anthropic's Model Control Protocol (MCP) and Basilisp's nREPL server, allowing Claude Code to interact directly with a Basilisp REPL. Actually, it should work with any nREPL, but the current prompts are Basilisp focused.

Features

  • Execute code and receive pretty-printed, syntax-highlighted results
  • Get documentation for symbols
  • List all available namespaces
  • Find all variables in a namespace
  • Check nREPL server connectivity
  • Basilisp: Python interop with proper syntax for attribute access and method calls
  • Enhanced error reporting and formatting

Requirements

Usage

  1. Start a Basilisp nREPL server:

    basilisp nrepl-server --port 36915

  2. Add the MCP bridge to Claude Code:

    claude mcp add /home/a/subjective/snr/basilisp_mcp_bridge.py

  3. Connect with Claude and use the available tools:

    • eval_code(code) - Evaluate Basilisp code
    • get_docs(symbol) - Get documentation for a symbol
    • find_namespace_vars(namespace) - List variables in a namespace
    • list_namespaces() - List all available namespaces
    • check_connection() - Verify nREPL connectivity

Python Interop Examples

;; Import a module
(import [math :as math])

;; Access an attribute
(. math -pi)  ;; or (.-pi math)

;; Call a method
(.sin math 0)

;; Create Python data structures
#py{"key" "value"}

Future Improvements

  • Implement a proper bencode parser (beyond regex)
  • Add session management for multiple REPLs
  • Add auto-completion support