Basilisp nREPL MCP Bridge

What is Basilisp nREPL MCP Bridge?

Basilisp nREPL MCP Bridge connects Anthropic’s Model Context Protocol (MCP) to a Basilisp nREPL server, enabling Claude Code to evaluate code, inspect namespaces, and get documentation directly from a Basilisp REPL. It is built for developers using Basilisp (or any nREPL) who want to interact with their Lisp environment through Claude.

How to use Basilisp nREPL MCP Bridge?

First, start a Basilisp nREPL server with basilisp nrepl-server --port 36915. Then add the bridge to Claude Code with claude mcp add /path/to/basilisp_mcp_bridge.py. After that, use the provided MCP tools (eval_code, get_docs, find_namespace_vars, list_namespaces, check_connection) inside Claude to interact with the REPL.

Key features of Basilisp nREPL MCP Bridge

• Execute Basilisp code with pretty-printed, syntax-highlighted results
• Get documentation for any symbol in the REPL
• List all available namespaces and their variables
• Check nREPL server connectivity
• Basilisp Python interop with proper attribute/method syntax
• Enhanced error reporting and formatting

Use cases of Basilisp nREPL MCP Bridge

• Evaluate Basilisp code snippets directly from Claude Code
• Look up documentation for functions or macros without leaving the editor
• Discover available symbols and namespaces in a running Basilisp project
• Verify that an nREPL server is reachable and responsive
• Execute Python interop code (imports, attribute access, method calls) within Basilisp

FAQ from Basilisp nREPL MCP Bridge

What are the requirements to run Basilisp nREPL MCP Bridge?

You need uv and basilisp installed.

How do I start the nREPL server?

Run basilisp nrepl-server --port 36915 (or any port of your choice).

How do I add the MCP bridge to Claude Code?

Use the command claude mcp add /path/to/basilisp_mcp_bridge.py.

What tools does the bridge expose?

It provides eval_code, get_docs, find_namespace_vars, list_namespaces, and check_connection.

Does it work with nREPL servers other than Basilisp?

Yes, it should work with any nREPL, but the current prompts are Basilisp focused.