lsp-mcp

Clojure LSP analysis addon for hive-mcp. Provides structural code analysis via three strategies:

1. Docker sidecar cache -- fast reads from pre-analyzed snapshots
2. In-process clojure-lsp -- fallback when cache is unavailable
3. Live Emacs LSP bridge -- real-time, position-aware queries via running clojure-lsp in Emacs

Registered as an IAddon (lsp.mcp). The engine discovers it automatically from the classpath manifest.

Project Structure

lsp-mcp/
  src/lsp_mcp/
    bridge.clj          # ILspBridge protocol (DIP abstraction)
    emacs_bridge.clj     # EmacsBridge -- Emacs backend (optional)
    tools.clj            # MCP tool handlers + command dispatch
    init.clj             # IAddon implementation + nil-railway pipeline
    core.clj             # Analysis orchestration
    cache.clj            # Docker sidecar cache client
    analysis.clj         # Extraction helpers (vars, calls, ns-graph)
    kg_bridge.clj        # Knowledge Graph sync bridge
    log.clj              # Logging shim (timbre/stderr)
  src-cljel/
    hive_lsp_bridge.cljel  # Elisp source (Clojure syntax)
  resources/
    elisp/
      hive-lsp-bridge.el   # Compiled output (checked in)
    META-INF/hive-addons/
      lsp-mcp.edn          # Addon manifest

Compiling .cljel to .el

The src-cljel/ directory contains Elisp source written in Clojure syntax using clojure-elisp. The compiler translates .cljel files to standard Emacs Lisp .el files.

One-time compilation

From the lsp-mcp project root:

clojure \
  -Sdeps '{:deps {io.github.lages/clojure-elisp {:local/root "/home/lages/PP/clojure-elisp"}}}' \
  -M -e '(require (quote [clojure-elisp.core :as clel]))
         (clel/compile-file "src-cljel/hive_lsp_bridge.cljel"
                            "resources/elisp/hive-lsp-bridge.el")'

This reads the .cljel source, compiles all forms through the clojure-elisp analyzer/emitter, and writes the output .el file. The compiled file:

• Starts with ;;; hive-lsp-bridge.el --- -*- lexical-binding: t; -*-
• Requires clojure-elisp-runtime (must be on Emacs load-path)
• Ends with (provide 'hive-lsp-bridge)

Naming conventions

.cljel source	compiled .el output	Elisp feature name
hive_lsp_bridge.cljel	hive-lsp-bridge.el	hive-lsp-bridge

The compiler converts underscores to hyphens and derives the feature name from the (ns ...) form.

Function name mapping

.cljel definition	compiled Elisp name
(defn status ...)	hive-lsp-bridge-status
(defn -find-workspace ...)	hive-lsp-bridge--find-workspace
(defn hover ...)	hive-lsp-bridge-hover

Public functions get the namespace prefix (hive-lsp-bridge-). Private functions (prefixed with -) get a double-dash (hive-lsp-bridge--).

Live development with CIDER

For interactive development without recompiling the whole file:

1. Open hive_lsp_bridge.cljel in Emacs
2. cider-jack-in to the clojure-elisp project
3. M-x cider-cljel-start to enable the cljel CIDER session
4. C-c C-e on any defn form -- compiles to Elisp and evals in Emacs immediately
5. M-: (hive-lsp-bridge-status) to verify the function works

When to recompile

Recompile and commit the .el output after changing any .cljel source. The compiled .el is checked into version control so that Emacs can load it at runtime without needing the compiler on the classpath.

Runtime: how the .el gets loaded

The compiled .el is loaded on-the-fly by the Clojure bridge, not by user Emacs config. The sequence:

1. MCP tool call arrives (e.g. lsp command=emacs-hover)
2. emacs_bridge.clj injects resources/elisp/ into Emacs load-path (once)
3. require-and-call-json generates: (progn (require 'hive-lsp-bridge nil t) (json-encode (hive-lsp-bridge-hover ...)))
4. eval-elisp-with-timeout sends it to Emacs via emacsclient --eval
5. Emacs loads the feature, calls the function, returns JSON

Prerequisites:

• clojure-elisp-runtime must be on Emacs load-path (from the clojure-elisp project)
• Emacs daemon running with lsp-mode and clojure-lsp active

MCP Commands

Static analysis (strategies 1 & 2)

Command	Description
analyze	Project summary (files, namespaces, vars)
definitions	List var definitions, optionally filtered by namespace
calls	Call graph, filtered by namespace/function
callers	Find callers of a function
references	Find references to a function
ns-graph	Namespace dependency graph
sync	Sync analysis to Knowledge Graph
status	Cache and bridge status

Live Emacs LSP bridge (strategy 3)

Command	Parameters	Description
emacs-status	--	Check bridge availability and workspace count
emacs-workspaces	--	List active LSP workspaces
emacs-hover	project_root, file_path, line, column	Hover info at position
emacs-definition	project_root, file_path, line, column	Go-to-definition
emacs-references	project_root, file_path, line, column	Find all references
emacs-symbols	project_root, file_path	Document symbols
emacs-cursor-info	project_root, file_path, line, column	clojure-lsp cursor info
emacs-server-info	project_root	clojure-lsp server info

line and column are 0-based.

Architecture

MCP tool call
  -> tools.clj (command dispatch)
       |
       +-- Static: core.clj -> cache.clj / clojure-lsp.api
       |
       +-- Live:   ILspBridge protocol
                     |
                     +-- EmacsBridge (emacs_bridge.clj)
                           |
                           +-- emacsclient --eval
                                 |
                                 +-- (require 'hive-lsp-bridge)  [compiled .el]
                                       |
                                       +-- lsp-request -> clojure-lsp in Emacs

The ILspBridge protocol (DIP) decouples tools.clj from any specific LSP backend. EmacsBridge is one implementation; a future StdioBridge could talk to clojure-lsp directly over stdio.

License

MIT