Claude Code /xref slash command

Drop this file into .claude/commands/xref.md in any Clojure project to add /xref as a Claude Code slash command.

Prerequisites

Add the :xref alias to your ~/.clojure/deps.edn (or project deps.edn):

:xref {:extra-deps {com.github.danlentz/clj-xref {:mvn/version "0.1.1"}}
       :main-opts  ["-m" "clj-xref.cli"]
       :ns-default clj-xref.tool}

The alias serves both clj -M:xref <cmd> (CLI subcommands used below) and clj -T:xref generate (tool invocation for database generation).

Ensure .clj-xref/ is in .gitignore.

Slash command file

Copy the following into .claude/commands/xref.md:

---

Cross-reference Clojure code with clj-xref

Query the cross-reference database for the current Clojure project. Built on clj-kondo static analysis.

How to run

/xref init                          — generate/regenerate the xref database
/xref who-calls ns/fn               — who calls this function?
/xref calls-who ns/fn               — what does this function call?
/xref who-implements ns/Protocol     — who implements this protocol?
/xref who-dispatches ns/multi        — defmethod dispatch values
/xref who-macroexpands ns/macro      — where is this macro expanded?
/xref unused                         — find dead code
/xref ns-deps ns                     — namespace dependencies
/xref ns-dependents ns               — reverse namespace dependencies
/xref apropos pattern                — search vars by name pattern
/xref graph ns/fn                    — transitive call graph

Instructions

All commands are run via the CLI:

clojure -M:xref <command> [args]

The database is auto-generated on first query if .clj-xref/xref.edn doesn't exist.

Using xref proactively

When working on code changes in this session, use xref proactively:

• Before changing a function signature: run who-calls to find all callers that need updating
• Before understanding unfamiliar code: run calls-who to see dependencies
• Before removing a function: run who-calls to verify nothing depends on it
• After refactoring: run init to regenerate, or use incremental mode:

clojure -M:xref init

Regenerating after edits

After significant code changes, regenerate the database:

clojure -M:xref init