--- a/gui_ze/gui_ze.bzl	Mon Jan 12 09:12:31 2026 -0800
+++ b/gui_ze/gui_ze.bzl	Mon Jan 12 15:20:39 2026 -0800
@@ -203,6 +203,69 @@
   },
 )
 
+def _bun_run_impl(ctx):
+    actual_exe = ctx.actions.declare_file(ctx.label.name)
+    
+    # 1. Get the workspace name (crucial for runfiles paths)
+    workspace_name = ctx.workspace_name
+
+    # 2. Define the paths relative to the runfiles root
+    bun_path = ctx.executable._bun.short_path
+    src_path = ctx.file.src.short_path
+
+    # 3. Create the launcher script
+    # We use a template to handle the environment and pathing
+    script_content = """#!/bin/bash
+# Find the runfiles directory
+if [[ -z "$RUNFILES_DIR" ]]; then
+  if [[ -d "$0.runfiles" ]]; then
+    RUNFILES_DIR="$0.runfiles"
+  fi
+fi
+
+# Navigate to the workspace root inside runfiles
+cd "$RUNFILES_DIR/{workspace}"
+pwd
+# Execute bun with the src file and any extra arguments
+exec "./{bun_bin}" run "./{src_file}" "$@"
+""".format(
+        workspace = workspace_name,
+        bun_bin = bun_path,
+        src_file = src_path
+    )
+
+    ctx.actions.write(
+        output = actual_exe,
+        content = script_content,
+        is_executable = True,
+    )
+
+    return [
+        DefaultInfo(
+            executable = actual_exe,
+            runfiles = ctx.runfiles(
+                files = [ctx.file.src] + ctx.files.data + ctx.files._bun_files
+            ).merge(ctx.attr._bun[DefaultInfo].default_runfiles),
+        ),
+    ]
+
+# TODO: Fix the rules so that it can do relative import.
+bun_run = rule(
+  implementation = _bun_run_impl,
+  executable = True,
+  attrs = {
+    "src": attr.label(allow_single_file = True, mandatory = True),
+    "data": attr.label_list(allow_files = True),
+    "_bun": attr.label(
+      default = Label("//third_party/bun:bun"), 
+      executable = True, 
+      cfg = "exec"
+    ),
+    "_bun_files": attr.label(default = Label("//third_party/bun:bun_files")),
+  },
+)
+
+
 def _move_files_into_dir_impl(ctx):
   srcs = ctx.files.srcs
   outs = []