diff --git a/.claude/Skills/Art/tools/generate-ulart-image.ts b/.claude/Skills/Art/tools/generate-ulart-image.ts
index 154d4296..96d2b976 100755
--- a/.claude/Skills/Art/tools/generate-ulart-image.ts
+++ b/.claude/Skills/Art/tools/generate-ulart-image.ts
@@ -18,6 +18,16 @@ import { GoogleGenAI } from "@google/genai";
 import { writeFile, readFile } from "node:fs/promises";
 import { extname, resolve } from "node:path";
 
+// ============================================================================
+// Constants
+// ============================================================================
+
+/**
+ * PAI_DIR - Root directory for PAI configuration
+ * Reads from environment variable PAI_DIR, falls back to ~/.claude
+ */
+const PAI_DIR = process.env.PAI_DIR || resolve(process.env.HOME!, '.claude');
+
 // ============================================================================
 // Environment Loading
 // ============================================================================