diff --git a/cookbook/pageindex_RAG_simple.ipynb b/cookbook/pageindex_RAG_simple.ipynb
index 36dd687..a56d15f 100644
--- a/cookbook/pageindex_RAG_simple.ipynb
+++ b/cookbook/pageindex_RAG_simple.ipynb
@@ -126,9 +126,9 @@
       },
       "outputs": [],
       "source": [
-        "import os, json, openai, requests, textwrap\n",
+        "import json, os, requests\n",
         "from pageindex import PageIndexClient\n",
-        "from pprint import pprint\n",
+        "import pageindex.utils as utils\n",
         "\n",
         "# Get your PageIndex API key from https://dash.pageindex.ai/api-keys\n",
         "PAGEINDEX_API_KEY = \"YOUR_PAGEINDEX_API_KEY\"\n",
@@ -137,60 +137,6 @@
         "pi_client = PageIndexClient(api_key=PAGEINDEX_API_KEY)"
       ]
     },
-    {
-      "cell_type": "markdown",
-      "metadata": {
-        "id": "AR7PLeVbcG1N"
-      },
-      "source": [
-        "#### 0.3 Define utility functions"
-      ]
-    },
-    {
-      "cell_type": "code",
-      "execution_count": 40,
-      "metadata": {
-        "id": "hmj3POkDcG1N"
-      },
-      "outputs": [],
-      "source": [
-        "async def call_llm(prompt, model=\"gpt-4.1\", temperature=0):\n",
-        "    client = openai.AsyncOpenAI(api_key=OPENAI_API_KEY)\n",
-        "    response = await client.chat.completions.create(\n",
-        "        model=model,\n",
-        "        messages=[{\"role\": \"user\", \"content\": prompt}],\n",
-        "        temperature=temperature\n",
-        "    )\n",
-        "    return response.choices[0].message.content.strip()\n",
-        "\n",
-        "def remove_fields(data, fields=['text'], max_len=None):\n",
-        "    if isinstance(data, dict):\n",
-        "        return {k: remove_fields(v, fields, max_len) for k, v in data.items() if k not in fields}\n",
-        "    elif isinstance(data, list):\n",
-        "        return [remove_fields(item, fields, max_len) for item in data]\n",
-        "    elif isinstance(data, str):\n",
-        "        return data[:max_len] + '...' if max_len is not None and len(data) > max_len else data\n",
-        "    return data\n",
-        "\n",
-        "def print_tree(tree, exclude_fields=['text', 'page_index']):\n",
-        "    cleaned_tree = remove_fields(tree.copy(), exclude_fields, max_len=40)\n",
-        "    pprint(cleaned_tree, sort_dicts=False, width=100)\n",
-        "\n",
-        "def show(text, width=100):\n",
-        "    for line in text.splitlines():\n",
-        "        print(textwrap.fill(line, width=width))\n",
-        "\n",
-        "def create_node_mapping(tree):\n",
-        "    \"\"\"Create a mapping of node_id to node for quick lookup\"\"\"\n",
-        "    def get_all_nodes(tree):\n",
-        "        if isinstance(tree, dict):\n",
-        "            return [tree] + [node for child in tree.get('nodes', []) for node in get_all_nodes(child)]\n",
-        "        elif isinstance(tree, list):\n",
-        "            return [node for item in tree for node in get_all_nodes(item)]\n",
-        "        return []\n",
-        "    return {node[\"node_id\"]: node for node in get_all_nodes(tree) if node.get(\"node_id\")}"
-      ]
-    },
     {
       "cell_type": "markdown",
       "metadata": {
@@ -346,7 +292,7 @@
         "if pi_client.is_retrieval_ready(doc_id):\n",
         "    tree = pi_client.get_tree(doc_id, node_summary=True)['result']\n",
         "    print('Simplified Tree Structure of the Document:')\n",
-        "    print_tree(tree)\n",
+        "    utils.print_tree(tree)\n",
         "else:\n",
         "    print(\"Processing document, please try again later...\")"
       ]
@@ -377,7 +323,7 @@
       "source": [
         "query = \"What are the conclusions in this document?\"\n",
         "\n",
-        "tree_without_text = remove_fields(tree.copy(), fields=['text'])\n",
+        "tree_without_text = utils.remove_fields(tree.copy(), fields=['text'])\n",
         "\n",
         "search_prompt = f\"\"\"\n",
         "You are given a question and a tree structure of a document.\n",
@@ -397,7 +343,7 @@
         "Directly return the final JSON structure. Do not output anything else.\n",
         "\"\"\"\n",
         "\n",
-        "tree_search_result = await call_llm(search_prompt)"
+        "tree_search_result = await utils.call_llm(search_prompt, api_key=OPENAI_API_KEY)"
       ]
     },
     {
@@ -438,11 +384,11 @@
         }
       ],
       "source": [
-        "node_map = create_node_mapping(tree)\n",
+        "node_map = utils.create_node_mapping(tree)\n",
         "tree_search_result_json = json.loads(tree_search_result)\n",
         "\n",
         "print('Reasoning Process:')\n",
-        "show(tree_search_result_json['thinking'])\n",
+        "utils.print_wrapped(tree_search_result_json['thinking'])\n",
         "\n",
         "print('\\nRetrieved Nodes:')\n",
         "for node_id in tree_search_result_json[\"node_list\"]:\n",
@@ -508,7 +454,7 @@
         "relevant_content = \"\\n\\n\".join(node_map[node_id][\"text\"] for node_id in node_list)\n",
         "\n",
         "print('Retrieved Context:\\n')\n",
-        "show(relevant_content[:1000] + '...')"
+        "utils.print_wrapped(relevant_content[:1000] + '...')"
       ]
     },
     {
@@ -562,8 +508,8 @@
         "\"\"\"\n",
         "\n",
         "print('Generated Answer:\\n')\n",
-        "answer = await call_llm(answer_prompt)\n",
-        "show(answer)"
+        "answer = await utils.call_llm(answer_prompt, api_key=OPENAI_API_KEY)\n",
+        "utils.print_wrapped(answer)"
       ]
     },
     {