diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..52dd8d2
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+.env
+*.venv
diff --git a/lab-chains-in-langchain.ipynb b/lab-chains-in-langchain.ipynb
index 290f3bb..ffcd8cf 100644
--- a/lab-chains-in-langchain.ipynb
+++ b/lab-chains-in-langchain.ipynb
@@ -18,13 +18,23 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 1,
+   "id": "3fddd30b",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#!pip install python-dotenv"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
    "id": "541eb2f1",
    "metadata": {},
    "outputs": [],
    "source": [
     "import warnings\n",
-    "warnings.filterwarnings('ignore')"
+    "warnings.filterwarnings('ignore')\n"
    ]
   },
   {
@@ -47,7 +57,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": 4,
    "id": "b84e441b",
    "metadata": {
     "tags": []
@@ -59,7 +69,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 13,
+   "execution_count": 5,
    "id": "974acf8e-8f88-42de-88f8-40a82cb58e8b",
    "metadata": {
     "tags": []
@@ -67,12 +77,12 @@
    "outputs": [],
    "source": [
     "import pandas as pd\n",
-    "df = pd.read_csv('./lab/data/Data.csv')"
+    "df = pd.read_csv('./data/Data.csv')"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 15,
+   "execution_count": 6,
    "id": "b7a09c35",
    "metadata": {
     "tags": []
@@ -126,7 +136,7 @@
        "    </tr>\n",
        "    <tr>\n",
        "      <th>4</th>\n",
-       "      <td>Milk Frother Handheld\\n</td>\n",
+       "      <td>Milk Frother Handheld\\r\\n</td>\n",
        "      <td>I loved this product. But they only seem to l...</td>\n",
        "    </tr>\n",
        "  </tbody>\n",
@@ -134,15 +144,22 @@
        "</div>"
       ],
       "text/plain": [
-       "                   Product                                             Review\n",
-       "0     Queen Size Sheet Set  I ordered a king size set. My only criticism w...\n",
-       "1   Waterproof Phone Pouch  I loved the waterproof sac, although the openi...\n",
-       "2      Luxury Air Mattress  This mattress had a small hole in the top of i...\n",
-       "3           Pillows Insert  This is the best throw pillow fillers on Amazo...\n",
-       "4  Milk Frother Handheld\\n   I loved this product. But they only seem to l..."
+       "                     Product  \\\n",
+       "0       Queen Size Sheet Set   \n",
+       "1     Waterproof Phone Pouch   \n",
+       "2        Luxury Air Mattress   \n",
+       "3             Pillows Insert   \n",
+       "4  Milk Frother Handheld\\r\\n   \n",
+       "\n",
+       "                                              Review  \n",
+       "0  I ordered a king size set. My only criticism w...  \n",
+       "1  I loved the waterproof sac, although the openi...  \n",
+       "2  This mattress had a small hole in the top of i...  \n",
+       "3  This is the best throw pillow fillers on Amazo...  \n",
+       "4   I loved this product. But they only seem to l...  "
       ]
      },
-     "execution_count": 15,
+     "execution_count": 6,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -161,71 +178,330 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 19,
    "id": "427e1119",
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Requirement already satisfied: langchain in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (1.3.14)\n",
+      "Requirement already satisfied: langchain-openai in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (1.4.1)\n",
+      "Requirement already satisfied: langchain-core in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (1.5.3)\n",
+      "Collecting langchain-community\n",
+      "  Using cached langchain_community-0.4.2-py3-none-any.whl.metadata (3.4 kB)\n",
+      "Requirement already satisfied: langgraph<1.3.0,>=1.2.5 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langchain) (1.2.10)\n",
+      "Requirement already satisfied: pydantic<3.0.0,>=2.7.4 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langchain) (2.13.4)\n",
+      "Requirement already satisfied: jsonpatch<2.0.0,>=1.33.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langchain-core) (1.33)\n",
+      "Requirement already satisfied: langchain-protocol>=0.0.17 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langchain-core) (0.0.18)\n",
+      "Requirement already satisfied: langsmith<1.0.0,>=0.3.45 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langchain-core) (0.10.15)\n",
+      "Requirement already satisfied: packaging>=23.2.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langchain-core) (26.2)\n",
+      "Requirement already satisfied: pyyaml<7.0.0,>=5.3.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langchain-core) (6.0.3)\n",
+      "Requirement already satisfied: tenacity!=8.4.0,<10.0.0,>=8.1.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langchain-core) (9.1.4)\n",
+      "Requirement already satisfied: typing-extensions<5.0.0,>=4.7.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langchain-core) (4.16.0)\n",
+      "Requirement already satisfied: uuid-utils<1.0,>=0.12.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langchain-core) (0.17.0)\n",
+      "Requirement already satisfied: jsonpointer>=1.9 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from jsonpatch<2.0.0,>=1.33.0->langchain-core) (3.1.1)\n",
+      "Requirement already satisfied: langgraph-checkpoint<5.0.0,>=4.1.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langgraph<1.3.0,>=1.2.5->langchain) (4.1.1)\n",
+      "Requirement already satisfied: langgraph-prebuilt<1.2.0,>=1.1.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langgraph<1.3.0,>=1.2.5->langchain) (1.1.0)\n",
+      "Requirement already satisfied: langgraph-sdk<0.5.0,>=0.4.2 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langgraph<1.3.0,>=1.2.5->langchain) (0.4.2)\n",
+      "Requirement already satisfied: xxhash>=3.5.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langgraph<1.3.0,>=1.2.5->langchain) (3.8.1)\n",
+      "Requirement already satisfied: ormsgpack>=1.12.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langgraph-checkpoint<5.0.0,>=4.1.0->langgraph<1.3.0,>=1.2.5->langchain) (1.12.2)\n",
+      "Requirement already satisfied: httpx>=0.25.2 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langgraph-sdk<0.5.0,>=0.4.2->langgraph<1.3.0,>=1.2.5->langchain) (0.28.1)\n",
+      "Requirement already satisfied: orjson>=3.11.5 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langgraph-sdk<0.5.0,>=0.4.2->langgraph<1.3.0,>=1.2.5->langchain) (3.11.9)\n",
+      "Requirement already satisfied: websockets<16,>=14 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langgraph-sdk<0.5.0,>=0.4.2->langgraph<1.3.0,>=1.2.5->langchain) (15.0.1)\n",
+      "Requirement already satisfied: anyio>=3.5.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langsmith<1.0.0,>=0.3.45->langchain-core) (4.14.2)\n",
+      "Requirement already satisfied: distro>=1.7.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langsmith<1.0.0,>=0.3.45->langchain-core) (1.9.0)\n",
+      "Requirement already satisfied: requests-toolbelt>=1.0.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langsmith<1.0.0,>=0.3.45->langchain-core) (1.0.0)\n",
+      "Requirement already satisfied: requests>=2.0.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langsmith<1.0.0,>=0.3.45->langchain-core) (2.34.2)\n",
+      "Requirement already satisfied: sniffio>=1.1 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langsmith<1.0.0,>=0.3.45->langchain-core) (1.3.1)\n",
+      "Requirement already satisfied: zstandard>=0.23.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langsmith<1.0.0,>=0.3.45->langchain-core) (0.25.0)\n",
+      "Requirement already satisfied: certifi in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from httpx>=0.25.2->langgraph-sdk<0.5.0,>=0.4.2->langgraph<1.3.0,>=1.2.5->langchain) (2026.7.22)\n",
+      "Requirement already satisfied: httpcore==1.* in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from httpx>=0.25.2->langgraph-sdk<0.5.0,>=0.4.2->langgraph<1.3.0,>=1.2.5->langchain) (1.0.9)\n",
+      "Requirement already satisfied: idna in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from httpx>=0.25.2->langgraph-sdk<0.5.0,>=0.4.2->langgraph<1.3.0,>=1.2.5->langchain) (3.18)\n",
+      "Requirement already satisfied: h11>=0.16 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from httpcore==1.*->httpx>=0.25.2->langgraph-sdk<0.5.0,>=0.4.2->langgraph<1.3.0,>=1.2.5->langchain) (0.16.0)\n",
+      "Requirement already satisfied: annotated-types>=0.6.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from pydantic<3.0.0,>=2.7.4->langchain) (0.8.0)\n",
+      "Requirement already satisfied: pydantic-core==2.46.4 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from pydantic<3.0.0,>=2.7.4->langchain) (2.46.4)\n",
+      "Requirement already satisfied: typing-inspection>=0.4.2 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from pydantic<3.0.0,>=2.7.4->langchain) (0.4.2)\n",
+      "Requirement already satisfied: openai<3.0.0,>=2.45.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langchain-openai) (2.53.0)\n",
+      "Requirement already satisfied: tiktoken<1.0.0,>=0.7.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langchain-openai) (0.13.0)\n",
+      "Requirement already satisfied: jiter<1,>=0.10.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from openai<3.0.0,>=2.45.0->langchain-openai) (0.16.0)\n",
+      "Requirement already satisfied: tqdm>4 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from openai<3.0.0,>=2.45.0->langchain-openai) (4.70.0)\n",
+      "Requirement already satisfied: regex in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from tiktoken<1.0.0,>=0.7.0->langchain-openai) (2026.7.19)\n",
+      "Collecting aiohttp<4.0.0,>=3.8.3 (from langchain-community)\n",
+      "  Using cached aiohttp-3.14.3-cp314-cp314-win_amd64.whl.metadata (8.5 kB)\n",
+      "Collecting httpx-sse<1.0.0,>=0.4.0 (from langchain-community)\n",
+      "  Using cached httpx_sse-0.4.3-py3-none-any.whl.metadata (9.7 kB)\n",
+      "Collecting langchain-classic<2.0.0,>=1.0.7 (from langchain-community)\n",
+      "  Using cached langchain_classic-1.0.8-py3-none-any.whl.metadata (5.1 kB)\n",
+      "Requirement already satisfied: numpy>=2.1.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from langchain-community) (2.5.1)\n",
+      "Collecting pydantic-settings<3.0.0,>=2.10.1 (from langchain-community)\n",
+      "  Using cached pydantic_settings-2.14.2-py3-none-any.whl.metadata (3.4 kB)\n",
+      "Collecting sqlalchemy<3.0.0,>=1.4.0 (from langchain-community)\n",
+      "  Using cached sqlalchemy-2.0.51-cp314-cp314-win_amd64.whl.metadata (9.8 kB)\n",
+      "Collecting aiohappyeyeballs>=2.5.0 (from aiohttp<4.0.0,>=3.8.3->langchain-community)\n",
+      "  Using cached aiohappyeyeballs-2.7.1-py3-none-any.whl.metadata (5.9 kB)\n",
+      "Collecting aiosignal>=1.4.0 (from aiohttp<4.0.0,>=3.8.3->langchain-community)\n",
+      "  Using cached aiosignal-1.4.0-py3-none-any.whl.metadata (3.7 kB)\n",
+      "Collecting attrs>=17.3.0 (from aiohttp<4.0.0,>=3.8.3->langchain-community)\n",
+      "  Using cached attrs-26.1.0-py3-none-any.whl.metadata (8.8 kB)\n",
+      "Collecting frozenlist>=1.1.1 (from aiohttp<4.0.0,>=3.8.3->langchain-community)\n",
+      "  Using cached frozenlist-1.8.0-cp314-cp314-win_amd64.whl.metadata (21 kB)\n",
+      "Collecting multidict<7.0,>=4.5 (from aiohttp<4.0.0,>=3.8.3->langchain-community)\n",
+      "  Using cached multidict-6.7.1-cp314-cp314-win_amd64.whl.metadata (5.5 kB)\n",
+      "Collecting propcache>=0.2.0 (from aiohttp<4.0.0,>=3.8.3->langchain-community)\n",
+      "  Using cached propcache-0.5.2-cp314-cp314-win_amd64.whl.metadata (17 kB)\n",
+      "Collecting yarl<2.0,>=1.17.0 (from aiohttp<4.0.0,>=3.8.3->langchain-community)\n",
+      "  Using cached yarl-1.24.5-cp314-cp314-win_amd64.whl.metadata (107 kB)\n",
+      "Collecting langchain-text-splitters<2.0.0,>=1.1.2 (from langchain-classic<2.0.0,>=1.0.7->langchain-community)\n",
+      "  Using cached langchain_text_splitters-1.1.2-py3-none-any.whl.metadata (3.3 kB)\n",
+      "Requirement already satisfied: python-dotenv>=0.21.0 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from pydantic-settings<3.0.0,>=2.10.1->langchain-community) (1.2.2)\n",
+      "Requirement already satisfied: charset_normalizer<4,>=2 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from requests>=2.0.0->langsmith<1.0.0,>=0.3.45->langchain-core) (3.4.9)\n",
+      "Requirement already satisfied: urllib3<3,>=1.26 in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from requests>=2.0.0->langsmith<1.0.0,>=0.3.45->langchain-core) (2.7.0)\n",
+      "Collecting greenlet>=1 (from sqlalchemy<3.0.0,>=1.4.0->langchain-community)\n",
+      "  Using cached greenlet-3.5.4-cp314-cp314-win_amd64.whl.metadata (3.9 kB)\n",
+      "Requirement already satisfied: colorama in c:\\users\\gbt h610m-\\documents\\ironhack\\task\\lab-chains-in-langchain\\.venv\\lib\\site-packages (from tqdm>4->openai<3.0.0,>=2.45.0->langchain-openai) (0.4.6)\n",
+      "Using cached langchain_community-0.4.2-py3-none-any.whl (2.4 MB)\n",
+      "Using cached aiohttp-3.14.3-cp314-cp314-win_amd64.whl (481 kB)\n",
+      "Using cached httpx_sse-0.4.3-py3-none-any.whl (9.0 kB)\n",
+      "Using cached langchain_classic-1.0.8-py3-none-any.whl (1.0 MB)\n",
+      "Using cached langchain_text_splitters-1.1.2-py3-none-any.whl (35 kB)\n",
+      "Using cached multidict-6.7.1-cp314-cp314-win_amd64.whl (45 kB)\n",
+      "Using cached pydantic_settings-2.14.2-py3-none-any.whl (61 kB)\n",
+      "Using cached sqlalchemy-2.0.51-cp314-cp314-win_amd64.whl (2.1 MB)\n",
+      "Using cached yarl-1.24.5-cp314-cp314-win_amd64.whl (99 kB)\n",
+      "Using cached aiohappyeyeballs-2.7.1-py3-none-any.whl (15 kB)\n",
+      "Using cached aiosignal-1.4.0-py3-none-any.whl (7.5 kB)\n",
+      "Using cached attrs-26.1.0-py3-none-any.whl (67 kB)\n",
+      "Using cached frozenlist-1.8.0-cp314-cp314-win_amd64.whl (44 kB)\n",
+      "Using cached greenlet-3.5.4-cp314-cp314-win_amd64.whl (248 kB)\n",
+      "Using cached propcache-0.5.2-cp314-cp314-win_amd64.whl (42 kB)\n",
+      "Installing collected packages: propcache, multidict, httpx-sse, greenlet, frozenlist, attrs, aiohappyeyeballs, yarl, sqlalchemy, aiosignal, pydantic-settings, aiohttp, langchain-text-splitters, langchain-classic, langchain-community\n",
+      "\n",
+      "   -------- -------------------------------  3/15 [greenlet]\n",
+      "   -------- -------------------------------  3/15 [greenlet]\n",
+      "   ------------- --------------------------  5/15 [attrs]\n",
+      "   --------------------- ------------------  8/15 [sqlalchemy]\n",
+      "   --------------------- ------------------  8/15 [sqlalchemy]\n",
+      "   --------------------- ------------------  8/15 [sqlalchemy]\n",
+      "   --------------------- ------------------  8/15 [sqlalchemy]\n",
+      "   --------------------- ------------------  8/15 [sqlalchemy]\n",
+      "   --------------------- ------------------  8/15 [sqlalchemy]\n",
+      "   --------------------- ------------------  8/15 [sqlalchemy]\n",
+      "   --------------------- ------------------  8/15 [sqlalchemy]\n",
+      "   --------------------- ------------------  8/15 [sqlalchemy]\n",
+      "   --------------------- ------------------  8/15 [sqlalchemy]\n",
+      "   --------------------- ------------------  8/15 [sqlalchemy]\n",
+      "   --------------------- ------------------  8/15 [sqlalchemy]\n",
+      "   --------------------- ------------------  8/15 [sqlalchemy]\n",
+      "   --------------------- ------------------  8/15 [sqlalchemy]\n",
+      "   --------------------- ------------------  8/15 [sqlalchemy]\n",
+      "   --------------------- ------------------  8/15 [sqlalchemy]\n",
+      "   --------------------- ------------------  8/15 [sqlalchemy]\n",
+      "   -------------------------- ------------- 10/15 [pydantic-settings]\n",
+      "   ----------------------------- ---------- 11/15 [aiohttp]\n",
+      "   ----------------------------- ---------- 11/15 [aiohttp]\n",
+      "   ----------------------------- ---------- 11/15 [aiohttp]\n",
+      "   -------------------------------- ------- 12/15 [langchain-text-splitters]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ---------------------------------- ----- 13/15 [langchain-classic]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ------------------------------------- -- 14/15 [langchain-community]\n",
+      "   ---------------------------------------- 15/15 [langchain-community]\n",
+      "\n",
+      "Successfully installed aiohappyeyeballs-2.7.1 aiohttp-3.14.3 aiosignal-1.4.0 attrs-26.1.0 frozenlist-1.8.0 greenlet-3.5.4 httpx-sse-0.4.3 langchain-classic-1.0.8 langchain-community-0.4.2 langchain-text-splitters-1.1.2 multidict-6.7.1 propcache-0.5.2 pydantic-settings-2.14.2 sqlalchemy-2.0.51 yarl-1.24.5\n"
+     ]
+    },
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      "[notice] A new release of pip is available: 25.3 -> 26.2\n",
+      "[notice] To update, run: python.exe -m pip install --upgrade pip\n"
+     ]
+    }
+   ],
    "source": [
-    "!pip install langchain_community"
+    "!pip install langchain langchain-openai langchain-core langchain-community"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 17,
+   "execution_count": 27,
    "id": "e92dff22",
    "metadata": {
     "tags": []
    },
    "outputs": [],
    "source": [
+    "\n",
     "from langchain_openai import ChatOpenAI\n",
-    "from langchain.prompts import ChatPromptTemplate\n",
-    "from langchain.chains import LLMChain"
+    "from langchain_core.prompts import ChatPromptTemplate\n",
+    "from langchain_core.output_parsers import StrOutputParser\n",
+    "#from langchain_.chains import LLMChain\n",
+    "#from langchain_community.chains import LLMChain\n",
+    "#from langchain.chains.llm import LLMChain"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 21,
    "id": "943237a7",
    "metadata": {},
    "outputs": [],
    "source": [
     "#Replace None by your own value and justify\n",
-    "llm = ChatOpenAI(temperature=None)\n"
+    "llm = ChatOpenAI(temperature=0.7)\n"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 22,
    "id": "cdcdb42d",
    "metadata": {},
    "outputs": [],
    "source": [
     "prompt = ChatPromptTemplate.from_template( #Write a query that would take a variable to describe any product\n",
-    " \n",
+    "  \"Describe the following product in detail: {product}\"\n",
     ")"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 28,
    "id": "d7abc20b",
    "metadata": {},
    "outputs": [],
    "source": [
     "\n",
-    "chain = LLMChain(llm=llm, prompt=prompt)"
+    "#chain = LLMChain(llm=llm, prompt=prompt)\n",
+    "chain = prompt | llm | StrOutputParser()"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 30,
    "id": "ad44d1fb",
    "metadata": {},
    "outputs": [],
    "source": [
-    "product = #Select a product type to be describe\n",
-    "chain.run(product)"
+    "product = \"smartphone\"\n",
+    "#chain.run(product)\n",
+    "result = chain.invoke({\"product\": product})"
    ]
   },
   {
@@ -238,10 +514,22 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 31,
    "id": "febee243",
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "ename": "ModuleNotFoundError",
+     "evalue": "No module named 'langchain.chains'",
+     "output_type": "error",
+     "traceback": [
+      "\u001b[31m---------------------------------------------------------------------------\u001b[39m",
+      "\u001b[31mModuleNotFoundError\u001b[39m                       Traceback (most recent call last)",
+      "\u001b[36mCell\u001b[39m\u001b[36m \u001b[39m\u001b[32mIn[31]\u001b[39m\u001b[32m, line 1\u001b[39m\n\u001b[32m----> \u001b[39m\u001b[32m1\u001b[39m \u001b[38;5;28;01mfrom\u001b[39;00m langchain.chains \u001b[38;5;28;01mimport\u001b[39;00m SimpleSequentialChain\n",
+      "\u001b[31mModuleNotFoundError\u001b[39m: No module named 'langchain.chains'"
+     ]
+    }
+   ],
    "source": [
     "from langchain.chains import SimpleSequentialChain"
    ]
@@ -257,7 +545,7 @@
     "\n",
     "# prompt template 1\n",
     "first_prompt = ChatPromptTemplate.from_template(\n",
-    "    #Repeat the initial query or create a new query that would feed into the second prompt\n",
+    "    \"What is a good name for a company that makes {product}?\"\n",
     ")\n",
     "\n",
     "# Chain 1\n",
@@ -274,7 +562,7 @@
     "\n",
     "# prompt template 2\n",
     "second_prompt = ChatPromptTemplate.from_template(\n",
-    "    #Write the second prompt query that takes an input variable whose input will come from the previous prompt\"\n",
+    "    \"give me a short description for a company named {company_name} that makes {product}\"\n",
     ")\n",
     "# chain 2\n",
     "chain_two = LLMChain(llm=llm, prompt=second_prompt)"
@@ -339,11 +627,11 @@
     "\n",
     "\n",
     "first_prompt = ChatPromptTemplate.from_template(\n",
-    "  #This prompt should translate a review\n",
+    "  \"Translate the following review to English:\\n\\n{Review}\"\n",
     ")\n",
     "\n",
     "chain_one = LLMChain(llm=llm, prompt=first_prompt, \n",
-    "                     output_key=None #Give a name to your output\n",
+    "                     output_key=\"English_Review\" #Give a name to your output\n",
     "                    )\n"
    ]
   },
@@ -355,11 +643,11 @@
    "outputs": [],
    "source": [
     "second_prompt = ChatPromptTemplate.from_template(\n",
-    "    #Write a promplt to summarize a review\n",
+    "    \"Can you summarize the following review in one short sentence?\\n\\n{English_Review}\"\n",
     ")\n",
     "\n",
     "chain_two = LLMChain(llm=llm, prompt=second_prompt, \n",
-    "                     output_key=None #give a name to this output\n",
+    "                     output_key=\"summary\" #give a name to this output\n",
     "                    )\n"
    ]
   },
@@ -372,11 +660,11 @@
    "source": [
     "# prompt template 3: translate to english or other language\n",
     "third_prompt = ChatPromptTemplate.from_template(\n",
-    "    None\n",
+    "     \"What language is the following review written in?\\n\\n{Review}\"\n",
     ")\n",
     "# chain 3: input= Review and output= language\n",
     "chain_three = LLMChain(llm=llm, prompt=third_prompt,\n",
-    "                       output_key=None\n",
+    "                       output_key=\"language\"\n",
     "                      )\n"
    ]
   },
@@ -390,10 +678,20 @@
     "\n",
     "# prompt template 4: follow up message that take as inputs the two previous prompts' variables\n",
     "fourth_prompt = ChatPromptTemplate.from_template(\n",
-    "        None\n",
+    "        \"\"\"Write a follow-up response to the following customer review.\n",
+    "\n",
+    "        Review language: {language}\n",
+    "\n",
+    "        Review:\n",
+    "        {English_Review}\n",
+    "\n",
+    "        Summary:\n",
+    "        {summary}\n",
+    "\n",
+    "        Response:\"\"\"\n",
     ")\n",
     "chain_four = LLMChain(llm=llm, prompt=fourth_prompt,\n",
-    "                      output_key=None\n",
+    "                      output_key=\"followup_message\"\n",
     "                     )\n"
    ]
   },
@@ -408,10 +706,13 @@
     "# and output= English_Review,summary, followup_message\n",
     "overall_chain = SequentialChain(\n",
     "    chains=[chain_one, chain_two, chain_three, chain_four],\n",
-    "    input_variables=None,\n",
-    "    output_variables=[None, None, None],\n",
-    "    verbose=True\n",
-    ")"
+    "    input_variables=[\"Review\"],\n",
+    "    output_variables=[\n",
+    "        \"English_Review\",\n",
+    "        \"summary\",\n",
+    "        \"followup_message\",\n",
+    "    ],\n",
+    "    verbose=True"
    ]
   },
   {
@@ -706,7 +1007,7 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3 (ipykernel)",
+   "display_name": ".venv (3.14.3.final.0)",
    "language": "python",
    "name": "python3"
   },
@@ -720,7 +1021,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.11.8"
+   "version": "3.14.3"
   }
  },
  "nbformat": 4,