diff --git a/.github/workflows/test-langchain.yml b/.github/workflows/test-langchain.yml
new file mode 100644
index 00000000..b8f0237c
--- /dev/null
+++ b/.github/workflows/test-langchain.yml
@@ -0,0 +1,62 @@
+name: LangChain
+on:
+
+  pull_request:
+    branches: ~
+    paths:
+    - '.github/workflows/test-langchain.yml'
+    - 'framework/langchain/**'
+    - 'testing/ngr.py'
+  push:
+    branches: [ main ]
+    paths:
+    - '.github/workflows/test-langchain.yml'
+    - 'framework/langchain/**'
+    - 'testing/ngr.py'
+
+  # Allow job to be triggered manually.
+  workflow_dispatch:
+
+# Cancel in-progress jobs when pushing to the same branch.
+concurrency:
+  cancel-in-progress: true
+  group: ${{ github.workflow }}-${{ github.ref }}
+
+jobs:
+  test:
+    name: "CrateDB: ${{ matrix.cratedb-version }}
+     Python: ${{ matrix.python-version }}
+     on ${{ matrix.os }}"
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ "ubuntu-latest" ]
+        cratedb-version: [ "nightly" ]
+        python-version: [ "3.11" ]
+
+    services:
+      cratedb:
+        image: crate/crate:nightly
+        ports:
+          - 4200:4200
+          - 5432:5432
+
+    steps:
+
+      - name: Acquire sources
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: ${{ matrix.python-version }}
+          architecture: x64
+          cache: 'pip'
+          cache-dependency-path: |
+            framework/langchain/requirements.txt
+            framework/langchain/requirements-dev.txt
+
+      - name: Validate framework/langchain
+        run: |
+          python testing/ngr.py --accept-no-venv framework/langchain
diff --git a/.gitignore b/.gitignore
index 77abd6ea..9c88f8af 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,5 @@
 .idea
 .venv*
+__pycache__
+.coverage
+coverage.xml
diff --git a/README.rst b/README.rst
index 640d586b..ea677da8 100644
--- a/README.rst
+++ b/README.rst
@@ -50,6 +50,7 @@ Examples::
 
 More examples::
 
+    python testing/ngr.py framework/langchain
     python testing/ngr.py testing/testcontainers/java
 
 It is recommended to invoke ``ngr`` from within a Python virtualenv.
diff --git a/framework/langchain/.gitignore b/framework/langchain/.gitignore
new file mode 100644
index 00000000..d1b811b7
--- /dev/null
+++ b/framework/langchain/.gitignore
@@ -0,0 +1 @@
+*.sql
diff --git a/framework/langchain/conftest.py b/framework/langchain/conftest.py
new file mode 100644
index 00000000..98f88569
--- /dev/null
+++ b/framework/langchain/conftest.py
@@ -0,0 +1,52 @@
+import typing as t
+
+import pytest
+
+
+def monkeypatch_pytest_notebook_treat_cell_exit_as_notebook_skip():
+    """
+    Patch `pytest-notebook`, in fact `nbclient.client.NotebookClient`,
+    to propagate cell-level `pytest.exit()` invocations as signals
+    to mark the whole notebook as skipped.
+
+    In order not to be too intrusive, the feature only skips notebooks
+    when being explicitly instructed, by adding `[skip-notebook]` at the
+    end of the `reason` string. Example:
+
+        import pytest
+        if "ACME_API_KEY" not in os.environ:
+            pytest.exit("ACME_API_KEY not given [skip-notebook]")
+
+    https://github.com/chrisjsewell/pytest-notebook/issues/43
+    """
+    from nbclient.client import NotebookClient
+    from nbclient.exceptions import CellExecutionError
+    from nbformat import NotebookNode
+
+    async_execute_cell_dist = NotebookClient.async_execute_cell
+
+    async def async_execute_cell(
+            self,
+            cell: NotebookNode,
+            cell_index: int,
+            execution_count: t.Optional[int] = None,
+            store_history: bool = True,
+    ) -> NotebookNode:
+        try:
+            return await async_execute_cell_dist(
+                self,
+                cell,
+                cell_index,
+                execution_count=execution_count,
+                store_history=store_history,
+            )
+        except CellExecutionError as ex:
+            if ex.ename == "Exit" and ex.evalue.endswith("[skip-notebook]"):
+                raise pytest.skip(ex.evalue)
+            else:
+                raise
+
+    NotebookClient.async_execute_cell = async_execute_cell
+
+
+monkeypatch_pytest_notebook_treat_cell_exit_as_notebook_skip()
diff --git a/framework/langchain/conversational_memory.ipynb b/framework/langchain/conversational_memory.ipynb
index da0b64bc..f3a0d1cb 100644
--- a/framework/langchain/conversational_memory.ipynb
+++ b/framework/langchain/conversational_memory.ipynb
@@ -58,12 +58,16 @@
    "source": [
     "from langchain.memory.chat_message_histories import CrateDBChatMessageHistory\n",
     "\n",
+    "# Connect to a self-managed CrateDB instance.\n",
     "CONNECTION_STRING = \"crate://crate@localhost/?schema=notebook\"\n",
     "\n",
     "chat_message_history = CrateDBChatMessageHistory(\n",
     "\tsession_id=\"test_session\",\n",
     "\tconnection_string=CONNECTION_STRING\n",
-    ")"
+    ")\n",
+    "\n",
+    "# Make sure to start with a blank canvas.\n",
+    "chat_message_history.clear()"
    ],
    "metadata": {
     "collapsed": false
@@ -101,9 +105,11 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[HumanMessage(content='Hello', additional_kwargs={}, example=False),\n AIMessage(content='Hi', additional_kwargs={}, example=False)]"
+      "text/plain": [
+       "[HumanMessage(content='Hello'), AIMessage(content='Hi')]"
+      ]
      },
-     "execution_count": 4,
+     "execution_count": 5,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -147,7 +153,6 @@
     "from datetime import datetime\n",
     "from typing import Any\n",
     "\n",
-    "from langchain.memory.chat_message_histories.cratedb import generate_autoincrement_identifier\n",
     "from langchain.memory.chat_message_histories.sql import BaseMessageConverter\n",
     "from langchain.schema import AIMessage, BaseMessage, HumanMessage, SystemMessage\n",
     "\n",
@@ -161,7 +166,7 @@
     "class CustomMessage(Base):\n",
     "\t__tablename__ = \"custom_message_store\"\n",
     "\n",
-    "\tid = sa.Column(sa.BigInteger, primary_key=True, default=generate_autoincrement_identifier)\n",
+    "\tid = sa.Column(sa.BigInteger, primary_key=True, server_default=sa.func.now())\n",
     "\tsession_id = sa.Column(sa.Text)\n",
     "\ttype = sa.Column(sa.Text)\n",
     "\tcontent = sa.Column(sa.Text)\n",
@@ -215,6 +220,9 @@
     "\t\t)\n",
     "\t)\n",
     "\n",
+    "\t# Make sure to start with a blank canvas.\n",
+    "\tchat_message_history.clear()\n",
+    "\n",
     "\tchat_message_history.add_user_message(\"Hello\")\n",
     "\tchat_message_history.add_ai_message(\"Hi\")"
    ],
@@ -233,9 +241,11 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[HumanMessage(content='Hello', additional_kwargs={}, example=False),\n AIMessage(content='Hi', additional_kwargs={}, example=False)]"
+      "text/plain": [
+       "[HumanMessage(content='Hello'), AIMessage(content='Hi')]"
+      ]
      },
-     "execution_count": 6,
+     "execution_count": 7,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -268,13 +278,13 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 8,
+   "execution_count": 7,
    "outputs": [],
    "source": [
     "import json\n",
     "import typing as t\n",
     "\n",
-    "from langchain.memory.chat_message_histories.cratedb import generate_autoincrement_identifier, CrateDBMessageConverter\n",
+    "from langchain.memory.chat_message_histories.cratedb import CrateDBMessageConverter\n",
     "from langchain.schema import _message_to_dict\n",
     "\n",
     "\n",
@@ -282,7 +292,7 @@
     "\n",
     "class MessageWithDifferentSessionIdColumn(Base):\n",
     "\t__tablename__ = \"message_store_different_session_id\"\n",
-    "\tid = sa.Column(sa.BigInteger, primary_key=True, default=generate_autoincrement_identifier)\n",
+    "\tid = sa.Column(sa.BigInteger, primary_key=True, server_default=sa.func.now())\n",
     "\tcustom_session_id = sa.Column(sa.Text)\n",
     "\tmessage = sa.Column(sa.Text)\n",
     "\n",
@@ -307,6 +317,9 @@
     "\t\tsession_id_field_name=\"custom_session_id\",\n",
     "\t)\n",
     "\n",
+    "\t# Make sure to start with a blank canvas.\n",
+    "\tchat_message_history.clear()\n",
+    "\n",
     "\tchat_message_history.add_user_message(\"Hello\")\n",
     "\tchat_message_history.add_ai_message(\"Hi\")"
    ],
@@ -316,11 +329,13 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 9,
+   "execution_count": 8,
    "outputs": [
     {
      "data": {
-      "text/plain": "[HumanMessage(content='Hello', additional_kwargs={}, example=False),\n AIMessage(content='Hi', additional_kwargs={}, example=False)]"
+      "text/plain": [
+       "[HumanMessage(content='Hello'), AIMessage(content='Hi')]"
+      ]
      },
      "execution_count": 9,
      "metadata": {},
diff --git a/framework/langchain/conversational_memory.py b/framework/langchain/conversational_memory.py
index 74934e40..4eef99f7 100644
--- a/framework/langchain/conversational_memory.py
+++ b/framework/langchain/conversational_memory.py
@@ -19,11 +19,17 @@
 from langchain.memory.chat_message_histories import CrateDBChatMessageHistory
 
 
+CONNECTION_STRING = os.environ.get(
+    "CRATEDB_CONNECTION_STRING",
+    "crate://crate@localhost/?schema=doc"
+)
+
+
 def main():
 
     chat_message_history = CrateDBChatMessageHistory(
         session_id="test_session",
-        connection_string=os.environ.get("CRATEDB_CONNECTION_STRING")
+        connection_string=CONNECTION_STRING,
     )
     chat_message_history.add_user_message("Hello")
     chat_message_history.add_ai_message("Hi")
diff --git a/framework/langchain/document_loader.ipynb b/framework/langchain/document_loader.ipynb
index b8756382..fea0437c 100644
--- a/framework/langchain/document_loader.ipynb
+++ b/framework/langchain/document_loader.ipynb
@@ -58,8 +58,8 @@
      "output_type": "stream",
      "text": [
       "\u001B[32mCONNECT OK\r\n",
-      "\u001B[0m\u001B[32mPSQL OK, 1 row affected (0.001 sec)\r\n",
-      "\u001B[0m\u001B[32mDELETE OK, 30 rows affected (0.010 sec)\r\n",
+      "\u001B[0m\u001B[32mPROVISIONING OK, 0 rows affected (0.001 sec)\r\n",
+      "\u001B[0m\u001B[32mCREATE OK, 1 row affected (0.010 sec)\r\n",
       "\u001B[0m\u001B[32mINSERT OK, 30 rows affected (0.011 sec)\r\n",
       "\u001B[0m\u001B[0m\u001B[32mCONNECT OK\r\n",
       "\u001B[0m\u001B[32mREFRESH OK, 1 row affected (0.026 sec)\r\n",
@@ -95,6 +95,7 @@
     "from langchain.document_loaders import CrateDBLoader\n",
     "from pprint import pprint\n",
     "\n",
+    "# Connect to a self-managed CrateDB instance.\n",
     "CONNECTION_STRING = \"crate://crate@localhost/?schema=notebook\"\n",
     "\n",
     "loader = CrateDBLoader(\n",
@@ -115,11 +116,11 @@
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "[Document(page_content='Team: Angels\\nPayroll (millions): 154.49\\nWins: 89', metadata={}),\n",
-      " Document(page_content='Team: Astros\\nPayroll (millions): 60.65\\nWins: 55', metadata={}),\n",
-      " Document(page_content='Team: Athletics\\nPayroll (millions): 55.37\\nWins: 94', metadata={}),\n",
-      " Document(page_content='Team: Blue Jays\\nPayroll (millions): 75.48\\nWins: 73', metadata={}),\n",
-      " Document(page_content='Team: Braves\\nPayroll (millions): 83.31\\nWins: 94', metadata={})]\n"
+      "[Document(page_content='Team: Angels\\nPayroll (millions): 154.49\\nWins: 89'),\n",
+      " Document(page_content='Team: Astros\\nPayroll (millions): 60.65\\nWins: 55'),\n",
+      " Document(page_content='Team: Athletics\\nPayroll (millions): 55.37\\nWins: 94'),\n",
+      " Document(page_content='Team: Blue Jays\\nPayroll (millions): 75.48\\nWins: 73'),\n",
+      " Document(page_content='Team: Braves\\nPayroll (millions): 83.31\\nWins: 94')]\n"
      ]
     }
    ],
diff --git a/framework/langchain/document_loader.py b/framework/langchain/document_loader.py
index e6710af2..48e2d9fa 100644
--- a/framework/langchain/document_loader.py
+++ b/framework/langchain/document_loader.py
@@ -28,10 +28,16 @@
 from pprint import pprint
 
 
+CONNECTION_STRING = os.environ.get(
+    "CRATEDB_CONNECTION_STRING",
+    "crate://crate@localhost/?schema=doc"
+)
+
+
 def main():
     loader = CrateDBLoader(
         query="SELECT * FROM mlb_teams_2012 LIMIT 3;",
-        url=os.environ.get("CRATEDB_CONNECTION_STRING"),
+        url=CONNECTION_STRING,
         include_rownum_into_metadata=True,
     )
     docs = loader.load()
diff --git a/framework/langchain/pyproject.toml b/framework/langchain/pyproject.toml
new file mode 100644
index 00000000..b9e54d6b
--- /dev/null
+++ b/framework/langchain/pyproject.toml
@@ -0,0 +1,45 @@
+[tool.pytest.ini_options]
+minversion = "2.0"
+addopts = """
+  -rfEX -p pytester --strict-markers --verbosity=3 --capture=no
+  """
+# --cov=. --cov-report=term-missing --cov-report=xml
+env = [
+    "CRATEDB_CONNECTION_STRING=crate://crate@localhost/?schema=testdrive",
+    "PYDEVD_DISABLE_FILE_VALIDATION=1",
+]
+
+#log_level = "DEBUG"
+#log_cli_level = "DEBUG"
+
+testpaths = [
+    "*.py",
+]
+xfail_strict = true
+markers = [
+]
+
+# pytest-notebook settings
+nb_test_files = true
+nb_coverage = true
+nb_diff_replace = [
+    # Compensate output of `crash`.
+    '"/cells/*/outputs/*/text" "\(\d.\d+ sec\)" "(0.000 sec)"',
+]
+# `vector_search.py` does not include any output(s).
+nb_diff_ignore = [
+    "/metadata/language_info",
+    "/cells/*/execution_count",
+    "/cells/*/outputs/*/execution_count",
+]
+
+[tool.coverage.run]
+branch = false
+
+[tool.coverage.report]
+fail_under = 0
+show_missing = true
+omit = [
+    "conftest.py",
+    "test*.py",
+]
diff --git a/framework/langchain/readme.md b/framework/langchain/readme.md
index fb6d52d4..f5ff852d 100644
--- a/framework/langchain/readme.md
+++ b/framework/langchain/readme.md
@@ -100,6 +100,25 @@ a cloud-based development environment is up and running. As soon as your project
 easily move to a different cluster tier or scale horizontally.
 
 
+## Testing
+
+Run all tests.
+```shell
+pytest
+```
+
+Run tests selectively.
+```shell
+pytest -k document_loader
+pytest -k "notebook and loader"
+```
+
+In order to force a regeneration of the Jupyter Notebook, use the
+`--nb-force-regen` option.
+```shell
+pytest -k document_loader --nb-force-regen
+```
+
 
 [Agents]: https://python.langchain.com/docs/modules/agents/
 [Callbacks]: https://python.langchain.com/docs/modules/callbacks/
diff --git a/framework/langchain/requirements-dev.txt b/framework/langchain/requirements-dev.txt
new file mode 100644
index 00000000..e0769c87
--- /dev/null
+++ b/framework/langchain/requirements-dev.txt
@@ -0,0 +1,6 @@
+coverage~=5.0
+ipykernel
+pytest<8
+pytest-cov<5
+pytest-env<2
+pytest-notebook<0.9
diff --git a/framework/langchain/test.py b/framework/langchain/test.py
new file mode 100644
index 00000000..b6f537e4
--- /dev/null
+++ b/framework/langchain/test.py
@@ -0,0 +1,122 @@
+import importlib
+import io
+import os
+import sys
+from pathlib import Path
+from unittest import mock
+
+import pytest
+from _pytest.python import Function
+
+HERE = Path(__file__).parent
+
+
+def list_files(path: Path, pattern: str):
+    """
+    Enumerate all files in given directory.
+    """
+    files = path.glob(pattern)
+    files = [item.relative_to(path) for item in files]
+    return files
+
+
+def list_notebooks(path: Path):
+    """
+    Enumerate all Jupyter Notebook files found in given directory.
+    """
+    return list_files(path, "**/*.ipynb")
+
+
+def list_pyfiles(path: Path):
+    """
+    Enumerate all regular Python files found in given directory.
+    """
+    pyfiles = []
+    for item in list_files(path, "**/*.py"):
+        if item.suffix != ".py" or item.name in ["conftest.py"] or item.name.startswith("test"):
+            continue
+        pyfiles.append(item)
+    return pyfiles
+
+
+def str_list(things):
+    """
+    Converge list to list of strings.
+    """
+    return map(str, things)
+
+
+@pytest.fixture(scope="function", autouse=True)
+def db_init():
+    """
+    Initialize database.
+    """
+    run_sql(statement="DROP TABLE IF EXISTS mlb_teams_2012;")
+
+
+def db_provision_mlb_teams_2012():
+    """
+    Provision database.
+    """
+    run_sql(file="mlb_teams_2012.sql")
+    run_sql(statement="REFRESH TABLE mlb_teams_2012;")
+
+
+def run_sql(statement: str = None, file: str = None):
+    """
+    Run SQL from string or file.
+    """
+    import crate.crash.command
+    sys.argv = ["foo", "--schema=testdrive"]
+    if statement:
+        sys.argv += ["--command", statement]
+    if file:
+        sys.stdin = io.StringIO(Path(file).read_text())
+    with \
+            mock.patch("crate.crash.repl.SQLCompleter._populate_keywords"), \
+            mock.patch("crate.crash.command.CrateShell.close"):
+        try:
+            crate.crash.command.main()
+        except SystemExit as ex:
+            if ex.code != 0:
+                raise
+
+
+@pytest.mark.parametrize("notebook", str_list(list_notebooks(HERE)))
+def test_notebook(request, notebook: str):
+    """
+    From individual Jupyter Notebook file, collect cells as pytest
+    test cases, and run them.
+
+    Not using `NBRegressionFixture`, because it would manually need to be configured.
+    """
+    from _pytest._py.path import LocalPath
+    from pytest_notebook.plugin import pytest_collect_file
+    tests = pytest_collect_file(LocalPath(notebook), request.node)
+    for test in tests.collect():
+        test.runtest()
+
+
+@pytest.mark.parametrize("pyfile", str_list(list_pyfiles(HERE)))
+def test_file(request, pyfile: Path):
+    """
+    From individual Python file, collect and wrap the `main` function into a test case.
+    """
+
+    # TODO: Make configurable.
+    entrypoint_symbol = "main"
+
+    # Skip `vector_search.py` example, when no `OPENAI_API_KEY` is supplied.
+    if str(pyfile).endswith("vector_search.py"):
+        if "OPENAI_API_KEY" not in os.environ:
+            raise pytest.skip("OPENAI_API_KEY not given")
+
+    # `document_loader.py` needs provisioning.
+    if str(pyfile).endswith("document_loader.py"):
+        db_provision_mlb_teams_2012()
+
+    path = Path(pyfile)
+    mod = importlib.import_module(path.stem)
+    fun = getattr(mod, entrypoint_symbol)
+    f = Function.from_parent(request.node, name="main", callobj=fun)
+    f.runtest()
diff --git a/framework/langchain/vector_search.ipynb b/framework/langchain/vector_search.ipynb
index 2b2353f6..00921d3f 100644
--- a/framework/langchain/vector_search.ipynb
+++ b/framework/langchain/vector_search.ipynb
@@ -61,8 +61,12 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "You need to provide an OpenAI API key, optionally using the environment\n",
-    "variable `OPENAI_API_KEY`."
+    "You need to provide an OpenAI API key, using the environment variable\n",
+    "`OPENAI_API_KEY`, or by defining it within an `.env` file.\n",
+    "\n",
+    "```shell\n",
+    "export OPENAI_API_KEY=sk-YOUR_OPENAI_API_KEY\n",
+    "```"
    ]
   },
   {
@@ -80,23 +84,29 @@
     "import getpass\n",
     "from dotenv import load_dotenv, find_dotenv\n",
     "\n",
-    "# Run `export OPENAI_API_KEY=sk-YOUR_OPENAI_API_KEY`.\n",
-    "# Get OpenAI api key from `.env` file.\n",
-    "# Otherwise, prompt for it.\n",
-    "_ = load_dotenv(find_dotenv())\n",
-    "OPENAI_API_KEY = os.environ.get('OPENAI_API_KEY', getpass.getpass(\"OpenAI API key:\"))\n",
-    "os.environ[\"OPENAI_API_KEY\"] = OPENAI_API_KEY"
+    "# Load OpenAI API key from `OPENAI_API_KEY` environment variable or `.env` file.\n",
+    "# If it is not defined, prompt interactively.\n",
+    "load_dotenv(find_dotenv())\n",
+    "if \"OPENAI_API_KEY\" not in os.environ:\n",
+    "    if \"PYTEST_CURRENT_TEST\" in os.environ:\n",
+    "        import pytest\n",
+    "        pytest.exit(\"OPENAI_API_KEY not given [skip-notebook]\")\n",
+    "    else:\n",
+    "        os.environ[\"OPENAI_API_KEY\"] = getpass.getpass(\"OpenAI API key:\")\n",
+    "\n",
+    "# FIXME: Needs a patch to work, see https://github.com/chrisjsewell/pytest-notebook/issues/43.\n",
+    "# TODO: Refactor to `pueblo.getenvpass(\"OPENAI_API_KEY\", prompt=\"OpenAI API key:\")`."
    ]
   },
   {
    "cell_type": "markdown",
    "source": [
-    "You also need to provide a connection string to your CrateDB database cluster,\n",
-    "optionally using the environment variable `CRATEDB_CONNECTION_STRING`.\n",
+    "You can also provide a connection string to your CrateDB database cluster,\n",
+    "using the environment variable `CRATEDB_CONNECTION_STRING`.\n",
     "\n",
-    "This example uses a CrateDB instance on your workstation, which you can start by\n",
-    "running [CrateDB using Docker]. Alternatively, you can also connect to a cluster\n",
-    "running on [CrateDB Cloud].\n",
+    "By default, the notebook will connect to a CrateDB server instance running on `localhost`.\n",
+    "You can start a sandbox instance on your workstation by running [CrateDB using Docker].\n",
+    "Alternatively, you can also connect to a cluster running on [CrateDB Cloud].\n",
     "\n",
     "[CrateDB Cloud]: https://console.cratedb.cloud/\n",
     "[CrateDB using Docker]: https://crate.io/docs/crate/tutorials/en/latest/basic/index.html#docker"
@@ -112,12 +122,13 @@
    "source": [
     "import os\n",
     "\n",
+    "# Connect to a self-managed CrateDB instance.\n",
     "CONNECTION_STRING = os.environ.get(\n",
     "    \"CRATEDB_CONNECTION_STRING\",\n",
     "    \"crate://crate@localhost/?schema=notebook\",\n",
     ")\n",
     "\n",
-    "# For CrateDB Cloud, use:\n",
+    "# Connect to CrateDB Cloud.\n",
     "# CONNECTION_STRING = os.environ.get(\n",
     "#     \"CRATEDB_CONNECTION_STRING\",\n",
     "#     \"crate://username:password@hostname/?ssl=true&schema=notebook\",\n",
@@ -134,11 +145,12 @@
     "ExecuteTime": {
      "end_time": "2023-09-09T08:02:28.174088Z",
      "start_time": "2023-09-09T08:02:28.162698Z"
-    }
+    },
+    "collapsed": true
    },
    "outputs": [],
    "source": [
-    "\"\"\"\n",
+    "_ = \"\"\"\n",
     "# Alternatively, the connection string can be assembled from individual\n",
     "# environment variables.\n",
     "import os\n",
@@ -399,7 +411,7 @@
     "### Overwriting a vector store\n",
     "\n",
     "If you have an existing collection, you can overwrite it by using `from_documents`,\n",
-    "aad setting `pre_delete_collection = True`."
+    "and setting `pre_delete_collection = True`."
    ]
   },
   {
diff --git a/framework/langchain/vector_search.py b/framework/langchain/vector_search.py
index 8b71d11d..28e0d770 100644
--- a/framework/langchain/vector_search.py
+++ b/framework/langchain/vector_search.py
@@ -23,7 +23,7 @@
     # Run program.
     python vector_search.py
 """  # noqa: E501
-from langchain.document_loaders import TextLoader
+from langchain.document_loaders import UnstructuredURLLoader
 from langchain.embeddings.openai import OpenAIEmbeddings
 from langchain.text_splitter import CharacterTextSplitter
 from langchain.vectorstores import CrateDBVectorSearch
@@ -33,7 +33,8 @@ def main():
 
     # Load the document, split it into chunks, embed each chunk,
     # and load it into the vector store.
-    raw_documents = TextLoader("state_of_the_union.txt").load()
+    state_of_the_union_url = "https://github.com/langchain-ai/langchain/raw/v0.0.325/docs/docs/modules/state_of_the_union.txt"
+    raw_documents = UnstructuredURLLoader(urls=[state_of_the_union_url]).load()
     text_splitter = CharacterTextSplitter(chunk_size=1000, chunk_overlap=0)
     documents = text_splitter.split_documents(raw_documents)
     db = CrateDBVectorSearch.from_documents(documents, OpenAIEmbeddings())