diff --git a/.github/workflows/verify.yml b/.github/workflows/verify.yml
index ad84ec7..82da1f4 100644
--- a/.github/workflows/verify.yml
+++ b/.github/workflows/verify.yml
@@ -41,6 +41,12 @@ jobs:
       matrix:
         python: ['3.12']
         os: [ubuntu-latest, macos-latest, windows-latest]
+        pydantic: ['true']
+        # Test pydantic at lower boundary of requirement compatibility spec.
+        include:
+          - python: '3.12'
+            os: ubuntu-latest
+            pydantic: 'pip install pydantic==2.6.4'
     steps:
       - uses: actions/checkout@v4
       - name: Set up Python
@@ -58,6 +64,7 @@ jobs:
       - name: Install dependencies.
         run: |
           python -m pip install --upgrade pip
+          ${{ matrix.pydantic }}
           pip install -e .[dev,docs]
           pip list
 
diff --git a/docs/examples/2022-10-pyodk-webinar.ipynb b/docs/examples/2022-10-pyodk-webinar.ipynb
index 5e29954..1504f69 100644
--- a/docs/examples/2022-10-pyodk-webinar.ipynb
+++ b/docs/examples/2022-10-pyodk-webinar.ipynb
@@ -371,10 +371,11 @@
     }
    ],
    "source": [
-    "json = client.submissions.get_table(form_id='participants')['value']\n",
-    "\n",
     "import pandas as pd\n",
-    "df = pd.json_normalize(json, sep='-')\n",
+    "\n",
+    "json = client.submissions.get_table(form_id=\"participants\")[\"value\"]\n",
+    "\n",
+    "df = pd.json_normalize(json, sep=\"-\")\n",
     "df.head(3)"
    ]
   },
@@ -416,7 +417,7 @@
     }
    ],
    "source": [
-    "df.pets.value_counts().plot(kind='pie')"
+    "df.pets.value_counts().plot(kind=\"pie\")"
    ]
   },
   {
@@ -445,8 +446,8 @@
     }
    ],
    "source": [
-    "df['height_code'] = df.height_units.astype('category').cat.codes\n",
-    "df['pets_code'] = df.pets.astype('category').cat.codes\n",
+    "df[\"height_code\"] = df.height_units.astype(\"category\").cat.codes\n",
+    "df[\"pets_code\"] = df.pets.astype(\"category\").cat.codes\n",
     "df.pets_code.corr(df.height_code)"
    ]
   },
@@ -529,7 +530,7 @@
     }
    ],
    "source": [
-    "df['__system-submitterName'].value_counts().plot(kind='bar', rot=45)"
+    "df[\"__system-submitterName\"].value_counts().plot(kind=\"bar\", rot=45)"
    ]
   },
   {
@@ -547,7 +548,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "df = df.drop(df.filter(regex = 'note_'), axis = 1)"
+    "df = df.drop(df.filter(regex=\"note_\"), axis=1)"
    ]
   },
   {
diff --git a/docs/examples/basic-analysis-pandas.ipynb b/docs/examples/basic-analysis-pandas.ipynb
index e14bd84..e7949ea 100644
--- a/docs/examples/basic-analysis-pandas.ipynb
+++ b/docs/examples/basic-analysis-pandas.ipynb
@@ -36,8 +36,8 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "from pyodk.client import Client\n",
-    "import pandas as pd"
+    "import pandas as pd\n",
+    "from pyodk.client import Client"
    ]
   },
   {
@@ -228,9 +228,9 @@
    ],
    "source": [
     "with Client() as client:\n",
-    "    submissions = client.submissions.get_table(form_id='fav_color')\n",
-    "    df = pd.json_normalize(data=submissions['value'], sep='/')\n",
-    "    \n",
+    "    submissions = client.submissions.get_table(form_id=\"fav_color\")\n",
+    "    df = pd.json_normalize(data=submissions[\"value\"], sep=\"/\")\n",
+    "\n",
     "df.head(3)"
    ]
   },
@@ -272,9 +272,11 @@
     }
    ],
    "source": [
-    "colors = {'g':'Green', 'o':'Orange', 'r':'Red', 'y':'Yellow'}\n",
-    "df['favorite_color_labels'] = df['favorite_color'].map(colors)\n",
-    "df['favorite_color_labels'].value_counts().plot(kind='bar', title='Count of favorite colors', xlabel=\"Color\", ylabel=\"Count\", rot=0)"
+    "colors = {\"g\": \"Green\", \"o\": \"Orange\", \"r\": \"Red\", \"y\": \"Yellow\"}\n",
+    "df[\"favorite_color_labels\"] = df[\"favorite_color\"].map(colors)\n",
+    "df[\"favorite_color_labels\"].value_counts().plot(\n",
+    "    kind=\"bar\", title=\"Count of favorite colors\", xlabel=\"Color\", ylabel=\"Count\", rot=0\n",
+    ")"
    ]
   },
   {
@@ -313,7 +315,9 @@
     }
    ],
    "source": [
-    "df['__system/reviewState'].value_counts().plot(kind='pie', title='Submission review state', ylabel='', rot=0)"
+    "df[\"__system/reviewState\"].value_counts().plot(\n",
+    "    kind=\"pie\", title=\"Submission review state\", ylabel=\"\", rot=0\n",
+    ")"
    ]
   },
   {
@@ -357,13 +361,17 @@
     "import geopandas\n",
     "from geopandas import GeoDataFrame\n",
     "\n",
-    "world = geopandas.read_file(geopandas.datasets.get_path('naturalearth_lowres'))\n",
-    "base = world.plot(color='lightgrey', figsize=(15, 10))\n",
+    "world = geopandas.read_file(geopandas.datasets.get_path(\"naturalearth_lowres\"))\n",
+    "base = world.plot(color=\"lightgrey\", figsize=(15, 10))\n",
     "base.set_axis_off()\n",
     "\n",
-    "locations = pd.DataFrame(df['location/coordinates'].dropna().to_list(), columns=['x', 'y', 'alt'])\n",
-    "geodf = GeoDataFrame(locations, geometry=geopandas.points_from_xy(locations['x'], locations['y']))\n",
-    "geodf.plot(ax=base, marker='o', color='blue', markersize=15)"
+    "locations = pd.DataFrame(\n",
+    "    df[\"location/coordinates\"].dropna().to_list(), columns=[\"x\", \"y\", \"alt\"]\n",
+    ")\n",
+    "geodf = GeoDataFrame(\n",
+    "    locations, geometry=geopandas.points_from_xy(locations[\"x\"], locations[\"y\"])\n",
+    ")\n",
+    "geodf.plot(ax=base, marker=\"o\", color=\"blue\", markersize=15)"
    ]
   },
   {
diff --git a/docs/examples/beyond-library-methods.ipynb b/docs/examples/beyond-library-methods.ipynb
index a618ec5..44aad90 100644
--- a/docs/examples/beyond-library-methods.ipynb
+++ b/docs/examples/beyond-library-methods.ipynb
@@ -168,7 +168,7 @@
     }
    ],
    "source": [
-    "response = client.get('/projects/7/forms/favorite_color/versions/2012060405.xlsx')\n",
+    "response = client.get(\"/projects/7/forms/favorite_color/versions/2012060405.xlsx\")\n",
     "response.content[:150]"
    ]
   },
@@ -188,7 +188,7 @@
    "outputs": [],
    "source": [
     "if response.status_code == 200:\n",
-    "    with open('2012060405.xlsx', 'wb') as f:\n",
+    "    with open(\"2012060405.xlsx\", \"wb\") as f:\n",
     "        f.write(response.content)"
    ]
   },
@@ -245,7 +245,7 @@
     }
    ],
    "source": [
-    "r = client.post('/projects/7/app-users', json={'displayName': 'Lab Tech'})\n",
+    "r = client.post(\"/projects/7/app-users\", json={\"displayName\": \"Lab Tech\"})\n",
     "r.json()"
    ]
   },
diff --git a/docs/examples/working-with-repeats.ipynb b/docs/examples/working-with-repeats.ipynb
index c2bb55e..e2ef5a0 100644
--- a/docs/examples/working-with-repeats.ipynb
+++ b/docs/examples/working-with-repeats.ipynb
@@ -31,11 +31,13 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "from pyodk.client import Client\n",
     "import pandas as pd\n",
+    "from pyodk.client import Client\n",
     "\n",
     "client = Client().open()\n",
-    "submissions = client.submissions.get_table(form_id='simple_repeat', filter=\"__system/reviewState ne 'rejected'\")"
+    "submissions = client.submissions.get_table(\n",
+    "    form_id=\"simple_repeat\", filter=\"__system/reviewState ne 'rejected'\"\n",
+    ")"
    ]
   },
   {
@@ -195,7 +197,7 @@
     }
    ],
    "source": [
-    "subs_df = pd.json_normalize(data=submissions['value'], sep='/')\n",
+    "subs_df = pd.json_normalize(data=submissions[\"value\"], sep=\"/\")\n",
     "subs_df.head(3)"
    ]
   },
@@ -288,8 +290,12 @@
     }
    ],
    "source": [
-    "repeats = client.submissions.get_table(form_id='simple_repeat', table_name='Submissions.observation', filter=\"__system/reviewState ne 'rejected'\")\n",
-    "obs_df = pd.json_normalize(data=repeats['value'], sep='/')\n",
+    "repeats = client.submissions.get_table(\n",
+    "    form_id=\"simple_repeat\",\n",
+    "    table_name=\"Submissions.observation\",\n",
+    "    filter=\"__system/reviewState ne 'rejected'\",\n",
+    ")\n",
+    "obs_df = pd.json_normalize(data=repeats[\"value\"], sep=\"/\")\n",
     "obs_df.head(3)"
    ]
   },
@@ -511,7 +517,7 @@
     }
    ],
    "source": [
-    "subs_df.set_index('__id', inplace=True)\n",
+    "subs_df.set_index(\"__id\", inplace=True)\n",
     "joined_df = obs_df.join(subs_df, on=\"__Submissions-id\")\n",
     "joined_df.head(4)"
    ]
@@ -629,7 +635,7 @@
     }
    ],
    "source": [
-    "grouped = joined_df.groupby(['name', 'thing']).sum('count')[['count']]\n",
+    "grouped = joined_df.groupby([\"name\", \"thing\"]).sum(\"count\")[[\"count\"]]\n",
     "grouped"
    ]
   },
@@ -651,7 +657,7 @@
     }
    ],
    "source": [
-    "ax = grouped.unstack(level=0).plot(kind='bar')\n",
+    "ax = grouped.unstack(level=0).plot(kind=\"bar\")\n",
     "ax.set_xlabel(\"Sighting\")\n",
     "ax.set_ylabel(\"Total count\")\n",
     "ax.legend().set_title(\"Data collector\")"
@@ -842,12 +848,14 @@
     "\n",
     "client = Client().open()\n",
     "# The expand option includes all repeats in the json returned by get_table\n",
-    "submissions = client.submissions.get_table(form_id='simple_repeat', expand='*', filter=\"__system/reviewState ne 'rejected'\")\n",
+    "submissions = client.submissions.get_table(\n",
+    "    form_id=\"simple_repeat\", expand=\"*\", filter=\"__system/reviewState ne 'rejected'\"\n",
+    ")\n",
     "# Flatten all repeats for each submission returned\n",
-    "df = pd.DataFrame([flatten_json(x) for x in submissions['value']])\n",
+    "df = pd.DataFrame([flatten_json(x) for x in submissions[\"value\"]])\n",
     "\n",
     "# Drop system columns so we can see more of the repeats\n",
-    "df.drop(list(df.filter(regex = '__system')), axis = 1, inplace = True)\n",
+    "df.drop(list(df.filter(regex=\"__system\")), axis=1, inplace=True)\n",
     "df.head(3)"
    ]
   }
diff --git a/pyodk/_endpoints/auth.py b/pyodk/_endpoints/auth.py
index da4b070..28d6783 100644
--- a/pyodk/_endpoints/auth.py
+++ b/pyodk/_endpoints/auth.py
@@ -12,7 +12,7 @@
 
 class AuthService:
     def __init__(self, session: "Session", cache_path: str | None = None) -> None:
-        self.session: "Session" = session
+        self.session: Session = session
         self.cache_path: str = cache_path
 
     def verify_token(self, token: str) -> str:
diff --git a/pyodk/_utils/session.py b/pyodk/_utils/session.py
index becef8e..fb19bfc 100644
--- a/pyodk/_utils/session.py
+++ b/pyodk/_utils/session.py
@@ -64,7 +64,7 @@ def send(self, request, **kwargs):
 
 class Auth(AuthBase):
     def __init__(self, session: "Session", username: str, password: str, cache_path: str):
-        self.session: "Session" = session
+        self.session: Session = session
         self.username: str = username
         self.password: str = password
         self.service: AuthService = AuthService(session=session, cache_path=cache_path)
diff --git a/pyproject.toml b/pyproject.toml
index bf3d9c8..588d11c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -8,16 +8,16 @@ description = "The official Python library for ODK 🐍"
 readme = "README.md"
 requires-python = ">=3.12"
 dependencies = [
-    "requests==2.32.0",  # HTTP with Central
+    "requests==2.32.3",  # HTTP with Central
     "toml==0.10.2",      # Configuration files
-    "pydantic==2.6.4",   # Data validation
+    "pydantic>=2.6.4,<2.9.3",   # Data validation
 ]
 
 [project.optional-dependencies]
 # Install with `pip install pyodk[dev]`.
 dev = [
-    "ruff==0.3.4",        # Format and lint
-    "openpyxl==3.1.2",    # Create test XLSX files
+    "ruff==0.7.1",        # Format and lint
+    "openpyxl==3.1.5",    # Create test XLSX files
     "xlwt==1.3.0",        # Create test XLS files
 ]
 docs = [