diff --git a/README.rst b/README.rst
index 70517550..d93f018a 100644
--- a/README.rst
+++ b/README.rst
@@ -47,6 +47,8 @@ Contents
 
   * `Action Attempts`_
 
+  * `Setting a Param to Null`_
+
   * `Pagination`_
 
     * `Manually fetch pages with the next_page_cursor`_
@@ -280,6 +282,56 @@ For example:
   except SeamActionAttemptTimeoutError as e:
       print("Door took too long to unlock")
 
+Setting a Param to Null
+~~~~~~~~~~~~~~~~~~~~~~~
+
+The Seam API tells an omitted param apart from one explicitly set to null.
+In an update request, an omitted param leaves the current value unchanged,
+while a null param unsets it.
+
+Python has a single nil value `None` which represents an undefined parameter. This SDK provides an explicit null value to send in requests.
+A param set to ``None`` is omitted, and a param set to ``NULL`` is sent as `null`:
+
+.. code-block:: python
+
+  from seam import NULL, Seam
+
+  seam = Seam()
+
+  # Leaves the name unchanged.
+  seam.devices.update(device_id="your-device-id", name=None)
+
+  # Unsets the name.
+  seam.devices.update(device_id="your-device-id", name=NULL)
+
+Because unsetting a value cannot be undone, ``None`` means the safe option of
+omitting the param, and sending null is always explicit.
+This is why a param is never sent as null by default,
+even though ``None`` is the natural way to spell null in Python.
+
+``NULL`` behaves the same way in a request body and in a URL search param.
+Its type is exported as ``Null`` for annotating your own code:
+
+.. code-block:: python
+
+  from typing import Optional, Union
+
+  from seam import NULL, Null
+
+  name: Optional[Union[str, Null]] = NULL
+
+Only params the Seam API documents as nullable accept ``NULL``.
+The generated method signatures say which ones those are,
+so a type checker rejects ``NULL`` anywhere else:
+
+.. code-block:: python
+
+  # name is nullable, so it may be unset.
+  seam.devices.update(device_id="your-device-id", name=NULL)
+
+  # is_managed is not, so this fails the type check.
+  seam.devices.update(device_id="your-device-id", is_managed=NULL)
+
 Pagination
 ~~~~~~~~~~
 
@@ -562,8 +614,9 @@ A client may percent-encode a few characters differently than
 ``URLSearchParams`` does, e.g. httpx escapes ``*`` and unescapes ``~``,
 which the Seam API reads as the same params either way.
 
-A param set to ``None`` is omitted, while a param set to ``seam.NULL``
-is serialized to an empty value, which the Seam API reads as null.
+A param set to ``None`` is omitted, while a param set to ``NULL``
+is serialized to an empty value, which the Seam API reads as null,
+as described in `Setting a Param to Null`_.
 A param that cannot be represented raises a ``seam.UnserializableParamError``.
 
 The Seam API parses these params with the corresponding `parser`_.
diff --git a/codegen/layouts/partials/method-signature.hbs b/codegen/layouts/partials/method-signature.hbs
index 10977db0..4e58dbd1 100644
--- a/codegen/layouts/partials/method-signature.hbs
+++ b/codegen/layouts/partials/method-signature.hbs
@@ -1 +1 @@
-{{name}}(self{{#if params}}, *{{else}}{{#if (eq returnType "ActionAttempt")}}, *{{/if}}{{/if}}{{#each params}}, {{name}}: {{#if required}}{{type}}{{else}}Optional[{{type}}] = None{{/if}}{{/each}}{{#if (eq returnType "ActionAttempt")}}, wait_for_action_attempt: Optional[Union[bool, Dict[str, float]]] = None{{/if}}) -> {{returnType}}
\ No newline at end of file
+{{name}}(self{{#if params}}, *{{else}}{{#if (eq returnType "ActionAttempt")}}, *{{/if}}{{/if}}{{#each params}}, {{name}}: {{#if required}}{{nullableType type isNullable}}{{else}}Optional[{{nullableType type isNullable}}] = None{{/if}}{{/each}}{{#if (eq returnType "ActionAttempt")}}, wait_for_action_attempt: Optional[Union[bool, Dict[str, float]]] = None{{/if}}) -> {{returnType}}
\ No newline at end of file
diff --git a/codegen/layouts/route.hbs b/codegen/layouts/route.hbs
index afaf2b43..32540f82 100644
--- a/codegen/layouts/route.hbs
+++ b/codegen/layouts/route.hbs
@@ -2,6 +2,9 @@ from typing import Optional, Any, List, Dict, Union
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+{{#if importNull}}
+from ..null import Null
+{{/if}}
 {{#if resourceClasses}}
 from ..resources import ({{#each resourceClasses}}{{this}}{{#unless @last}},{{/unless}}{{/each}})
 {{/if}}
diff --git a/codegen/lib/class-model.ts b/codegen/lib/class-model.ts
index 9ecca230..d9333b65 100644
--- a/codegen/lib/class-model.ts
+++ b/codegen/lib/class-model.ts
@@ -4,6 +4,7 @@
 export interface ClassMethodParameter {
   name: string
   type: string
+  isNullable: boolean
   description: string
   isDeprecated: boolean
   deprecationMessage: string
diff --git a/codegen/lib/handlebars-helpers.ts b/codegen/lib/handlebars-helpers.ts
index dd4abeda..4b8a4227 100644
--- a/codegen/lib/handlebars-helpers.ts
+++ b/codegen/lib/handlebars-helpers.ts
@@ -53,6 +53,12 @@ export const indent = (value: string, spaces: number): string =>
 export const pythonIdentifier = (name: string): string =>
   PYTHON_KEYWORDS.has(name) ? `${name}_` : name
 
+// A param the API documents as nullable may be set to the NULL sentinel, which
+// the client serializes to null. Params that are merely optional may not: they
+// are omitted by passing None, and sending null would unset a value instead.
+export const nullableType = (type: string, isNullable: boolean): string =>
+  isNullable ? `Union[${type}, Null]` : type
+
 export const isListType = (type: string): boolean => type.startsWith('List[')
 
 export const listItemType = (type: string): string => type.slice(5, -1)
diff --git a/codegen/lib/layouts/route.ts b/codegen/lib/layouts/route.ts
index be784fdc..00c57863 100644
--- a/codegen/lib/layouts/route.ts
+++ b/codegen/lib/layouts/route.ts
@@ -23,6 +23,7 @@ export interface MethodLayoutContext {
   params: Array<{
     name: string
     type: string
+    isNullable: boolean
     description: string
     isDeprecated: boolean
     deprecationMessage: string
@@ -53,6 +54,7 @@ export interface RouteLayoutContext {
     module: string
   }>
   importResolveActionAttempt: boolean
+  importNull: boolean
   methods: MethodLayoutContext[]
 }
 
@@ -83,6 +85,7 @@ export const getMethodLayoutContext = (
   params: sortClassMethodParameters(method.parameters).map((parameter) => ({
     name: parameter.name,
     type: parameter.type,
+    isNullable: parameter.isNullable,
     description: parameter.description,
     isDeprecated: parameter.isDeprecated,
     deprecationMessage: parameter.deprecationMessage,
@@ -108,6 +111,10 @@ export const setRouteLayoutContext = (cls: ClassModel): RouteLayoutContext => {
   const abstractClassName = `Abstract${cls.name}`
   const methods = cls.methods.map(getMethodLayoutContext)
 
+  const importNull = methods.some(({ params }) =>
+    params.some(({ isNullable }) => isNullable),
+  )
+
   return {
     className: cls.name,
     abstractClassName,
@@ -131,6 +138,7 @@ export const setRouteLayoutContext = (cls: ClassModel): RouteLayoutContext => {
       module: `${cls.namespace}_${identifier.namespace}`,
     })),
     importResolveActionAttempt,
+    importNull,
     methods,
   }
 }
diff --git a/codegen/lib/routes.ts b/codegen/lib/routes.ts
index 2d5f33d1..cbc0a98a 100644
--- a/codegen/lib/routes.ts
+++ b/codegen/lib/routes.ts
@@ -99,6 +99,7 @@ export const routes = (
         parameters: endpoint.request.parameters.map((parameter) => ({
           name: parameter.name,
           type: mapParameterToPythonType(parameter),
+          isNullable: parameter.isNullable,
           description: parameter.description,
           isDeprecated: parameter.isDeprecated,
           deprecationMessage: parameter.deprecationMessage,
diff --git a/seam/client.py b/seam/client.py
index 723037f8..f78fefdf 100644
--- a/seam/client.py
+++ b/seam/client.py
@@ -1,3 +1,4 @@
+from collections.abc import Mapping
 from typing import Any, Dict, Optional
 from importlib.metadata import version
 import abc
@@ -12,6 +13,8 @@
     SeamHttpInvalidInputError,
     SeamHttpUnauthorizedError,
 )
+from .null import replace_null
+from .url_search_params_serializer import serialize_url_search_params
 
 SDK_HEADERS = {
     "seam-sdk-name": "seamapi/python",
@@ -102,6 +105,12 @@ def delete(self, url, json=None, **kwargs) -> Any:
         return self.request("DELETE", url, json=json, **kwargs)
 
     def request(self, method, url, *args, **kwargs) -> Any:
+        if isinstance(kwargs.get("params"), Mapping):
+            url = with_search_params(url, kwargs.pop("params"))
+
+        if "json" in kwargs:
+            kwargs["json"] = replace_null(kwargs["json"])
+
         response = super().request(method, url, *args, **kwargs)
 
         return self._handle_response(response)
@@ -142,6 +151,15 @@ def _handle_error_response(self, response: Response):
         raise SeamHttpApiError(error_details, status_code, request_id)
 
 
+def with_search_params(url: Any, params: Mapping[str, Any]) -> Any:
+    query = serialize_url_search_params(params)
+
+    if not query:
+        return url
+
+    return httpx.URL(url, query=query.encode())
+
+
 def is_api_error_response(response: Response) -> bool:
     try:
         content_type = response.headers.get("content-type", "")
diff --git a/seam/null.py b/seam/null.py
index 42c3b481..66a1cbd6 100644
--- a/seam/null.py
+++ b/seam/null.py
@@ -10,6 +10,7 @@
 Sending null is explicit and always spelled :data:`NULL`.
 """
 
+from collections.abc import Mapping, Sequence
 from typing import Any
 
 
@@ -60,3 +61,27 @@ def is_null(value: Any) -> bool:
     :returns: Whether the value is the ``NULL`` sentinel"""
 
     return isinstance(value, Null)
+
+
+def replace_null(value: Any) -> Any:
+    """Returns a copy of a value with every :data:`NULL` sentinel replaced by ``None``.
+
+    The sentinel only distinguishes an explicit null from an omitted param
+    within this SDK. Once a request body is being serialized, the param is
+    known to be present, so the sentinel becomes the null that JSON has.
+
+    :param value: The value to copy
+    :type value: Any
+
+    :returns: The value with each ``NULL`` sentinel replaced by ``None``"""
+
+    if is_null(value):
+        return None
+
+    if isinstance(value, Mapping):
+        return {key: replace_null(item) for key, item in value.items()}
+
+    if isinstance(value, Sequence) and not isinstance(value, (str, bytes)):
+        return [replace_null(item) for item in value]
+
+    return value
diff --git a/seam/routes/access_codes.py b/seam/routes/access_codes.py
index 82231033..3f5053f5 100644
--- a/seam/routes/access_codes.py
+++ b/seam/routes/access_codes.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import AccessCode
 from .access_codes_simulate import AbstractAccessCodesSimulate, AccessCodesSimulate
 from .access_codes_unmanaged import AbstractAccessCodesUnmanaged, AccessCodesUnmanaged
@@ -205,7 +206,7 @@ def list(
         customer_key: Optional[str] = None,
         device_id: Optional[str] = None,
         limit: Optional[float] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         user_identifier_key: Optional[str] = None,
     ) -> List[AccessCode]:
@@ -704,7 +705,7 @@ def list(
         customer_key: Optional[str] = None,
         device_id: Optional[str] = None,
         limit: Optional[float] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         user_identifier_key: Optional[str] = None,
     ) -> List[AccessCode]:
diff --git a/seam/routes/access_codes_unmanaged.py b/seam/routes/access_codes_unmanaged.py
index d8f35bc6..8a6e67d4 100644
--- a/seam/routes/access_codes_unmanaged.py
+++ b/seam/routes/access_codes_unmanaged.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import UnmanagedAccessCode
 
 
@@ -71,7 +72,7 @@ def list(
         *,
         device_id: str,
         limit: Optional[float] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         user_identifier_key: Optional[str] = None,
     ) -> List[UnmanagedAccessCode]:
@@ -253,7 +254,7 @@ def list(
         *,
         device_id: str,
         limit: Optional[float] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         user_identifier_key: Optional[str] = None,
     ) -> List[UnmanagedAccessCode]:
diff --git a/seam/routes/access_grants.py b/seam/routes/access_grants.py
index dfad2ccd..fbc7685a 100644
--- a/seam/routes/access_grants.py
+++ b/seam/routes/access_grants.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import AccessGrant, Batch
 from .access_grants_unmanaged import (
     AbstractAccessGrantsUnmanaged,
@@ -27,10 +28,10 @@ def create(
         acs_entrance_ids: Optional[List[str]] = None,
         customization_profile_id: Optional[str] = None,
         device_ids: Optional[List[str]] = None,
-        ends_at: Optional[str] = None,
+        ends_at: Optional[Union[str, Null]] = None,
         location: Optional[Dict[str, Any]] = None,
         location_ids: Optional[List[str]] = None,
-        name: Optional[str] = None,
+        name: Optional[Union[str, Null]] = None,
         reservation_key: Optional[str] = None,
         space_ids: Optional[List[str]] = None,
         space_keys: Optional[List[str]] = None,
@@ -130,14 +131,14 @@ def list(
         *,
         access_code_id: Optional[str] = None,
         access_grant_ids: Optional[List[str]] = None,
-        access_grant_key: Optional[str] = None,
+        access_grant_key: Optional[Union[str, Null]] = None,
         acs_entrance_id: Optional[str] = None,
         acs_system_id: Optional[str] = None,
         customer_key: Optional[str] = None,
         device_id: Optional[str] = None,
         limit: Optional[float] = None,
         location_id: Optional[str] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         reservation_key: Optional[str] = None,
         space_id: Optional[str] = None,
         user_identity_id: Optional[str] = None,
@@ -194,8 +195,8 @@ def update(
         *,
         access_grant_id: Optional[str] = None,
         access_grant_key: Optional[str] = None,
-        ends_at: Optional[str] = None,
-        name: Optional[str] = None,
+        ends_at: Optional[Union[str, Null]] = None,
+        name: Optional[Union[str, Null]] = None,
         starts_at: Optional[str] = None,
     ) -> None:
         """Updates an existing Access Grant's time window.
@@ -237,10 +238,10 @@ def create(
         acs_entrance_ids: Optional[List[str]] = None,
         customization_profile_id: Optional[str] = None,
         device_ids: Optional[List[str]] = None,
-        ends_at: Optional[str] = None,
+        ends_at: Optional[Union[str, Null]] = None,
         location: Optional[Dict[str, Any]] = None,
         location_ids: Optional[List[str]] = None,
-        name: Optional[str] = None,
+        name: Optional[Union[str, Null]] = None,
         reservation_key: Optional[str] = None,
         space_ids: Optional[List[str]] = None,
         space_keys: Optional[List[str]] = None,
@@ -434,14 +435,14 @@ def list(
         *,
         access_code_id: Optional[str] = None,
         access_grant_ids: Optional[List[str]] = None,
-        access_grant_key: Optional[str] = None,
+        access_grant_key: Optional[Union[str, Null]] = None,
         acs_entrance_id: Optional[str] = None,
         acs_system_id: Optional[str] = None,
         customer_key: Optional[str] = None,
         device_id: Optional[str] = None,
         limit: Optional[float] = None,
         location_id: Optional[str] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         reservation_key: Optional[str] = None,
         space_id: Optional[str] = None,
         user_identity_id: Optional[str] = None,
@@ -551,8 +552,8 @@ def update(
         *,
         access_grant_id: Optional[str] = None,
         access_grant_key: Optional[str] = None,
-        ends_at: Optional[str] = None,
-        name: Optional[str] = None,
+        ends_at: Optional[Union[str, Null]] = None,
+        name: Optional[Union[str, Null]] = None,
         starts_at: Optional[str] = None,
     ) -> None:
         """Updates an existing Access Grant's time window.
diff --git a/seam/routes/access_grants_unmanaged.py b/seam/routes/access_grants_unmanaged.py
index 78eb8918..843709e8 100644
--- a/seam/routes/access_grants_unmanaged.py
+++ b/seam/routes/access_grants_unmanaged.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import UnmanagedAccessGrant
 
 
@@ -25,7 +26,7 @@ def list(
         acs_entrance_id: Optional[str] = None,
         acs_system_id: Optional[str] = None,
         limit: Optional[float] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         reservation_key: Optional[str] = None,
         user_identity_id: Optional[str] = None,
     ) -> List[UnmanagedAccessGrant]:
@@ -113,7 +114,7 @@ def list(
         acs_entrance_id: Optional[str] = None,
         acs_system_id: Optional[str] = None,
         limit: Optional[float] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         reservation_key: Optional[str] = None,
         user_identity_id: Optional[str] = None,
     ) -> List[UnmanagedAccessGrant]:
diff --git a/seam/routes/access_methods.py b/seam/routes/access_methods.py
index 8c9ca9ee..915c4773 100644
--- a/seam/routes/access_methods.py
+++ b/seam/routes/access_methods.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import ActionAttempt, AccessMethod, Batch
 from .access_methods_unmanaged import (
     AbstractAccessMethodsUnmanaged,
@@ -120,7 +121,7 @@ def list(
         acs_entrance_id: Optional[str] = None,
         device_id: Optional[str] = None,
         limit: Optional[int] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         space_id: Optional[str] = None,
     ) -> List[AccessMethod]:
         """Lists all access methods, usually filtered by Access Grant.
@@ -393,7 +394,7 @@ def list(
         acs_entrance_id: Optional[str] = None,
         device_id: Optional[str] = None,
         limit: Optional[int] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         space_id: Optional[str] = None,
     ) -> List[AccessMethod]:
         """Lists all access methods, usually filtered by Access Grant.
diff --git a/seam/routes/acs_credentials.py b/seam/routes/acs_credentials.py
index 68a56846..ceff9409 100644
--- a/seam/routes/acs_credentials.py
+++ b/seam/routes/acs_credentials.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import AcsCredential, AcsEntrance
 
 
@@ -107,7 +108,7 @@ def list(
         created_before: Optional[str] = None,
         is_multi_phone_sync_credential: Optional[bool] = None,
         limit: Optional[float] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
     ) -> List[AcsCredential]:
         """Returns a list of all `credentials <https://docs.seam.co/low-level-apis/access-systems/managing-credentials>`_.
@@ -382,7 +383,7 @@ def list(
         created_before: Optional[str] = None,
         is_multi_phone_sync_credential: Optional[bool] = None,
         limit: Optional[float] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
     ) -> List[AcsCredential]:
         """Returns a list of all `credentials <https://docs.seam.co/low-level-apis/access-systems/managing-credentials>`_.
diff --git a/seam/routes/acs_encoders.py b/seam/routes/acs_encoders.py
index 194008aa..5b6d9c8a 100644
--- a/seam/routes/acs_encoders.py
+++ b/seam/routes/acs_encoders.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import ActionAttempt, AcsEncoder
 from .acs_encoders_simulate import AbstractAcsEncodersSimulate, AcsEncodersSimulate
 from ..modules.action_attempts import resolve_action_attempt
@@ -57,7 +58,7 @@ def list(
         acs_system_ids: Optional[List[str]] = None,
         acs_encoder_ids: Optional[List[str]] = None,
         limit: Optional[float] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
     ) -> List[AcsEncoder]:
         """Returns a list of all `encoders <https://docs.seam.co/low-level-apis/access-systems/working-with-card-encoders-and-scanners>`_.
 
@@ -220,7 +221,7 @@ def list(
         acs_system_ids: Optional[List[str]] = None,
         acs_encoder_ids: Optional[List[str]] = None,
         limit: Optional[float] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
     ) -> List[AcsEncoder]:
         """Returns a list of all `encoders <https://docs.seam.co/low-level-apis/access-systems/working-with-card-encoders-and-scanners>`_.
 
diff --git a/seam/routes/acs_entrances.py b/seam/routes/acs_entrances.py
index 353929ca..ddb863d4 100644
--- a/seam/routes/acs_entrances.py
+++ b/seam/routes/acs_entrances.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import AcsEntrance, AcsCredential, ActionAttempt
 from ..modules.action_attempts import resolve_action_attempt
 
@@ -49,8 +50,8 @@ def list(
         connected_account_id: Optional[str] = None,
         customer_key: Optional[str] = None,
         limit: Optional[int] = None,
-        location_id: Optional[str] = None,
-        page_cursor: Optional[str] = None,
+        location_id: Optional[Union[str, Null]] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         space_id: Optional[str] = None,
     ) -> List[AcsEntrance]:
@@ -200,8 +201,8 @@ def list(
         connected_account_id: Optional[str] = None,
         customer_key: Optional[str] = None,
         limit: Optional[int] = None,
-        location_id: Optional[str] = None,
-        page_cursor: Optional[str] = None,
+        location_id: Optional[Union[str, Null]] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         space_id: Optional[str] = None,
     ) -> List[AcsEntrance]:
diff --git a/seam/routes/acs_users.py b/seam/routes/acs_users.py
index 6e905b5e..1da621eb 100644
--- a/seam/routes/acs_users.py
+++ b/seam/routes/acs_users.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import AcsUser, AcsEntrance
 
 
@@ -103,7 +104,7 @@ def list(
         acs_system_id: Optional[str] = None,
         created_before: Optional[str] = None,
         limit: Optional[int] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         user_identity_email_address: Optional[str] = None,
         user_identity_id: Optional[str] = None,
@@ -231,7 +232,7 @@ def unsuspend(
     def update(
         self,
         *,
-        access_schedule: Optional[Dict[str, Any]] = None,
+        access_schedule: Optional[Union[Dict[str, Any], Null]] = None,
         acs_system_id: Optional[str] = None,
         acs_user_id: Optional[str] = None,
         email: Optional[str] = None,
@@ -444,7 +445,7 @@ def list(
         acs_system_id: Optional[str] = None,
         created_before: Optional[str] = None,
         limit: Optional[int] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         user_identity_email_address: Optional[str] = None,
         user_identity_id: Optional[str] = None,
@@ -691,7 +692,7 @@ def unsuspend(
     def update(
         self,
         *,
-        access_schedule: Optional[Dict[str, Any]] = None,
+        access_schedule: Optional[Union[Dict[str, Any], Null]] = None,
         acs_system_id: Optional[str] = None,
         acs_user_id: Optional[str] = None,
         email: Optional[str] = None,
diff --git a/seam/routes/action_attempts.py b/seam/routes/action_attempts.py
index 977ad01b..8f0c221c 100644
--- a/seam/routes/action_attempts.py
+++ b/seam/routes/action_attempts.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import ActionAttempt
 from ..modules.action_attempts import resolve_action_attempt
 
@@ -33,7 +34,7 @@ def list(
         action_attempt_ids: Optional[List[str]] = None,
         device_id: Optional[str] = None,
         limit: Optional[int] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
     ) -> List[ActionAttempt]:
         """Returns a list of the `action attempts <https://docs.seam.co/core-concepts/action-attempts>`_ that you specify as an array of ``action_attempt_id``s.
 
@@ -105,7 +106,7 @@ def list(
         action_attempt_ids: Optional[List[str]] = None,
         device_id: Optional[str] = None,
         limit: Optional[int] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
     ) -> List[ActionAttempt]:
         """Returns a list of the `action attempts <https://docs.seam.co/core-concepts/action-attempts>`_ that you specify as an array of ``action_attempt_id``s.
 
diff --git a/seam/routes/connect_webviews.py b/seam/routes/connect_webviews.py
index 2310a432..053ed685 100644
--- a/seam/routes/connect_webviews.py
+++ b/seam/routes/connect_webviews.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import ConnectWebview
 
 
@@ -84,7 +85,7 @@ def list(
         custom_metadata_has: Optional[Dict[str, Any]] = None,
         customer_key: Optional[str] = None,
         limit: Optional[float] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         user_identifier_key: Optional[str] = None,
     ) -> List[ConnectWebview]:
@@ -253,7 +254,7 @@ def list(
         custom_metadata_has: Optional[Dict[str, Any]] = None,
         customer_key: Optional[str] = None,
         limit: Optional[float] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         user_identifier_key: Optional[str] = None,
     ) -> List[ConnectWebview]:
diff --git a/seam/routes/connected_accounts.py b/seam/routes/connected_accounts.py
index 1d8a6a6f..7c50bfd2 100644
--- a/seam/routes/connected_accounts.py
+++ b/seam/routes/connected_accounts.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import ConnectedAccount
 from .connected_accounts_simulate import (
     AbstractConnectedAccountsSimulate,
@@ -51,7 +52,7 @@ def list(
         custom_metadata_has: Optional[Dict[str, Any]] = None,
         customer_key: Optional[str] = None,
         limit: Optional[int] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         space_id: Optional[str] = None,
         user_identifier_key: Optional[str] = None,
@@ -196,7 +197,7 @@ def list(
         custom_metadata_has: Optional[Dict[str, Any]] = None,
         customer_key: Optional[str] = None,
         limit: Optional[int] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         space_id: Optional[str] = None,
         user_identifier_key: Optional[str] = None,
diff --git a/seam/routes/devices.py b/seam/routes/devices.py
index 8fe8841c..e1b6dfbb 100644
--- a/seam/routes/devices.py
+++ b/seam/routes/devices.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import Device, DeviceProvider
 from .devices_simulate import AbstractDevicesSimulate, DevicesSimulate
 from .devices_unmanaged import AbstractDevicesUnmanaged, DevicesUnmanaged
@@ -51,10 +52,10 @@ def list(
         device_types: Optional[List[str]] = None,
         limit: Optional[float] = None,
         manufacturer: Optional[str] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         space_id: Optional[str] = None,
-        unstable_location_id: Optional[str] = None,
+        unstable_location_id: Optional[Union[str, Null]] = None,
         user_identifier_key: Optional[str] = None,
     ) -> List[Device]:
         """Returns a list of all `devices <https://docs.seam.co/core-concepts/devices>`_.
@@ -126,7 +127,7 @@ def update(
         backup_access_code_pool_enabled: Optional[bool] = None,
         custom_metadata: Optional[Dict[str, Any]] = None,
         is_managed: Optional[bool] = None,
-        name: Optional[str] = None,
+        name: Optional[Union[str, Null]] = None,
         properties: Optional[Dict[str, Any]] = None,
     ) -> None:
         """Updates a specified `device <https://docs.seam.co/core-concepts/devices>`_.
@@ -212,10 +213,10 @@ def list(
         device_types: Optional[List[str]] = None,
         limit: Optional[float] = None,
         manufacturer: Optional[str] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         space_id: Optional[str] = None,
-        unstable_location_id: Optional[str] = None,
+        unstable_location_id: Optional[Union[str, Null]] = None,
         user_identifier_key: Optional[str] = None,
     ) -> List[Device]:
         """Returns a list of all `devices <https://docs.seam.co/core-concepts/devices>`_.
@@ -353,7 +354,7 @@ def update(
         backup_access_code_pool_enabled: Optional[bool] = None,
         custom_metadata: Optional[Dict[str, Any]] = None,
         is_managed: Optional[bool] = None,
-        name: Optional[str] = None,
+        name: Optional[Union[str, Null]] = None,
         properties: Optional[Dict[str, Any]] = None,
     ) -> None:
         """Updates a specified `device <https://docs.seam.co/core-concepts/devices>`_.
diff --git a/seam/routes/devices_unmanaged.py b/seam/routes/devices_unmanaged.py
index 4b8b5792..12987d60 100644
--- a/seam/routes/devices_unmanaged.py
+++ b/seam/routes/devices_unmanaged.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import UnmanagedDevice
 
 
@@ -40,7 +41,7 @@ def list(
         device_types: Optional[List[str]] = None,
         limit: Optional[float] = None,
         manufacturer: Optional[str] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
     ) -> List[UnmanagedDevice]:
         """Returns a list of all `unmanaged devices <https://docs.seam.co/core-concepts/devices/managed-and-unmanaged-devices>`_.
@@ -156,7 +157,7 @@ def list(
         device_types: Optional[List[str]] = None,
         limit: Optional[float] = None,
         manufacturer: Optional[str] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
     ) -> List[UnmanagedDevice]:
         """Returns a list of all `unmanaged devices <https://docs.seam.co/core-concepts/devices/managed-and-unmanaged-devices>`_.
diff --git a/seam/routes/spaces.py b/seam/routes/spaces.py
index b72ea972..56f80f37 100644
--- a/seam/routes/spaces.py
+++ b/seam/routes/spaces.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import Space, Batch
 
 
@@ -129,7 +130,7 @@ def list(
         *,
         customer_key: Optional[str] = None,
         limit: Optional[float] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         space_key: Optional[str] = None,
     ) -> List[Space]:
@@ -465,7 +466,7 @@ def list(
         *,
         customer_key: Optional[str] = None,
         limit: Optional[float] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         space_key: Optional[str] = None,
     ) -> List[Space]:
diff --git a/seam/routes/thermostats.py b/seam/routes/thermostats.py
index b5ec077f..231090d3 100644
--- a/seam/routes/thermostats.py
+++ b/seam/routes/thermostats.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import ActionAttempt, Device
 from .thermostats_daily_programs import (
     AbstractThermostatsDailyPrograms,
@@ -89,7 +90,7 @@ def create_climate_preset(
         heating_set_point_fahrenheit: Optional[float] = None,
         hvac_mode_setting: Optional[str] = None,
         manual_override_allowed: Optional[bool] = None,
-        name: Optional[str] = None,
+        name: Optional[Union[str, Null]] = None,
     ) -> None:
         """Creates a `climate preset <https://docs.seam.co/capability-guides/thermostats/creating-and-managing-climate-presets>`_ for a specified `thermostat <https://docs.seam.co/capability-guides/thermostats>`_.
 
@@ -306,10 +307,10 @@ def set_temperature_threshold(
         self,
         *,
         device_id: str,
-        lower_limit_celsius: Optional[float] = None,
-        lower_limit_fahrenheit: Optional[float] = None,
-        upper_limit_celsius: Optional[float] = None,
-        upper_limit_fahrenheit: Optional[float] = None,
+        lower_limit_celsius: Optional[Union[float, Null]] = None,
+        lower_limit_fahrenheit: Optional[Union[float, Null]] = None,
+        upper_limit_celsius: Optional[Union[float, Null]] = None,
+        upper_limit_fahrenheit: Optional[Union[float, Null]] = None,
     ) -> None:
         """Sets a `temperature threshold <https://docs.seam.co/capability-guides/thermostats/setting-and-monitoring-temperature-thresholds>`_ for a specified thermostat. Seam emits a ``thermostat.temperature_threshold_exceeded`` event and adds a warning on a thermostat if it reports a temperature outside the threshold range.
 
@@ -341,7 +342,7 @@ def update_climate_preset(
         heating_set_point_fahrenheit: Optional[float] = None,
         hvac_mode_setting: Optional[str] = None,
         manual_override_allowed: Optional[bool] = None,
-        name: Optional[str] = None,
+        name: Optional[Union[str, Null]] = None,
     ) -> None:
         """Updates a specified `climate preset <https://docs.seam.co/capability-guides/thermostats/creating-and-managing-climate-presets>`_ for a specified `thermostat <https://docs.seam.co/capability-guides/thermostats>`_.
 
@@ -377,13 +378,13 @@ def update_weekly_program(
         self,
         *,
         device_id: str,
-        friday_program_id: Optional[str] = None,
-        monday_program_id: Optional[str] = None,
-        saturday_program_id: Optional[str] = None,
-        sunday_program_id: Optional[str] = None,
-        thursday_program_id: Optional[str] = None,
-        tuesday_program_id: Optional[str] = None,
-        wednesday_program_id: Optional[str] = None,
+        friday_program_id: Optional[Union[str, Null]] = None,
+        monday_program_id: Optional[Union[str, Null]] = None,
+        saturday_program_id: Optional[Union[str, Null]] = None,
+        sunday_program_id: Optional[Union[str, Null]] = None,
+        thursday_program_id: Optional[Union[str, Null]] = None,
+        tuesday_program_id: Optional[Union[str, Null]] = None,
+        wednesday_program_id: Optional[Union[str, Null]] = None,
         wait_for_action_attempt: Optional[Union[bool, Dict[str, float]]] = None,
     ) -> ActionAttempt:
         """Updates the thermostat weekly program for a thermostat device. To configure a weekly program, specify the ID of the daily program that you want to use for each day of the week. When you update a weekly program, the set of programs that you specify overwrites any previous weekly program for the thermostat.
@@ -554,7 +555,7 @@ def create_climate_preset(
         heating_set_point_fahrenheit: Optional[float] = None,
         hvac_mode_setting: Optional[str] = None,
         manual_override_allowed: Optional[bool] = None,
-        name: Optional[str] = None,
+        name: Optional[Union[str, Null]] = None,
     ) -> None:
         """Creates a `climate preset <https://docs.seam.co/capability-guides/thermostats/creating-and-managing-climate-presets>`_ for a specified `thermostat <https://docs.seam.co/capability-guides/thermostats>`_.
 
@@ -1012,10 +1013,10 @@ def set_temperature_threshold(
         self,
         *,
         device_id: str,
-        lower_limit_celsius: Optional[float] = None,
-        lower_limit_fahrenheit: Optional[float] = None,
-        upper_limit_celsius: Optional[float] = None,
-        upper_limit_fahrenheit: Optional[float] = None,
+        lower_limit_celsius: Optional[Union[float, Null]] = None,
+        lower_limit_fahrenheit: Optional[Union[float, Null]] = None,
+        upper_limit_celsius: Optional[Union[float, Null]] = None,
+        upper_limit_fahrenheit: Optional[Union[float, Null]] = None,
     ) -> None:
         """Sets a `temperature threshold <https://docs.seam.co/capability-guides/thermostats/setting-and-monitoring-temperature-thresholds>`_ for a specified thermostat. Seam emits a ``thermostat.temperature_threshold_exceeded`` event and adds a warning on a thermostat if it reports a temperature outside the threshold range.
 
@@ -1071,7 +1072,7 @@ def update_climate_preset(
         heating_set_point_fahrenheit: Optional[float] = None,
         hvac_mode_setting: Optional[str] = None,
         manual_override_allowed: Optional[bool] = None,
-        name: Optional[str] = None,
+        name: Optional[Union[str, Null]] = None,
     ) -> None:
         """Updates a specified `climate preset <https://docs.seam.co/capability-guides/thermostats/creating-and-managing-climate-presets>`_ for a specified `thermostat <https://docs.seam.co/capability-guides/thermostats>`_.
 
@@ -1145,13 +1146,13 @@ def update_weekly_program(
         self,
         *,
         device_id: str,
-        friday_program_id: Optional[str] = None,
-        monday_program_id: Optional[str] = None,
-        saturday_program_id: Optional[str] = None,
-        sunday_program_id: Optional[str] = None,
-        thursday_program_id: Optional[str] = None,
-        tuesday_program_id: Optional[str] = None,
-        wednesday_program_id: Optional[str] = None,
+        friday_program_id: Optional[Union[str, Null]] = None,
+        monday_program_id: Optional[Union[str, Null]] = None,
+        saturday_program_id: Optional[Union[str, Null]] = None,
+        sunday_program_id: Optional[Union[str, Null]] = None,
+        thursday_program_id: Optional[Union[str, Null]] = None,
+        tuesday_program_id: Optional[Union[str, Null]] = None,
+        wednesday_program_id: Optional[Union[str, Null]] = None,
         wait_for_action_attempt: Optional[Union[bool, Dict[str, float]]] = None,
     ) -> ActionAttempt:
         """Updates the thermostat weekly program for a thermostat device. To configure a weekly program, specify the ID of the daily program that you want to use for each day of the week. When you update a weekly program, the set of programs that you specify overwrites any previous weekly program for the thermostat.
diff --git a/seam/routes/thermostats_schedules.py b/seam/routes/thermostats_schedules.py
index d708149e..7c4787ad 100644
--- a/seam/routes/thermostats_schedules.py
+++ b/seam/routes/thermostats_schedules.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import ThermostatSchedule
 
 
@@ -16,7 +17,7 @@ def create(
         ends_at: str,
         starts_at: str,
         is_override_allowed: Optional[bool] = None,
-        max_override_period_minutes: Optional[int] = None,
+        max_override_period_minutes: Optional[Union[int, Null]] = None,
         name: Optional[str] = None,
     ) -> ThermostatSchedule:
         """Creates a new `thermostat schedule <https://docs.seam.co/capability-guides/thermostats/creating-and-managing-thermostat-schedules>`_ for a specified `thermostat <https://docs.seam.co/capability-guides/thermostats>`_.
@@ -83,7 +84,7 @@ def update(
         climate_preset_key: Optional[str] = None,
         ends_at: Optional[str] = None,
         is_override_allowed: Optional[bool] = None,
-        max_override_period_minutes: Optional[int] = None,
+        max_override_period_minutes: Optional[Union[int, Null]] = None,
         name: Optional[str] = None,
         starts_at: Optional[str] = None,
     ) -> None:
@@ -125,7 +126,7 @@ def create(
         ends_at: str,
         starts_at: str,
         is_override_allowed: Optional[bool] = None,
-        max_override_period_minutes: Optional[int] = None,
+        max_override_period_minutes: Optional[Union[int, Null]] = None,
         name: Optional[str] = None,
     ) -> ThermostatSchedule:
         """Creates a new `thermostat schedule <https://docs.seam.co/capability-guides/thermostats/creating-and-managing-thermostat-schedules>`_ for a specified `thermostat <https://docs.seam.co/capability-guides/thermostats>`_.
@@ -272,7 +273,7 @@ def update(
         climate_preset_key: Optional[str] = None,
         ends_at: Optional[str] = None,
         is_override_allowed: Optional[bool] = None,
-        max_override_period_minutes: Optional[int] = None,
+        max_override_period_minutes: Optional[Union[int, Null]] = None,
         name: Optional[str] = None,
         starts_at: Optional[str] = None,
     ) -> None:
diff --git a/seam/routes/user_identities.py b/seam/routes/user_identities.py
index ab7442b2..a9107bc6 100644
--- a/seam/routes/user_identities.py
+++ b/seam/routes/user_identities.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import (
     UserIdentity,
     InstantKey,
@@ -51,10 +52,10 @@ def create(
         self,
         *,
         acs_system_ids: Optional[List[str]] = None,
-        email_address: Optional[str] = None,
-        full_name: Optional[str] = None,
-        phone_number: Optional[str] = None,
-        user_identity_key: Optional[str] = None,
+        email_address: Optional[Union[str, Null]] = None,
+        full_name: Optional[Union[str, Null]] = None,
+        phone_number: Optional[Union[str, Null]] = None,
+        user_identity_key: Optional[Union[str, Null]] = None,
     ) -> UserIdentity:
         """Creates a new `user identity <https://docs.seam.co/capability-guides/mobile-access/managing-mobile-app-user-accounts-with-user-identities#what-is-a-user-identity>`_.
 
@@ -137,7 +138,7 @@ def list(
         created_before: Optional[str] = None,
         credential_manager_acs_system_id: Optional[str] = None,
         limit: Optional[int] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         user_identity_ids: Optional[List[str]] = None,
     ) -> List[UserIdentity]:
@@ -229,10 +230,10 @@ def update(
         self,
         *,
         user_identity_id: str,
-        email_address: Optional[str] = None,
-        full_name: Optional[str] = None,
-        phone_number: Optional[str] = None,
-        user_identity_key: Optional[str] = None,
+        email_address: Optional[Union[str, Null]] = None,
+        full_name: Optional[Union[str, Null]] = None,
+        phone_number: Optional[Union[str, Null]] = None,
+        user_identity_key: Optional[Union[str, Null]] = None,
     ) -> None:
         """Updates a specified `user identity <https://docs.seam.co/capability-guides/mobile-access/managing-mobile-app-user-accounts-with-user-identities#what-is-a-user-identity>`_.
 
@@ -312,10 +313,10 @@ def create(
         self,
         *,
         acs_system_ids: Optional[List[str]] = None,
-        email_address: Optional[str] = None,
-        full_name: Optional[str] = None,
-        phone_number: Optional[str] = None,
-        user_identity_key: Optional[str] = None,
+        email_address: Optional[Union[str, Null]] = None,
+        full_name: Optional[Union[str, Null]] = None,
+        phone_number: Optional[Union[str, Null]] = None,
+        user_identity_key: Optional[Union[str, Null]] = None,
     ) -> UserIdentity:
         """Creates a new `user identity <https://docs.seam.co/capability-guides/mobile-access/managing-mobile-app-user-accounts-with-user-identities#what-is-a-user-identity>`_.
 
@@ -487,7 +488,7 @@ def list(
         created_before: Optional[str] = None,
         credential_manager_acs_system_id: Optional[str] = None,
         limit: Optional[int] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
         user_identity_ids: Optional[List[str]] = None,
     ) -> List[UserIdentity]:
@@ -704,10 +705,10 @@ def update(
         self,
         *,
         user_identity_id: str,
-        email_address: Optional[str] = None,
-        full_name: Optional[str] = None,
-        phone_number: Optional[str] = None,
-        user_identity_key: Optional[str] = None,
+        email_address: Optional[Union[str, Null]] = None,
+        full_name: Optional[Union[str, Null]] = None,
+        phone_number: Optional[Union[str, Null]] = None,
+        user_identity_key: Optional[Union[str, Null]] = None,
     ) -> None:
         """Updates a specified `user identity <https://docs.seam.co/capability-guides/mobile-access/managing-mobile-app-user-accounts-with-user-identities#what-is-a-user-identity>`_.
 
diff --git a/seam/routes/user_identities_unmanaged.py b/seam/routes/user_identities_unmanaged.py
index 31627ad2..b177177a 100644
--- a/seam/routes/user_identities_unmanaged.py
+++ b/seam/routes/user_identities_unmanaged.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import UnmanagedUserIdentity
 
 
@@ -24,7 +25,7 @@ def list(
         *,
         created_before: Optional[str] = None,
         limit: Optional[int] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
     ) -> List[UnmanagedUserIdentity]:
         """Returns a list of all unmanaged `user identities <https://docs.seam.co/capability-guides/mobile-access/managing-mobile-app-user-accounts-with-user-identities#what-is-a-user-identity>`_ (where is_managed = false).
@@ -104,7 +105,7 @@ def list(
         *,
         created_before: Optional[str] = None,
         limit: Optional[int] = None,
-        page_cursor: Optional[str] = None,
+        page_cursor: Optional[Union[str, Null]] = None,
         search: Optional[str] = None,
     ) -> List[UnmanagedUserIdentity]:
         """Returns a list of all unmanaged `user identities <https://docs.seam.co/capability-guides/mobile-access/managing-mobile-app-user-accounts-with-user-identities#what-is-a-user-identity>`_ (where is_managed = false).
diff --git a/seam/routes/workspaces.py b/seam/routes/workspaces.py
index 09bbb529..01ee6655 100644
--- a/seam/routes/workspaces.py
+++ b/seam/routes/workspaces.py
@@ -2,6 +2,7 @@
 import abc
 from ..client import SeamHttpClient
 from ..route import route_metadata
+from ..null import Null
 from ..resources import Workspace, ActionAttempt
 from ..modules.action_attempts import resolve_action_attempt
 
@@ -14,7 +15,7 @@ def create(
         *,
         name: str,
         company_name: Optional[str] = None,
-        connect_partner_name: Optional[str] = None,
+        connect_partner_name: Optional[Union[str, Null]] = None,
         connect_webview_customization: Optional[Dict[str, Any]] = None,
         is_sandbox: Optional[bool] = None,
         organization_id: Optional[str] = None,
@@ -116,7 +117,7 @@ def create(
         *,
         name: str,
         company_name: Optional[str] = None,
-        connect_partner_name: Optional[str] = None,
+        connect_partner_name: Optional[Union[str, Null]] = None,
         connect_webview_customization: Optional[Dict[str, Any]] = None,
         is_sandbox: Optional[bool] = None,
         organization_id: Optional[str] = None,
diff --git a/test/conftest.py b/test/conftest.py
index 39a47693..0af77f8d 100755
--- a/test/conftest.py
+++ b/test/conftest.py
@@ -62,6 +62,8 @@ def recording_server(responses):
     content type inferred from the body, e.g. to serve malformed JSON.
 
     Yields the endpoint along with the list of requests received so far.
+    Each request records the ``method``, the raw request ``target``, the
+    ``path`` and ``query`` it splits into, the ``headers``, and the ``body``.
     """
 
     requests = []
@@ -70,21 +72,17 @@ def recording_server(responses):
     class Handler(BaseHTTPRequestHandler):
         protocol_version = "HTTP/1.1"
 
-        # pylint: disable-next=invalid-name
-        def do_GET(self):
-            self._handle_request()
-
-        # pylint: disable-next=invalid-name
-        def do_POST(self):
-            self._handle_request()
-
         def _handle_request(self):
             content_length = int(self.headers.get("content-length", 0))
             raw_body = self.rfile.read(content_length)
+            path, _, query = self.path.partition("?")
 
             requests.append(
                 {
-                    "path": self.path,
+                    "method": self.command,
+                    "target": self.path,
+                    "path": path,
+                    "query": query,
                     "headers": {k.lower(): v for k, v in self.headers.items()},
                     "body": json.loads(raw_body) if raw_body else None,
                 }
@@ -112,6 +110,14 @@ def _handle_request(self):
         def log_message(self, *args):
             pass
 
+        # Every verb the SDK sends is recorded and answered the same way.
+        # pylint: disable=invalid-name
+        do_GET = _handle_request
+        do_POST = _handle_request
+        do_PUT = _handle_request
+        do_PATCH = _handle_request
+        do_DELETE = _handle_request
+
     server = ThreadingHTTPServer(("localhost", 0), Handler)
     thread = threading.Thread(target=server.serve_forever, daemon=True)
     thread.start()
diff --git a/test/headers_test.py b/test/headers_test.py
index dfb040e0..ffdf34e6 100644
--- a/test/headers_test.py
+++ b/test/headers_test.py
@@ -17,7 +17,8 @@ def test_seam_sends_default_headers(recording_server):
     assert len(requests) == 1
     [request] = requests
 
-    assert request["path"] == f"/devices/get?device_id={device_id}"
+    assert request["path"] == "/devices/get"
+    assert request["query"] == f"device_id={device_id}"
     assert request["body"] is None
 
     assert request["headers"]["seam-sdk-name"] == "seamapi/python"
diff --git a/test/null_test.py b/test/null_test.py
index 83db727c..e329bb3a 100644
--- a/test/null_test.py
+++ b/test/null_test.py
@@ -1,4 +1,4 @@
-from seam.null import NULL, Null, is_null
+from seam.null import NULL, Null, is_null, replace_null
 
 
 def test_null_is_a_singleton():
@@ -20,3 +20,37 @@ def test_null_is_falsy():
 
 def test_null_repr():
     assert repr(NULL) == "NULL"
+
+
+def test_replace_null_replaces_the_sentinel_with_none():
+    assert replace_null(NULL) is None
+
+
+def test_replace_null_recurses_into_dicts_and_lists():
+    assert replace_null(
+        {
+            "name": NULL,
+            "properties": {"code": NULL, "kind": "lock"},
+            "codes": [NULL, "1234", [NULL]],
+            "pairs": (NULL, "1234"),
+        }
+    ) == {
+        "name": None,
+        "properties": {"code": None, "kind": "lock"},
+        "codes": [None, "1234", [None]],
+        "pairs": [None, "1234"],
+    }
+
+
+def test_replace_null_leaves_other_values_alone():
+    values = [None, "", 0, False, "NULL", {"a": 1}, ["b"]]
+
+    assert replace_null(values) == values
+
+
+def test_replace_null_does_not_mutate_its_argument():
+    body = {"name": NULL, "codes": [NULL]}
+
+    replace_null(body)
+
+    assert body == {"name": NULL, "codes": [NULL]}
diff --git a/test/nullable_param_test.py b/test/nullable_param_test.py
new file mode 100644
index 00000000..9557020d
--- /dev/null
+++ b/test/nullable_param_test.py
@@ -0,0 +1,52 @@
+"""Tests that generated params accept the NULL sentinel where the API allows it.
+
+These assertions are about types as much as behavior: the SDK is type checked,
+so a nullable param losing its ``Null`` type, or a param that is merely
+optional gaining one, fails the type check rather than any assertion here.
+"""
+
+from seam import NULL, Seam
+
+DEVICE = {"device": {"device_id": "device1"}}
+
+
+def test_a_nullable_param_is_sent_as_null(recording_server):
+    with recording_server([(200, DEVICE)]) as (endpoint, requests):
+        seam = Seam.from_api_key("seam_apikey_token", endpoint=endpoint)
+
+        # The API documents name as nullable, so it may be unset.
+        seam.devices.update(device_id="device1", name=NULL)
+
+    [request] = requests
+
+    assert request["body"] == {"device_id": "device1", "name": None}
+
+
+def test_a_nullable_number_param_is_sent_as_null(recording_server):
+    with recording_server([(200, {})]) as (endpoint, requests):
+        seam = Seam.from_api_key("seam_apikey_token", endpoint=endpoint)
+
+        seam.thermostats.set_temperature_threshold(
+            device_id="device1",
+            lower_limit_celsius=NULL,
+            upper_limit_celsius=20.5,
+        )
+
+    [request] = requests
+
+    assert request["body"] == {
+        "device_id": "device1",
+        "lower_limit_celsius": None,
+        "upper_limit_celsius": 20.5,
+    }
+
+
+def test_an_omitted_param_is_not_sent(recording_server):
+    with recording_server([(200, DEVICE)]) as (endpoint, requests):
+        seam = Seam.from_api_key("seam_apikey_token", endpoint=endpoint)
+
+        seam.devices.update(device_id="device1", name=None)
+
+    [request] = requests
+
+    assert request["body"] == {"device_id": "device1"}
diff --git a/test/search_params_test.py b/test/search_params_test.py
new file mode 100644
index 00000000..79545daf
--- /dev/null
+++ b/test/search_params_test.py
@@ -0,0 +1,176 @@
+from typing import Any, Dict, List
+
+import pytest
+
+from seam import NULL, Seam, UnserializableParamError
+
+DEVICE = {"device": {"device_id": "device1"}}
+DEVICES: Dict[str, List[Any]] = {"devices": []}
+
+
+def test_client_serializes_search_params(recording_server):
+    with recording_server([(200, DEVICES)]) as (endpoint, requests):
+        seam = Seam.from_api_key("seam_apikey_token", endpoint=endpoint)
+
+        seam.client.get(
+            "/devices/list",
+            params={
+                "device_ids": ["device1", "device2"],
+                "custom_metadata_has": {"tag": "front", "floor": 2},
+                "limit": 20,
+            },
+        )
+
+    [request] = requests
+
+    assert request["method"] == "GET"
+    assert request["path"] == "/devices/list"
+    assert request["query"] == (
+        "custom_metadata_has.floor=2"
+        "&custom_metadata_has.tag=front"
+        "&device_ids=device1"
+        "&device_ids=device2"
+        "&limit=20"
+    )
+
+
+def test_client_does_not_reencode_the_serialized_search_params(recording_server):
+    """The serializer and httpx disagree on exactly two characters.
+
+    httpx escapes ``*`` and leaves ``~`` alone, so a query it encodes is not
+    the one the serializer produced. Setting the query on the url keeps ours.
+    """
+
+    with recording_server([(200, DEVICES)]) as (endpoint, requests):
+        seam = Seam.from_api_key("seam_apikey_token", endpoint=endpoint)
+
+        seam.client.get("/devices/list", params={"search": "a *~ b"})
+
+    [request] = requests
+
+    assert request["query"] == "search=a+*%7E+b"
+
+
+def test_client_omits_search_params_set_to_none(recording_server):
+    with recording_server([(200, DEVICES)]) as (endpoint, requests):
+        seam = Seam.from_api_key("seam_apikey_token", endpoint=endpoint)
+
+        seam.client.get("/devices/list", params={"search": None, "limit": 20})
+
+    [request] = requests
+
+    assert request["query"] == "limit=20"
+
+
+def test_client_serializes_search_params_set_to_null(recording_server):
+    with recording_server([(200, DEVICES)]) as (endpoint, requests):
+        seam = Seam.from_api_key("seam_apikey_token", endpoint=endpoint)
+
+        seam.client.get("/devices/list", params={"search": NULL, "limit": 20})
+
+    [request] = requests
+
+    assert request["query"] == "limit=20&search="
+
+
+def test_client_sends_no_query_string_without_search_params(recording_server):
+    with recording_server([(200, DEVICES)]) as (endpoint, requests):
+        seam = Seam.from_api_key("seam_apikey_token", endpoint=endpoint)
+
+        seam.client.get("/devices/list", params={})
+        seam.client.get("/devices/list", params={"search": None})
+        seam.client.get("/devices/list")
+
+    for request in requests:
+        assert request["target"] == "/devices/list"
+
+
+def test_client_serializes_search_params_of_every_verb(recording_server):
+    with recording_server([(200, DEVICES)]) as (endpoint, requests):
+        seam = Seam.from_api_key("seam_apikey_token", endpoint=endpoint)
+
+        seam.client.get("/devices/list", params={"device_ids": ["device1"]})
+        seam.client.delete("/access_codes/delete", params={"sync": True})
+
+    assert [(request["method"], request["query"]) for request in requests] == [
+        ("GET", "device_ids=device1"),
+        ("DELETE", "sync=true"),
+    ]
+
+
+def test_client_passes_search_params_it_did_not_serialize_to_httpx(recording_server):
+    """Params that are not a mapping are left for httpx to encode.
+
+    A caller who serialized the params themselves, e.g. to the pairs of a
+    ``UrlSearchParams``, has already chosen how they are represented.
+    """
+
+    with recording_server([(200, DEVICES)]) as (endpoint, requests):
+        seam = Seam.from_api_key("seam_apikey_token", endpoint=endpoint)
+
+        seam.client.get("/devices/list", params=[("device_ids", "device1")])
+
+    [request] = requests
+
+    assert request["query"] == "device_ids=device1"
+
+
+def test_client_rejects_a_search_param_it_cannot_serialize(recording_server):
+    with recording_server([(200, DEVICES)]) as (endpoint, requests):
+        seam = Seam.from_api_key("seam_apikey_token", endpoint=endpoint)
+
+        with pytest.raises(UnserializableParamError):
+            seam.client.get("/devices/list", params={"search": object()})
+
+    assert requests == []
+
+
+def test_client_serializes_null_in_a_json_body_to_null(recording_server):
+    with recording_server([(200, DEVICE)]) as (endpoint, requests):
+        seam = Seam.from_api_key("seam_apikey_token", endpoint=endpoint)
+
+        seam.client.post(
+            "/devices/update",
+            json={
+                "device_id": "device1",
+                "name": NULL,
+                "properties": {"code": NULL},
+                "codes": [NULL, "1234"],
+            },
+        )
+
+    [request] = requests
+
+    assert request["method"] == "POST"
+    assert request["body"] == {
+        "device_id": "device1",
+        "name": None,
+        "properties": {"code": None},
+        "codes": [None, "1234"],
+    }
+
+
+def test_client_leaves_a_json_body_without_null_unchanged(recording_server):
+    body = {"device_id": "device1", "name": "Front Door", "limit": 20, "sync": True}
+
+    with recording_server([(200, DEVICE)]) as (endpoint, requests):
+        seam = Seam.from_api_key("seam_apikey_token", endpoint=endpoint)
+
+        seam.client.post("/devices/update", json=body)
+
+    [request] = requests
+
+    assert request["body"] == body
+
+
+def test_client_serializes_the_search_params_of_a_generated_route(recording_server):
+    with recording_server([(200, DEVICE)]) as (endpoint, requests):
+        seam = Seam.from_api_key("seam_apikey_token", endpoint=endpoint)
+
+        seam.devices.get(name="Front Door")
+
+    [request] = requests
+
+    assert request["method"] == "GET"
+    assert request["path"] == "/devices/get"
+    assert request["query"] == "name=Front+Door"