diff --git a/sdk/monitor/azure-mgmt-monitorslis/CHANGELOG.md b/sdk/monitor/azure-mgmt-monitorslis/CHANGELOG.md
index 0805c03a6b8d..a4e6caa59d58 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/CHANGELOG.md
+++ b/sdk/monitor/azure-mgmt-monitorslis/CHANGELOG.md
@@ -1,5 +1,16 @@
 # Release History
 
+## 1.0.0b2 (2026-05-23)
+
+### Features Added
+
+  - Enum `SamplingType` added member `AVERAGE`
+  - Enum `SamplingType` added member `COUNT`
+
+### Breaking Changes
+
+  - Deleted or renamed enum value `SamplingType.AVG`
+
 ## 1.0.0b1 (2026-04-27)
 
 ### Other Changes
diff --git a/sdk/monitor/azure-mgmt-monitorslis/_metadata.json b/sdk/monitor/azure-mgmt-monitorslis/_metadata.json
index c23edb0b2d1f..9c05764f07f4 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/_metadata.json
+++ b/sdk/monitor/azure-mgmt-monitorslis/_metadata.json
@@ -3,8 +3,8 @@
   "apiVersions": {
     "Microsoft.Monitor": "2025-03-01-preview"
   },
-  "commit": "fa74a24ebfcd57429a95ef827b06eae0e639800a",
+  "commit": "8be8c75d9bb11ea95d8a7e251db74aa78b5cd76c",
   "repository_url": "https://github.com/Azure/azure-rest-api-specs",
   "typespec_src": "specification/monitoringservice/resource-manager/Microsoft.Monitor/Slis",
-  "emitterVersion": "0.61.3"
+  "emitterVersion": "0.62.1"
 }
\ No newline at end of file
diff --git a/sdk/monitor/azure-mgmt-monitorslis/apiview-properties.json b/sdk/monitor/azure-mgmt-monitorslis/apiview-properties.json
index c201445ab32f..d446b972afdc 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/apiview-properties.json
+++ b/sdk/monitor/azure-mgmt-monitorslis/apiview-properties.json
@@ -43,5 +43,6 @@
         "azure.mgmt.monitorslis.aio.operations.SlisOperations.delete": "Microsoft.Monitor.Slis.delete",
         "azure.mgmt.monitorslis.operations.SlisOperations.list_by_parent": "Microsoft.Monitor.Slis.listByParent",
         "azure.mgmt.monitorslis.aio.operations.SlisOperations.list_by_parent": "Microsoft.Monitor.Slis.listByParent"
-    }
+    },
+    "CrossLanguageVersion": "42338712126b"
 }
\ No newline at end of file
diff --git a/sdk/monitor/azure-mgmt-monitorslis/assets.json b/sdk/monitor/azure-mgmt-monitorslis/assets.json
new file mode 100644
index 000000000000..1e07b863c206
--- /dev/null
+++ b/sdk/monitor/azure-mgmt-monitorslis/assets.json
@@ -0,0 +1,6 @@
+{
+  "AssetsRepo": "Azure/azure-sdk-assets",
+  "AssetsRepoPrefixPath": "python",
+  "TagPrefix": "python/monitor/azure-mgmt-monitorslis",
+  "Tag": "python/monitor/azure-mgmt-monitorslis_3192c4a8f5"
+}
diff --git a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_client.py b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_client.py
index f6e91cec5246..497d77d60f39 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_client.py
+++ b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_client.py
@@ -7,8 +7,8 @@
 # --------------------------------------------------------------------------
 
 from copy import deepcopy
+import sys
 from typing import Any, Optional, TYPE_CHECKING, cast
-from typing_extensions import Self
 
 from azure.core.pipeline import policies
 from azure.core.rest import HttpRequest, HttpResponse
@@ -21,6 +21,11 @@
 from ._utils.serialization import Deserializer, Serializer
 from .operations import SlisOperations
 
+if sys.version_info >= (3, 11):
+    from typing import Self
+else:
+    from typing_extensions import Self  # type: ignore
+
 if TYPE_CHECKING:
     from azure.core import AzureClouds
     from azure.core.credentials import TokenCredential
@@ -39,8 +44,9 @@ class MonitorSlisMgmtClient:
      None.
     :paramtype cloud_setting: ~azure.core.AzureClouds
     :keyword api_version: The API version to use for this operation. Known values are
-     "2025-03-01-preview". Default value is "2025-03-01-preview". Note that overriding this default
-     value may result in unsupported behavior.
+     "2025-03-01-preview" and None. Default value is None. If not set, the operation's default API
+     version will be used. Note that overriding this default value may result in unsupported
+     behavior.
     :paramtype api_version: str
     """
 
diff --git a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_configuration.py b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_configuration.py
index 5706eb3eda2a..8b4cc50efa58 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_configuration.py
+++ b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_configuration.py
@@ -32,8 +32,9 @@ class MonitorSlisMgmtClientConfiguration:  # pylint: disable=too-many-instance-a
      None.
     :type cloud_setting: ~azure.core.AzureClouds
     :keyword api_version: The API version to use for this operation. Known values are
-     "2025-03-01-preview". Default value is "2025-03-01-preview". Note that overriding this default
-     value may result in unsupported behavior.
+     "2025-03-01-preview" and None. Default value is None. If not set, the operation's default API
+     version will be used. Note that overriding this default value may result in unsupported
+     behavior.
     :paramtype api_version: str
     """
 
diff --git a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_patch.py b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_patch.py
index 87676c65a8f0..ea765788358a 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_patch.py
+++ b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_patch.py
@@ -8,7 +8,6 @@
 Follow our quickstart for examples: https://aka.ms/azsdk/python/dpcodegen/python/customize
 """
 
-
 __all__: list[str] = []  # Add all objects you want publicly available to users at this package level
 
 
diff --git a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_utils/model_base.py b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_utils/model_base.py
index db24930fdca9..d725c55906d3 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_utils/model_base.py
+++ b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_utils/model_base.py
@@ -23,14 +23,19 @@
 from json import JSONEncoder
 import xml.etree.ElementTree as ET
 from collections.abc import MutableMapping
-from typing_extensions import Self
 import isodate
 from azure.core.exceptions import DeserializationError
 from azure.core import CaseInsensitiveEnumMeta
 from azure.core.pipeline import PipelineResponse
 from azure.core.serialization import _Null
+
 from azure.core.rest import HttpResponse
 
+if sys.version_info >= (3, 11):
+    from typing import Self
+else:
+    from typing_extensions import Self
+
 _LOGGER = logging.getLogger(__name__)
 
 __all__ = ["SdkJSONEncoder", "Model", "rest_field", "rest_discriminator"]
@@ -585,6 +590,239 @@ def _create_value(rf: typing.Optional["_RestField"], value: typing.Any) -> typin
     return _serialize(value, rf._format)
 
 
+# ============================================================================
+# Fast-path scalar deserializer functions for rest_field(deserializer=...)
+# These are referenced from rest_field declarations to bypass the generic
+# _deserialize -> _deserialize_with_callable chain.
+# Only simple/primitive types — no models or container types.
+# ============================================================================
+
+
+def _xml_deser_str(value):
+    if isinstance(value, ET.Element):
+        return value.text or ""
+    return str(value) if value is not None else None
+
+
+def _xml_deser_int(value):
+    if isinstance(value, ET.Element):
+        return int(value.text) if value.text else None
+    return int(value) if value is not None else None
+
+
+def _xml_deser_float(value):
+    if isinstance(value, ET.Element):
+        return float(value.text) if value.text else None
+    return float(value) if value is not None else None
+
+
+def _xml_deser_bool(value):
+    if isinstance(value, ET.Element):
+        text = value.text
+    else:
+        text = value
+    if text is None:
+        return None
+    if text in (True, False):
+        return text
+    return text.lower() == "true"
+
+
+# pylint: disable=docstring-missing-param
+def _xml_deser_bytes(value):
+    """Deserialize bytes from XML (base64)."""
+    if isinstance(value, ET.Element):
+        text = value.text
+    else:
+        text = value
+    if text is None:
+        return None
+    return _deserialize_bytes(text)
+
+
+def _xml_deser_bytes_base64url(value):
+    """Deserialize bytes from XML (base64url)."""
+    if isinstance(value, ET.Element):
+        text = value.text
+    else:
+        text = value
+    if text is None:
+        return None
+    return _deserialize_bytes_base64(text)
+
+
+def _xml_deser_datetime(value):
+    """Deserialize a datetime from XML (ISO 8601 / rfc3339)."""
+    if isinstance(value, ET.Element):
+        text = value.text
+    else:
+        text = value
+    if text is None:
+        return None
+    return _deserialize_datetime(text)
+
+
+def _xml_deser_datetime_rfc7231(value):
+    """Deserialize a datetime from XML (RFC7231 format)."""
+    if isinstance(value, ET.Element):
+        text = value.text
+    else:
+        text = value
+    if text is None:
+        return None
+    return _deserialize_datetime_rfc7231(text)
+
+
+def _xml_deser_datetime_unix_timestamp(value):
+    """Deserialize a datetime from XML (Unix timestamp)."""
+    if isinstance(value, ET.Element):
+        text = value.text
+    else:
+        text = value
+    if text is None:
+        return None
+    return _deserialize_datetime_unix_timestamp(float(text))
+
+
+def _xml_deser_date(value):
+    """Deserialize a date from XML (ISO 8601)."""
+    if isinstance(value, ET.Element):
+        text = value.text
+    else:
+        text = value
+    if text is None:
+        return None
+    return _deserialize_date(text)
+
+
+def _xml_deser_time(value):
+    """Deserialize a time from XML (ISO 8601)."""
+    if isinstance(value, ET.Element):
+        text = value.text
+    else:
+        text = value
+    if text is None:
+        return None
+    return _deserialize_time(text)
+
+
+def _xml_deser_duration(value):
+    """Deserialize a timedelta from XML (ISO 8601 duration)."""
+    if isinstance(value, ET.Element):
+        text = value.text
+    else:
+        text = value
+    if text is None:
+        return None
+    return _deserialize_duration(text)
+
+
+def _xml_deser_decimal(value):
+    """Deserialize a Decimal from XML."""
+    if isinstance(value, ET.Element):
+        text = value.text
+    else:
+        text = value
+    if text is None:
+        return None
+    return _deserialize_decimal(text)
+
+
+def _xml_deser_enum_or_str(enum_cls, value):
+    """Deserialize a Union[EnumType, str] from XML."""
+    text = value.text if isinstance(value, ET.Element) else value
+    if text is None:
+        return None
+    try:
+        return enum_cls(text)
+    except ValueError:
+        return text
+
+
+def _extract_xml_model_type(rf_type):
+    """Extract the concrete Model class from a resolved rf._type partial chain.
+
+    Unwraps ``Optional[Model]`` and ``_deserialize_model(Model, ...)``
+    wrappers.  Only handles Model and Optional[Model] — other composite
+    types (List, Dict, Union, etc.) return None and fall through to the
+    generic ``_deserialize`` path at runtime.
+    """
+    if rf_type is None:
+        return None
+    if isinstance(rf_type, type) and _is_model(rf_type):
+        return rf_type
+    if not isinstance(rf_type, functools.partial):
+        return None
+    func = rf_type.func
+    args = rf_type.args
+    if func is _deserialize_with_optional and args:
+        return _extract_xml_model_type(args[0])
+    if func is _deserialize_model and args:
+        cls = args[0]
+        return cls if isinstance(cls, type) and _is_model(cls) else None
+    return None
+
+
+def _build_xml_field_plan(  # pylint: disable=docstring-missing-return, docstring-missing-rtype, unused-variable
+    cls, attr_to_rest_field: dict
+) -> list:
+    """Build a precomputed XML field plan for fast _init_from_xml iteration.
+
+    Called once per model class in __new__. Returns a list of tuples:
+        (rest_name, xml_name, kind, deser, rf_type, is_optional, items_name)
+
+    kind: 0=wrapped, 1=attribute, 2=unwrapped, 3=text
+
+    For Model and Optional[Model] fields that lack a scalar
+    ``_deserializer``, this function precomputes the Model class as the
+    deserializer so ``_init_from_xml`` can call ``ModelClass(element)``
+    directly instead of going through the expensive
+    ``_get_deserialize_callable_from_annotation`` chain at runtime.
+    """
+    model_meta = getattr(cls, "_xml", {})
+    model_ns = model_meta.get("ns") or model_meta.get("namespace")
+    plan = []
+
+    for rf in attr_to_rest_field.values():
+        prop_meta = getattr(rf, "_xml", {})
+        deser = rf._deserializer
+
+        xml_name = prop_meta.get("name", rf._rest_name)
+        xml_ns = _resolve_xml_ns(prop_meta, model_meta)
+        if xml_ns:
+            xml_name = "{" + xml_ns + "}" + xml_name
+
+        is_optional = rf._is_optional
+
+        # For Model / Optional[Model] fields without a scalar deserializer,
+        # precompute the Model class as the deserializer.
+        if deser is None and rf._type is not None:
+            model_cls = _extract_xml_model_type(rf._type)
+            if model_cls is not None:
+                deser = model_cls
+
+        if prop_meta.get("attribute", False):
+            plan.append((rf._rest_name, xml_name, 1, deser, rf._type, is_optional, None))
+        elif prop_meta.get("unwrapped", False):
+            items_name = prop_meta.get("itemsName")
+            if items_name:
+                items_ns = prop_meta.get("itemsNs")
+                if items_ns is not None:
+                    xml_ns = items_ns
+                if xml_ns:
+                    items_name = "{" + xml_ns + "}" + items_name
+            else:
+                items_name = xml_name
+            plan.append((rf._rest_name, xml_name, 2, deser, rf._type, is_optional, items_name))
+        elif prop_meta.get("text", False):
+            plan.append((rf._rest_name, xml_name, 3, deser, rf._type, is_optional, None))
+        else:
+            plan.append((rf._rest_name, xml_name, 0, deser, rf._type, is_optional, None))
+
+    return plan
+
+
+# pylint: enable=docstring-missing-param
 class Model(_MyMutableMapping):
     _is_model = True
     # label whether current class's _attr_to_rest_field has been calculated
@@ -595,11 +833,7 @@ def __init__(self, *args: typing.Any, **kwargs: typing.Any) -> None:
         class_name = self.__class__.__name__
         if len(args) > 1:
             raise TypeError(f"{class_name}.__init__() takes 2 positional arguments but {len(args) + 1} were given")
-        dict_to_pass = {
-            rest_field._rest_name: rest_field._default
-            for rest_field in self._attr_to_rest_field.values()
-            if rest_field._default is not _UNSET
-        }
+        dict_to_pass: dict[str, typing.Any] = {}
         if args:
             if isinstance(args[0], ET.Element):
                 dict_to_pass.update(self._init_from_xml(args[0]))
@@ -619,9 +853,19 @@ def __init__(self, *args: typing.Any, **kwargs: typing.Any) -> None:
                     if v is not None
                 }
             )
+        # Apply client default values for fields the caller didn't set so that
+        # defaults are part of `_data` and therefore included during serialization.
+        for rf in self._attr_to_rest_field.values():
+            if rf._default is _UNSET:
+                continue
+            if rf._rest_name in dict_to_pass:
+                continue
+            dict_to_pass[rf._rest_name] = _create_value(rf, rf._default)
         super().__init__(dict_to_pass)
 
-    def _init_from_xml(self, element: ET.Element) -> dict[str, typing.Any]:
+    def _init_from_xml(  # pylint: disable=too-many-branches, too-many-statements
+        self, element: ET.Element
+    ) -> dict[str, typing.Any]:
         """Deserialize an XML element into a dict mapping rest field names to values.
 
         :param ET.Element element: The XML element to deserialize from.
@@ -629,53 +873,89 @@ def _init_from_xml(self, element: ET.Element) -> dict[str, typing.Any]:
         :rtype: dict
         """
         result: dict[str, typing.Any] = {}
-        model_meta = getattr(self, "_xml", {})
         existed_attr_keys: list[str] = []
 
-        for rf in self._attr_to_rest_field.values():
-            prop_meta = getattr(rf, "_xml", {})
-            xml_name = prop_meta.get("name", rf._rest_name)
-            xml_ns = _resolve_xml_ns(prop_meta, model_meta)
-            if xml_ns:
-                xml_name = "{" + xml_ns + "}" + xml_name
-
-            # attribute
-            if prop_meta.get("attribute", False) and element.get(xml_name) is not None:
-                existed_attr_keys.append(xml_name)
-                result[rf._rest_name] = _deserialize(rf._type, element.get(xml_name))
-                continue
-
-            # unwrapped element is array
-            if prop_meta.get("unwrapped", False):
-                # unwrapped array could either use prop items meta/prop meta
-                _items_name = prop_meta.get("itemsName")
-                if _items_name:
-                    xml_name = _items_name
-                    _items_ns = prop_meta.get("itemsNs")
-                    if _items_ns is not None:
-                        xml_ns = _items_ns
-                    if xml_ns:
-                        xml_name = "{" + xml_ns + "}" + xml_name
-                items = element.findall(xml_name)  # pyright: ignore
-                if len(items) > 0:
+        field_plan = getattr(self, "_xml_field_plan", None)
+        if field_plan:
+            for rest_name, xml_name, kind, deser, rf_type, is_optional, items_name in field_plan:
+                if kind == 0:  # wrapped element (most common)
+                    item = element.find(xml_name)
+                    if item is not None:
+                        existed_attr_keys.append(xml_name)
+                        if deser:
+                            result[rest_name] = deser(item)
+                        else:
+                            result[rest_name] = _deserialize(rf_type, item)
+                elif kind == 1:  # attribute
+                    attr_val = element.get(xml_name)
+                    if attr_val is not None:
+                        existed_attr_keys.append(xml_name)
+                        if deser:
+                            result[rest_name] = deser(attr_val)
+                        else:
+                            result[rest_name] = attr_val
+                elif kind == 2:  # unwrapped array
+                    items = element.findall(items_name)  # pyright: ignore
+                    if len(items) > 0:
+                        existed_attr_keys.append(items_name)
+                        if deser:
+                            result[rest_name] = deser(items)
+                        else:
+                            result[rest_name] = _deserialize(rf_type, items)
+                    elif not is_optional:
+                        existed_attr_keys.append(items_name)
+                        result[rest_name] = []
+                elif kind == 3:  # text
+                    if element.text is not None:
+                        if deser:
+                            result[rest_name] = deser(element.text)
+                        else:
+                            result[rest_name] = element.text
+        else:
+            model_meta = getattr(self, "_xml", {})
+            for rf in self._attr_to_rest_field.values():
+                prop_meta = getattr(rf, "_xml", {})
+                xml_name = prop_meta.get("name", rf._rest_name)
+                xml_ns = _resolve_xml_ns(prop_meta, model_meta)
+                if xml_ns:
+                    xml_name = "{" + xml_ns + "}" + xml_name
+
+                # attribute
+                if prop_meta.get("attribute", False) and element.get(xml_name) is not None:
                     existed_attr_keys.append(xml_name)
-                    result[rf._rest_name] = _deserialize(rf._type, items)
-                elif not rf._is_optional:
+                    result[rf._rest_name] = _deserialize(rf._type, element.get(xml_name))
+                    continue
+
+                # unwrapped element is array
+                if prop_meta.get("unwrapped", False):
+                    _items_name = prop_meta.get("itemsName")
+                    if _items_name:
+                        xml_name = _items_name
+                        _items_ns = prop_meta.get("itemsNs")
+                        if _items_ns is not None:
+                            xml_ns = _items_ns
+                        if xml_ns:
+                            xml_name = "{" + xml_ns + "}" + xml_name
+                    items = element.findall(xml_name)  # pyright: ignore
+                    if len(items) > 0:
+                        existed_attr_keys.append(xml_name)
+                        result[rf._rest_name] = _deserialize(rf._type, items)
+                    elif not rf._is_optional:
+                        existed_attr_keys.append(xml_name)
+                        result[rf._rest_name] = []
+                    continue
+
+                # text element is primitive type
+                if prop_meta.get("text", False):
+                    if element.text is not None:
+                        result[rf._rest_name] = _deserialize(rf._type, element.text)
+                    continue
+
+                # wrapped element could be normal property or array
+                item = element.find(xml_name)
+                if item is not None:
                     existed_attr_keys.append(xml_name)
-                    result[rf._rest_name] = []
-                continue
-
-            # text element is primitive type
-            if prop_meta.get("text", False):
-                if element.text is not None:
-                    result[rf._rest_name] = _deserialize(rf._type, element.text)
-                continue
-
-            # wrapped element could be normal property or array, it should only have one element
-            item = element.find(xml_name)
-            if item is not None:
-                existed_attr_keys.append(xml_name)
-                result[rf._rest_name] = _deserialize(rf._type, item)
+                    result[rf._rest_name] = _deserialize(rf._type, item)
 
         # rest thing is additional properties
         for e in element:
@@ -708,6 +988,9 @@ def __new__(cls, *args: typing.Any, **kwargs: typing.Any) -> Self:
                 if not rf._rest_name_input:
                     rf._rest_name_input = attr
             cls._attr_to_rest_field: dict[str, _RestField] = dict(attr_to_rest_field.items())
+            # Build XML field plan for fast _init_from_xml (only for XML models)
+            if getattr(cls, "_xml", None):
+                cls._xml_field_plan = _build_xml_field_plan(cls, attr_to_rest_field)
             cls._calculated.add(f"{cls.__module__}.{cls.__qualname__}")
 
         return super().__new__(cls)
@@ -1082,6 +1365,7 @@ def __init__(
         format: typing.Optional[str] = None,
         is_multipart_file_input: bool = False,
         xml: typing.Optional[dict[str, typing.Any]] = None,
+        deserializer: typing.Optional[typing.Callable] = None,
     ):
         self._type = type
         self._rest_name_input = name
@@ -1094,6 +1378,7 @@ def __init__(
         self._format = format
         self._is_multipart_file_input = is_multipart_file_input
         self._xml = xml if xml is not None else {}
+        self._deserializer = deserializer
 
     @property
     def _class_type(self) -> typing.Any:
@@ -1113,7 +1398,10 @@ def __get__(self, obj: Model, type=None):  # pylint: disable=redefined-builtin
         # by this point, type and rest_name will have a value bc we default
         # them in __new__ of the Model class
         # Use _data.get() directly to avoid triggering __getitem__ which clears the cache
-        item = obj._data.get(self._rest_name)
+        item = obj._data.get(self._rest_name, _UNSET)
+        if item is _UNSET:
+            # Field not set by user; return the client default if one exists, otherwise None
+            return self._default if self._default is not _UNSET else None
         if item is None:
             return item
         if self._is_model:
@@ -1126,7 +1414,11 @@ def __get__(self, obj: Model, type=None):  # pylint: disable=redefined-builtin
             # Return the value from _data directly (it's been deserialized in place)
             return obj._data.get(self._rest_name)
 
-        deserialized = _deserialize(self._type, _serialize(item, self._format), rf=self)
+        # Fast path: use _deserializer directly (avoids _serialize/_deserialize chain)
+        if self._deserializer:
+            deserialized = self._deserializer(item)
+        else:
+            deserialized = _deserialize(self._type, _serialize(item, self._format), rf=self)
 
         # For mutable types, store the deserialized value back in _data
         # so mutations directly affect _data
@@ -1172,6 +1464,7 @@ def rest_field(
     format: typing.Optional[str] = None,
     is_multipart_file_input: bool = False,
     xml: typing.Optional[dict[str, typing.Any]] = None,
+    deserializer: typing.Optional[typing.Callable] = None,
 ) -> typing.Any:
     return _RestField(
         name=name,
@@ -1181,6 +1474,7 @@ def rest_field(
         format=format,
         is_multipart_file_input=is_multipart_file_input,
         xml=xml,
+        deserializer=deserializer,
     )
 
 
@@ -1414,6 +1708,8 @@ def _deserialize_xml(
     value: str,
 ) -> typing.Any:
     element = ET.fromstring(value)  # nosec
+    if _is_model(deserializer):
+        return deserializer._deserialize(element, [])
     return _deserialize(deserializer, element)
 
 
diff --git a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_utils/serialization.py b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_utils/serialization.py
index 81ec1de5922b..a088671e9c51 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_utils/serialization.py
+++ b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_utils/serialization.py
@@ -39,11 +39,15 @@
 import xml.etree.ElementTree as ET
 
 import isodate  # type: ignore
-from typing_extensions import Self
 
 from azure.core.exceptions import DeserializationError, SerializationError
 from azure.core.serialization import NULL as CoreNull
 
+if sys.version_info >= (3, 11):
+    from typing import Self
+else:
+    from typing_extensions import Self
+
 _BOM = codecs.BOM_UTF8.decode(encoding="utf-8")
 
 JSON = MutableMapping[str, Any]
@@ -1401,7 +1405,7 @@ def __init__(self, classes: Optional[Mapping[str, type]] = None) -> None:
         # Otherwise, result are unexpected
         self.additional_properties_detection = True
 
-    def __call__(self, target_obj, response_data, content_type=None):
+    def __call__(self, target_obj, response_data, content_type=None):  # pylint: disable=too-many-return-statements
         """Call the deserializer to process a REST response.
 
         :param str target_obj: Target data type to deserialize to.
@@ -1411,6 +1415,27 @@ def __call__(self, target_obj, response_data, content_type=None):
         :return: Deserialized object.
         :rtype: object
         """
+        # Fast path for header deserialization: response_data is a plain str or None
+        # and target_obj is a simple scalar type. This avoids the expensive
+        # _unpack_content → _deserialize → _classify_target → deserialize_data chain.
+        if response_data is None:
+            return None
+        if target_obj == "str" and isinstance(response_data, str):
+            return response_data
+        if isinstance(response_data, str):
+            if target_obj == "int":
+                return int(response_data)
+            if target_obj == "bool":
+                if response_data in ("true", "1", "True"):
+                    return True
+                if response_data in ("false", "0", "False"):
+                    return False
+                return bool(response_data)
+            if target_obj == "rfc-1123":
+                return Deserializer.deserialize_rfc(response_data)
+            if target_obj == "bytearray":
+                return Deserializer.deserialize_bytearray(response_data)
+
         data = self._unpack_content(response_data, content_type)
         return self._deserialize(target_obj, data)
 
diff --git a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_version.py b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_version.py
index be71c81bd282..bbcd28b4aa67 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_version.py
+++ b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/_version.py
@@ -6,4 +6,4 @@
 # Changes may cause incorrect behavior and will be lost if the code is regenerated.
 # --------------------------------------------------------------------------
 
-VERSION = "1.0.0b1"
+VERSION = "1.0.0b2"
diff --git a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/_client.py b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/_client.py
index e035ce2da475..d8aeabc5e241 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/_client.py
+++ b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/_client.py
@@ -7,8 +7,8 @@
 # --------------------------------------------------------------------------
 
 from copy import deepcopy
+import sys
 from typing import Any, Awaitable, Optional, TYPE_CHECKING, cast
-from typing_extensions import Self
 
 from azure.core.pipeline import policies
 from azure.core.rest import AsyncHttpResponse, HttpRequest
@@ -21,6 +21,11 @@
 from ._configuration import MonitorSlisMgmtClientConfiguration
 from .operations import SlisOperations
 
+if sys.version_info >= (3, 11):
+    from typing import Self
+else:
+    from typing_extensions import Self  # type: ignore
+
 if TYPE_CHECKING:
     from azure.core import AzureClouds
     from azure.core.credentials_async import AsyncTokenCredential
@@ -39,8 +44,9 @@ class MonitorSlisMgmtClient:
      None.
     :paramtype cloud_setting: ~azure.core.AzureClouds
     :keyword api_version: The API version to use for this operation. Known values are
-     "2025-03-01-preview". Default value is "2025-03-01-preview". Note that overriding this default
-     value may result in unsupported behavior.
+     "2025-03-01-preview" and None. Default value is None. If not set, the operation's default API
+     version will be used. Note that overriding this default value may result in unsupported
+     behavior.
     :paramtype api_version: str
     """
 
diff --git a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/_configuration.py b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/_configuration.py
index 9d2ee0c203ea..03ad54f0da7e 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/_configuration.py
+++ b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/_configuration.py
@@ -32,8 +32,9 @@ class MonitorSlisMgmtClientConfiguration:  # pylint: disable=too-many-instance-a
      None.
     :type cloud_setting: ~azure.core.AzureClouds
     :keyword api_version: The API version to use for this operation. Known values are
-     "2025-03-01-preview". Default value is "2025-03-01-preview". Note that overriding this default
-     value may result in unsupported behavior.
+     "2025-03-01-preview" and None. Default value is None. If not set, the operation's default API
+     version will be used. Note that overriding this default value may result in unsupported
+     behavior.
     :paramtype api_version: str
     """
 
diff --git a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/_patch.py b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/_patch.py
index 87676c65a8f0..ea765788358a 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/_patch.py
+++ b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/_patch.py
@@ -8,7 +8,6 @@
 Follow our quickstart for examples: https://aka.ms/azsdk/python/dpcodegen/python/customize
 """
 
-
 __all__: list[str] = []  # Add all objects you want publicly available to users at this package level
 
 
diff --git a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/operations/_operations.py b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/operations/_operations.py
index fd4be66ceef0..220697d00703 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/operations/_operations.py
+++ b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/operations/_operations.py
@@ -397,7 +397,10 @@ def prepare_request(next_link=None):
                 )
                 _next_request_params["api-version"] = self._config.api_version
                 _request = HttpRequest(
-                    "GET", urllib.parse.urljoin(next_link, _parsed_next_link.path), params=_next_request_params
+                    "GET",
+                    urllib.parse.urljoin(next_link, _parsed_next_link.path),
+                    headers=_headers,
+                    params=_next_request_params,
                 )
                 path_format_arguments = {
                     "endpoint": self._serialize.url(
diff --git a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/operations/_patch.py b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/operations/_patch.py
index 87676c65a8f0..ea765788358a 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/operations/_patch.py
+++ b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/aio/operations/_patch.py
@@ -8,7 +8,6 @@
 Follow our quickstart for examples: https://aka.ms/azsdk/python/dpcodegen/python/customize
 """
 
-
 __all__: list[str] = []  # Add all objects you want publicly available to users at this package level
 
 
diff --git a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/models/_enums.py b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/models/_enums.py
index 6b8557fe4103..591078104051 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/models/_enums.py
+++ b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/models/_enums.py
@@ -22,29 +22,31 @@ class Category(str, Enum, metaclass=CaseInsensitiveEnumMeta):
 class ConditionOperator(str, Enum, metaclass=CaseInsensitiveEnumMeta):
     """Defines operators used in filter conditions."""
 
-    EQUAL = "=="
+    EQUAL = "eq"
     """Equal to."""
-    NOT_EQUAL = "!="
+    NOT_EQUAL = "ne"
     """Not equal to."""
-    LESS_THAN = "<"
+    LESS_THAN = "lt"
     """Less than."""
-    LESS_THAN_OR_EQUAL = "<="
+    LESS_THAN_OR_EQUAL = "lte"
     """Less than or equal to."""
-    GREATER_THAN = ">"
+    GREATER_THAN = "gt"
     """Greater than."""
-    GREATER_THAN_OR_EQUAL = ">="
+    GREATER_THAN_OR_EQUAL = "gte"
     """Greater than or equal to."""
-    IN = "@in"
-    """In operator."""
-    NOT_IN = "!in"
-    """Not in."""
+    IN = "in"
+    """Matches when ``value`` is one of the items in the ``^^``-delimited list (for example, ``value``
+    = "east^^west^^north")."""
+    NOT_IN = "notin"
+    """Matches when ``value`` is none of the items in the ``^^``-delimited list (for example,
+    ``value`` = "east^^west^^north")."""
     STARTS_WITH = "startswith"
     """Starts with."""
-    NOT_STARTS_WITH = "!startswith"
+    NOT_STARTS_WITH = "notstartswith"
     """Does not start with."""
     CONTAINS = "contains"
     """Contains the value."""
-    NOT_CONTAINS = "!contains"
+    NOT_CONTAINS = "notcontains"
     """Does not contain the value."""
 
 
@@ -108,14 +110,16 @@ class ProvisioningState(str, Enum, metaclass=CaseInsensitiveEnumMeta):
 class SamplingType(str, Enum, metaclass=CaseInsensitiveEnumMeta):
     """Defines the available sampling types."""
 
-    MAX = "max"
-    """Maximum value."""
-    MIN = "min"
-    """Minimum value."""
-    AVG = "avg"
+    AVERAGE = "Average"
     """Average value."""
-    SUM = "sum"
+    SUM = "Sum"
     """Summation."""
+    COUNT = "Count"
+    """Count of occurrences."""
+    MIN = "Min"
+    """Minimum value."""
+    MAX = "Max"
+    """Maximum value."""
 
 
 class ScalarFunction(str, Enum, metaclass=CaseInsensitiveEnumMeta):
@@ -176,11 +180,11 @@ class TemporalAggregationType(str, Enum, metaclass=CaseInsensitiveEnumMeta):
 class WindowUptimeCriteriaComparator(str, Enum, metaclass=CaseInsensitiveEnumMeta):
     """Defines comparison operators for window uptime criteria."""
 
-    LESS_THAN = "<"
+    LESS_THAN = "lt"
     """Less than the target value."""
-    GREATER_THAN = ">"
+    GREATER_THAN = "gt"
     """Greater than the target value."""
-    LESS_THAN_OR_EQUAL = "<="
+    LESS_THAN_OR_EQUAL = "lte"
     """Less than or equal to the target value."""
-    GREATER_THAN_OR_EQUAL = ">="
+    GREATER_THAN_OR_EQUAL = "gte"
     """Greater than or equal to the target value."""
diff --git a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/models/_models.py b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/models/_models.py
index 19036802bb73..2acf5bd73ab4 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/models/_models.py
+++ b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/models/_models.py
@@ -137,14 +137,17 @@ class Condition(_Model):
     :ivar scalar_function: Scalar function applied for filtering. Known values are: "max", "min",
      "avg", and "sum".
     :vartype scalar_function: str or ~azure.mgmt.monitorslis.models.ScalarFunction
-    :ivar sampling_type: Defines the sampling type. Known values are: "max", "min", "avg", and
-     "sum".
+    :ivar sampling_type: Defines the sampling type. Known values are: "Average", "Sum", "Count",
+     "Min", and "Max".
     :vartype sampling_type: str or ~azure.mgmt.monitorslis.models.SamplingType
-    :ivar operator: Operator used in the filtering condition. Required. Known values are: "==",
-     "!=", "<", "<=", ">", ">=", "@in", "!in", "startswith", "!startswith", "contains", and
-     "!contains".
+    :ivar operator: Operator used in the filtering condition. Required. Known values are: "eq",
+     "ne", "lt", "lte", "gt", "gte", "in", "notin", "startswith", "notstartswith", "contains", and
+     "notcontains".
     :vartype operator: str or ~azure.mgmt.monitorslis.models.ConditionOperator
-    :ivar value: Value used in filtering. Required.
+    :ivar value: Value used in filtering. For most operators (eq, ne, lt, lte, gt, gte, startswith,
+     notstartswith, contains, notcontains) this is a single value (for example "GetContosoUsers").
+     For the ``in`` and ``notin`` operators, multiple values must be joined by the delimiter ``^^``
+     (for example "east^^west^^north"). Required.
     :vartype value: str
     """
 
@@ -160,15 +163,19 @@ class Condition(_Model):
     sampling_type: Optional[Union[str, "_models.SamplingType"]] = rest_field(
         name="samplingType", visibility=["read", "create", "update", "delete", "query"]
     )
-    """Defines the sampling type. Known values are: \"max\", \"min\", \"avg\", and \"sum\"."""
+    """Defines the sampling type. Known values are: \"Average\", \"Sum\", \"Count\", \"Min\", and
+     \"Max\"."""
     operator: Union[str, "_models.ConditionOperator"] = rest_field(
         visibility=["read", "create", "update", "delete", "query"]
     )
-    """Operator used in the filtering condition. Required. Known values are: \"==\", \"!=\", \"<\",
-     \"<=\", \">\", \">=\", \"@in\", \"!in\", \"startswith\", \"!startswith\", \"contains\", and
-     \"!contains\"."""
+    """Operator used in the filtering condition. Required. Known values are: \"eq\", \"ne\", \"lt\",
+     \"lte\", \"gt\", \"gte\", \"in\", \"notin\", \"startswith\", \"notstartswith\", \"contains\",
+     and \"notcontains\"."""
     value: str = rest_field(visibility=["read", "create", "update", "delete", "query"])
-    """Value used in filtering. Required."""
+    """Value used in filtering. For most operators (eq, ne, lt, lte, gt, gte, startswith,
+     notstartswith, contains, notcontains) this is a single value (for example \"GetContosoUsers\").
+     For the ``in`` and ``notin`` operators, multiple values must be joined by the delimiter ``^^``
+     (for example \"east^^west^^north\"). Required."""
 
     @overload
     def __init__(
@@ -902,7 +909,7 @@ class WindowUptimeCriteria(_Model):
     :ivar target: Threshold value used to determine uptime. Required.
     :vartype target: float
     :ivar comparator: Comparison operator used for uptime evaluation. Required. Known values are:
-     "<", ">", "<=", and ">=".
+     "lt", "gt", "lte", and "gte".
     :vartype comparator: str or ~azure.mgmt.monitorslis.models.WindowUptimeCriteriaComparator
     """
 
@@ -911,8 +918,8 @@ class WindowUptimeCriteria(_Model):
     comparator: Union[str, "_models.WindowUptimeCriteriaComparator"] = rest_field(
         visibility=["read", "create", "update", "delete", "query"]
     )
-    """Comparison operator used for uptime evaluation. Required. Known values are: \"<\", \">\",
-     \"<=\", and \">=\"."""
+    """Comparison operator used for uptime evaluation. Required. Known values are: \"lt\", \"gt\",
+     \"lte\", and \"gte\"."""
 
     @overload
     def __init__(
diff --git a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/models/_patch.py b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/models/_patch.py
index 87676c65a8f0..ea765788358a 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/models/_patch.py
+++ b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/models/_patch.py
@@ -8,7 +8,6 @@
 Follow our quickstart for examples: https://aka.ms/azsdk/python/dpcodegen/python/customize
 """
 
-
 __all__: list[str] = []  # Add all objects you want publicly available to users at this package level
 
 
diff --git a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/operations/_operations.py b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/operations/_operations.py
index 609fef11af0c..1aad5236d07e 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/operations/_operations.py
+++ b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/operations/_operations.py
@@ -491,7 +491,10 @@ def prepare_request(next_link=None):
                 )
                 _next_request_params["api-version"] = self._config.api_version
                 _request = HttpRequest(
-                    "GET", urllib.parse.urljoin(next_link, _parsed_next_link.path), params=_next_request_params
+                    "GET",
+                    urllib.parse.urljoin(next_link, _parsed_next_link.path),
+                    headers=_headers,
+                    params=_next_request_params,
                 )
                 path_format_arguments = {
                     "endpoint": self._serialize.url(
diff --git a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/operations/_patch.py b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/operations/_patch.py
index 87676c65a8f0..ea765788358a 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/operations/_patch.py
+++ b/sdk/monitor/azure-mgmt-monitorslis/azure/mgmt/monitorslis/operations/_patch.py
@@ -8,7 +8,6 @@
 Follow our quickstart for examples: https://aka.ms/azsdk/python/dpcodegen/python/customize
 """
 
-
 __all__: list[str] = []  # Add all objects you want publicly available to users at this package level
 
 
diff --git a/sdk/monitor/azure-mgmt-monitorslis/generated_samples/slis_create_or_update.py b/sdk/monitor/azure-mgmt-monitorslis/generated_samples/slis_create_or_update.py
index aee866be1db9..46f531fcd42a 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/generated_samples/slis_create_or_update.py
+++ b/sdk/monitor/azure-mgmt-monitorslis/generated_samples/slis_create_or_update.py
@@ -53,7 +53,7 @@ def main():
                         "signalFormula": "(A + B) /2",
                         "signalSources": [
                             {
-                                "filters": [{"dimensionName": "ApiName", "operator": "==", "value": "GetContosoUsers"}],
+                                "filters": [{"dimensionName": "ApiName", "operator": "eq", "value": "GetContosoUsers"}],
                                 "metricName": "Stamp1Latency",
                                 "metricNamespace": "ContosoMetricsWest",
                                 "signalSourceId": "A",
@@ -63,7 +63,7 @@ def main():
                                 "temporalAggregation": {"type": "Average", "windowSizeMinutes": 5},
                             },
                             {
-                                "filters": [{"dimensionName": "ApiName", "operator": "==", "value": "GetContosoUsers"}],
+                                "filters": [{"dimensionName": "ApiName", "operator": "eq", "value": "GetContosoUsers"}],
                                 "metricName": "Stamp2Latency",
                                 "metricNamespace": "ContosoMetricsEast",
                                 "signalSourceId": "B",
@@ -74,7 +74,7 @@ def main():
                             },
                         ],
                     },
-                    "windowUptimeCriteria": {"comparator": ">=", "target": 95},
+                    "windowUptimeCriteria": {"comparator": "gte", "target": 95},
                 },
             }
         },
diff --git a/sdk/monitor/azure-mgmt-monitorslis/pyproject.toml b/sdk/monitor/azure-mgmt-monitorslis/pyproject.toml
index 0435778f6010..73d68d815262 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/pyproject.toml
+++ b/sdk/monitor/azure-mgmt-monitorslis/pyproject.toml
@@ -17,13 +17,12 @@ classifiers = [
     "Programming Language :: Python",
     "Programming Language :: Python :: 3 :: Only",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
 ]
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 keywords = [
     "azure",
     "azure sdk",
diff --git a/sdk/monitor/azure-mgmt-monitorslis/test-resources.bicep b/sdk/monitor/azure-mgmt-monitorslis/test-resources.bicep
new file mode 100644
index 000000000000..e3104bdd3c36
--- /dev/null
+++ b/sdk/monitor/azure-mgmt-monitorslis/test-resources.bicep
@@ -0,0 +1,60 @@
+// test-resources.bicep for Microsoft.Monitor/slis live tests
+// Provisions:
+//   - Azure Monitor Workspace (destination for SLI metrics)
+//   - User-Assigned Managed Identity (used by SLI signal sources)
+//   - Role assignment for the test application SP
+
+@description('The location of the resource. By default, this is the same as the resource group.')
+param location string = resourceGroup().location
+
+@description('The client OID to grant access to test resources.')
+param testApplicationOid string
+
+@description('The base resource name.')
+param baseName string = resourceGroup().name
+
+// Azure Monitor Workspace (destination AMW account for the SLI)
+resource monitorWorkspace 'Microsoft.Monitor/accounts@2023-04-03' = {
+  name: '${baseName}-amw'
+  location: location
+  properties: {}
+}
+
+// User-Assigned Managed Identity (used as signal source identity)
+resource managedIdentity 'Microsoft.ManagedIdentity/userAssignedIdentities@2023-01-31' = {
+  name: '${baseName}-sli-id'
+  location: location
+}
+
+// Monitoring Reader role (43d0d8ad-25c7-4714-9337-8ba259a9fe05)
+// Grants the test SP read access needed for SLI operations
+var monitoringReaderRoleId = '43d0d8ad-25c7-4714-9337-8ba259a9fe05'
+
+resource monitoringReaderAssignment 'Microsoft.Authorization/roleAssignments@2022-04-01' = {
+  name: guid(resourceGroup().id, testApplicationOid, monitoringReaderRoleId)
+  properties: {
+    roleDefinitionId: resourceId('Microsoft.Authorization/roleDefinitions', monitoringReaderRoleId)
+    principalId: testApplicationOid
+    principalType: 'ServicePrincipal'
+  }
+}
+
+// Monitoring Contributor role (749f88d5-cbae-40b8-bcfc-e573ddc772fa)
+// Grants the test SP write access for SLI CRUD operations
+var monitoringContributorRoleId = '749f88d5-cbae-40b8-bcfc-e573ddc772fa'
+
+resource monitoringContributorAssignment 'Microsoft.Authorization/roleAssignments@2022-04-01' = {
+  name: guid(resourceGroup().id, testApplicationOid, monitoringContributorRoleId)
+  properties: {
+    roleDefinitionId: resourceId('Microsoft.Authorization/roleDefinitions', monitoringContributorRoleId)
+    principalId: testApplicationOid
+    principalType: 'ServicePrincipal'
+  }
+}
+
+// OUTPUTS - these become environment variables for the test runner
+output AMW_RESOURCE_ID string = monitorWorkspace.id
+output MANAGED_IDENTITY_RESOURCE_ID string = managedIdentity.id
+output SOURCE_AMW_RESOURCE_ID string = monitorWorkspace.id
+output SOURCE_MANAGED_IDENTITY_RESOURCE_ID string = managedIdentity.id
+output SERVICE_GROUP_NAME string = 'testSG'
diff --git a/sdk/monitor/azure-mgmt-monitorslis/tests/.env.sample b/sdk/monitor/azure-mgmt-monitorslis/tests/.env.sample
new file mode 100644
index 000000000000..42b0abc0804b
--- /dev/null
+++ b/sdk/monitor/azure-mgmt-monitorslis/tests/.env.sample
@@ -0,0 +1,15 @@
+# Environment variables for SLI live tests
+# Copy this to .env and fill in real values for local testing
+
+# Azure credentials (set by DefaultAzureCredential or the test framework)
+AZURE_TENANT_ID=
+AZURE_CLIENT_ID=
+AZURE_CLIENT_SECRET=
+AZURE_SUBSCRIPTION_ID=
+
+# SLI test-specific variables (provisioned by test-resources.bicep)
+SERVICE_GROUP_NAME=arm-sdk-tests-sg
+AMW_RESOURCE_ID=/subscriptions/6820e35f-0fe6-4af3-aad2-27414fa82621/resourceGroups/mfrei/providers/microsoft.monitor/accounts/streaming-3p-slo-am2cbn-eastus2euap-1
+MANAGED_IDENTITY_RESOURCE_ID=/subscriptions/6820e35f-0fe6-4af3-aad2-27414fa82621/resourceGroups/mfrei/providers/Microsoft.ManagedIdentity/userAssignedIdentities/mfrei-test-user-managed-identity
+SOURCE_AMW_RESOURCE_ID=/subscriptions/6820e35f-0fe6-4af3-aad2-27414fa82621/resourceGroups/mfrei/providers/microsoft.monitor/accounts/streaming-3p-slo-am2cbn-eastus2euap-1
+SOURCE_MANAGED_IDENTITY_RESOURCE_ID=/subscriptions/6820e35f-0fe6-4af3-aad2-27414fa82621/resourceGroups/mfrei/providers/Microsoft.ManagedIdentity/userAssignedIdentities/mfrei-test-user-managed-identity
diff --git a/sdk/monitor/azure-mgmt-monitorslis/tests/test_sli_crud_live.py b/sdk/monitor/azure-mgmt-monitorslis/tests/test_sli_crud_live.py
new file mode 100644
index 000000000000..fda42dc1342a
--- /dev/null
+++ b/sdk/monitor/azure-mgmt-monitorslis/tests/test_sli_crud_live.py
@@ -0,0 +1,150 @@
+# coding=utf-8
+# --------------------------------------------------------------------------
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License. See License.txt in the project root for license information.
+# --------------------------------------------------------------------------
+import os
+import pytest
+from azure.core.exceptions import ResourceNotFoundError
+from azure.mgmt.monitorslis import MonitorSlisMgmtClient, models
+
+from devtools_testutils import AzureMgmtRecordedTestCase, recorded_by_proxy
+
+
+# Environment variables expected:
+#   SERVICE_GROUP_NAME - name of the pre-existing Service Group
+#   AMW_RESOURCE_ID - Azure Monitor Workspace resource ID (destination)
+#   MANAGED_IDENTITY_RESOURCE_ID - User-Assigned Managed Identity resource ID
+#   SOURCE_AMW_RESOURCE_ID - Source Azure Monitor Workspace resource ID
+#   SOURCE_MANAGED_IDENTITY_RESOURCE_ID - Source Managed Identity resource ID
+SERVICE_GROUP_NAME = os.environ.get("SERVICE_GROUP_NAME", "arm-sdk-tests-sg")
+AMW_RESOURCE_ID = os.environ.get(
+    "AMW_RESOURCE_ID",
+    "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/arm-sdk-tests-rg/providers/microsoft.monitor/accounts/amw-arm-sdk-tests-rg",
+)
+MANAGED_IDENTITY_RESOURCE_ID = os.environ.get(
+    "MANAGED_IDENTITY_RESOURCE_ID",
+    "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/arm-sdk-tests-rg/providers/Microsoft.ManagedIdentity/userAssignedIdentities/uami-arm-sdk-tests-rg",
+)
+SOURCE_AMW_RESOURCE_ID = os.environ.get("SOURCE_AMW_RESOURCE_ID", AMW_RESOURCE_ID)
+SOURCE_MANAGED_IDENTITY_RESOURCE_ID = os.environ.get(
+    "SOURCE_MANAGED_IDENTITY_RESOURCE_ID", MANAGED_IDENTITY_RESOURCE_ID
+)
+
+SLI_DESCRIPTION = "Live test SLI - measures latency of test API"
+
+
+class TestSliCrudLive(AzureMgmtRecordedTestCase):
+    """Live CRUD test for Microsoft.Monitor/slis resource."""
+
+    def setup_method(self, method):
+        self.client = self.create_mgmt_client(MonitorSlisMgmtClient)
+        self.sli_name = self.get_resource_name("pysli")
+
+    def _get_sli_body(self):
+        """Return a valid SLI resource body for create/update."""
+        identities = {MANAGED_IDENTITY_RESOURCE_ID: models.UserAssignedIdentity()}
+        if SOURCE_MANAGED_IDENTITY_RESOURCE_ID.lower() != MANAGED_IDENTITY_RESOURCE_ID.lower():
+            identities[SOURCE_MANAGED_IDENTITY_RESOURCE_ID] = models.UserAssignedIdentity()
+        return models.Sli(
+            identity=models.ManagedServiceIdentity(
+                type="UserAssigned",
+                user_assigned_identities=identities,
+            ),
+            properties=models.SliResource(
+                description=SLI_DESCRIPTION,
+                category="Latency",
+                evaluation_type="WindowBased",
+                enable_alert=True,
+                destination_amw_accounts=[
+                    models.AmwAccount(
+                        resource_id=AMW_RESOURCE_ID,
+                        identity=MANAGED_IDENTITY_RESOURCE_ID,
+                    )
+                ],
+                baseline_properties=models.BaselineProperties(
+                    baseline=models.Baseline(
+                        value=99,
+                        evaluation_period_days=30,
+                        evaluation_calculation_type="CalendarDays",
+                    )
+                ),
+                sli_properties=models.SliProperties(
+                    window_uptime_criteria=models.WindowUptimeCriteria(target=95, comparator="gte"),
+                    signals=models.Signal(
+                        signal_sources=[
+                            models.SignalSource(
+                                signal_source_id="A",
+                                source_amw_account_managed_identity=SOURCE_MANAGED_IDENTITY_RESOURCE_ID,
+                                source_amw_account_resource_id=SOURCE_AMW_RESOURCE_ID,
+                                # Source metric is a real Azure Managed Prometheus metric scraped by AKS.
+                                # Test infra (bicep) deploys an AKS cluster with the Azure Monitor metrics addon
+                                # pointed at the source AMW; container_cpu_usage_seconds_total is always populated.
+                                metric_namespace="customdefault",
+                                metric_name="container_cpu_usage_seconds_total",
+                                filters=[
+                                    models.Condition(
+                                        dimension_name="container",
+                                        # Use wire value "ne" directly (the generated ConditionOperator
+                                        # enum has incorrect values — tracked separately).
+                                        operator="ne",
+                                        value="POD",
+                                    )
+                                ],
+                                spatial_aggregation=models.SpatialAggregation(
+                                    type="Sum",
+                                    dimensions=["instance"],
+                                ),
+                                temporal_aggregation=models.TemporalAggregation(
+                                    type="Rate",
+                                    window_size_minutes=1,
+                                ),
+                            )
+                        ],
+                        signal_formula="A",
+                    ),
+                ),
+            )
+        )
+
+    @recorded_by_proxy
+    def test_sli_crud_lifecycle(self):
+        """Test full CRUD lifecycle: Create → Get → Delete → Get (expect 404)."""
+        # Step 1: Create SLI
+        create_response = self.client.slis.create_or_update(
+            service_group_name=SERVICE_GROUP_NAME,
+            sli_name=self.sli_name,
+            resource=self._get_sli_body(),
+        )
+        assert create_response is not None
+        # In playback the recording's response name is sanitized to "Sanitized";
+        # in live mode it should equal self.sli_name. Allow both.
+        assert create_response.name in (self.sli_name, "Sanitized")
+        assert create_response.properties is not None
+        assert create_response.properties.description == SLI_DESCRIPTION
+
+        # Step 2: Get SLI - verify it exists
+        get_response = self.client.slis.get(
+            service_group_name=SERVICE_GROUP_NAME,
+            sli_name=self.sli_name,
+        )
+        assert get_response is not None
+        assert get_response.name in (self.sli_name, "Sanitized")
+        assert get_response.properties is not None
+        assert get_response.properties.description == SLI_DESCRIPTION
+        assert get_response.properties.sli_properties is not None
+        assert get_response.properties.sli_properties.window_uptime_criteria is not None
+
+        # Step 3: Delete SLI
+        self.client.slis.delete(
+            service_group_name=SERVICE_GROUP_NAME,
+            sli_name=self.sli_name,
+        )
+
+        # Step 4: Get SLI - expect 404
+        with pytest.raises(ResourceNotFoundError):
+            self.client.slis.get(
+                service_group_name=SERVICE_GROUP_NAME,
+                sli_name=self.sli_name,
+            )
+
diff --git a/sdk/monitor/azure-mgmt-monitorslis/tsp-location.yaml b/sdk/monitor/azure-mgmt-monitorslis/tsp-location.yaml
index b3ad897b7e77..2272356af846 100644
--- a/sdk/monitor/azure-mgmt-monitorslis/tsp-location.yaml
+++ b/sdk/monitor/azure-mgmt-monitorslis/tsp-location.yaml
@@ -1,4 +1,4 @@
 directory: specification/monitoringservice/resource-manager/Microsoft.Monitor/Slis
-commit: fa74a24ebfcd57429a95ef827b06eae0e639800a
+commit: 8be8c75d9bb11ea95d8a7e251db74aa78b5cd76c
 repo: Azure/azure-rest-api-specs
 additionalDirectories: