diff --git a/.changelog/5402.fixed b/.changelog/5402.fixed
new file mode 100644
index 00000000000..7ba5f9b424b
--- /dev/null
+++ b/.changelog/5402.fixed
@@ -0,0 +1 @@
+`opentelemetry-codegen-json`: support decoding enums from names
diff --git a/codegen/opentelemetry-codegen-json/src/opentelemetry/codegen/json/generator.py b/codegen/opentelemetry-codegen-json/src/opentelemetry/codegen/json/generator.py
index b8be0355246..76ba0c712dd 100644
--- a/codegen/opentelemetry-codegen-json/src/opentelemetry/codegen/json/generator.py
+++ b/codegen/opentelemetry-codegen-json/src/opentelemetry/codegen/json/generator.py
@@ -325,7 +325,6 @@ def _generate_imports(
         std_imports = [
             "builtins",
             "dataclasses",
-            "functools",
             "typing",
         ]
         if include_enum:
@@ -336,12 +335,6 @@ def _generate_imports(
 
         writer.blank_line()
 
-        writer.assignment(
-            "_dataclass",
-            "functools.partial(dataclasses.dataclass, slots=True)",
-        )
-        writer.blank_line()
-
         # Collect all imports needed
         imports = self._collect_imports(proto_file)
         imports.add(f"import {self._get_codec_module_path()}")
@@ -428,7 +421,7 @@ def _generate_message_class(
             msg_desc.name,
             bases=(f"{codec}.JsonMessage",),
             decorators=("typing.final",),
-            decorator_name="_dataclass",
+            slots=True,
         ):
             if msg_desc.field or msg_desc.nested_type or msg_desc.enum_type:
                 writer.docstring(
@@ -770,12 +763,9 @@ def _generate_deserialization_statements(
             enum_type = self._resolve_enum_type(
                 field_desc.type_name, proto_file
             )
-            writer.writeln(
-                f'{codec}.validate_type({var_name}, builtins.int, "{field_desc.name}")'
-            )
             writer.assignment(
                 f'{target_dict}["{field_desc.name}"]',
-                f"{enum_type}({var_name})",
+                f'{codec}.decode_enum({var_name}, {enum_type}, "{field_desc.name}")',
             )
         elif is_hex_encoded_field(field_desc.name):
             writer.assignment(
@@ -837,7 +827,7 @@ def _get_deserialization_expr(
             enum_type = self._resolve_enum_type(
                 field_desc.type_name, proto_file
             )
-            return f"{enum_type}({var_name})"
+            return f'{codec}.decode_enum({var_name}, {enum_type}, "{field_desc.name}")'
         if is_hex_encoded_field(field_desc.name):
             return f'{codec}.decode_hex({var_name}, "{field_desc.name}")'
         if is_int64_type(field_desc.type):
diff --git a/codegen/opentelemetry-codegen-json/src/opentelemetry/codegen/json/runtime/json_codec.py b/codegen/opentelemetry-codegen-json/src/opentelemetry/codegen/json/runtime/json_codec.py
index 72c315d1eaa..67f52c1370c 100644
--- a/codegen/opentelemetry-codegen-json/src/opentelemetry/codegen/json/runtime/json_codec.py
+++ b/codegen/opentelemetry-codegen-json/src/opentelemetry/codegen/json/runtime/json_codec.py
@@ -6,12 +6,14 @@
 import abc
 import base64
 import collections.abc
+import enum
 import json
 import math
 import typing
 
 T = typing.TypeVar("T")
 M = typing.TypeVar("M", bound="JsonMessage")
+EnumT = typing.TypeVar("EnumT", bound=enum.IntEnum)
 
 
 class JsonMessage(abc.ABC):
@@ -246,3 +248,27 @@ def validate_type(
             f"Field '{field_name}' expected {expected_types}, "
             f"got {type(value).__name__}"
         )
+
+
+def decode_enum(
+    value: typing.Any,
+    enum_type: type[EnumT],
+    field_name: str,
+) -> EnumT:
+    """
+    Decode a JSON enum value into an enum member.
+
+    Per the ProtoJSON spec, parsers must accept both enum names (str)
+    and integer values (int).
+
+    Args:
+        value: The enum name or integer value to decode.
+        enum_type: The enum class to decode into.
+        field_name: The name of the field being decoded (for error messages).
+    Returns:
+        The corresponding enum member.
+    """
+    validate_type(value, (int, str), field_name)
+    if isinstance(value, str):
+        return enum_type[value]
+    return enum_type(value)
diff --git a/codegen/opentelemetry-codegen-json/tests/test_json_codec.py b/codegen/opentelemetry-codegen-json/tests/test_json_codec.py
index aa24f838d51..432e2b8e661 100644
--- a/codegen/opentelemetry-codegen-json/tests/test_json_codec.py
+++ b/codegen/opentelemetry-codegen-json/tests/test_json_codec.py
@@ -1,12 +1,15 @@
 # Copyright The OpenTelemetry Authors
 # SPDX-License-Identifier: Apache-2.0
 
+import enum
 import math
+from typing import Any
 
 import pytest  # type: ignore
 
 from opentelemetry.codegen.json.runtime.json_codec import (
     decode_base64,
+    decode_enum,
     decode_float,
     decode_hex,
     decode_int64,
@@ -20,6 +23,12 @@
 )
 
 
+class _Color(enum.IntEnum):
+    RED = 0
+    GREEN = 1
+    BLUE = 2
+
+
 @pytest.mark.parametrize(
     "value, expected",
     [
@@ -189,3 +198,31 @@ def test_validate_type() -> None:
         match=r"Field 'field' expected \(<class 'int'>, <class 'float'>\), got str",
     ):
         validate_type("s", (int, float), "field")
+
+
+@pytest.mark.parametrize(
+    "value, expected",
+    [
+        (1, _Color.GREEN),
+        ("GREEN", _Color.GREEN),
+        (0, _Color.RED),
+        ("RED", _Color.RED),
+    ],
+)
+def test_decode_enum(value: int | str, expected: _Color) -> None:
+    assert decode_enum(value, _Color, "field") is expected
+
+
+@pytest.mark.parametrize(
+    "value, expected_error",
+    [
+        ([], TypeError),
+        (99, ValueError),
+        ("NOT_A_COLOR", KeyError),
+    ],
+)
+def test_decode_enum_errors(
+    value: Any, expected_error: type[Exception]
+) -> None:
+    with pytest.raises(expected_error):
+        decode_enum(value, _Color, "field")
diff --git a/codegen/opentelemetry-codegen-json/tests/test_serde.py b/codegen/opentelemetry-codegen-json/tests/test_serde.py
index e89453ea6a6..962417261a0 100644
--- a/codegen/opentelemetry-codegen-json/tests/test_serde.py
+++ b/codegen/opentelemetry-codegen-json/tests/test_serde.py
@@ -105,6 +105,19 @@ def test_generated_message_roundtrip(
     assert new_msg == msg
 
 
+def test_enum_field_accepts_name_and_int(
+    test_v1_types: tuple[type[Any], type[Any]],
+) -> None:
+    TestMessage, _ = test_v1_types
+
+    from_name = TestMessage.from_dict({"enumValue": "SUCCESS"})
+    from_int = TestMessage.from_dict({"enumValue": 1})
+
+    assert from_name.enum_value == TestMessage.TestEnum.SUCCESS
+    assert from_int.enum_value == TestMessage.TestEnum.SUCCESS
+    assert from_name == from_int
+
+
 def test_cross_reference(
     common_v1_types: type[Any], trace_v1_types: type[Any]
 ) -> None:
@@ -256,6 +269,25 @@ def test_nested_enum_suite(complex_v1_types: tuple[type[Any], ...]) -> None:
     assert new_msg.repeated_nested == msg.repeated_nested
 
 
+def test_nested_enum_suite_accepts_names(
+    complex_v1_types: tuple[type[Any], ...],
+) -> None:
+    NestedEnumSuite = complex_v1_types[3]
+
+    msg = NestedEnumSuite.from_dict(
+        {
+            "nested": "NESTED_FOO",
+            "repeatedNested": ["NESTED_FOO", "NESTED_BAR"],
+        }
+    )
+
+    assert msg.nested == NestedEnumSuite.NestedEnum.NESTED_FOO
+    assert msg.repeated_nested == [
+        NestedEnumSuite.NestedEnum.NESTED_FOO,
+        NestedEnumSuite.NestedEnum.NESTED_BAR,
+    ]
+
+
 def test_deeply_nested(complex_v1_types: tuple[type[Any], ...]) -> None:
     DeeplyNested = complex_v1_types[4]
 
@@ -304,7 +336,8 @@ def test_defaults_and_none(
         ({"listStrings": "not a list"}, TypeError, "expected <class 'list'>"),
         ({"name": 123}, TypeError, "expected <class 'str'>"),
         ({"subMessage": "not a dict"}, TypeError, "expected <class 'dict'>"),
-        ({"enumValue": "SUCCESS"}, TypeError, "expected <class 'int'>"),
+        ({"enumValue": []}, TypeError, "expected"),
+        ({"enumValue": "NOT_A_NAME"}, KeyError, None),
         ({"listMessages": [None]}, TypeError, "expected <class 'dict'>"),
     ],
 )
diff --git a/opentelemetry-proto-json/src/opentelemetry/proto_json/_json_codec.py b/opentelemetry-proto-json/src/opentelemetry/proto_json/_json_codec.py
index 72c315d1eaa..67f52c1370c 100644
--- a/opentelemetry-proto-json/src/opentelemetry/proto_json/_json_codec.py
+++ b/opentelemetry-proto-json/src/opentelemetry/proto_json/_json_codec.py
@@ -6,12 +6,14 @@
 import abc
 import base64
 import collections.abc
+import enum
 import json
 import math
 import typing
 
 T = typing.TypeVar("T")
 M = typing.TypeVar("M", bound="JsonMessage")
+EnumT = typing.TypeVar("EnumT", bound=enum.IntEnum)
 
 
 class JsonMessage(abc.ABC):
@@ -246,3 +248,27 @@ def validate_type(
             f"Field '{field_name}' expected {expected_types}, "
             f"got {type(value).__name__}"
         )
+
+
+def decode_enum(
+    value: typing.Any,
+    enum_type: type[EnumT],
+    field_name: str,
+) -> EnumT:
+    """
+    Decode a JSON enum value into an enum member.
+
+    Per the ProtoJSON spec, parsers must accept both enum names (str)
+    and integer values (int).
+
+    Args:
+        value: The enum name or integer value to decode.
+        enum_type: The enum class to decode into.
+        field_name: The name of the field being decoded (for error messages).
+    Returns:
+        The corresponding enum member.
+    """
+    validate_type(value, (int, str), field_name)
+    if isinstance(value, str):
+        return enum_type[value]
+    return enum_type(value)
diff --git a/opentelemetry-proto-json/src/opentelemetry/proto_json/collector/logs/v1/logs_service.py b/opentelemetry-proto-json/src/opentelemetry/proto_json/collector/logs/v1/logs_service.py
index 899c965fa3c..8ff1dda343e 100644
--- a/opentelemetry-proto-json/src/opentelemetry/proto_json/collector/logs/v1/logs_service.py
+++ b/opentelemetry-proto-json/src/opentelemetry/proto_json/collector/logs/v1/logs_service.py
@@ -8,17 +8,14 @@
 
 import builtins
 import dataclasses
-import functools
 import typing
 
-_dataclass = functools.partial(dataclasses.dataclass, slots=True)
-
 import opentelemetry.proto_json._json_codec
 import opentelemetry.proto_json.logs.v1.logs
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ExportLogsServiceRequest(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ExportLogsServiceRequest
@@ -59,7 +56,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ExportLogs
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ExportLogsServiceResponse(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ExportLogsServiceResponse
@@ -100,7 +97,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ExportLogs
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ExportLogsPartialSuccess(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ExportLogsPartialSuccess
diff --git a/opentelemetry-proto-json/src/opentelemetry/proto_json/collector/metrics/v1/metrics_service.py b/opentelemetry-proto-json/src/opentelemetry/proto_json/collector/metrics/v1/metrics_service.py
index 6537d1031f4..6603920e9d2 100644
--- a/opentelemetry-proto-json/src/opentelemetry/proto_json/collector/metrics/v1/metrics_service.py
+++ b/opentelemetry-proto-json/src/opentelemetry/proto_json/collector/metrics/v1/metrics_service.py
@@ -8,17 +8,14 @@
 
 import builtins
 import dataclasses
-import functools
 import typing
 
-_dataclass = functools.partial(dataclasses.dataclass, slots=True)
-
 import opentelemetry.proto_json._json_codec
 import opentelemetry.proto_json.metrics.v1.metrics
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ExportMetricsServiceRequest(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ExportMetricsServiceRequest
@@ -59,7 +56,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ExportMetr
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ExportMetricsServiceResponse(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ExportMetricsServiceResponse
@@ -100,7 +97,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ExportMetr
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ExportMetricsPartialSuccess(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ExportMetricsPartialSuccess
diff --git a/opentelemetry-proto-json/src/opentelemetry/proto_json/collector/profiles/v1development/profiles_service.py b/opentelemetry-proto-json/src/opentelemetry/proto_json/collector/profiles/v1development/profiles_service.py
index faaaa6105c1..ab73f0fc1ab 100644
--- a/opentelemetry-proto-json/src/opentelemetry/proto_json/collector/profiles/v1development/profiles_service.py
+++ b/opentelemetry-proto-json/src/opentelemetry/proto_json/collector/profiles/v1development/profiles_service.py
@@ -8,17 +8,14 @@
 
 import builtins
 import dataclasses
-import functools
 import typing
 
-_dataclass = functools.partial(dataclasses.dataclass, slots=True)
-
 import opentelemetry.proto_json._json_codec
 import opentelemetry.proto_json.profiles.v1development.profiles
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ExportProfilesServiceRequest(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ExportProfilesServiceRequest
@@ -64,7 +61,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ExportProf
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ExportProfilesServiceResponse(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ExportProfilesServiceResponse
@@ -105,7 +102,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ExportProf
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ExportProfilesPartialSuccess(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ExportProfilesPartialSuccess
diff --git a/opentelemetry-proto-json/src/opentelemetry/proto_json/collector/trace/v1/trace_service.py b/opentelemetry-proto-json/src/opentelemetry/proto_json/collector/trace/v1/trace_service.py
index 27d3a1a1e0a..39175e2b1e4 100644
--- a/opentelemetry-proto-json/src/opentelemetry/proto_json/collector/trace/v1/trace_service.py
+++ b/opentelemetry-proto-json/src/opentelemetry/proto_json/collector/trace/v1/trace_service.py
@@ -8,17 +8,14 @@
 
 import builtins
 import dataclasses
-import functools
 import typing
 
-_dataclass = functools.partial(dataclasses.dataclass, slots=True)
-
 import opentelemetry.proto_json._json_codec
 import opentelemetry.proto_json.trace.v1.trace
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ExportTraceServiceRequest(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ExportTraceServiceRequest
@@ -59,7 +56,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ExportTrac
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ExportTraceServiceResponse(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ExportTraceServiceResponse
@@ -100,7 +97,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ExportTrac
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ExportTracePartialSuccess(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ExportTracePartialSuccess
diff --git a/opentelemetry-proto-json/src/opentelemetry/proto_json/common/v1/common.py b/opentelemetry-proto-json/src/opentelemetry/proto_json/common/v1/common.py
index 6942227f98b..b3adcb8f477 100644
--- a/opentelemetry-proto-json/src/opentelemetry/proto_json/common/v1/common.py
+++ b/opentelemetry-proto-json/src/opentelemetry/proto_json/common/v1/common.py
@@ -8,16 +8,13 @@
 
 import builtins
 import dataclasses
-import functools
 import typing
 
-_dataclass = functools.partial(dataclasses.dataclass, slots=True)
-
 import opentelemetry.proto_json._json_codec
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class AnyValue(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message AnyValue
@@ -96,7 +93,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "AnyValue":
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ArrayValue(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ArrayValue
@@ -137,7 +134,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ArrayValue
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class KeyValueList(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message KeyValueList
@@ -178,7 +175,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "KeyValueLi
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class KeyValue(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message KeyValue
@@ -231,7 +228,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "KeyValue":
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class InstrumentationScope(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message InstrumentationScope
@@ -290,7 +287,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Instrument
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class EntityRef(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message EntityRef
diff --git a/opentelemetry-proto-json/src/opentelemetry/proto_json/logs/v1/logs.py b/opentelemetry-proto-json/src/opentelemetry/proto_json/logs/v1/logs.py
index e978df472f3..ca4486b221f 100644
--- a/opentelemetry-proto-json/src/opentelemetry/proto_json/logs/v1/logs.py
+++ b/opentelemetry-proto-json/src/opentelemetry/proto_json/logs/v1/logs.py
@@ -9,11 +9,8 @@
 import builtins
 import dataclasses
 import enum
-import functools
 import typing
 
-_dataclass = functools.partial(dataclasses.dataclass, slots=True)
-
 import opentelemetry.proto_json._json_codec
 import opentelemetry.proto_json.common.v1.common
 import opentelemetry.proto_json.resource.v1.resource
@@ -61,7 +58,7 @@ class LogRecordFlags(enum.IntEnum):
     LOG_RECORD_FLAGS_TRACE_FLAGS_MASK = 255
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class LogsData(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message LogsData
@@ -102,7 +99,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "LogsData":
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ResourceLogs(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ResourceLogs
@@ -154,7 +151,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ResourceLo
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ScopeLogs(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ScopeLogs
@@ -206,7 +203,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ScopeLogs"
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class LogRecord(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message LogRecord
@@ -275,8 +272,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "LogRecord"
         if (_value := data.get("observedTimeUnixNano")) is not None:
             _args["observed_time_unix_nano"] = opentelemetry.proto_json._json_codec.decode_int64(_value, "observed_time_unix_nano")
         if (_value := data.get("severityNumber")) is not None:
-            opentelemetry.proto_json._json_codec.validate_type(_value, builtins.int, "severity_number")
-            _args["severity_number"] = SeverityNumber(_value)
+            _args["severity_number"] = opentelemetry.proto_json._json_codec.decode_enum(_value, SeverityNumber, "severity_number")
         if (_value := data.get("severityText")) is not None:
             opentelemetry.proto_json._json_codec.validate_type(_value, builtins.str, "severity_text")
             _args["severity_text"] = _value
diff --git a/opentelemetry-proto-json/src/opentelemetry/proto_json/metrics/v1/metrics.py b/opentelemetry-proto-json/src/opentelemetry/proto_json/metrics/v1/metrics.py
index a5f63651352..51c0798cbad 100644
--- a/opentelemetry-proto-json/src/opentelemetry/proto_json/metrics/v1/metrics.py
+++ b/opentelemetry-proto-json/src/opentelemetry/proto_json/metrics/v1/metrics.py
@@ -9,11 +9,8 @@
 import builtins
 import dataclasses
 import enum
-import functools
 import typing
 
-_dataclass = functools.partial(dataclasses.dataclass, slots=True)
-
 import opentelemetry.proto_json._json_codec
 import opentelemetry.proto_json.common.v1.common
 import opentelemetry.proto_json.resource.v1.resource
@@ -39,7 +36,7 @@ class DataPointFlags(enum.IntEnum):
     DATA_POINT_FLAGS_NO_RECORDED_VALUE_MASK = 1
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class MetricsData(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message MetricsData
@@ -80,7 +77,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "MetricsDat
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ResourceMetrics(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ResourceMetrics
@@ -132,7 +129,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ResourceMe
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ScopeMetrics(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ScopeMetrics
@@ -184,7 +181,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ScopeMetri
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class Metric(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message Metric
@@ -268,7 +265,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Metric":
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class Gauge(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message Gauge
@@ -309,7 +306,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Gauge":
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class Sum(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message Sum
@@ -352,8 +349,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Sum":
         if (_value := data.get("dataPoints")) is not None:
             _args["data_points"] = opentelemetry.proto_json._json_codec.decode_repeated(_value, lambda _v: NumberDataPoint.from_dict(_v), "data_points")
         if (_value := data.get("aggregationTemporality")) is not None:
-            opentelemetry.proto_json._json_codec.validate_type(_value, builtins.int, "aggregation_temporality")
-            _args["aggregation_temporality"] = AggregationTemporality(_value)
+            _args["aggregation_temporality"] = opentelemetry.proto_json._json_codec.decode_enum(_value, AggregationTemporality, "aggregation_temporality")
         if (_value := data.get("isMonotonic")) is not None:
             opentelemetry.proto_json._json_codec.validate_type(_value, builtins.bool, "is_monotonic")
             _args["is_monotonic"] = _value
@@ -362,7 +358,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Sum":
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class Histogram(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message Histogram
@@ -402,14 +398,13 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Histogram"
         if (_value := data.get("dataPoints")) is not None:
             _args["data_points"] = opentelemetry.proto_json._json_codec.decode_repeated(_value, lambda _v: HistogramDataPoint.from_dict(_v), "data_points")
         if (_value := data.get("aggregationTemporality")) is not None:
-            opentelemetry.proto_json._json_codec.validate_type(_value, builtins.int, "aggregation_temporality")
-            _args["aggregation_temporality"] = AggregationTemporality(_value)
+            _args["aggregation_temporality"] = opentelemetry.proto_json._json_codec.decode_enum(_value, AggregationTemporality, "aggregation_temporality")
 
         return cls(**_args)
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ExponentialHistogram(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ExponentialHistogram
@@ -449,14 +444,13 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Exponentia
         if (_value := data.get("dataPoints")) is not None:
             _args["data_points"] = opentelemetry.proto_json._json_codec.decode_repeated(_value, lambda _v: ExponentialHistogramDataPoint.from_dict(_v), "data_points")
         if (_value := data.get("aggregationTemporality")) is not None:
-            opentelemetry.proto_json._json_codec.validate_type(_value, builtins.int, "aggregation_temporality")
-            _args["aggregation_temporality"] = AggregationTemporality(_value)
+            _args["aggregation_temporality"] = opentelemetry.proto_json._json_codec.decode_enum(_value, AggregationTemporality, "aggregation_temporality")
 
         return cls(**_args)
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class Summary(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message Summary
@@ -497,7 +491,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Summary":
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class NumberDataPoint(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message NumberDataPoint
@@ -569,7 +563,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "NumberData
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class HistogramDataPoint(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message HistogramDataPoint
@@ -661,14 +655,14 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "HistogramD
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ExponentialHistogramDataPoint(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ExponentialHistogramDataPoint
     """
 
     @typing.final
-    @_dataclass
+    @dataclasses.dataclass(slots=True)
     class Buckets(opentelemetry.proto_json._json_codec.JsonMessage):
         """
         Generated from protobuf message Buckets
@@ -815,14 +809,14 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Exponentia
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class SummaryDataPoint(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message SummaryDataPoint
     """
 
     @typing.final
-    @_dataclass
+    @dataclasses.dataclass(slots=True)
     class ValueAtQuantile(opentelemetry.proto_json._json_codec.JsonMessage):
         """
         Generated from protobuf message ValueAtQuantile
@@ -932,7 +926,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "SummaryDat
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class Exemplar(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message Exemplar
diff --git a/opentelemetry-proto-json/src/opentelemetry/proto_json/profiles/v1development/profiles.py b/opentelemetry-proto-json/src/opentelemetry/proto_json/profiles/v1development/profiles.py
index 3d3bd90d22f..b769e9a6ca4 100644
--- a/opentelemetry-proto-json/src/opentelemetry/proto_json/profiles/v1development/profiles.py
+++ b/opentelemetry-proto-json/src/opentelemetry/proto_json/profiles/v1development/profiles.py
@@ -8,18 +8,15 @@
 
 import builtins
 import dataclasses
-import functools
 import typing
 
-_dataclass = functools.partial(dataclasses.dataclass, slots=True)
-
 import opentelemetry.proto_json._json_codec
 import opentelemetry.proto_json.common.v1.common
 import opentelemetry.proto_json.resource.v1.resource
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ProfilesDictionary(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ProfilesDictionary
@@ -90,7 +87,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ProfilesDi
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ProfilesData(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ProfilesData
@@ -136,7 +133,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ProfilesDa
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ResourceProfiles(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ResourceProfiles
@@ -188,7 +185,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ResourcePr
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ScopeProfiles(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ScopeProfiles
@@ -240,7 +237,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ScopeProfi
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class Profile(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message Profile
@@ -333,7 +330,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Profile":
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class Link(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message Link
@@ -379,7 +376,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Link":
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ValueType(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ValueType
@@ -427,7 +424,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ValueType"
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class Sample(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message Sample
@@ -490,7 +487,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Sample":
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class Mapping(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message Mapping
@@ -552,7 +549,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Mapping":
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class Stack(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message Stack
@@ -593,7 +590,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Stack":
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class Location(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message Location
@@ -650,7 +647,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Location":
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class Line(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message Line
@@ -702,7 +699,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Line":
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class Function(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message Function
@@ -761,7 +758,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Function":
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class KeyValueAndUnit(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message KeyValueAndUnit
diff --git a/opentelemetry-proto-json/src/opentelemetry/proto_json/resource/v1/resource.py b/opentelemetry-proto-json/src/opentelemetry/proto_json/resource/v1/resource.py
index 3c76082759f..ce29a7e2748 100644
--- a/opentelemetry-proto-json/src/opentelemetry/proto_json/resource/v1/resource.py
+++ b/opentelemetry-proto-json/src/opentelemetry/proto_json/resource/v1/resource.py
@@ -8,17 +8,14 @@
 
 import builtins
 import dataclasses
-import functools
 import typing
 
-_dataclass = functools.partial(dataclasses.dataclass, slots=True)
-
 import opentelemetry.proto_json._json_codec
 import opentelemetry.proto_json.common.v1.common
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class Resource(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message Resource
diff --git a/opentelemetry-proto-json/src/opentelemetry/proto_json/trace/v1/trace.py b/opentelemetry-proto-json/src/opentelemetry/proto_json/trace/v1/trace.py
index 16112213715..c800b70d3de 100644
--- a/opentelemetry-proto-json/src/opentelemetry/proto_json/trace/v1/trace.py
+++ b/opentelemetry-proto-json/src/opentelemetry/proto_json/trace/v1/trace.py
@@ -9,11 +9,8 @@
 import builtins
 import dataclasses
 import enum
-import functools
 import typing
 
-_dataclass = functools.partial(dataclasses.dataclass, slots=True)
-
 import opentelemetry.proto_json._json_codec
 import opentelemetry.proto_json.common.v1.common
 import opentelemetry.proto_json.resource.v1.resource
@@ -31,7 +28,7 @@ class SpanFlags(enum.IntEnum):
     SPAN_FLAGS_CONTEXT_IS_REMOTE_MASK = 512
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class TracesData(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message TracesData
@@ -72,7 +69,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "TracesData
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ResourceSpans(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ResourceSpans
@@ -124,7 +121,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ResourceSp
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class ScopeSpans(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message ScopeSpans
@@ -176,7 +173,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "ScopeSpans
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class Span(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message Span
@@ -196,7 +193,7 @@ class SpanKind(enum.IntEnum):
         SPAN_KIND_CONSUMER = 5
 
     @typing.final
-    @_dataclass
+    @dataclasses.dataclass(slots=True)
     class Event(opentelemetry.proto_json._json_codec.JsonMessage):
         """
         Generated from protobuf message Event
@@ -253,7 +250,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Span.Event
             return cls(**_args)
 
     @typing.final
-    @_dataclass
+    @dataclasses.dataclass(slots=True)
     class Link(opentelemetry.proto_json._json_codec.JsonMessage):
         """
         Generated from protobuf message Link
@@ -409,8 +406,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Span":
             opentelemetry.proto_json._json_codec.validate_type(_value, builtins.str, "name")
             _args["name"] = _value
         if (_value := data.get("kind")) is not None:
-            opentelemetry.proto_json._json_codec.validate_type(_value, builtins.int, "kind")
-            _args["kind"] = Span.SpanKind(_value)
+            _args["kind"] = opentelemetry.proto_json._json_codec.decode_enum(_value, Span.SpanKind, "kind")
         if (_value := data.get("startTimeUnixNano")) is not None:
             _args["start_time_unix_nano"] = opentelemetry.proto_json._json_codec.decode_int64(_value, "start_time_unix_nano")
         if (_value := data.get("endTimeUnixNano")) is not None:
@@ -437,7 +433,7 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Span":
 
 
 @typing.final
-@_dataclass
+@dataclasses.dataclass(slots=True)
 class Status(opentelemetry.proto_json._json_codec.JsonMessage):
     """
     Generated from protobuf message Status
@@ -488,7 +484,6 @@ def from_dict(cls, data: builtins.dict[builtins.str, typing.Any]) -> "Status":
             opentelemetry.proto_json._json_codec.validate_type(_value, builtins.str, "message")
             _args["message"] = _value
         if (_value := data.get("code")) is not None:
-            opentelemetry.proto_json._json_codec.validate_type(_value, builtins.int, "code")
-            _args["code"] = Status.StatusCode(_value)
+            _args["code"] = opentelemetry.proto_json._json_codec.decode_enum(_value, Status.StatusCode, "code")
 
         return cls(**_args)