diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 0c02950d..e1eb2bdf 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "0.4.4"
+  ".": "0.4.5"
 }
\ No newline at end of file
diff --git a/.stats.yml b/.stats.yml
index 93a8d335..53739925 100644
--- a/.stats.yml
+++ b/.stats.yml
@@ -1,4 +1,4 @@
 configured_endpoints: 34
-openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/sgp%2Fagentex-sdk-29501785fbb6de9348a558389e9d0a9a94dddd50021f6f3ea8ff0fa95dddbeaf.yml
-openapi_spec_hash: 523525acdac5482a17e6c99aa9382a50
-config_hash: c90254d21aa8a5ea34eb8d11a9dd05cb
+openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/sgp%2Fagentex-sdk-80f1ace5353bc55b63c3065f7229699cacf3bdb3dc3ce4a5a479dd35c919c2bf.yml
+openapi_spec_hash: 222d76b1af70ef4b692dee4dcf05e57c
+config_hash: aeabb3a919ad2763f5d0f41961a2520a
diff --git a/CHANGELOG.md b/CHANGELOG.md
index af69c34b..3ec82df4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,24 @@
 # Changelog
 
+## 0.4.5 (2025-08-20)
+
+Full Changelog: [v0.4.4...v0.4.5](https://github.com/scaleapi/agentex-python/compare/v0.4.4...v0.4.5)
+
+### Features
+
+* **api:** manual updates ([34a53aa](https://github.com/scaleapi/agentex-python/commit/34a53aa28b8f862d74dd1603d92b7dd5dd28ddb1))
+
+
+### Bug Fixes
+
+* enable FunctionTool serialization for Temporal worker nodes ([c9eb040](https://github.com/scaleapi/agentex-python/commit/c9eb04002825195187cd58f34c9185349a63566e))
+* **tools:** handle callable objects in model serialization to facilitate tool calling ([4e9bb87](https://github.com/scaleapi/agentex-python/commit/4e9bb87d7faa2c2e1643893a168f7c6affd2809d))
+
+
+### Chores
+
+* demonstrate FunctionTool use in a (temporal) tutorial ([3a72043](https://github.com/scaleapi/agentex-python/commit/3a7204333c328fab8ba0f1d31fd26994ea176ecf))
+
 ## 0.4.4 (2025-08-17)
 
 Full Changelog: [v0.4.3...v0.4.4](https://github.com/scaleapi/agentex-python/compare/v0.4.3...v0.4.4)
diff --git a/api.md b/api.md
index 7f67632d..4e3e6f83 100644
--- a/api.md
+++ b/api.md
@@ -68,6 +68,7 @@ from agentex.types import (
     ReasoningContent,
     TaskMessage,
     TextContent,
+    TextFormat,
     ToolRequestContent,
     ToolResponseContent,
     MessageListResponse,
diff --git a/pyproject.toml b/pyproject.toml
index 9ca24d62..03bc8bd4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "agentex-sdk"
-version = "0.4.4"
+version = "0.4.5"
 description = "The official Python library for the agentex API"
 dynamic = ["readme"]
 license = "Apache-2.0"
diff --git a/src/agentex/_version.py b/src/agentex/_version.py
index 2814e289..5f41f496 100644
--- a/src/agentex/_version.py
+++ b/src/agentex/_version.py
@@ -1,4 +1,4 @@
 # File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
 
 __title__ = "agentex"
-__version__ = "0.4.4"  # x-release-please-version
+__version__ = "0.4.5"  # x-release-please-version
diff --git a/src/agentex/types/__init__.py b/src/agentex/types/__init__.py
index 62c11a73..0445dfad 100644
--- a/src/agentex/types/__init__.py
+++ b/src/agentex/types/__init__.py
@@ -11,6 +11,7 @@
 from .acp_type import AcpType as AcpType
 from .data_delta import DataDelta as DataDelta
 from .text_delta import TextDelta as TextDelta
+from .text_format import TextFormat as TextFormat
 from .data_content import DataContent as DataContent
 from .task_message import TaskMessage as TaskMessage
 from .text_content import TextContent as TextContent
diff --git a/src/agentex/types/text_content.py b/src/agentex/types/text_content.py
index f4586698..df8ea167 100644
--- a/src/agentex/types/text_content.py
+++ b/src/agentex/types/text_content.py
@@ -4,6 +4,7 @@
 from typing_extensions import Literal
 
 from .._models import BaseModel
+from .text_format import TextFormat
 from .message_style import MessageStyle
 from .message_author import MessageAuthor
 
@@ -37,7 +38,7 @@ class TextContent(BaseModel):
     attachments: Optional[List[Attachment]] = None
     """Optional list of file attachments with structured metadata."""
 
-    format: Literal["markdown", "plain", "code"] = "plain"
+    format: TextFormat = "plain"
     """The format of the message.
 
     This is used by the client to determine how to display the message.
diff --git a/src/agentex/types/text_content_param.py b/src/agentex/types/text_content_param.py
index 87f357e0..9923a2a8 100644
--- a/src/agentex/types/text_content_param.py
+++ b/src/agentex/types/text_content_param.py
@@ -5,6 +5,7 @@
 from typing import Iterable, Optional
 from typing_extensions import Literal, Required, TypedDict
 
+from .text_format import TextFormat
 from .message_style import MessageStyle
 from .message_author import MessageAuthor
 
@@ -38,7 +39,7 @@ class TextContentParam(TypedDict, total=False):
     attachments: Optional[Iterable[Attachment]]
     """Optional list of file attachments with structured metadata."""
 
-    format: Literal["markdown", "plain", "code"]
+    format: TextFormat
     """The format of the message.
 
     This is used by the client to determine how to display the message.
diff --git a/src/agentex/types/text_format.py b/src/agentex/types/text_format.py
new file mode 100644
index 00000000..dea8ca30
--- /dev/null
+++ b/src/agentex/types/text_format.py
@@ -0,0 +1,7 @@
+# File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
+
+from typing_extensions import Literal, TypeAlias
+
+__all__ = ["TextFormat"]
+
+TextFormat: TypeAlias = Literal["markdown", "plain", "code"]