diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 6b7b74c5..da59f99e 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "0.3.0"
+  ".": "0.4.0"
 }
\ No newline at end of file
diff --git a/.stats.yml b/.stats.yml
index 9614f3c1..93a8d335 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-0f2236db4ff4adacf2e97ed9ad85269500786dbc4c6c83a2ac45b33fba43e259.yml
-openapi_spec_hash: 43ad0cbb20696a241cdc83dd5f1366e2
-config_hash: c59262d25b94481ba4fe8f302e48e36d
+openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/sgp%2Fagentex-sdk-29501785fbb6de9348a558389e9d0a9a94dddd50021f6f3ea8ff0fa95dddbeaf.yml
+openapi_spec_hash: 523525acdac5482a17e6c99aa9382a50
+config_hash: c90254d21aa8a5ea34eb8d11a9dd05cb
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6f33d0ed..4d73853f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,14 @@
 # Changelog
 
+## 0.4.0 (2025-08-15)
+
+Full Changelog: [v0.3.0...v0.4.0](https://github.com/scaleapi/agentex-python/compare/v0.3.0...v0.4.0)
+
+### Features
+
+* **api:** manual updates ([ce2a201](https://github.com/scaleapi/agentex-python/commit/ce2a201227ff6659874672fc7c6a890f25dfaa08))
+* **api:** manual updates ([7afbafd](https://github.com/scaleapi/agentex-python/commit/7afbafd03fdcbd464305fe6f0592141117d3527c))
+
 ## 0.3.0 (2025-08-14)
 
 Full Changelog: [v0.2.10...v0.3.0](https://github.com/scaleapi/agentex-python/compare/v0.2.10...v0.3.0)
diff --git a/api.md b/api.md
index e63cb04f..7f67632d 100644
--- a/api.md
+++ b/api.md
@@ -16,6 +16,8 @@ from agentex.types import (
     AgentRpcResponse,
     AgentRpcResult,
     DataDelta,
+    ReasoningContentDelta,
+    ReasoningSummaryDelta,
     TaskMessageContent,
     TaskMessageDelta,
     TaskMessageUpdate,
diff --git a/pyproject.toml b/pyproject.toml
index 304323e8..096ce8bc 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "agentex-sdk"
-version = "0.3.0"
+version = "0.4.0"
 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 310ce27e..cc4ed840 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__ = "0.3.0"  # x-release-please-version
+__version__ = "0.4.0"  # x-release-please-version
diff --git a/src/agentex/types/__init__.py b/src/agentex/types/__init__.py
index 8ddda1c8..62c11a73 100644
--- a/src/agentex/types/__init__.py
+++ b/src/agentex/types/__init__.py
@@ -51,7 +51,9 @@
 from .tool_response_content import ToolResponseContent as ToolResponseContent
 from .tracker_list_response import TrackerListResponse as TrackerListResponse
 from .tracker_update_params import TrackerUpdateParams as TrackerUpdateParams
+from .reasoning_content_delta import ReasoningContentDelta as ReasoningContentDelta
 from .reasoning_content_param import ReasoningContentParam as ReasoningContentParam
+from .reasoning_summary_delta import ReasoningSummaryDelta as ReasoningSummaryDelta
 from .agent_rpc_by_name_params import AgentRpcByNameParams as AgentRpcByNameParams
 from .task_message_content_param import TaskMessageContentParam as TaskMessageContentParam
 from .tool_request_content_param import ToolRequestContentParam as ToolRequestContentParam
diff --git a/src/agentex/types/reasoning_content_delta.py b/src/agentex/types/reasoning_content_delta.py
new file mode 100644
index 00000000..ae79ca8a
--- /dev/null
+++ b/src/agentex/types/reasoning_content_delta.py
@@ -0,0 +1,16 @@
+# File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
+
+from typing import Optional
+from typing_extensions import Literal
+
+from .._models import BaseModel
+
+__all__ = ["ReasoningContentDelta"]
+
+
+class ReasoningContentDelta(BaseModel):
+    content_index: int
+
+    content_delta: Optional[str] = None
+
+    type: Optional[Literal["reasoning_content"]] = None
diff --git a/src/agentex/types/reasoning_summary_delta.py b/src/agentex/types/reasoning_summary_delta.py
new file mode 100644
index 00000000..607cbec2
--- /dev/null
+++ b/src/agentex/types/reasoning_summary_delta.py
@@ -0,0 +1,16 @@
+# File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
+
+from typing import Optional
+from typing_extensions import Literal
+
+from .._models import BaseModel
+
+__all__ = ["ReasoningSummaryDelta"]
+
+
+class ReasoningSummaryDelta(BaseModel):
+    summary_index: int
+
+    summary_delta: Optional[str] = None
+
+    type: Optional[Literal["reasoning_summary"]] = None
diff --git a/src/agentex/types/task_message_delta.py b/src/agentex/types/task_message_delta.py
index 5a477e5a..7fce76b7 100644
--- a/src/agentex/types/task_message_delta.py
+++ b/src/agentex/types/task_message_delta.py
@@ -8,9 +8,12 @@
 from .text_delta import TextDelta
 from .tool_request_delta import ToolRequestDelta
 from .tool_response_delta import ToolResponseDelta
+from .reasoning_content_delta import ReasoningContentDelta
+from .reasoning_summary_delta import ReasoningSummaryDelta
 
 __all__ = ["TaskMessageDelta"]
 
 TaskMessageDelta: TypeAlias = Annotated[
-    Union[TextDelta, DataDelta, ToolRequestDelta, ToolResponseDelta], PropertyInfo(discriminator="type")
+    Union[TextDelta, DataDelta, ToolRequestDelta, ToolResponseDelta, ReasoningSummaryDelta, ReasoningContentDelta],
+    PropertyInfo(discriminator="type"),
 ]