diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 991b7eab9..01103ab41 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,5 +1,5 @@
 {
-  "packages/toolbox-langchain": "1.3.0",
+  "packages/toolbox-langchain": "1.4.0",
   "packages/toolbox-core": "1.4.0",
   "packages/toolbox-llamaindex": "0.8.0",
   "packages/toolbox-adk": "1.4.0"
diff --git a/packages/toolbox-langchain/CHANGELOG.md b/packages/toolbox-langchain/CHANGELOG.md
index 4ea4ed194..77632ca60 100644
--- a/packages/toolbox-langchain/CHANGELOG.md
+++ b/packages/toolbox-langchain/CHANGELOG.md
@@ -1,5 +1,17 @@
 # Changelog
 
+## [1.4.0](https://github.com/googleapis/mcp-toolbox-sdk-python/compare/toolbox-langchain-v1.3.0...toolbox-langchain-v1.4.0) (2026-09-01)
+
+
+### Features
+
+* **langchain:** pass telemetry attributes ([#740](https://github.com/googleapis/mcp-toolbox-sdk-python/issues/740)) ([c74c7e0](https://github.com/googleapis/mcp-toolbox-sdk-python/commit/c74c7e0ef00632cea4a82aaf6c14926900d4d4b9))
+* **langchain:** support secure parameters in langchain tools and clients ([bff0b2f](https://github.com/googleapis/mcp-toolbox-sdk-python/commit/bff0b2ff9d5fde705a821ed650d451422151b992))
+
+
+> [!NOTE]
+> For additional changelogs of the underlying `toolbox-core` package, visit: https://github.com/googleapis/mcp-toolbox-sdk-python/releases/tag/toolbox-core-v1.4.0
+
 ## [1.3.0](https://github.com/googleapis/mcp-toolbox-sdk-python/compare/toolbox-langchain-v1.2.0...toolbox-langchain-v1.3.0) (2026-07-28)
 
 
diff --git a/packages/toolbox-langchain/pyproject.toml b/packages/toolbox-langchain/pyproject.toml
index d586b3dcb..08b8df121 100644
--- a/packages/toolbox-langchain/pyproject.toml
+++ b/packages/toolbox-langchain/pyproject.toml
@@ -9,7 +9,7 @@ authors = [
     {name = "Google LLC", email = "googleapis-packages@google.com"}
 ]
 dependencies = [
-    "toolbox-core==1.3.0",
+    "toolbox-core==1.4.0",
     "langchain-core>=0.2.23,<2.0.0",
     "PyYAML>=6.0.1,<7.0.0",
     "pydantic>=2.7.0,<3.0.0",
diff --git a/packages/toolbox-langchain/src/toolbox_langchain/version.py b/packages/toolbox-langchain/src/toolbox_langchain/version.py
index 4f78e99d5..60cfa0734 100644
--- a/packages/toolbox-langchain/src/toolbox_langchain/version.py
+++ b/packages/toolbox-langchain/src/toolbox_langchain/version.py
@@ -12,4 +12,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-__version__ = "1.3.0"
+__version__ = "1.4.0"