diff --git a/python/agents/ai-security-agent/pyproject.toml b/python/agents/ai-security-agent/pyproject.toml
index b5ecd67593..e4d0917656 100644
--- a/python/agents/ai-security-agent/pyproject.toml
+++ b/python/agents/ai-security-agent/pyproject.toml
@@ -10,7 +10,7 @@ readme = "README.md"
 requires-python = ">=3.12"
 
 dependencies = [
-    "google-adk>=1.18.0",
+    "google-adk>=1.31.1",
     "google-genai>=1.9.0",
     "google-cloud-aiplatform>=1.127.0",
     "python-dotenv>=1.2.1",
@@ -22,7 +22,7 @@ dependencies = [
 dev = [
     "pytest>=8.3.5",
     "pytest-asyncio>=0.26.0",
-    "google-adk[eval]>=1.0.0",
+    "google-adk[eval]>=1.31.1",
     "ruff>=0.4.6",
     "mypy>=1.18.2",
     "agent-starter-pack>=0.32.0",
diff --git a/python/agents/airflow_version_upgrade_agent/pyproject.toml b/python/agents/airflow_version_upgrade_agent/pyproject.toml
index e9f9e426bf..97c0ee0662 100644
--- a/python/agents/airflow_version_upgrade_agent/pyproject.toml
+++ b/python/agents/airflow_version_upgrade_agent/pyproject.toml
@@ -11,7 +11,7 @@ readme = "README.md"
 requires-python = ">=3.11,<3.13"
 
 dependencies = [
-    "google-adk==1.28.0",
+    "google-adk==1.28.1",
     "mcp>=1.26.0",
     "google-cloud-aiplatform>=1.144.0",
     "google-cloud-storage>=3.10.0",
diff --git a/python/agents/blog-writer/requirements.txt b/python/agents/blog-writer/requirements.txt
index 46b3c358cb..cc53c14c4c 100644
--- a/python/agents/blog-writer/requirements.txt
+++ b/python/agents/blog-writer/requirements.txt
@@ -1,4 +1,4 @@
-google-adk==1.19.0
+google-adk==1.28.1
 pytest==9.0.1
 pytest-asyncio==1.3.0
 deprecated
diff --git a/python/agents/brand-aligner/pyproject.toml b/python/agents/brand-aligner/pyproject.toml
index 0654ebf4be..1911417c32 100644
--- a/python/agents/brand-aligner/pyproject.toml
+++ b/python/agents/brand-aligner/pyproject.toml
@@ -8,7 +8,7 @@ readme = "README.md"
 requires-python = ">=3.12"
 dependencies = [
   "fastapi>=0.121.0",
-  "google-adk==1.17.0",
+  "google-adk==1.28.1",
   "google-api-python-client>=2.187.0",
   "google-auth>=2.43.0",
   "google-auth-oauthlib>=1.2.2",
diff --git a/python/agents/camel/pyproject.toml b/python/agents/camel/pyproject.toml
index b0c72c8498..f3c838eb95 100644
--- a/python/agents/camel/pyproject.toml
+++ b/python/agents/camel/pyproject.toml
@@ -10,7 +10,7 @@ readme = "README.md"
 requires-python = ">=3.12"
 
 dependencies = [
-    "google-adk>=1.0.0",
+    "google-adk>=1.31.1",
     "google-genai>=1.5.0",
     "pdfplumber>=0.11.5",
     "pydantic>=2.11.7",
diff --git a/python/agents/currency-agent/pyproject.toml b/python/agents/currency-agent/pyproject.toml
index eef6dfa456..6a670fdeef 100644
--- a/python/agents/currency-agent/pyproject.toml
+++ b/python/agents/currency-agent/pyproject.toml
@@ -12,7 +12,7 @@ requires-python = ">=3.10"
 dependencies = [
     "a2a-sdk==0.3.3",
     "fastmcp==2.11.3",
-    "google-adk==1.13.0",
+    "google-adk==1.28.1",
     "google-genai>=1.17.0",
     "python-dotenv>=1.1.0",
 ]
diff --git a/python/agents/customer-service/pyproject.toml b/python/agents/customer-service/pyproject.toml
index 04e5c1c06a..6dbdbd1bec 100644
--- a/python/agents/customer-service/pyproject.toml
+++ b/python/agents/customer-service/pyproject.toml
@@ -11,7 +11,7 @@ requires-python = ">=3.10,<3.13"
 
 dependencies = [
     "google-cloud-aiplatform[adk,agent_engine]>=1.93.0",
-    "google-adk>=1.0.0",
+    "google-adk>=1.31.1",
     "pydantic-settings>=2.8.1",
     "tabulate>=0.9.0",
     "cloudpickle>=3.1.1",
diff --git a/python/agents/data-science/pyproject.toml b/python/agents/data-science/pyproject.toml
index 9f95c20b81..3837afc545 100644
--- a/python/agents/data-science/pyproject.toml
+++ b/python/agents/data-science/pyproject.toml
@@ -11,7 +11,7 @@ requires-python = ">=3.12"
 
 dependencies = [
     "python-dotenv>=1.0.1",
-    "google-adk>=1.14",
+    "google-adk>=1.31.1",
     "immutabledict>=4.2.1",
     "sqlglot>=26.10.1",
     "db-dtypes>=1.4.2",
@@ -33,7 +33,7 @@ dev = [
     "google-cloud-aiplatform[adk,agent-engines,evaluation]>=1.93.0",
     "pytest>=8.3.5",
     "pytest-asyncio>=0.26.0",
-    "google-adk[eval]>=1.14",
+    "google-adk[eval]>=1.31.1",
     "ruff>=0.4.6",
     "agent-starter-pack>=0.14.1",
 ]
diff --git a/python/agents/hierarchical-workflow-automation/requirements.txt b/python/agents/hierarchical-workflow-automation/requirements.txt
index 67dcd8ff84..b03b2c3e1f 100644
--- a/python/agents/hierarchical-workflow-automation/requirements.txt
+++ b/python/agents/hierarchical-workflow-automation/requirements.txt
@@ -23,7 +23,7 @@ docstring_parser==0.17.0
 dotenv==0.9.9
 fastapi==0.116.1
 frozenlist==1.7.0
-google-adk==1.13.0
+google-adk==1.28.1
 google-api-core==2.25.1
 google-api-python-client==2.181.0
 google-auth==2.40.3
diff --git a/python/agents/parallel_task_decomposition_execution/pyproject.toml b/python/agents/parallel_task_decomposition_execution/pyproject.toml
index 5083e4d4c2..8d6d5ddbe3 100644
--- a/python/agents/parallel_task_decomposition_execution/pyproject.toml
+++ b/python/agents/parallel_task_decomposition_execution/pyproject.toml
@@ -10,7 +10,7 @@ readme = "README.md"
 requires-python = ">=3.10"
 
 dependencies = [
-    "google-adk==1.19.0",
+    "google-adk==1.28.1",
     "python-dotenv==1.2.1",
     "google-cloud-aiplatform[adk,agent-engines]==1.128.0",
     "mcp==1.21.2",
diff --git a/python/agents/parallel_task_decomposition_execution/requirements.txt b/python/agents/parallel_task_decomposition_execution/requirements.txt
index 9a534b0983..03fd4738c0 100644
--- a/python/agents/parallel_task_decomposition_execution/requirements.txt
+++ b/python/agents/parallel_task_decomposition_execution/requirements.txt
@@ -1,4 +1,4 @@
-google-adk==1.19.0
+google-adk==1.28.1
 python-dotenv==1.2.1
 google-cloud-aiplatform==1.128.0
 google-cloud-aiplatform[adk,agent_engines]
diff --git a/python/agents/plumber-data-engineering-assistant/pyproject.toml b/python/agents/plumber-data-engineering-assistant/pyproject.toml
index 583b82582c..fe133f0470 100644
--- a/python/agents/plumber-data-engineering-assistant/pyproject.toml
+++ b/python/agents/plumber-data-engineering-assistant/pyproject.toml
@@ -25,7 +25,7 @@ dependencies = [
     "fastapi==0.116.1",
     "uvicorn==0.35.0",
     "GitPython==3.1.45",
-    "google-adk==1.16.0",
+    "google-adk==1.28.1",
     "google-api-python-client==2.177.0",
     "google-cloud-monitoring==2.27.2",
     "google-cloud-dataform==0.7.0",
diff --git a/python/agents/policy-as-code/pyproject.toml b/python/agents/policy-as-code/pyproject.toml
index efb965acd5..71551840ba 100644
--- a/python/agents/policy-as-code/pyproject.toml
+++ b/python/agents/policy-as-code/pyproject.toml
@@ -8,7 +8,7 @@ license = { text = "Apache-2.0" }
 requires-python = ">=3.11"
 dependencies = [
     "PyYAML==6.0.3",
-    "google-adk[eval]==1.21.0",
+    "google-adk[eval]==1.28.1",
     "google-cloud-storage==2.19.0",
     "vertexai==1.43.0",
     "google-cloud-dataplex==2.14.0",
diff --git a/python/agents/tau2-benchmark-agent/pyproject.toml b/python/agents/tau2-benchmark-agent/pyproject.toml
index c5f1b9deca..3d8e5d49fa 100644
--- a/python/agents/tau2-benchmark-agent/pyproject.toml
+++ b/python/agents/tau2-benchmark-agent/pyproject.toml
@@ -8,7 +8,7 @@ readme = "README.md"
 requires-python = ">=3.10"
 
 dependencies = [
-    "google-adk==1.19.0",
+    "google-adk==1.28.1",
     "google-genai==1.51.0",
     "loguru==0.7.3",
     "tenacity==9.1.2",