diff --git a/py/Makefile b/py/Makefile
index 498ddd27..a14a5530 100644
--- a/py/Makefile
+++ b/py/Makefile
@@ -60,7 +60,7 @@ install-dev: install-build-deps
 	$(UV) pip install -r requirements-dev.txt
 
 install-optional: install-dev
-	$(UV) pip install anthropic openai pydantic_ai agno google-genai google-adk dspy langsmith
+	$(UV) pip install -r requirements-optional.txt
 	$(UV) pip install -e .[temporal,otel]
 
 .DEFAULT_GOAL := help
diff --git a/py/noxfile.py b/py/noxfile.py
index 4c99cb00..0e32cf57 100644
--- a/py/noxfile.py
+++ b/py/noxfile.py
@@ -82,7 +82,8 @@ def _pinned_python_version():
 ANTHROPIC_VERSIONS = (LATEST, "0.50.0", "0.49.0", "0.48.0")
 OPENAI_VERSIONS = (LATEST, "1.77.0", "1.71", "1.91", "1.92")
 # litellm latest requires Python >= 3.10
-LITELLM_VERSIONS = (LATEST, "1.74.0")
+# Pin litellm because 1.82.7-1.82.8 are compromised: https://github.com/BerriAI/litellm/issues/24512
+LITELLM_VERSIONS = ("1.82.0", "1.74.0")
 # CLI bundling started in 0.1.10 - older versions require external Claude Code installation
 CLAUDE_AGENT_SDK_VERSIONS = (LATEST, "0.1.10")
 # Keep LATEST for newest API coverage, and pin 2.4.0 to cover the 2.4 -> 2.5 breaking change
diff --git a/py/requirements-optional.txt b/py/requirements-optional.txt
new file mode 100644
index 00000000..1fdb21fd
--- /dev/null
+++ b/py/requirements-optional.txt
@@ -0,0 +1,9 @@
+anthropic==0.84.0
+openai==2.24.0
+pydantic_ai==1.66.0
+agno==2.5.7
+google-genai==1.66.0
+google-adk==1.14.1
+dspy==3.1.3
+langsmith==0.7.12
+litellm==1.82.0