diff --git a/requirements.txt b/requirements.txt
index 45c8b0c..50a3cfb 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,10 +4,10 @@
 
 # For LLM-backed iterative planning only (agent-side):
 # Keep these lean so sandbox tests pass reliably.
-# DeepAgents + LangChain are optional until the iterative skill is invoked.
-# Use conservative version ranges known to work on Python 3.11.
-deepagents>=0.4,<1.0
-langchain>=0.2.14,<0.4
-langchain-openai>=0.1.15,<0.3
-langgraph>=0.1.0,<0.8
+# Pin to a compatible matrix with a2a_pack's DeepAgents middleware imports.
+
+deepagents==0.5.1
+langchain==0.2.16
+langchain-openai==0.1.24
+langgraph==0.1.12
 beautifulsoup4>=4.12