diff --git a/langchain-tutorials/4-TUI_LangGraph_agent_PostgreSQL_memory_LangSmith_observability/README.md b/langchain-tutorials/4-TUI_LangGraph_agent_PostgreSQL_memory_LangSmith_observability/README.md
index e69de29..64d486d 100644
--- a/langchain-tutorials/4-TUI_LangGraph_agent_PostgreSQL_memory_LangSmith_observability/README.md
+++ b/langchain-tutorials/4-TUI_LangGraph_agent_PostgreSQL_memory_LangSmith_observability/README.md
@@ -0,0 +1,20 @@
+> [!IMPORTANT]
+> Your `.env` file should contain the following environment variables:
+>
+> ```bash
+> MISTRAL_API_KEY="xxxxxxxxxxxxxxxxxxxxxxxxx"
+>
+> TAVILY_API_KEY = "tvly-xxxxxxxxxxxxxxxxxxxxxxxxx"
+>
+> PSQL_USERNAME = "postgres"
+> PSQL_PASSWORD = "xxxxx"
+> PSQL_HOST = "localhost"
+> PSQL_PORT = "5432"
+> PSQL_DATABASE = "agent_chat"
+> PSQL_SSLMODE = "disable"
+> 
+> LANGCHAIN_TRACING_V2=true
+> LANGCHAIN_ENDPOINT="https://api.smith.langchain.com"
+> LANGCHAIN_API_KEY="lsv2_pt_xxxxxxxxxxxxxxxxxxxxxxxxx"
+> LANGCHAIN_PROJECT="YouTube LangSmith tutorial"
+> ```