diff --git a/src/interface.jl b/src/interface.jl
index 15a29c4..603df06 100644
--- a/src/interface.jl
+++ b/src/interface.jl
@@ -22,7 +22,7 @@ end
 
 @kwdef mutable struct agent
     availableRole=["system", "user", "assistant"]
-    maxUserMsg::Int= 5
+    maxUserMsg::Int= 10
     llmAIRequestTopic_openblas = "llm/openblas/request"
     llmAIRequestTopic_gpu = "llm/api/v0.0.1/gpu/request"
     self_llmReceiveTopic = "chatbothub/llm/respond"
@@ -40,6 +40,26 @@ end
     messages=[Dict(:role=>"system", :content=> "You are a helpful assistant.", :timestamp=> Dates.now()),]
 end
 
+@kwdef mutable struct agentLangchain
+  availableRole=["system", "user", "assistant"]
+  maxUserMsg::Int= 10
+  llmAIRequestTopic_openblas = "llm/openblas/request"
+  llmAIRequestTopic_gpu = "llm/api/v0.0.1/gpu/request"
+  self_llmReceiveTopic = "chatbothub/llm/respond"
+
+  """ Dict(Role=> Content)  ;   Role can be system, user, assistant
+    Example:
+      messages=[
+            Dict(:role=>"system", :content=> "You are a helpful assistant."),
+            Dict(:role=>"assistant", :content=> "How may I help you"),
+            Dict(:role=>"user", :content=> "Hello, how are you"),
+            ]
+  """
+  # Ref: https://huggingface.co/TheBloke/Llama-2-7B-Chat-GGML/discussions/3
+  # 
+  messages=[Dict(:role=>"system", :content=> "You are a helpful assistant.", :timestamp=> Dates.now()),]
+end
+
 """ 
   add new message to agent
 # Example