diff --git a/src/interface.jl b/src/interface.jl
index 4fef87e..57cda40 100644
--- a/src/interface.jl
+++ b/src/interface.jl
@@ -176,21 +176,44 @@ function decisionMaker(a::T1, state::T2)::Dict{Symbol, Any} where {T1<:agent, T2
       )
     )
 
-  _response = GeneralUtils.sendReceiveMqttMsg(outgoingMsg)
-  _thoughtJsonStr = _response[:response][:text]
-  expectedJsonExample =
-  """
-  Here is an expected JSON format:
-  {
-    "thought": "...",
-    "action": {"name": "...", "input": "..."},
-    "observation": "..."
-  }
-  """
-  thoughtJsonStr = jsoncorrection(a, _thoughtJsonStr, expectedJsonExample)
-  thoughtDict = copy(JSON3.read(thoughtJsonStr)) 
+  attempt = 0
+  while attempt <= 5
+    attempt += 1
+    try
+      response = GeneralUtils.sendReceiveMqttMsg(outgoingMsg)
+      _responseJsonStr = response[:response][:text]
+      expectedJsonExample =
+      """
+      Here is an expected JSON format:
+      {
+        "thought": "...",
+        "action": {"name": "...", "input": "..."},
+        "observation": "..."
+      }
+      """
+      responseJsonStr = jsoncorrection(a, _responseJsonStr, expectedJsonExample)
+      thoughtDict = copy(JSON3.read(responseJsonStr)) 
 
-  return thoughtDict
+      # check if dict has all required value
+      dummya::AbstractString = thoughtDict[:thought]
+      dummyb::AbstractString = thoughtDict[:action][:name]
+      dummyc::AbstractString = thoughtDict[:action][:input]
+
+      return thoughtDict
+    catch e
+      io = IOBuffer()
+      showerror(io, e)
+      errorMsg = String(take!(io))
+      st = sprint((io, v) -> show(io, "text/plain", v), stacktrace(catch_backtrace()))
+      println("")
+      @warn "Error occurred: $errorMsg\n$st"
+      println("")
+    end
+
+    if attempt > 5
+      error("DecisionMaker failed to generate a thought")
+    end
+  end
 end
 
 
@@ -286,17 +309,39 @@ function progressValueEstimator(a::T1, state::T2)::Tuple{String, Integer} where
       )
     )
 
-  _response = GeneralUtils.sendReceiveMqttMsg(outgoingMsg)
-  _thoughtJsonStr = _response[:response][:text]
-  expectedJsonExample =
-  """
-  Here is an expected JSON format:
-  {"evaluation": "...", "score": "..."}
-  """
-  resultJsonStr = jsoncorrection(a, _thoughtJsonStr, expectedJsonExample)
-  resultDict = copy(JSON3.read(resultJsonStr)) 
+  attempt = 0
+  while attempt <= 5
+    attempt += 1
+    try
+      response = GeneralUtils.sendReceiveMqttMsg(outgoingMsg)
+      _responseJsonStr = response[:response][:text]
+      expectedJsonExample =
+      """
+      Here is an expected JSON format:
+      {"evaluation": "...", "score": "..."}
+      """
+      responseJsonStr = jsoncorrection(a, _responseJsonStr, expectedJsonExample)
+      evaluationDict = copy(JSON3.read(responseJsonStr)) 
 
-  return resultDict[:evaluation], resultDict[:score]
+      # check if dict has all required value
+      dummya::AbstractString = evaluationDict[:evaluation]
+      dummyb::AbstractString = evaluationDict[:score]
+
+      return (evaluationDict[:evaluation], evaluationDict[:score])
+    catch e
+      io = IOBuffer()
+      showerror(io, e)
+      errorMsg = String(take!(io))
+      st = sprint((io, v) -> show(io, "text/plain", v), stacktrace(catch_backtrace()))
+      println("")
+      @warn "Error occurred: $errorMsg\n$st"
+      println("")
+    end
+
+    if attempt > 5
+      error("progressValueEstimator failed to generate a thought")
+    end
+  end
 end
 
 
@@ -313,8 +358,8 @@ julia>
 
 # TODO
   - [] update docstring
-  - [WORKING] implement the function
-  - [PENDING] add try block. check result that it is expected before returning
+  - [x] implement the function
+  - [x] add try block. check result that it is expected before returning
 
 # Signature
 """
@@ -400,21 +445,38 @@ function reflector(a::T1, state::T2)::String where {T1<:agent, T2<:AbstractDict}
       )
     )
 
-  _response = GeneralUtils.sendReceiveMqttMsg(outgoingMsg)
-  _thoughtJsonStr = _response[:response][:text]
+  attempt = 0
+  while attempt <= 5
+    attempt += 1
+    try
+      response = GeneralUtils.sendReceiveMqttMsg(outgoingMsg)
+      _responseJsonStr = response[:response][:text]
+      expectedJsonExample =
+      """
+      Here is an expected JSON format:
+      {"reflection": "..."}
+      """
+      responseJsonStr = jsoncorrection(a, _responseJsonStr, expectedJsonExample)
+      reflectionDict = copy(JSON3.read(responseJsonStr)) 
 
-  # expectedJsonExample =
-  # """
-  # Here is an expected JSON format:
-  # {"evaluation": "...", "score": "..."}
-  # """
-  # resultJsonStr = jsoncorrection(a, _thoughtJsonStr, expectedJsonExample)
-  # resultDict = copy(JSON3.read(resultJsonStr)) 
+      # check if dict has all required value
+      dummya::AbstractString = reflectionDict[:reflection]
 
-  # return resultDict[:evaluation], resultDict[:score]
+      return reflectionDict[:reflection]
+    catch e
+      io = IOBuffer()
+      showerror(io, e)
+      errorMsg = String(take!(io))
+      st = sprint((io, v) -> show(io, "text/plain", v), stacktrace(catch_backtrace()))
+      println("")
+      @warn "Error occurred: $errorMsg\n$st"
+      println("")
+    end
 
-
-  return _thoughtJsonStr
+    if attempt > 5
+      error("reflector failed to generate a thought")
+    end
+  end
 end