diff --git a/src/sail_json_backend/json.ml b/src/sail_json_backend/json.ml
index 5213ce55e..08083f371 100644
--- a/src/sail_json_backend/json.ml
+++ b/src/sail_json_backend/json.ml
@@ -232,12 +232,55 @@ let parse_encdec i mc format =
       end
   | _ -> assert false
   
+let extract_operands k =
+  let components = Hashtbl.find assembly k in
+  let regex = Str.regexp ".+(\\(.*\\))" in
+  let rec pre_filter acc = function
+    | [] -> List.rev acc
+    | hd :: tl ->
+      if String.trim hd = "spc" then
+        tl
+      else
+        pre_filter ( hd :: acc ) tl
+  in
+  let filtered_components = pre_filter [] components in 
+  let rec extract acc = function
+    | [] -> List.rev acc
+    | hd :: tl ->
+      if Str.string_match regex hd 0 then
+        let operand = Str.matched_group 1 hd in
+        let trimmed_operand = 
+          try
+            let comma_index = String.index operand ',' in
+            let trimmed = String.sub operand 0 comma_index in
+            debug_print ("Trimmed operand using comma: " ^ trimmed);
+            trimmed
+          with Not_found -> 
+          debug_print ("No comma found in operand: " ^ operand);
+          operand
+        in     
+        debug_print ("Final trimmed operand: " ^ trimmed_operand);  
+        extract (trimmed_operand :: acc) tl
+    else
+      extract acc tl
+  in
+  let operandl = extract [] filtered_components in
+  let opmap = List.combine (Hashtbl.find inputs k) (Hashtbl.find sigs k) in
+  let operand_with_type = List.map (fun op ->
+    match List.find_opt (fun (name,_) -> String.equal name op) opmap with
+    | Some (_, t) -> (op, t)
+    | None -> (op, "")
+  ) operandl in
+  debug_print ("Adding to operands hashtable: " ^ k ^ " -> " ^ 
+    String.concat ", " (List.map (fun (op, t) -> Printf.sprintf "(%s, %s)" op t) operand_with_type)); 
+  Hashtbl.add operands k operand_with_type
 
 let add_assembly app_id p =
   let x = string_list_of_mpat p in
   begin
     debug_print ("assembly.add " ^ string_of_id app_id ^ " : " ^ List.hd x);
-    Hashtbl.add assembly (string_of_id app_id) x
+    Hashtbl.add assembly (string_of_id app_id) x;
+    extract_operands (string_of_id app_id)
   end
 
 let parse_assembly_mpat mp pb =
@@ -396,9 +439,8 @@ let parse_funcl fcl =
           Hashtbl.add functions id source_code
       | Pat_exp (P_aux (P_app (i, pl), _), e) | Pat_when (P_aux (P_app (i, pl), _), e, _) ->
           debug_print ("FCL_funcl execute " ^ string_of_id i);
-          let operandl = List.concat (List.map string_list_of_pat pl) in
-          if not (String.equal (List.hd operandl) "()") then Hashtbl.add operands (string_of_id i) operandl;
-          Hashtbl.add executes (string_of_id i) (extract_source_code (Ast_util.exp_loc e))
+          let source_code = extract_source_code (Ast_util.exp_loc e) in
+          Hashtbl.add executes (string_of_id i) source_code
       | _ -> ()
     end
   | _ -> debug_print "FCL_funcl other"
@@ -536,7 +578,7 @@ let default_operand optional opt_operand =
 
 let json_of_operand k op =
   debug_print ("json_of_operand " ^ k ^ ":" ^ op);
-  let opmap = List.combine (Hashtbl.find operands k) (Hashtbl.find sigs k) in
+  let opmap = Hashtbl.find operands k in
   let opplus = remove_identity_funcs op in
   let opname = List.hd (String.split_on_char ',' opplus) in
   let optional, opt_operand = optional_operand k op in
@@ -555,9 +597,9 @@ let json_of_operands k =
   | Some ops ->
       String.concat ","
         (List.map
-           (fun op -> json_of_operand k op)
+           (fun (op, _) -> json_of_operand k op)
            (List.filter
-              (fun s -> not (String.equal s "(" || String.equal s ")" || String.equal s "spc" || String.equal s "sep"))
+              (fun (s, _) -> not (String.equal s "(" || String.equal s ")" || String.equal s "spc" || String.equal s "sep"))
               ops
            )
         )
@@ -595,7 +637,7 @@ let rec string_of_sizeof_field k f =
     )
   else begin
     (* match operand names to function signature types *)
-    let opmap = List.combine (Hashtbl.find operands k) (Hashtbl.find sigs k) in
+    let opmap = Hashtbl.find operands k in
     begin
       (* find matching operand type *)
       match List.assoc_opt f opmap with
@@ -746,7 +788,7 @@ let defs { defs; _ } =
   debug_print "DESCRIPTIONS";
   Hashtbl.iter (fun k v -> debug_print (k ^ ":" ^ v)) descriptions;
   debug_print "OPERANDS";
-  Hashtbl.iter (fun k v -> debug_print (k ^ ":" ^ Util.string_of_list ", " (fun x -> x) v)) operands;
+  Hashtbl.iter (fun k v -> debug_print (k ^ ":" ^ Util.string_of_list ", " (fun (op, t) -> "(" ^ op ^ ", " ^ t ^ ")") v)) operands;
   debug_print "ENCODINGS";
   Hashtbl.iter (fun k v -> debug_print (k ^ ":" ^ Util.string_of_list ", " (fun x -> x) v)) encodings;
   debug_print "ASSEMBLY";