diff --git a/luprex/cpp/core/invocation.cpp b/luprex/cpp/core/invocation.cpp
index 155f6f91..0d63497f 100644
--- a/luprex/cpp/core/invocation.cpp
+++ b/luprex/cpp/core/invocation.cpp
@@ -31,11 +31,12 @@ eng::string Invocation::debug_string() const {
     oss << "inv[";
     switch (kind_) {
     case InvocationKind::INVALID: oss << "invalid"; break;
-    case InvocationKind::LUA_CALL: oss << "lua_call"; break;
-    case InvocationKind::LUA_EXPR: oss << "lua"; break;
+    case InvocationKind::LUA_INVOKE: oss << "lua_invoke"; break;
+    case InvocationKind::LUA_PROBE: oss << "lua_probe"; break;
+    case InvocationKind::LUA_EXPR: oss << "lua_expr"; break;
+    case InvocationKind::LUA_SOURCE: oss << "lua_source"; break;
     case InvocationKind::FLUSH_PRINTS: oss << "flush_prints"; break;
     case InvocationKind::TICK: oss << "tick"; break;
-    case InvocationKind::LUA_SOURCE: oss << "lua_source"; break;
     default: oss << "UNKNOWN"; break;
     }
     oss << " a=" << actor_;
diff --git a/luprex/cpp/core/lpxclient.cpp b/luprex/cpp/core/lpxclient.cpp
index 8b2f60b9..d0cb1cdd 100644
--- a/luprex/cpp/core/lpxclient.cpp
+++ b/luprex/cpp/core/lpxclient.cpp
@@ -247,7 +247,16 @@ public:
     }
 
     virtual void event_call_function(InvocationKind kind, int64_t place_id, std::string_view datapk, StreamBuffer *retpk) override {
-        delayed_invocations_.emplace_back(kind, actor_id_, place_id, datapk);
+        switch (kind) {
+            case InvocationKind::LUA_PROBE: {
+                world_to_asynchronous();
+                world_->probe_lua_call(actor_id_, place_id, datapk, retpk);
+                break;
+            }
+            default: {
+                delayed_invocations_.emplace_back(kind, actor_id_, place_id, datapk);
+            }
+        }
     }
 
     virtual void event_update() override {
diff --git a/luprex/cpp/core/lpxserver.cpp b/luprex/cpp/core/lpxserver.cpp
index e09f34fa..785990af 100644
--- a/luprex/cpp/core/lpxserver.cpp
+++ b/luprex/cpp/core/lpxserver.cpp
@@ -194,7 +194,17 @@ public:
     }
     
     virtual void event_call_function(InvocationKind kind, int64_t place_id, std::string_view datapk, StreamBuffer *retpk) override {
-        delayed_invocations_.emplace_back(kind, admin_id_, place_id, datapk);
+        switch (kind) {
+            case InvocationKind::LUA_PROBE: {
+                master_->snapshot();
+                master_->probe_lua_call(admin_id_, place_id, datapk, retpk);
+                master_->rollback();
+                break;
+            }
+            default: {
+                delayed_invocations_.emplace_back(kind, admin_id_, place_id, datapk);
+            }
+        }
     }
 
     virtual void event_update() override {
diff --git a/luprex/cpp/core/world-core.cpp b/luprex/cpp/core/world-core.cpp
index cd771eb5..5f4235c5 100644
--- a/luprex/cpp/core/world-core.cpp
+++ b/luprex/cpp/core/world-core.cpp
@@ -700,7 +700,7 @@ void World::run_unittests() {
 
 void World::invoke(const Invocation &inv) {
     switch (inv.kind()) {
-    case InvocationKind::LUA_CALL:
+    case InvocationKind::LUA_INVOKE:
         invoke_lua_call(inv.actor(), inv.place(), inv.datapack());
         break;
     case InvocationKind::LUA_EXPR:
diff --git a/luprex/ext/base-buffer.hpp b/luprex/ext/base-buffer.hpp
index 07971072..ee3d22e3 100644
--- a/luprex/ext/base-buffer.hpp
+++ b/luprex/ext/base-buffer.hpp
@@ -543,7 +543,7 @@ public:
     int16_t read_int16() { return read_value_core<int16_t>(); }
     int32_t read_int32() { return read_value_core<int32_t>(); }
     int64_t read_int64() { return read_value_core<int64_t>(); }
-    
+        
     // Read other primitive types.
     //
     bool read_bool() { return (bool)read_uint8(); }
diff --git a/luprex/lua/login.lua b/luprex/lua/login.lua
index e0b45bb9..185b41ab 100644
--- a/luprex/lua/login.lua
+++ b/luprex/lua/login.lua
@@ -47,9 +47,9 @@ function bechar()
 makeclass("engio")
 function engio.myfunction(actor, place, a, b, c)
     print("Myfunction actor=", actor," place=", place)
-    pprint("A:", a)
-    pprint("B:", b)
-    pprint("C:", c)
+    print("A:", a)
+    print("B:", b)
+    print("C:", c)
     return {13, "chicken", {2,3,4}, false}
     end