diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index dd29134..a0567fc 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -18,7 +18,7 @@ set(KLOTSKI_CORE_SRC
         short_code/internal/convert.cc
         short_code/internal/serialize.cc
 
-        core/internal/core.cc
+        mover/internal/mover.cc
 
         fast_cal/internal/cal_core.cc
         fast_cal/internal/fast_cal.cc
diff --git a/src/core/fast_cal/fast_cal.h b/src/core/fast_cal/fast_cal.h
index e8384da..73de499 100644
--- a/src/core/fast_cal/fast_cal.h
+++ b/src/core/fast_cal/fast_cal.h
@@ -10,11 +10,11 @@
 #include <functional>
 #include <unordered_map>
 
-#include "core/core.h"
+#include "mover/mover.h"
 #include "raw_code/raw_code.h"
 
-using klotski::core::Core;
 using klotski::codec::RawCode;
+using klotski::mover::MaskMover;
 
 // TODO: using prime number
 const uint32_t FC_MAP_RESERVE = 65536 * 8;
@@ -60,6 +60,6 @@ private:
     std::queue<fast_cal_t*> cache;
     std::unordered_map<uint64_t, fast_cal_t> cases;
 
-    inline Core init(uint64_t code);
+    inline MaskMover init(uint64_t code);
     void new_case(uint64_t code, uint64_t mask);
 };
diff --git a/src/core/fast_cal/internal/cal_core.cc b/src/core/fast_cal/internal/cal_core.cc
index 6eed096..e37fd06 100644
--- a/src/core/fast_cal/internal/cal_core.cc
+++ b/src/core/fast_cal/internal/cal_core.cc
@@ -1,6 +1,6 @@
 #include "fast_cal/fast_cal.h"
 
-Core FastCal::init(uint64_t code) { // initialize process
+MaskMover FastCal::init(uint64_t code) { // initialize process
     /// reset working data
     cases.clear();
     cases.reserve(FC_MAP_RESERVE); // hashmap pre-reserve
@@ -13,8 +13,8 @@ Core FastCal::init(uint64_t code) { // initialize process
         .last = nullptr, // without parent node
     }).first->second);
 
-    /// import klotski core
-    return Core(
+    /// import klotski mover
+    return MaskMover(
         [this](auto &&code, auto &&mask) { // lambda as function pointer
             new_case(std::forward<decltype(code)>(code), std::forward<decltype(mask)>(mask));
         }
diff --git a/src/core/group/internal/group.cc b/src/core/group/internal/group.cc
index 76d21fb..c5ea6a6 100644
--- a/src/core/group/internal/group.cc
+++ b/src/core/group/internal/group.cc
@@ -1,14 +1,15 @@
 #include <absl/container/flat_hash_map.h>
 
-#include "core/core.h"
+#include "mover/mover.h"
 #include "group/group.h"
 
-using klotski::core::Core;
 using klotski::cases::Group;
 using klotski::codec::RawCode;
 using klotski::codec::CommonCode;
 using klotski::cases::RangesUnion;
 
+using klotski::mover::MaskMover;
+
 std::vector<RawCode> Group::extend(RawCode raw_code, uint32_t reserve) {
     std::vector<RawCode> codes;
     absl::flat_hash_map<uint64_t, uint64_t> cases; // <code, mask>
@@ -16,7 +17,7 @@ std::vector<RawCode> Group::extend(RawCode raw_code, uint32_t reserve) {
     codes.reserve(reserve);
     cases.reserve(reserve);
 
-    auto core = Core([&codes, &cases](uint64_t code, uint64_t mask) {
+    auto core = MaskMover([&codes, &cases](uint64_t code, uint64_t mask) {
         if (const auto match = cases.find(code); match != cases.end()) {
             match->second |= mask; // update mask
             return;
diff --git a/src/core/group/internal/group_union.cc b/src/core/group/internal/group_union.cc
index c203bdd..6d807ea 100644
--- a/src/core/group/internal/group_union.cc
+++ b/src/core/group/internal/group_union.cc
@@ -1,4 +1,4 @@
-#include "core/core.h"
+#include "mover/mover.h"
 #include "group/group.h"
 #include "constant/group_union.h"
 
diff --git a/src/core/main.cc b/src/core/main.cc
index 5b9137e..4ab1b40 100644
--- a/src/core/main.cc
+++ b/src/core/main.cc
@@ -6,8 +6,8 @@
 #include <unordered_set>
 #include <ranges/ranges.h>
 
-#include "core/core.h"
 #include "group/group.h"
+#include "mover/mover.h"
 #include "raw_code/raw_code.h"
 #include "fast_cal/fast_cal.h"
 #include "all_cases/all_cases.h"
@@ -16,7 +16,7 @@
 
 #include "../../third_party/thread-pool/include/BS_thread_pool.hpp"
 
-using klotski::core::Core;
+using klotski::mover::MaskMover;
 
 using klotski::cases::AllCases;
 using klotski::cases::BasicRanges;
diff --git a/src/core/core/internal/core.cc b/src/core/mover/internal/mover.cc
similarity index 91%
rename from src/core/core/internal/core.cc
rename to src/core/mover/internal/mover.cc
index 5be9af3..4ce4906 100644
--- a/src/core/core/internal/core.cc
+++ b/src/core/mover/internal/mover.cc
@@ -1,4 +1,4 @@
-#include "core/core.h"
+#include "mover/mover.h"
 #include "utils/common.h"
 
 /// block move direction
@@ -73,9 +73,9 @@
 
 ///////////////////////////////////////////////
 
-using klotski::core::Core;
+using klotski::mover::MaskMover;
 
-inline void Core::cache_insert(cache_t next_case) { // try to insert into cache
+inline void MaskMover::cache_insert(cache_t next_case) { // try to insert into cache
     auto *cache_ptr = cache_;
     for (; cache_ptr < cache_ + cache_size_; ++cache_ptr) {
         if (cache_ptr->code == next_case.code) {
@@ -86,7 +86,7 @@ inline void Core::cache_insert(cache_t next_case) { // try to insert into cache
     ++cache_size_;
 }
 
-void Core::move_1x1(uint64_t code, int addr) { // try to move target 1x1 block
+void MaskMover::move_1x1(uint64_t code, int addr) { // try to move target 1x1 block
     BFS_INIT
     while (!BFS_STOP) { // bfs search process
         BFS_LOAD
@@ -105,7 +105,7 @@ void Core::move_1x1(uint64_t code, int addr) { // try to move target 1x1 block
     }
 }
 
-void Core::move_1x2(uint64_t code, int addr) { // try to move target 1x2 block
+void MaskMover::move_1x2(uint64_t code, int addr) { // try to move target 1x2 block
     BFS_INIT
     while (!BFS_STOP) { // bfs search process
         BFS_LOAD
@@ -124,7 +124,7 @@ void Core::move_1x2(uint64_t code, int addr) { // try to move target 1x2 block
     }
 }
 
-void Core::move_2x1(uint64_t code, int addr) { // try to move target 2x1 block
+void MaskMover::move_2x1(uint64_t code, int addr) { // try to move target 2x1 block
     BFS_INIT
     while (!BFS_STOP) { // bfs search process
         BFS_LOAD
@@ -143,7 +143,7 @@ void Core::move_2x1(uint64_t code, int addr) { // try to move target 2x1 block
     }
 }
 
-void Core::move_2x2(uint64_t code, int addr) { // try to move target 2x2 block
+void MaskMover::move_2x2(uint64_t code, int addr) { // try to move target 2x2 block
     BFS_INIT
     while (!BFS_STOP) { // bfs search process
         BFS_LOAD
@@ -162,7 +162,7 @@ void Core::move_2x2(uint64_t code, int addr) { // try to move target 2x2 block
     }
 }
 
-void Core::next_cases(uint64_t code, uint64_t mask) { // search next step cases
+void MaskMover::next_cases(uint64_t code, uint64_t mask) { // search next step cases
     cache_[0].filter = 0; // without filter
     cache_[0].code = code; // bfs root code
     auto range = code | mask;
diff --git a/src/core/core/core.h b/src/core/mover/mover.h
similarity index 94%
rename from src/core/core/core.h
rename to src/core/mover/mover.h
index 5b00299..b2b3d3b 100644
--- a/src/core/core/core.h
+++ b/src/core/mover/mover.h
@@ -52,7 +52,7 @@
 /// be obtained at the same time, which marks the moved block as `111`, which
 /// will speed up subsequent calculations. The generated layout will be
 /// inserted into the cache, and after the BFS search for each block is
-/// completed, the core will use the callback function to output these
+/// completed, the mover will use the callback function to output these
 /// results.
 
 #pragma once
@@ -61,20 +61,20 @@
 #include <utility>
 #include <functional>
 
-namespace klotski::core {
+namespace klotski::mover {
 
 // TODO: new version without mask
 
 // TODO: allow wrap as a function directly
 
-class Core {
+class MaskMover {
 public:
     /// Release with code and mask
     typedef std::function<void(uint64_t, uint64_t)> release_t;
 
     /// Core interface
     void next_cases(uint64_t code, uint64_t mask);
-    explicit Core(release_t release_func) : release_(std::move(release_func)) {}
+    explicit MaskMover(release_t release_func) : release_(std::move(release_func)) {}
 
 private:
     struct cache_t {
@@ -95,4 +95,4 @@ private:
     inline void cache_insert(cache_t next_case);
 };
 
-} // namespace klotski::core
+} // namespace klotski::mover
diff --git a/src/core_test/CMakeLists.txt b/src/core_test/CMakeLists.txt
index 04c6a34..98e2ee6 100644
--- a/src/core_test/CMakeLists.txt
+++ b/src/core_test/CMakeLists.txt
@@ -62,12 +62,12 @@ add_test(NAME klotski_codec COMMAND test_klotski_codec)
 
 # ------------------------------------------------------------------------------------ #
 
-set(KLSK_TEST_CORE_SRC
-    core/core.cc
+set(KLSK_TEST_MOVER_SRC
+    mover/mover.cc
 )
 
-add_executable(test_klotski_core ${KLSK_TEST_CORE_SRC})
-target_link_libraries(test_klotski_core PRIVATE ${KLSK_TEST_DEPS})
-add_test(NAME klotski_core COMMAND test_klotski_core)
+add_executable(test_klotski_mover ${KLSK_TEST_MOVER_SRC})
+target_link_libraries(test_klotski_mover PRIVATE ${KLSK_TEST_DEPS} test_helper)
+add_test(NAME klotski_mover COMMAND test_klotski_mover)
 
 # ------------------------------------------------------------------------------------ #
diff --git a/src/core_test/cases/helper/group_impl.cc b/src/core_test/cases/helper/group_impl.cc
index 325557c..f5aa338 100644
--- a/src/core_test/cases/helper/group_impl.cc
+++ b/src/core_test/cases/helper/group_impl.cc
@@ -6,7 +6,7 @@
 
 /// Extend ordered Group from the specified CommonCode seed.
 static std::vector<CommonCode> extend_cases(CommonCode seed) {
-    // TODO: using inner build process -> only allow calling klotski::core
+    // TODO: using inner build process -> only allow calling klotski::mover
     auto raw_codes = klotski::cases::Group::extend(seed.to_raw_code());
     std::vector<CommonCode> common_codes {raw_codes.begin(), raw_codes.end()};
     std::ranges::sort(common_codes.begin(), common_codes.end());
diff --git a/src/core_test/helper/internal/group.cc b/src/core_test/helper/internal/group.cc
index f15d20a..987f12b 100644
--- a/src/core_test/helper/internal/group.cc
+++ b/src/core_test/helper/internal/group.cc
@@ -52,7 +52,7 @@ const std::vector<CommonCode>& helper::group_union_cases(const uint32_t type_id)
 
 /// Extend ordered Group from the specified CommonCode seed.
 static std::vector<CommonCode> extend_cases(CommonCode seed) {
-    // TODO: using inner build process -> only allow calling klotski::core
+    // TODO: using inner build process -> only allow calling klotski::mover
     auto raw_codes = klotski::cases::Group::extend(seed.to_raw_code());
     std::vector<CommonCode> common_codes {raw_codes.begin(), raw_codes.end()};
     std::ranges::sort(common_codes.begin(), common_codes.end());
diff --git a/src/core_test/core/core.cc b/src/core_test/mover/mover.cc
similarity index 94%
rename from src/core_test/core/core.cc
rename to src/core_test/mover/mover.cc
index 33b06d8..fdaab64 100644
--- a/src/core_test/core/core.cc
+++ b/src/core_test/mover/mover.cc
@@ -5,7 +5,7 @@
 #include <numeric>
 #include <ranges>
 
-#include "core/core.h"
+#include "mover/mover.h"
 #include "utils/common.h"
 #include "all_cases/all_cases.h"
 #include "common_code/common_code.h"
@@ -19,7 +19,7 @@ constexpr auto NEXT_CASES_XXH3 = std::to_array<uint64_t>({
     0x4a7599e1bdbffbb3, 0xb3cf1fdea988466a, 0x21226a4f692e1892, 0x2d06800538d394c2,
 });
 
-using klotski::core::Core;
+using klotski::mover::MaskMover;
 using klotski::cases::AllCases;
 using klotski::codec::CommonCode;
 
@@ -54,7 +54,7 @@ TEST(Core, core) {
     std::vector<uint64_t> codes;
     codes.reserve(402258220);
 
-    auto core = Core([&codes](uint64_t ret, uint64_t) {
+    auto core = MaskMover([&codes](uint64_t ret, uint64_t) {
         codes.emplace_back(klotski::codec::RawCode::unsafe_create(ret).to_common_code().unwrap());
     });
 
@@ -82,7 +82,7 @@ TEST(Core, mask) {
 
     uint64_t src;
 
-    auto core = Core([&src](uint64_t ret, uint64_t mask) {
+    auto core = MaskMover([&src](uint64_t ret, uint64_t mask) {
 
         EXPECT_EQ(std::popcount(mask), 3);
 
@@ -184,7 +184,7 @@ TEST(Core, next_cases) {
     std::vector<CommonCode> result {};
 
     std::vector<CommonCode> tmp;
-    auto core = Core([&tmp](uint64_t ret, uint64_t mask) {
+    auto core = MaskMover([&tmp](uint64_t ret, uint64_t mask) {
         tmp.emplace_back(CommonCode::from_raw_code(ret).value());
     });
 
@@ -212,6 +212,6 @@ TEST(Core, next_cases) {
 
 //    std::cout << std::hex << hash::xxh3(result) << std::endl;
 
-    EXPECT_EQ(hash::xxh3(result), NEXT_CASES_XXH3[0]);
+    EXPECT_EQ(helper::xxh3(result), NEXT_CASES_XXH3[0]);
 
 }