diff --git a/.github/workflows/license.yml b/.github/workflows/license.yml
new file mode 100644
index 00000000..a84e0268
--- /dev/null
+++ b/.github/workflows/license.yml
@@ -0,0 +1,21 @@
+name: license
+
+on:
+  push:
+    branches: [ master ]
+    paths-ignore: '**.md'
+  pull_request:
+    branches: [ master ]
+    paths-ignore: '**.md'
+
+jobs:
+  license_check:
+    name: License check
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Check license
+        run: |
+          find include/gtsam_points src/gtsam_points -type f | xargs -I filename bash -c 'if ! grep -q Copyright filename; then echo filename : lisence not found; exit 1; fi'
\ No newline at end of file
diff --git a/include/gtsam_points/ann/knn_result.hpp b/include/gtsam_points/ann/knn_result.hpp
index 0380aeb9..0fdaee6e 100644
--- a/include/gtsam_points/ann/knn_result.hpp
+++ b/include/gtsam_points/ann/knn_result.hpp
@@ -1,3 +1,5 @@
+// SPDX-FileCopyrightText: Copyright 2024 Kenji Koide
+// SPDX-License-Identifier: MIT
 #pragma once
 
 #include <iostream>
diff --git a/include/gtsam_points/cuda/cuda_malloc_async.hpp b/include/gtsam_points/cuda/cuda_malloc_async.hpp
index db9585b9..f3805c69 100644
--- a/include/gtsam_points/cuda/cuda_malloc_async.hpp
+++ b/include/gtsam_points/cuda/cuda_malloc_async.hpp
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #pragma once
 
 #if (CUDA_VERSION < 11000)
diff --git a/include/gtsam_points/cuda/gl_buffer_map.hpp b/include/gtsam_points/cuda/gl_buffer_map.hpp
index b0dd150e..6ad96081 100644
--- a/include/gtsam_points/cuda/gl_buffer_map.hpp
+++ b/include/gtsam_points/cuda/gl_buffer_map.hpp
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #pragma once
 
 #include <cstdlib>
diff --git a/include/gtsam_points/cuda/kernels/inlier_access_kernel.cuh b/include/gtsam_points/cuda/kernels/inlier_access_kernel.cuh
index 7e760778..0b28d643 100644
--- a/include/gtsam_points/cuda/kernels/inlier_access_kernel.cuh
+++ b/include/gtsam_points/cuda/kernels/inlier_access_kernel.cuh
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #pragma once
 
 #include <iostream>
diff --git a/include/gtsam_points/optimizers/dogleg_optimizer_ext.hpp b/include/gtsam_points/optimizers/dogleg_optimizer_ext.hpp
index 730392a7..1286d2d0 100644
--- a/include/gtsam_points/optimizers/dogleg_optimizer_ext.hpp
+++ b/include/gtsam_points/optimizers/dogleg_optimizer_ext.hpp
@@ -44,7 +44,10 @@ class GTSAM_EXPORT DoglegOptimizerExt : public gtsam::NonlinearOptimizer {
    * @param initialValues The initial variable assignments
    * @param params The optimization parameters
    */
-  DoglegOptimizerExt(const gtsam::NonlinearFactorGraph& graph, const gtsam::Values& initialValues, const gtsam::DoglegParams& params = gtsam::DoglegParams());
+  DoglegOptimizerExt(
+    const gtsam::NonlinearFactorGraph& graph,
+    const gtsam::Values& initialValues,
+    const gtsam::DoglegParams& params = gtsam::DoglegParams());
 
   /** Standard constructor, requires a nonlinear factor graph, initial
    * variable assignments, and optimization parameters.  For convenience this
diff --git a/include/gtsam_points/optimizers/dogleg_optimizer_ext_impl.hpp b/include/gtsam_points/optimizers/dogleg_optimizer_ext_impl.hpp
index 871b5517..5ee0fd72 100644
--- a/include/gtsam_points/optimizers/dogleg_optimizer_ext_impl.hpp
+++ b/include/gtsam_points/optimizers/dogleg_optimizer_ext_impl.hpp
@@ -122,7 +122,8 @@ struct GTSAM_EXPORT DoglegOptimizerImplExt {
    * @param dx_n The Gauss-Newton point
    * @return The dogleg point \f$ \delta x_d \f$
    */
-  static gtsam::VectorValues ComputeDoglegPoint(double delta, const gtsam::VectorValues& dx_u, const gtsam::VectorValues& dx_n, const bool verbose = false);
+  static gtsam::VectorValues
+  ComputeDoglegPoint(double delta, const gtsam::VectorValues& dx_u, const gtsam::VectorValues& dx_n, const bool verbose = false);
 
   /** Compute the point on the line between the steepest descent point and the
    * Newton's method point intersecting the trust region boundary.
@@ -158,7 +159,11 @@ typename DoglegOptimizerImplExt::IterationResult DoglegOptimizerImplExt::Iterate
   IterationResult result;
 
   bool stay = true;
-  enum { NONE, INCREASED_DELTA, DECREASED_DELTA } lastAction = NONE;  // Used to prevent alternating between increasing and decreasing in one iteration
+  enum {
+    NONE,
+    INCREASED_DELTA,
+    DECREASED_DELTA
+  } lastAction = NONE;  // Used to prevent alternating between increasing and decreasing in one iteration
   while (stay) {
     gttic(Dog_leg_point);
     // Compute dog leg point
@@ -189,7 +194,9 @@ typename DoglegOptimizerImplExt::IterationResult DoglegOptimizerImplExt::Iterate
     gttic(adjust_delta);
     // Compute gain ratio.  Here we take advantage of the invariant that the
     // Bayes' net error at zero is equal to the nonlinear error
-    const double rho = std::abs(f_error - result.f_error) < 1e-15 || std::abs(M_error - new_M_error) < 1e-15 ? 0.5 : (f_error - result.f_error) / (M_error - new_M_error);
+    const double rho = std::abs(f_error - result.f_error) < 1e-15 || std::abs(M_error - new_M_error) < 1e-15
+                         ? 0.5
+                         : (f_error - result.f_error) / (M_error - new_M_error);
 
     if (verbose) std::cout << std::setprecision(15) << "rho = " << rho << std::endl;
 
diff --git a/include/gtsam_points/optimizers/isam2_ext_dummy.hpp b/include/gtsam_points/optimizers/isam2_ext_dummy.hpp
index 41f02470..911d8e70 100644
--- a/include/gtsam_points/optimizers/isam2_ext_dummy.hpp
+++ b/include/gtsam_points/optimizers/isam2_ext_dummy.hpp
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #pragma once
 
 #include <gtsam_points/optimizers/isam2_ext.hpp>
diff --git a/include/gtsam_points/types/dummy_frame.hpp b/include/gtsam_points/types/dummy_frame.hpp
index a0285bb4..317e8486 100644
--- a/include/gtsam_points/types/dummy_frame.hpp
+++ b/include/gtsam_points/types/dummy_frame.hpp
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #pragma once
 
 namespace gtsam_points {
diff --git a/include/gtsam_points/util/easy_profiler.hpp b/include/gtsam_points/util/easy_profiler.hpp
index ecc473b4..68fc0ca3 100644
--- a/include/gtsam_points/util/easy_profiler.hpp
+++ b/include/gtsam_points/util/easy_profiler.hpp
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #pragma once
 
 #include <chrono>
@@ -63,7 +66,8 @@ class EasyProfiler {
     times.push_back(std::chrono::high_resolution_clock::now());
 
     if (debug) {
-      ost << ">> " << label << " (" << std::chrono::duration_cast<std::chrono::nanoseconds>(times.back() - times.front()).count() / 1e6 << "[msec])" << std::endl;
+      ost << ">> " << label << " (" << std::chrono::duration_cast<std::chrono::nanoseconds>(times.back() - times.front()).count() / 1e6 << "[msec])"
+          << std::endl;
     }
   }
 
@@ -78,4 +82,4 @@ class EasyProfiler {
   std::ostream& ost;
   std::ofstream ofs;
 };
-}  // namespace glim
\ No newline at end of file
+}  // namespace gtsam_points
\ No newline at end of file
diff --git a/include/gtsam_points/util/easy_profiler_cuda.hpp b/include/gtsam_points/util/easy_profiler_cuda.hpp
index b50a0fd9..68015b12 100644
--- a/include/gtsam_points/util/easy_profiler_cuda.hpp
+++ b/include/gtsam_points/util/easy_profiler_cuda.hpp
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #pragma once
 
 #include <vector>
diff --git a/src/gtsam_points/cuda/cuda_stream.cu b/src/gtsam_points/cuda/cuda_stream.cu
index e46adf27..473b6287 100644
--- a/src/gtsam_points/cuda/cuda_stream.cu
+++ b/src/gtsam_points/cuda/cuda_stream.cu
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #include <gtsam_points/cuda/cuda_stream.hpp>
 
 #include <iostream>
diff --git a/src/gtsam_points/cuda/gl_buffer_map.cu b/src/gtsam_points/cuda/gl_buffer_map.cu
index 5296a57c..fbd34c39 100644
--- a/src/gtsam_points/cuda/gl_buffer_map.cu
+++ b/src/gtsam_points/cuda/gl_buffer_map.cu
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #include <gtsam_points/cuda/gl_buffer_map.hpp>
 
 #include <cuda_runtime.h>
diff --git a/src/gtsam_points/factors/integrated_color_consistency_factor.cpp b/src/gtsam_points/factors/integrated_color_consistency_factor.cpp
index 955d042c..5cf02996 100644
--- a/src/gtsam_points/factors/integrated_color_consistency_factor.cpp
+++ b/src/gtsam_points/factors/integrated_color_consistency_factor.cpp
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #include <gtsam_points/ann/ivox.hpp>
 #include <gtsam_points/types/point_cloud.hpp>
 // #include <gtsam_points/factors/intensity_gradients_ivox.hpp>
diff --git a/src/gtsam_points/factors/integrated_colored_gicp_factor.cpp b/src/gtsam_points/factors/integrated_colored_gicp_factor.cpp
index d617c34e..d433ad13 100644
--- a/src/gtsam_points/factors/integrated_colored_gicp_factor.cpp
+++ b/src/gtsam_points/factors/integrated_colored_gicp_factor.cpp
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #include <gtsam_points/ann/ivox.hpp>
 #include <gtsam_points/types/point_cloud.hpp>
 // #include <gtsam_points/factors/intensity_gradients_ivox.hpp>
diff --git a/src/gtsam_points/factors/integrated_ct_gicp_factor.cpp b/src/gtsam_points/factors/integrated_ct_gicp_factor.cpp
index 89d38243..d4ecadcf 100644
--- a/src/gtsam_points/factors/integrated_ct_gicp_factor.cpp
+++ b/src/gtsam_points/factors/integrated_ct_gicp_factor.cpp
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #include <gtsam_points/ann/ivox.hpp>
 #include <gtsam_points/ann/ivox_covariance_estimation.hpp>
 #include <gtsam_points/types/point_cloud.hpp>
diff --git a/src/gtsam_points/factors/integrated_ct_icp_factor.cpp b/src/gtsam_points/factors/integrated_ct_icp_factor.cpp
index 75cd8e21..61c4eb92 100644
--- a/src/gtsam_points/factors/integrated_ct_icp_factor.cpp
+++ b/src/gtsam_points/factors/integrated_ct_icp_factor.cpp
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #include <gtsam_points/ann/ivox.hpp>
 #include <gtsam_points/ann/ivox_covariance_estimation.hpp>
 #include <gtsam_points/types/point_cloud.hpp>
diff --git a/src/gtsam_points/factors/integrated_gicp_factor.cpp b/src/gtsam_points/factors/integrated_gicp_factor.cpp
index 7729d842..6120538e 100644
--- a/src/gtsam_points/factors/integrated_gicp_factor.cpp
+++ b/src/gtsam_points/factors/integrated_gicp_factor.cpp
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #include <gtsam_points/ann/ivox.hpp>
 #include <gtsam_points/ann/ivox_covariance_estimation.hpp>
 #include <gtsam_points/types/point_cloud.hpp>
diff --git a/src/gtsam_points/factors/integrated_loam_factor.cpp b/src/gtsam_points/factors/integrated_loam_factor.cpp
index dd3abe62..48860c27 100644
--- a/src/gtsam_points/factors/integrated_loam_factor.cpp
+++ b/src/gtsam_points/factors/integrated_loam_factor.cpp
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #include <gtsam_points/ann/ivox.hpp>
 #include <gtsam_points/types/point_cloud.hpp>
 #include <gtsam_points/factors/integrated_loam_factor.hpp>
diff --git a/src/gtsam_points/factors/integrated_vgicp_factor.cpp b/src/gtsam_points/factors/integrated_vgicp_factor.cpp
index 92031ce9..4d023cf3 100644
--- a/src/gtsam_points/factors/integrated_vgicp_factor.cpp
+++ b/src/gtsam_points/factors/integrated_vgicp_factor.cpp
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #include <gtsam_points/types/point_cloud.hpp>
 #include <gtsam_points/factors/integrated_vgicp_factor.hpp>
 #include <gtsam_points/factors/impl/integrated_vgicp_factor_impl.hpp>
diff --git a/src/gtsam_points/optimizers/fast_scatter.cpp b/src/gtsam_points/optimizers/fast_scatter.cpp
index 5671ca48..2d5c2cab 100644
--- a/src/gtsam_points/optimizers/fast_scatter.cpp
+++ b/src/gtsam_points/optimizers/fast_scatter.cpp
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #include <gtsam_points/optimizers/fast_scatter.hpp>
 
 #include <unordered_set>
diff --git a/src/gtsam_points/optimizers/gaussian_factor_graph_solver.cpp b/src/gtsam_points/optimizers/gaussian_factor_graph_solver.cpp
index 21991d35..2d929db8 100644
--- a/src/gtsam_points/optimizers/gaussian_factor_graph_solver.cpp
+++ b/src/gtsam_points/optimizers/gaussian_factor_graph_solver.cpp
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #include <gtsam_points/optimizers/gaussian_factor_graph_solver.hpp>
 
 #include <gtsam_points/optimizers/linear_solver.hpp>
diff --git a/src/gtsam_points/optimizers/incremental_fixed_lag_smoother_ext_with_fallback.cpp b/src/gtsam_points/optimizers/incremental_fixed_lag_smoother_ext_with_fallback.cpp
index 24b5e354..63ee68d1 100644
--- a/src/gtsam_points/optimizers/incremental_fixed_lag_smoother_ext_with_fallback.cpp
+++ b/src/gtsam_points/optimizers/incremental_fixed_lag_smoother_ext_with_fallback.cpp
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #include <gtsam_points/optimizers/incremental_fixed_lag_smoother_with_fallback.hpp>
 
 #include <chrono>
@@ -71,7 +74,7 @@ const gtsam::Value& IncrementalFixedLagSmootherExtWithFallback::calculateEstimat
   try {
     const auto& value = smoother->calculateEstimate(key);
     auto found = values.find(key);
-    if(found != values.end()) {
+    if (found != values.end()) {
       found->value = value;
     }
 
@@ -125,7 +128,7 @@ void IncrementalFixedLagSmootherExtWithFallback::update_fallback_state() {
   gtsam::NonlinearFactorGraph next_factors;
   next_factors.reserve(factors.size());
   for (const auto& factor : factors) {
-    if(!factors_to_eliminate.count(factor.get())) {
+    if (!factors_to_eliminate.count(factor.get())) {
       next_factors.add(factor);
     }
   }
@@ -149,7 +152,7 @@ void IncrementalFixedLagSmootherExtWithFallback::fallback_smoother() const {
   std::unordered_map<char, size_t> max_ids;
   for (const auto& value : values) {
     const auto found = stamps.find(value.key);
-    if(found == stamps.end()) {
+    if (found == stamps.end()) {
       std::cerr << "warning: corresponding stamp is not found for " << gtsam::Symbol(value.key) << std::endl;
       continue;
     }
@@ -158,14 +161,14 @@ void IncrementalFixedLagSmootherExtWithFallback::fallback_smoother() const {
     const gtsam::Symbol symbol(value.key);
 
     auto min_stamp = min_stamps.find(symbol.chr());
-    if(min_stamp == min_stamps.end()) {
+    if (min_stamp == min_stamps.end()) {
       min_stamps.emplace_hint(min_stamp, symbol.chr(), stamp);
     } else {
       min_stamp->second = std::min(min_stamp->second, stamp);
     }
 
     auto max_id = max_ids.find(symbol.chr());
-    if(max_id == max_ids.end()) {
+    if (max_id == max_ids.end()) {
       max_ids.emplace_hint(max_id, symbol.chr(), symbol.index());
     } else {
       max_id->second = std::max<size_t>(max_id->second, max_id->second);
@@ -183,7 +186,7 @@ void IncrementalFixedLagSmootherExtWithFallback::fallback_smoother() const {
   // connectivity check
   std::unordered_map<gtsam::Key, std::vector<gtsam::NonlinearFactor*>> factormap;
   for (const auto& factor : factors) {
-    for(const auto key: factor->keys()) {
+    for (const auto key : factor->keys()) {
       factormap[key].push_back(factor.get());
     }
   }
@@ -204,27 +207,27 @@ void IncrementalFixedLagSmootherExtWithFallback::fallback_smoother() const {
     traverse_queue.pop_back();
 
     for (const auto key : factor->keys()) {
-      if(traversed_keys.count(key)) {
+      if (traversed_keys.count(key)) {
         continue;
       }
 
       traversed_keys.insert(key);
       const auto found = factormap.find(key);
-      if(found != factormap.end()) {
+      if (found != factormap.end()) {
         traverse_queue.insert(traverse_queue.end(), found->second.begin(), found->second.end());
       }
     }
   }
 
   std::unordered_set<gtsam::Key> keys_to_remove;
-  for(const auto& value: values) {
-    if(!traversed_keys.count(value.key)) {
+  for (const auto& value : values) {
+    if (!traversed_keys.count(value.key)) {
       std::cerr << "unreached key found:" << gtsam::Symbol(value.key) << std::endl;
       keys_to_remove.insert(value.key);
     }
   }
 
-  for(const auto& key: keys_to_remove) {
+  for (const auto& key : keys_to_remove) {
     values.erase(key);
     stamps.erase(key);
   }
@@ -266,7 +269,6 @@ void IncrementalFixedLagSmootherExtWithFallback::fallback_smoother() const {
   std::cout << "factors:" << factors.size() << " fixed:" << new_factors.size() - factors.size() << " values:" << values.size()
             << " stamps:" << stamps.size() << std::endl;
 
-
   for (const auto& factor : new_factors) {
     for (const auto key : factor->keys()) {
       if (!values.exists(key)) {
@@ -278,8 +280,8 @@ void IncrementalFixedLagSmootherExtWithFallback::fallback_smoother() const {
     }
   }
 
-  for(const auto& stamp: stamps) {
-    if(!values.exists(stamp.first)) {
+  for (const auto& stamp : stamps) {
+    if (!values.exists(stamp.first)) {
       std::cout << "illegal stamp found!! " << gtsam::Symbol(stamp.first) << std::endl;
     }
   }
diff --git a/src/gtsam_points/util/easy_profiler_cuda.cu b/src/gtsam_points/util/easy_profiler_cuda.cu
index 74a0a696..4f2bedd0 100644
--- a/src/gtsam_points/util/easy_profiler_cuda.cu
+++ b/src/gtsam_points/util/easy_profiler_cuda.cu
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021  Kenji Koide (k.koide@aist.go.jp)
+
 #include <gtsam_points/util/easy_profiler_cuda.hpp>
 
 #include <cuda_runtime.h>