diff --git a/.clang-format b/.clang-format
index 7dc18ab95..0f8e3254c 100644
--- a/.clang-format
+++ b/.clang-format
@@ -8,7 +8,32 @@ BinPackParameters: false
 AllowAllParametersOfDeclarationOnNextLine: true
 AlignAfterOpenBracket: AlwaysBreak
 BreakBeforeBinaryOperators: NonAssignment
-SortIncludes: false
+SortIncludes: true
 CommentPragmas:  '^@.+'
 BreakStringLiterals: false
 PackConstructorInitializers: CurrentLine
+# Regroup includes with a priority system
+IncludeBlocks: Regroup
+IncludeCategories:
+  # by default, the main header of a cpp will get priority 0
+  # regex here are sorted by search pattern, not by sort priority
+  - Regex:           "^<ipc\/[^/]*>" # this libraries
+    Priority:        2    # internal library group
+    SortPriority:    2
+    CaseSensitive:   true
+  - Regex:           "^<ipc\/.*\/.*>" # this libraries
+    Priority:        2    # internal library group
+    SortPriority:    3
+    CaseSensitive:   true
+  - Regex:           "^<(.*\\.h[px]*)|(Eigen\/.*)>"
+    Priority:        4    # libraries (because they end in .h)
+    SortPriority:    4
+    CaseSensitive:   false
+  - Regex:           "^<.*"
+    Priority:        5    # system (without .h, because that is captured by the other group)
+    SortPriority:    5
+    CaseSensitive:   false
+  - Regex:           ".*" # catch-all for internal files
+    Priority:        1    # internal file group
+    SortPriority:    1
+    CaseSensitive:   true
\ No newline at end of file
diff --git a/python/.clang-format b/python/.clang-format
new file mode 100644
index 000000000..81b665b3c
--- /dev/null
+++ b/python/.clang-format
@@ -0,0 +1,2 @@
+BasedOnStyle: InheritParentConfig
+SortIncludes: false
\ No newline at end of file
diff --git a/python/src/utils/eigen_ext.cpp b/python/src/utils/eigen_ext.cpp
index 803891557..029d23732 100644
--- a/python/src/utils/eigen_ext.cpp
+++ b/python/src/utils/eigen_ext.cpp
@@ -9,9 +9,11 @@ void define_eigen_ext(py::module_& m)
 {
     m.def(
         "project_to_pd",
+        // clang-format off
         &project_to_pd<
             double, Eigen::Dynamic, Eigen::Dynamic,
             Eigen::ColMajor | Eigen::AutoAlign, Eigen::Dynamic, Eigen::Dynamic>,
+        // clang-format on
         R"ipc_Qu8mg5v7(
         Matrix projection onto positive definite cone
 
@@ -35,9 +37,11 @@ void define_eigen_ext(py::module_& m)
 
     m.def(
         "project_to_psd",
+        // clang-format off
         &project_to_psd<
             double, Eigen::Dynamic, Eigen::Dynamic,
             Eigen::ColMajor | Eigen::AutoAlign, Eigen::Dynamic, Eigen::Dynamic>,
+        // clang-format on
         R"ipc_Qu8mg5v7(
         Matrix projection onto positive semi-definite cone
 
diff --git a/src/ipc/broad_phase/aabb.cpp b/src/ipc/broad_phase/aabb.cpp
index f276536c5..d9d0bd556 100644
--- a/src/ipc/broad_phase/aabb.cpp
+++ b/src/ipc/broad_phase/aabb.cpp
@@ -1,7 +1,7 @@
 #include "aabb.hpp"
 
-#include <tbb/parallel_for.h>
 #include <tbb/blocked_range.h>
+#include <tbb/parallel_for.h>
 
 #include <cfenv>
 
diff --git a/src/ipc/broad_phase/broad_phase.cpp b/src/ipc/broad_phase/broad_phase.cpp
index 8d10fa797..e816006d5 100644
--- a/src/ipc/broad_phase/broad_phase.cpp
+++ b/src/ipc/broad_phase/broad_phase.cpp
@@ -1,15 +1,14 @@
 #include "broad_phase.hpp"
 
+#include <ipc/config.hpp>
 #include <ipc/broad_phase/brute_force.hpp>
 #include <ipc/broad_phase/bvh.hpp>
-#include <ipc/broad_phase/spatial_hash.hpp>
 #include <ipc/broad_phase/hash_grid.hpp>
+#include <ipc/broad_phase/spatial_hash.hpp>
 #include <ipc/broad_phase/sweep_and_prune.hpp>
 #include <ipc/broad_phase/sweep_and_tiniest_queue.hpp>
 #include <ipc/candidates/candidates.hpp>
 
-#include <ipc/config.hpp>
-
 namespace ipc {
 
 void BroadPhase::build(
diff --git a/src/ipc/broad_phase/brute_force.cpp b/src/ipc/broad_phase/brute_force.cpp
index 0b3150b05..e6bed7560 100644
--- a/src/ipc/broad_phase/brute_force.cpp
+++ b/src/ipc/broad_phase/brute_force.cpp
@@ -2,9 +2,9 @@
 
 #include <ipc/utils/merge_thread_local.hpp>
 
+#include <tbb/blocked_range2d.h>
 #include <tbb/enumerable_thread_specific.h>
 #include <tbb/parallel_for.h>
-#include <tbb/blocked_range2d.h>
 
 #include <algorithm> // std::min/max
 
diff --git a/src/ipc/broad_phase/bvh.cpp b/src/ipc/broad_phase/bvh.cpp
index 4ce4c2a0f..860b75671 100644
--- a/src/ipc/broad_phase/bvh.cpp
+++ b/src/ipc/broad_phase/bvh.cpp
@@ -2,9 +2,9 @@
 
 #include <ipc/utils/merge_thread_local.hpp>
 
-#include <tbb/parallel_for.h>
 #include <tbb/blocked_range.h>
 #include <tbb/enumerable_thread_specific.h>
+#include <tbb/parallel_for.h>
 
 using namespace std::placeholders;
 
diff --git a/src/ipc/broad_phase/hash_grid.cpp b/src/ipc/broad_phase/hash_grid.cpp
index 5aa08513a..425e1ef56 100644
--- a/src/ipc/broad_phase/hash_grid.cpp
+++ b/src/ipc/broad_phase/hash_grid.cpp
@@ -1,11 +1,11 @@
 #include "hash_grid.hpp"
 
 #include <ipc/broad_phase/voxel_size_heuristic.hpp>
-#include <ipc/utils/merge_thread_local.hpp>
 #include <ipc/utils/logger.hpp>
+#include <ipc/utils/merge_thread_local.hpp>
 
-#include <tbb/enumerable_thread_specific.h>
 #include <tbb/blocked_range2d.h>
+#include <tbb/enumerable_thread_specific.h>
 #include <tbb/parallel_for.h>
 #include <tbb/parallel_sort.h>
 
diff --git a/src/ipc/broad_phase/spatial_hash.cpp b/src/ipc/broad_phase/spatial_hash.cpp
index f7be36cc2..0382ca97f 100644
--- a/src/ipc/broad_phase/spatial_hash.cpp
+++ b/src/ipc/broad_phase/spatial_hash.cpp
@@ -2,12 +2,11 @@
 // Originally created by Minchen Li.
 #include "spatial_hash.hpp"
 
-#include <ipc/ccd/aabb.hpp>
+#include <ipc/config.hpp>
 #include <ipc/broad_phase/voxel_size_heuristic.hpp>
+#include <ipc/ccd/aabb.hpp>
 #include <ipc/utils/merge_thread_local.hpp>
 
-#include <ipc/config.hpp>
-
 #include <tbb/enumerable_thread_specific.h>
 #include <tbb/parallel_for.h>
 #include <tbb/parallel_sort.h>
diff --git a/src/ipc/broad_phase/spatial_hash.hpp b/src/ipc/broad_phase/spatial_hash.hpp
index 3f6192517..8ddcc094a 100644
--- a/src/ipc/broad_phase/spatial_hash.hpp
+++ b/src/ipc/broad_phase/spatial_hash.hpp
@@ -3,8 +3,8 @@
 #pragma once
 
 #include <ipc/broad_phase/broad_phase.hpp>
-#include <ipc/utils/unordered_map_and_set.hpp>
 #include <ipc/utils/eigen_ext.hpp>
+#include <ipc/utils/unordered_map_and_set.hpp>
 
 #include <vector>
 
diff --git a/src/ipc/broad_phase/sweep_and_tiniest_queue.hpp b/src/ipc/broad_phase/sweep_and_tiniest_queue.hpp
index b8b44ed91..23fe69821 100644
--- a/src/ipc/broad_phase/sweep_and_tiniest_queue.hpp
+++ b/src/ipc/broad_phase/sweep_and_tiniest_queue.hpp
@@ -5,6 +5,7 @@
 #ifdef IPC_TOOLKIT_WITH_CUDA
 
 #include <ipc/broad_phase/broad_phase.hpp>
+
 #include <scalable_ccd/cuda/broad_phase/broad_phase.cuh>
 
 namespace ipc {
diff --git a/src/ipc/candidates/candidates.cpp b/src/ipc/candidates/candidates.cpp
index ca3519839..5a0f9cd8b 100644
--- a/src/ipc/candidates/candidates.cpp
+++ b/src/ipc/candidates/candidates.cpp
@@ -1,17 +1,16 @@
 #include "candidates.hpp"
 
+#include <ipc/config.hpp>
 #include <ipc/ipc.hpp>
-#include <ipc/utils/save_obj.hpp>
 #include <ipc/utils/eigen_ext.hpp>
-
-#include <ipc/config.hpp>
+#include <ipc/utils/save_obj.hpp>
 
 #include <igl/remove_unreferenced.h>
-#include <tbb/parallel_for.h>
 #include <tbb/blocked_range.h>
-#include <shared_mutex>
+#include <tbb/parallel_for.h>
 
 #include <fstream>
+#include <shared_mutex>
 
 namespace ipc {
 
diff --git a/src/ipc/candidates/candidates.hpp b/src/ipc/candidates/candidates.hpp
index 2173abd27..41088cad6 100644
--- a/src/ipc/candidates/candidates.hpp
+++ b/src/ipc/candidates/candidates.hpp
@@ -1,10 +1,10 @@
 #pragma once
 
 #include <ipc/broad_phase/broad_phase.hpp>
-#include <ipc/candidates/vertex_vertex.hpp>
-#include <ipc/candidates/edge_vertex.hpp>
 #include <ipc/candidates/edge_edge.hpp>
+#include <ipc/candidates/edge_vertex.hpp>
 #include <ipc/candidates/face_vertex.hpp>
+#include <ipc/candidates/vertex_vertex.hpp>
 
 #include <Eigen/Core>
 
diff --git a/src/ipc/candidates/continuous_collision_candidate.hpp b/src/ipc/candidates/continuous_collision_candidate.hpp
index 767239eae..2acf1552e 100644
--- a/src/ipc/candidates/continuous_collision_candidate.hpp
+++ b/src/ipc/candidates/continuous_collision_candidate.hpp
@@ -1,10 +1,10 @@
 #pragma once
 
-#include <ipc/ccd/default_narrow_phase_ccd.hpp>
 #include <ipc/candidates/collision_stencil.hpp>
+#include <ipc/ccd/default_narrow_phase_ccd.hpp>
 
-#include <vector>
 #include <ostream>
+#include <vector>
 
 namespace ipc {
 
diff --git a/src/ipc/ccd/additive_ccd.cpp b/src/ipc/ccd/additive_ccd.cpp
index 6f33adfb6..fe7975433 100644
--- a/src/ipc/ccd/additive_ccd.cpp
+++ b/src/ipc/ccd/additive_ccd.cpp
@@ -21,10 +21,10 @@
 
 #include "additive_ccd.hpp"
 
-#include <ipc/distance/point_point.hpp>
+#include <ipc/distance/edge_edge.hpp>
 #include <ipc/distance/point_edge.hpp>
+#include <ipc/distance/point_point.hpp>
 #include <ipc/distance/point_triangle.hpp>
-#include <ipc/distance/edge_edge.hpp>
 
 namespace ipc {
 
diff --git a/src/ipc/ccd/inexact_ccd.cpp b/src/ipc/ccd/inexact_ccd.cpp
index ef743a0c8..4bd22c690 100644
--- a/src/ipc/ccd/inexact_ccd.cpp
+++ b/src/ipc/ccd/inexact_ccd.cpp
@@ -3,9 +3,9 @@
 #ifdef IPC_TOOLKIT_WITH_INEXACT_CCD
 
 #include <ipc/ccd/check_initial_distance.hpp>
-#include <ipc/distance/point_point.hpp>
-#include <ipc/distance/point_edge.hpp>
 #include <ipc/distance/edge_edge.hpp>
+#include <ipc/distance/point_edge.hpp>
+#include <ipc/distance/point_point.hpp>
 #include <ipc/distance/point_triangle.hpp>
 
 #include <CTCD.h>
diff --git a/src/ipc/ccd/nonlinear_ccd.cpp b/src/ipc/ccd/nonlinear_ccd.cpp
index c53f6f701..e9f3c3c6f 100644
--- a/src/ipc/ccd/nonlinear_ccd.cpp
+++ b/src/ipc/ccd/nonlinear_ccd.cpp
@@ -1,9 +1,9 @@
 #include "nonlinear_ccd.hpp"
 
 #include <ipc/ccd/check_initial_distance.hpp>
-#include <ipc/distance/point_point.hpp>
-#include <ipc/distance/point_edge.hpp>
 #include <ipc/distance/edge_edge.hpp>
+#include <ipc/distance/point_edge.hpp>
+#include <ipc/distance/point_point.hpp>
 #include <ipc/distance/point_triangle.hpp>
 
 #include <tight_inclusion/ccd.hpp>
diff --git a/src/ipc/ccd/nonlinear_ccd.hpp b/src/ipc/ccd/nonlinear_ccd.hpp
index 2fc84c334..1c65c9354 100644
--- a/src/ipc/ccd/nonlinear_ccd.hpp
+++ b/src/ipc/ccd/nonlinear_ccd.hpp
@@ -1,7 +1,6 @@
 #pragma once
 
 #include <ipc/config.hpp>
-
 #include <ipc/ccd/tight_inclusion_ccd.hpp>
 #ifdef IPC_TOOLKIT_WITH_FILIB
 #include <ipc/utils/interval.hpp>
diff --git a/src/ipc/ccd/tight_inclusion_ccd.cpp b/src/ipc/ccd/tight_inclusion_ccd.cpp
index 9fdc7c784..72175c857 100644
--- a/src/ipc/ccd/tight_inclusion_ccd.cpp
+++ b/src/ipc/ccd/tight_inclusion_ccd.cpp
@@ -1,9 +1,9 @@
 #include "tight_inclusion_ccd.hpp"
 
 #include <ipc/ccd/check_initial_distance.hpp>
-#include <ipc/distance/point_point.hpp>
-#include <ipc/distance/point_edge.hpp>
 #include <ipc/distance/edge_edge.hpp>
+#include <ipc/distance/point_edge.hpp>
+#include <ipc/distance/point_point.hpp>
 #include <ipc/distance/point_triangle.hpp>
 
 #include <tight_inclusion/ccd.hpp>
diff --git a/src/ipc/collision_mesh.cpp b/src/ipc/collision_mesh.cpp
index 4a116a12d..64e8faf42 100644
--- a/src/ipc/collision_mesh.cpp
+++ b/src/ipc/collision_mesh.cpp
@@ -1,10 +1,10 @@
 #include "collision_mesh.hpp"
 
-#include <ipc/utils/unordered_map_and_set.hpp>
-#include <ipc/utils/logger.hpp>
+#include <ipc/utils/area_gradient.hpp>
 #include <ipc/utils/eigen_ext.hpp>
 #include <ipc/utils/local_to_global.hpp>
-#include <ipc/utils/area_gradient.hpp>
+#include <ipc/utils/logger.hpp>
+#include <ipc/utils/unordered_map_and_set.hpp>
 
 namespace ipc {
 
diff --git a/src/ipc/collisions/collisions.cpp b/src/ipc/collisions/collisions.cpp
index 6b8a1965f..86e0d9dcc 100644
--- a/src/ipc/collisions/collisions.cpp
+++ b/src/ipc/collisions/collisions.cpp
@@ -1,18 +1,18 @@
 #include "collisions.hpp"
 
 #include <ipc/collisions/collisions_builder.hpp>
-#include <ipc/distance/point_point.hpp>
-#include <ipc/distance/point_line.hpp>
-#include <ipc/distance/point_edge.hpp>
 #include <ipc/distance/edge_edge.hpp>
+#include <ipc/distance/point_edge.hpp>
+#include <ipc/distance/point_line.hpp>
 #include <ipc/distance/point_plane.hpp>
+#include <ipc/distance/point_point.hpp>
 #include <ipc/utils/local_to_global.hpp>
 
+#include <tbb/blocked_range.h>
+#include <tbb/enumerable_thread_specific.h>
 #include <tbb/parallel_for.h>
 #include <tbb/parallel_reduce.h>
 #include <tbb/parallel_sort.h>
-#include <tbb/blocked_range.h>
-#include <tbb/enumerable_thread_specific.h>
 
 #include <stdexcept> // std::out_of_range
 
diff --git a/src/ipc/collisions/collisions.hpp b/src/ipc/collisions/collisions.hpp
index ca8117737..515218b6f 100644
--- a/src/ipc/collisions/collisions.hpp
+++ b/src/ipc/collisions/collisions.hpp
@@ -1,14 +1,14 @@
 #pragma once
 
 #include <ipc/collision_mesh.hpp>
+#include <ipc/broad_phase/broad_phase.hpp>
+#include <ipc/candidates/candidates.hpp>
 #include <ipc/collisions/collision.hpp>
-#include <ipc/collisions/vertex_vertex.hpp>
-#include <ipc/collisions/edge_vertex.hpp>
 #include <ipc/collisions/edge_edge.hpp>
+#include <ipc/collisions/edge_vertex.hpp>
 #include <ipc/collisions/face_vertex.hpp>
 #include <ipc/collisions/plane_vertex.hpp>
-#include <ipc/broad_phase/broad_phase.hpp>
-#include <ipc/candidates/candidates.hpp>
+#include <ipc/collisions/vertex_vertex.hpp>
 
 #include <Eigen/Core>
 
diff --git a/src/ipc/collisions/collisions_builder.cpp b/src/ipc/collisions/collisions_builder.cpp
index 5295e70e4..ed61a1fde 100644
--- a/src/ipc/collisions/collisions_builder.cpp
+++ b/src/ipc/collisions/collisions_builder.cpp
@@ -1,10 +1,10 @@
 #include "collisions_builder.hpp"
 
 #include <ipc/distance/distance_type.hpp>
-#include <ipc/distance/point_point.hpp>
-#include <ipc/distance/point_edge.hpp>
 #include <ipc/distance/edge_edge.hpp>
 #include <ipc/distance/edge_edge_mollifier.hpp>
+#include <ipc/distance/point_edge.hpp>
+#include <ipc/distance/point_point.hpp>
 #include <ipc/distance/point_triangle.hpp>
 
 namespace ipc {
diff --git a/src/ipc/collisions/collisions_builder.hpp b/src/ipc/collisions/collisions_builder.hpp
index 6df686331..1fd07c8ae 100644
--- a/src/ipc/collisions/collisions_builder.hpp
+++ b/src/ipc/collisions/collisions_builder.hpp
@@ -3,9 +3,8 @@
 #include <ipc/collision_mesh.hpp>
 #include <ipc/collisions/collisions.hpp>
 
-#include <tbb/enumerable_thread_specific.h>
-
 #include <Eigen/Core>
+#include <tbb/enumerable_thread_specific.h>
 
 namespace ipc {
 
diff --git a/src/ipc/distance/edge_edge.cpp b/src/ipc/distance/edge_edge.cpp
index 5b3f6ac82..d64a3bb95 100644
--- a/src/ipc/distance/edge_edge.cpp
+++ b/src/ipc/distance/edge_edge.cpp
@@ -2,9 +2,9 @@
 
 #include "edge_edge.hpp"
 
-#include <ipc/distance/point_point.hpp>
-#include <ipc/distance/point_line.hpp>
 #include <ipc/distance/line_line.hpp>
+#include <ipc/distance/point_line.hpp>
+#include <ipc/distance/point_point.hpp>
 
 #include <stdexcept> // std::invalid_argument
 
diff --git a/src/ipc/distance/point_plane.cpp b/src/ipc/distance/point_plane.cpp
index 0b85280f2..cb16e6436 100644
--- a/src/ipc/distance/point_plane.cpp
+++ b/src/ipc/distance/point_plane.cpp
@@ -1,6 +1,7 @@
 #include "point_plane.hpp"
 
 #include <ipc/utils/eigen_ext.hpp>
+
 #include <Eigen/Geometry>
 
 namespace ipc {
diff --git a/src/ipc/friction/closest_point.cpp b/src/ipc/friction/closest_point.cpp
index 26c15c717..b6df8c1e7 100644
--- a/src/ipc/friction/closest_point.cpp
+++ b/src/ipc/friction/closest_point.cpp
@@ -1,7 +1,7 @@
 #include "closest_point.hpp"
 
-#include <Eigen/Core>
 #include <Eigen/Cholesky>
+#include <Eigen/Core>
 
 namespace ipc {
 
diff --git a/src/ipc/friction/collisions/edge_edge.cpp b/src/ipc/friction/collisions/edge_edge.cpp
index c05dadab8..d5a51a86b 100644
--- a/src/ipc/friction/collisions/edge_edge.cpp
+++ b/src/ipc/friction/collisions/edge_edge.cpp
@@ -1,9 +1,9 @@
 #include "edge_edge.hpp"
 
+#include <ipc/distance/edge_edge.hpp>
 #include <ipc/friction/closest_point.hpp>
 #include <ipc/friction/relative_velocity.hpp>
 #include <ipc/friction/tangent_basis.hpp>
-#include <ipc/distance/edge_edge.hpp>
 
 namespace ipc {
 
diff --git a/src/ipc/friction/collisions/edge_edge.hpp b/src/ipc/friction/collisions/edge_edge.hpp
index 1971781f6..4220d7be1 100644
--- a/src/ipc/friction/collisions/edge_edge.hpp
+++ b/src/ipc/friction/collisions/edge_edge.hpp
@@ -1,7 +1,7 @@
 #pragma once
 
-#include <ipc/friction/collisions/friction_collision.hpp>
 #include <ipc/candidates/edge_edge.hpp>
+#include <ipc/friction/collisions/friction_collision.hpp>
 #include <ipc/utils/eigen_ext.hpp>
 
 namespace ipc {
diff --git a/src/ipc/friction/collisions/edge_vertex.cpp b/src/ipc/friction/collisions/edge_vertex.cpp
index b51ac8ea3..42b37c22a 100644
--- a/src/ipc/friction/collisions/edge_vertex.cpp
+++ b/src/ipc/friction/collisions/edge_vertex.cpp
@@ -1,9 +1,9 @@
 #include "edge_vertex.hpp"
 
+#include <ipc/distance/point_edge.hpp>
 #include <ipc/friction/closest_point.hpp>
 #include <ipc/friction/relative_velocity.hpp>
 #include <ipc/friction/tangent_basis.hpp>
-#include <ipc/distance/point_edge.hpp>
 
 namespace ipc {
 
diff --git a/src/ipc/friction/collisions/edge_vertex.hpp b/src/ipc/friction/collisions/edge_vertex.hpp
index 89f67c3e8..579ff2792 100644
--- a/src/ipc/friction/collisions/edge_vertex.hpp
+++ b/src/ipc/friction/collisions/edge_vertex.hpp
@@ -1,7 +1,7 @@
 #pragma once
 
-#include <ipc/friction/collisions/friction_collision.hpp>
 #include <ipc/candidates/edge_vertex.hpp>
+#include <ipc/friction/collisions/friction_collision.hpp>
 #include <ipc/utils/eigen_ext.hpp>
 
 namespace ipc {
diff --git a/src/ipc/friction/collisions/face_vertex.cpp b/src/ipc/friction/collisions/face_vertex.cpp
index 8bd6fa1ab..5103d9dcf 100644
--- a/src/ipc/friction/collisions/face_vertex.cpp
+++ b/src/ipc/friction/collisions/face_vertex.cpp
@@ -1,9 +1,9 @@
 #include "face_vertex.hpp"
 
+#include <ipc/distance/point_triangle.hpp>
 #include <ipc/friction/closest_point.hpp>
 #include <ipc/friction/relative_velocity.hpp>
 #include <ipc/friction/tangent_basis.hpp>
-#include <ipc/distance/point_triangle.hpp>
 
 namespace ipc {
 
diff --git a/src/ipc/friction/collisions/face_vertex.hpp b/src/ipc/friction/collisions/face_vertex.hpp
index 97e4624b0..f58f10388 100644
--- a/src/ipc/friction/collisions/face_vertex.hpp
+++ b/src/ipc/friction/collisions/face_vertex.hpp
@@ -1,7 +1,7 @@
 #pragma once
 
-#include <ipc/friction/collisions/friction_collision.hpp>
 #include <ipc/candidates/face_vertex.hpp>
+#include <ipc/friction/collisions/friction_collision.hpp>
 #include <ipc/utils/eigen_ext.hpp>
 
 namespace ipc {
diff --git a/src/ipc/friction/collisions/friction_collision.cpp b/src/ipc/friction/collisions/friction_collision.cpp
index bcb3a5257..7ec4fd962 100644
--- a/src/ipc/friction/collisions/friction_collision.cpp
+++ b/src/ipc/friction/collisions/friction_collision.cpp
@@ -1,8 +1,7 @@
 #include "friction_collision.hpp"
 
-#include <ipc/friction/normal_force_magnitude.hpp>
-
 #include <ipc/config.hpp>
+#include <ipc/friction/normal_force_magnitude.hpp>
 
 #include <stdexcept> // std::out_of_range
 
diff --git a/src/ipc/friction/collisions/friction_collision.hpp b/src/ipc/friction/collisions/friction_collision.hpp
index cc916d68d..30126997a 100644
--- a/src/ipc/friction/collisions/friction_collision.hpp
+++ b/src/ipc/friction/collisions/friction_collision.hpp
@@ -1,12 +1,11 @@
 #pragma once
 
-#include <ipc/potentials/barrier_potential.hpp>
+#include <ipc/config.hpp>
+#include <ipc/barrier/barrier.hpp>
 #include <ipc/friction/relative_velocity.hpp>
 #include <ipc/friction/smooth_friction_mollifier.hpp>
+#include <ipc/potentials/barrier_potential.hpp>
 #include <ipc/utils/eigen_ext.hpp>
-#include <ipc/barrier/barrier.hpp>
-
-#include <ipc/config.hpp>
 
 namespace ipc {
 
diff --git a/src/ipc/friction/collisions/vertex_vertex.cpp b/src/ipc/friction/collisions/vertex_vertex.cpp
index 2f88a8bc7..493e1035f 100644
--- a/src/ipc/friction/collisions/vertex_vertex.cpp
+++ b/src/ipc/friction/collisions/vertex_vertex.cpp
@@ -1,9 +1,9 @@
 #include "vertex_vertex.hpp"
 
+#include <ipc/distance/point_point.hpp>
 #include <ipc/friction/closest_point.hpp>
 #include <ipc/friction/relative_velocity.hpp>
 #include <ipc/friction/tangent_basis.hpp>
-#include <ipc/distance/point_point.hpp>
 
 namespace ipc {
 
diff --git a/src/ipc/friction/collisions/vertex_vertex.hpp b/src/ipc/friction/collisions/vertex_vertex.hpp
index fe24be512..d7e349494 100644
--- a/src/ipc/friction/collisions/vertex_vertex.hpp
+++ b/src/ipc/friction/collisions/vertex_vertex.hpp
@@ -1,7 +1,7 @@
 #pragma once
 
-#include <ipc/friction/collisions/friction_collision.hpp>
 #include <ipc/candidates/vertex_vertex.hpp>
+#include <ipc/friction/collisions/friction_collision.hpp>
 #include <ipc/utils/eigen_ext.hpp>
 
 namespace ipc {
diff --git a/src/ipc/friction/friction_collisions.cpp b/src/ipc/friction/friction_collisions.cpp
index 5a1331d52..68d0208e5 100644
--- a/src/ipc/friction/friction_collisions.cpp
+++ b/src/ipc/friction/friction_collisions.cpp
@@ -3,9 +3,9 @@
 #include <ipc/distance/edge_edge_mollifier.hpp>
 #include <ipc/utils/local_to_global.hpp>
 
-#include <tbb/parallel_for.h>
 #include <tbb/blocked_range.h>
 #include <tbb/enumerable_thread_specific.h>
+#include <tbb/parallel_for.h>
 
 #include <stdexcept> // std::out_of_range
 
diff --git a/src/ipc/friction/friction_collisions.hpp b/src/ipc/friction/friction_collisions.hpp
index 12297eeb7..2a32e523b 100644
--- a/src/ipc/friction/friction_collisions.hpp
+++ b/src/ipc/friction/friction_collisions.hpp
@@ -1,13 +1,12 @@
 #pragma once
 
-#include <ipc/friction/collisions/friction_collision.hpp>
-#include <ipc/friction/collisions/vertex_vertex.hpp>
-#include <ipc/friction/collisions/edge_vertex.hpp>
-#include <ipc/friction/collisions/edge_edge.hpp>
-#include <ipc/friction/collisions/face_vertex.hpp>
-
 #include <ipc/collision_mesh.hpp>
 #include <ipc/collisions/collisions.hpp>
+#include <ipc/friction/collisions/edge_edge.hpp>
+#include <ipc/friction/collisions/edge_vertex.hpp>
+#include <ipc/friction/collisions/face_vertex.hpp>
+#include <ipc/friction/collisions/friction_collision.hpp>
+#include <ipc/friction/collisions/vertex_vertex.hpp>
 #include <ipc/utils/eigen_ext.hpp>
 
 #include <Eigen/Core>
diff --git a/src/ipc/implicits/plane.cpp b/src/ipc/implicits/plane.cpp
index 0ae4767f9..0e78444c7 100644
--- a/src/ipc/implicits/plane.cpp
+++ b/src/ipc/implicits/plane.cpp
@@ -1,10 +1,10 @@
 #include "plane.hpp"
 
-#include <ipc/distance/point_plane.hpp>
 #include <ipc/ccd/point_static_plane.hpp>
+#include <ipc/distance/point_plane.hpp>
 
-#include <tbb/parallel_reduce.h>
 #include <tbb/blocked_range.h>
+#include <tbb/parallel_reduce.h>
 
 namespace ipc {
 
diff --git a/src/ipc/ipc.cpp b/src/ipc/ipc.cpp
index 51f5dc61b..7737a3ffb 100644
--- a/src/ipc/ipc.cpp
+++ b/src/ipc/ipc.cpp
@@ -1,11 +1,10 @@
 #include "ipc.hpp"
 
+#include <ipc/config.hpp>
 #include <ipc/candidates/candidates.hpp>
 #include <ipc/utils/intersection.hpp>
 #include <ipc/utils/world_bbox_diagonal_length.hpp>
 
-#include <ipc/config.hpp>
-
 #ifdef IPC_TOOLKIT_WITH_CUDA
 #include <scalable_ccd/cuda/ipc_ccd_strategy.hpp>
 #endif
diff --git a/src/ipc/ipc.hpp b/src/ipc/ipc.hpp
index 9c0c2f87a..697b7c688 100644
--- a/src/ipc/ipc.hpp
+++ b/src/ipc/ipc.hpp
@@ -1,7 +1,7 @@
 #pragma once
 
-#include <ipc/broad_phase/broad_phase.hpp>
 #include <ipc/collision_mesh.hpp>
+#include <ipc/broad_phase/broad_phase.hpp>
 
 #include <Eigen/Core>
 #include <Eigen/Sparse>
diff --git a/src/ipc/potentials/barrier_potential.hpp b/src/ipc/potentials/barrier_potential.hpp
index 37920c618..939a7b71c 100644
--- a/src/ipc/potentials/barrier_potential.hpp
+++ b/src/ipc/potentials/barrier_potential.hpp
@@ -1,7 +1,7 @@
 #pragma once
 
-#include <ipc/potentials/distance_based_potential.hpp>
 #include <ipc/barrier/barrier.hpp>
+#include <ipc/potentials/distance_based_potential.hpp>
 
 #include <memory>
 
diff --git a/src/ipc/potentials/distance_based_potential.hpp b/src/ipc/potentials/distance_based_potential.hpp
index 2ee21369f..150f5cd3b 100644
--- a/src/ipc/potentials/distance_based_potential.hpp
+++ b/src/ipc/potentials/distance_based_potential.hpp
@@ -1,7 +1,7 @@
 #pragma once
 
-#include <ipc/potentials/potential.hpp>
 #include <ipc/collisions/collisions.hpp>
+#include <ipc/potentials/potential.hpp>
 
 namespace ipc {
 
diff --git a/src/ipc/potentials/friction_potential.hpp b/src/ipc/potentials/friction_potential.hpp
index 345d026be..13ad9c185 100644
--- a/src/ipc/potentials/friction_potential.hpp
+++ b/src/ipc/potentials/friction_potential.hpp
@@ -1,7 +1,7 @@
 #pragma once
 
-#include <ipc/potentials/potential.hpp>
 #include <ipc/friction/friction_collisions.hpp>
+#include <ipc/potentials/potential.hpp>
 
 namespace ipc {
 
diff --git a/src/ipc/utils/intersection.cpp b/src/ipc/utils/intersection.cpp
index c6f991bae..f35b51885 100644
--- a/src/ipc/utils/intersection.cpp
+++ b/src/ipc/utils/intersection.cpp
@@ -1,11 +1,10 @@
 #include "intersection.hpp"
 
-#include <ipc/utils/eigen_ext.hpp>
 #include <ipc/config.hpp>
-
-#include <igl/predicates/predicates.h>
+#include <ipc/utils/eigen_ext.hpp>
 
 #include <Eigen/Geometry>
+#include <igl/predicates/predicates.h>
 
 #ifdef IPC_TOOLKIT_WITH_RATIONAL_INTERSECTION
 #include <rational/rational.hpp>
diff --git a/src/ipc/utils/interval.hpp b/src/ipc/utils/interval.hpp
index 69f1b15af..2943ae8ec 100644
--- a/src/ipc/utils/interval.hpp
+++ b/src/ipc/utils/interval.hpp
@@ -7,7 +7,6 @@
 #include <ipc/utils/eigen_ext.hpp>
 
 #include <filib/interval.hpp>
-
 #include <spdlog/fmt/bundled/ostream.h>
 
 namespace filib {
diff --git a/src/ipc/utils/merge_thread_local.hpp b/src/ipc/utils/merge_thread_local.hpp
index 38363cf46..394df63a1 100644
--- a/src/ipc/utils/merge_thread_local.hpp
+++ b/src/ipc/utils/merge_thread_local.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <tbb/enumerable_thread_specific.h>
+
 #include <vector>
 
 namespace ipc {
diff --git a/src/ipc/utils/save_obj.cpp b/src/ipc/utils/save_obj.cpp
index 1f2bfdad5..2e8bf8801 100644
--- a/src/ipc/utils/save_obj.cpp
+++ b/src/ipc/utils/save_obj.cpp
@@ -1,10 +1,10 @@
 #include "save_obj.hpp"
 
-#include <ipc/candidates/vertex_vertex.hpp>
-#include <ipc/candidates/edge_vertex.hpp>
 #include <ipc/candidates/edge_edge.hpp>
-#include <ipc/candidates/face_vertex.hpp>
 #include <ipc/candidates/edge_face.hpp>
+#include <ipc/candidates/edge_vertex.hpp>
+#include <ipc/candidates/face_vertex.hpp>
+#include <ipc/candidates/vertex_vertex.hpp>
 #include <ipc/utils/eigen_ext.hpp>
 
 namespace ipc {
diff --git a/src/ipc/utils/save_obj.hpp b/src/ipc/utils/save_obj.hpp
index 006197296..4cd004ae4 100644
--- a/src/ipc/utils/save_obj.hpp
+++ b/src/ipc/utils/save_obj.hpp
@@ -2,9 +2,9 @@
 
 #include <Eigen/Core>
 
-#include <vector>
-#include <ostream>
 #include <fstream>
+#include <ostream>
+#include <vector>
 
 namespace ipc {
 
diff --git a/tests/.clang-format b/tests/.clang-format
new file mode 100644
index 000000000..81b665b3c
--- /dev/null
+++ b/tests/.clang-format
@@ -0,0 +1,2 @@
+BasedOnStyle: InheritParentConfig
+SortIncludes: false
\ No newline at end of file