diff --git a/.circleci/config.yml b/.circleci/config.yml
deleted file mode 100644
index a9fe0b4..0000000
--- a/.circleci/config.yml
+++ /dev/null
@@ -1,33 +0,0 @@
-version: 2
-jobs:
-  test_debug:
-    docker:
-      - image: tschijnmo/drudge:corebase
-    steps:
-      - run: |
-          git clone --recurse-submodules https://github.com/tschijnmo/libparenth.git
-          mkdir cmake-test-debug
-          cd cmake-test-debug
-          cmake -DCMAKE_BUILD_TYPE=debug ../libparenth
-          make
-          ./test/testmain
-
-  test_release:
-    docker:
-      - image: tschijnmo/gccpython:latest
-    steps:
-      - run: |
-          git clone --recurse-submodules https://github.com/tschijnmo/libparenth.git
-          mkdir cmake-test-release
-          cd cmake-test-release
-          cmake -DCMAKE_BUILD_TYPE=release ../libparenth
-          make
-          ./test/testmain
-
-workflows:
-  version: 2
-  tests:
-    jobs:
-      - test_debug
-      - test_release
-
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 0000000..5a181ce
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,15 @@
+version: 2
+updates:
+  # Maintain dependencies for GitHub Actions
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    open-pull-requests-limit: 10
+
+  # Maintain dependencies for git submodules
+  - package-ecosystem: "gitsubmodule"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    open-pull-requests-limit: 10
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..3f349fa
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,47 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - master
+      - 'release/*'
+  pull_request:
+    branches:
+      - master
+  workflow_dispatch:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    strategy:
+      matrix:
+        build_type: [Debug, Release]
+    
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+      with:
+        submodules: recursive
+    
+    - name: Install dependencies
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y cmake g++
+    
+    - name: Configure CMake
+      run: |
+        mkdir build
+        cd build
+        cmake -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} ..
+    
+    - name: Build
+      run: |
+        cd build
+        make
+    
+    - name: Run tests
+      run: |
+        cd build
+        ./test/testmain
diff --git a/.gitignore b/.gitignore
index cc97520..04e66d7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -33,5 +33,6 @@
 
 /.idea/
 /cmake-*/
+/build-*/
 /test/catch.hpp
 
diff --git a/.gitmodules b/.gitmodules
index da8c0df..be85c24 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,3 @@
 [submodule "deps/fbitset"]
 	path = deps/fbitset
-	url = https://github.com/tschijnmo/fbitset
+	url = https://github.com/DrudgeCAS/fbitset
diff --git a/.ycm_extra_conf.py b/.ycm_extra_conf.py
deleted file mode 100644
index bcc19e2..0000000
--- a/.ycm_extra_conf.py
+++ /dev/null
@@ -1,12 +0,0 @@
-import os.path
-def FlagsForFile(filename, **kwargs):
-    proj_dir = os.path.dirname(os.path.realpath(__file__))
-
-    proj_include = os.path.join(proj_dir, 'include');
-    fbitset_include = os.path.join(proj_dir, 'deps', 'fbitset', 'include')
-    flags = [
-            '-std=gnu++1z', '-I/usr/local/include',
-            '-I' + proj_include, '-I' + fbitset_include,
-            '-I.'
-    ]
-    return {'flags': flags}
diff --git a/README.md b/README.md
index 4064b3c..48538a3 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-[![Build Status](https://circleci.com/gh/tschijnmo/libparenth.svg?style=shield)](https://circleci.com/gh/tschijnmo/libparenth)
+[![CI](https://github.com/DrudgeCAS/libparenth/actions/workflows/ci.yml/badge.svg)](https://github.com/DrudgeCAS/libparenth/actions/workflows/ci.yml)
 
 # libparenth
 Fast searching for optimal parenthesization of tensor contractions
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index a51ce5e..dd78f0b 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -1,16 +1,17 @@
-# Download the Catch2 single header.
+# Fetch Catch2 v3.11.0
+include(FetchContent)
 
-file(DOWNLOAD
-        "https://github.com/catchorg/Catch2/releases/download/v2.0.1/catch.hpp"
-        "${CMAKE_CURRENT_BINARY_DIR}/catch.hpp"
-        )
+FetchContent_Declare(
+  Catch2
+  GIT_REPOSITORY https://github.com/catchorg/Catch2.git
+  GIT_TAG        v3.11.0
+)
 
-include_directories(testmain
-        PRIVATE ${CMAKE_CURRENT_BINARY_DIR}
-        )
+FetchContent_MakeAvailable(Catch2)
 
 # The main test driver.
 add_executable(testmain
-        testmain.cpp
         matrixchain.cpp
         )
+
+target_link_libraries(testmain PRIVATE Catch2::Catch2WithMain)
diff --git a/test/matrixchain.cpp b/test/matrixchain.cpp
index 1e720c9..642517b 100644
--- a/test/matrixchain.cpp
+++ b/test/matrixchain.cpp
@@ -10,12 +10,22 @@
  */
 
 #include <initializer_list>
+#include <sstream>
 #include <vector>
 
-#include <catch.hpp>
-
 #include <libparenth.hpp>
 
+// Disable Catch2's range detection for fbitset by providing stream insertion operator
+namespace fbitset {
+    template<int N>
+    inline std::ostream& operator<<(std::ostream& os, const Fbitset<N>& fs) {
+        os << "Fbitset<" << N << ">{count=" << fs.count() << "}";
+        return os;
+    }
+}
+
+#include <catch2/catch_test_macros.hpp>
+
 using namespace libparenth;
 
 TEST_CASE("A simple chain product of three matrices can be parenthesized")
diff --git a/test/testmain.cpp b/test/testmain.cpp
index f442470..772e440 100644
--- a/test/testmain.cpp
+++ b/test/testmain.cpp
@@ -1,8 +1,2 @@
-#define CATCH_CONFIG_RUNNER
-#include <catch.hpp>
-
-int main(int argc, char* argv[])
-{
-    int result = Catch::Session().run(argc, argv);
-    return result;
-}
+// Main test runner is provided by Catch2::Catch2WithMain
+// This file is kept for potential future custom main() if needed