diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 000000000..b51c1ccd1
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,16 @@
+version: 2
+updates:
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: daily
+
+  - package-ecosystem: pip
+    directory: /docs/mkdocs
+    schedule:
+      interval: daily
+
+  - package-ecosystem: pip
+    directory: /tools/serve_header
+    schedule:
+      interval: daily
diff --git a/.github/workflows/check_amalgamation.yml b/.github/workflows/check_amalgamation.yml
index 2475874a5..f223bb118 100644
--- a/.github/workflows/check_amalgamation.yml
+++ b/.github/workflows/check_amalgamation.yml
@@ -9,12 +9,17 @@ jobs:
   save:
     runs-on: ubuntu-latest
     steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
       - name: Save PR number
         run: |
           mkdir -p ./pr
           echo ${{ github.event.number }} > ./pr/number
           echo ${{ github.event.pull_request.user.login }} > ./pr/author
-      - uses: actions/upload-artifact@v4
+      - uses: actions/upload-artifact@b4b15b8c7c6ac21ea08fcf65892d2ee8f75cf882 # v4.4.3
         with:
           name: pr
           path: pr/
@@ -32,14 +37,19 @@ jobs:
         --formatted
 
     steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
       - name: Checkout pull request
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           path: main
           ref: ${{ github.event.pull_request.head.sha }}
 
       - name: Checkout tools
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           path: tools
           ref: develop
diff --git a/.github/workflows/cifuzz.yml b/.github/workflows/cifuzz.yml
index 4e93d431d..d82d0b569 100644
--- a/.github/workflows/cifuzz.yml
+++ b/.github/workflows/cifuzz.yml
@@ -8,22 +8,27 @@ jobs:
   Fuzzing:
     runs-on: ubuntu-latest
     steps:
+    - name: Harden Runner
+      uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+      with:
+        egress-policy: audit
+
     - name: Build Fuzzers
       id: build
-      uses: google/oss-fuzz/infra/cifuzz/actions/build_fuzzers@master
+      uses: google/oss-fuzz/infra/cifuzz/actions/build_fuzzers@57fe4475324c5506adbfecdcdd2917f65c86ee9e # master
       with:
         oss-fuzz-project-name: 'json'
         dry-run: false
         language: c++
     - name: Run Fuzzers
-      uses: google/oss-fuzz/infra/cifuzz/actions/run_fuzzers@master
+      uses: google/oss-fuzz/infra/cifuzz/actions/run_fuzzers@57fe4475324c5506adbfecdcdd2917f65c86ee9e # master
       with:
         oss-fuzz-project-name: 'json'
         fuzz-seconds: 300
         dry-run: false
         language: c++
     - name: Upload Crash
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@b4b15b8c7c6ac21ea08fcf65892d2ee8f75cf882 # v4.4.3
       if: failure() && steps.build.outcome == 'success'
       with:
         name: artifacts
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
index 7cbf7b39a..5872a6b23 100644
--- a/.github/workflows/codeql-analysis.yml
+++ b/.github/workflows/codeql-analysis.yml
@@ -26,19 +26,24 @@ jobs:
       security-events: write
 
     steps:
+    - name: Harden Runner
+      uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+      with:
+        egress-policy: audit
+
     - name: Checkout repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@v3
+      uses: github/codeql-action/init@df409f7d9260372bd5f19e5b04e83cb3c43714ae # v3.27.9
       with:
         languages: c-cpp
 
     # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
     # If this step fails, then you should remove it and run the build manually (see below)
     - name: Autobuild
-      uses: github/codeql-action/autobuild@v2
+      uses: github/codeql-action/autobuild@277b89701e930e6af7a758f50afa5185bfc53c81 # v2.27.9
 
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v2
+      uses: github/codeql-action/analyze@277b89701e930e6af7a758f50afa5185bfc53c81 # v2.27.9
diff --git a/.github/workflows/comment_check_amalgamation.yml b/.github/workflows/comment_check_amalgamation.yml
index 2ab5ebb97..15d1bb5ec 100644
--- a/.github/workflows/comment_check_amalgamation.yml
+++ b/.github/workflows/comment_check_amalgamation.yml
@@ -17,6 +17,11 @@ jobs:
       issues: read
       pull-requests: write
     steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
       - name: 'Download artifact'
         uses: actions/github-script@98814c53be79b1d30f795b907e553d8679345975 # v6.4.0
         with:
diff --git a/.github/workflows/dependency-review.yml b/.github/workflows/dependency-review.yml
new file mode 100644
index 000000000..21a469b13
--- /dev/null
+++ b/.github/workflows/dependency-review.yml
@@ -0,0 +1,27 @@
+# Dependency Review Action
+#
+# This Action will scan dependency manifest files that change as part of a Pull Request,
+# surfacing known-vulnerable versions of the packages declared or updated in the PR.
+# Once installed, if the workflow run is marked as required,
+# PRs introducing known-vulnerable packages will be blocked from merging.
+#
+# Source repository: https://github.com/actions/dependency-review-action
+name: 'Dependency Review'
+on: [pull_request]
+
+permissions:
+  contents: read
+
+jobs:
+  dependency-review:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - name: 'Checkout Repository'
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - name: 'Dependency Review'
+        uses: actions/dependency-review-action@3b139cfc5fae8b618d3eae3675e383bb1769c019 # v4.5.0
diff --git a/.github/workflows/labeler.yml b/.github/workflows/labeler.yml
index 11925e1af..3d15f7f1e 100644
--- a/.github/workflows/labeler.yml
+++ b/.github/workflows/labeler.yml
@@ -15,6 +15,11 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: srvaroa/labeler@master
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: srvaroa/labeler@1b3cdb1af3e59155a08b9b2436d0d54feaff49e2 # master
         env:
           GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index 4ba491a83..0378d6665 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -27,7 +27,7 @@ jobs:
 #      DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer
 #
 #    steps:
-#      - uses: actions/checkout@v4
+#      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 #      - name: Run CMake
 #        run: cmake -S . -B build -D CMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On -DJSON_FastTests=ON
 #      - name: Build
@@ -45,7 +45,7 @@ jobs:
 #      DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer
 #
 #    steps:
-#      - uses: actions/checkout@v4
+#      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 #      - name: Run CMake
 #        run: cmake -S . -B build -D CMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On -DJSON_FastTests=ON
 #      - name: Build
@@ -62,7 +62,12 @@ jobs:
       DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer
 
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Run CMake
         run: cmake -S . -B build -D CMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On -DJSON_FastTests=ON
       - name: Build
@@ -79,7 +84,12 @@ jobs:
       DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer
 
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Run CMake
         run: cmake -S . -B build -D CMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On -DJSON_FastTests=ON
       - name: Build
@@ -96,7 +106,12 @@ jobs:
       DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer
 
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Run CMake
         run: cmake -S . -B build -D CMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On -DJSON_FastTests=ON
       - name: Build
@@ -111,7 +126,12 @@ jobs:
         standard: [11, 14, 17, 20, 23]
 
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Run CMake
         run: cmake -S . -B build -D CMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On -DJSON_TestStandards=${{ matrix.standard }}
       - name: Build
diff --git a/.github/workflows/publish_documentation.yml b/.github/workflows/publish_documentation.yml
index 750af74a8..29f0e4bf4 100644
--- a/.github/workflows/publish_documentation.yml
+++ b/.github/workflows/publish_documentation.yml
@@ -23,7 +23,12 @@ jobs:
     if: github.repository == 'nlohmann/json'
     runs-on: ubuntu-22.04
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
       - name: Install virtual environment
         run: make install_venv -C docs/mkdocs
@@ -32,7 +37,7 @@ jobs:
         run: make build -C docs/mkdocs
 
       - name: Deploy documentation
-        uses: peaceiris/actions-gh-pages@v4
+        uses: peaceiris/actions-gh-pages@4f9cc6602d3f66b9c108549d475ec49e8ef4d45e # v4.0.0
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           publish_dir: ./docs/mkdocs/site
diff --git a/.github/workflows/scorecards.yml b/.github/workflows/scorecards.yml
new file mode 100644
index 000000000..7b55f73fe
--- /dev/null
+++ b/.github/workflows/scorecards.yml
@@ -0,0 +1,81 @@
+# This workflow uses actions that are not certified by GitHub. They are provided
+# by a third-party and are governed by separate terms of service, privacy
+# policy, and support documentation.
+
+name: Scorecard supply-chain security
+on:
+  # For Branch-Protection check. Only the default branch is supported. See
+  # https://github.com/ossf/scorecard/blob/main/docs/checks.md#branch-protection
+  branch_protection_rule:
+  # To guarantee Maintained check is occasionally updated. See
+  # https://github.com/ossf/scorecard/blob/main/docs/checks.md#maintained
+  schedule:
+    - cron: '20 7 * * 2'
+  push:
+    branches: ["develop"]
+
+# Declare default permissions as read only.
+permissions: read-all
+
+jobs:
+  analysis:
+    name: Scorecard analysis
+    runs-on: ubuntu-latest
+    permissions:
+      # Needed to upload the results to code-scanning dashboard.
+      security-events: write
+      # Needed to publish results and get a badge (see publish_results below).
+      id-token: write
+      contents: read
+      actions: read
+      # To allow GraphQL ListCommits to work
+      issues: read
+      pull-requests: read
+      # To detect SAST tools
+      checks: read
+
+    steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - name: "Checkout code"
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          persist-credentials: false
+
+      - name: "Run analysis"
+        uses: ossf/scorecard-action@dc50aa9510b46c811795eb24b2f1ba02a914e534 # v2.3.3
+        with:
+          results_file: results.sarif
+          results_format: sarif
+          # (Optional) "write" PAT token. Uncomment the `repo_token` line below if:
+          # - you want to enable the Branch-Protection check on a *public* repository, or
+          # - you are installing Scorecards on a *private* repository
+          # To create the PAT, follow the steps in https://github.com/ossf/scorecard-action#authentication-with-pat.
+          # repo_token: ${{ secrets.SCORECARD_TOKEN }}
+
+          # Public repositories:
+          #   - Publish results to OpenSSF REST API for easy access by consumers
+          #   - Allows the repository to include the Scorecard badge.
+          #   - See https://github.com/ossf/scorecard-action#publishing-results.
+          # For private repositories:
+          #   - `publish_results` will always be set to `false`, regardless
+          #     of the value entered here.
+          publish_results: true
+
+      # Upload the results as artifacts (optional). Commenting out will disable uploads of run results in SARIF
+      # format to the repository Actions tab.
+      - name: "Upload artifact"
+        uses: actions/upload-artifact@b4b15b8c7c6ac21ea08fcf65892d2ee8f75cf882 # v4.4.3
+        with:
+          name: SARIF file
+          path: results.sarif
+          retention-days: 5
+
+      # Upload the results to GitHub's code scanning dashboard.
+      - name: "Upload to code-scanning"
+        uses: github/codeql-action/upload-sarif@df409f7d9260372bd5f19e5b04e83cb3c43714ae # v3.27.9
+        with:
+          sarif_file: results.sarif
diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index 955065199..bc7f3698a 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -21,11 +21,16 @@ jobs:
     runs-on: ubuntu-latest
     container: silkeh/clang:dev
     steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
       - name: Install git and unzip
         run: apt-get update ; apt-get install -y git unzip
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@v3.31.0
+        uses: lukka/get-cmake@71b7adfe2603f48bb9ed50d2b01a72499ae94885 # v3.31.0
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
@@ -35,9 +40,14 @@ jobs:
     runs-on: ubuntu-latest
     container: gcc:latest
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@v3.31.0
+        uses: lukka/get-cmake@71b7adfe2603f48bb9ed50d2b01a72499ae94885 # v3.31.0
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
@@ -56,7 +66,12 @@ jobs:
           ci_single_binaries    # needs iwyu
         ]
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
@@ -66,9 +81,14 @@ jobs:
     runs-on: ubuntu-latest
     container: gcc:latest
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@v3.31.0
+        uses: lukka/get-cmake@71b7adfe2603f48bb9ed50d2b01a72499ae94885 # v3.31.0
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
@@ -80,9 +100,14 @@ jobs:
       matrix:
         target: [ci_cpplint, ci_reproducible_tests, ci_non_git_tests, ci_offline_testdata]
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@v3.31.0
+        uses: lukka/get-cmake@71b7adfe2603f48bb9ed50d2b01a72499ae94885 # v3.31.0
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
@@ -95,11 +120,16 @@ jobs:
       matrix:
         target: [ci_clang_tidy, ci_test_clang_sanitizer, ci_clang_analyze]
     steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
       - name: Install git, clang-tools, and unzip
         run: apt-get update ; apt-get install -y git clang-tools unzip
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@v3.31.0
+        uses: lukka/get-cmake@71b7adfe2603f48bb9ed50d2b01a72499ae94885 # v3.31.0
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
@@ -112,11 +142,16 @@ jobs:
       matrix:
         target: [ci_cmake_flags, ci_test_diagnostics, ci_test_noexceptions, ci_test_noimplicitconversions, ci_test_legacycomparison, ci_test_noglobaludls]
     steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
       - name: Install build-essential
         run: apt-get update ; apt-get install -y build-essential unzip wget git
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@v3.31.0
+        uses: lukka/get-cmake@71b7adfe2603f48bb9ed50d2b01a72499ae94885 # v3.31.0
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
@@ -128,7 +163,12 @@ jobs:
       contents: read
       checks: write
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Install dependencies and de_DE locale
         run: |
           sudo apt-get clean
@@ -141,12 +181,12 @@ jobs:
       - name: Build
         run: cmake --build build --target ci_test_coverage
       - name: Archive coverage report
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@b4b15b8c7c6ac21ea08fcf65892d2ee8f75cf882 # v4.4.3
         with:
           name: code-coverage-report
           path: ${{ github.workspace }}/build/html
       - name: Publish report to Coveralls
-        uses: coverallsapp/github-action@v2.3.4
+        uses: coverallsapp/github-action@cfd0633edbd2411b532b808ba7a8b5e04f76d2c8 # v2.3.4
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
           path-to-lcov: ${{ github.workspace }}/build/json.info.filtered.noexcept
@@ -158,7 +198,12 @@ jobs:
         compiler: ['4.8', '4.9', '5', '6']
     container: ghcr.io/nlohmann/json-ci:v2.4.0
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Run CMake
         run: CXX=g++-${{ matrix.compiler }} cmake -S . -B build -DJSON_CI=On
       - name: Build
@@ -172,9 +217,14 @@ jobs:
         compiler: ['7', '8', '9', '10', '11', '12', '13', '14', 'latest']
     container: gcc:${{ matrix.compiler }}
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@v3.31.0
+        uses: lukka/get-cmake@71b7adfe2603f48bb9ed50d2b01a72499ae94885 # v3.31.0
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
@@ -187,11 +237,16 @@ jobs:
         compiler: ['3.5', '3.6', '3.7', '3.8', '3.9', '4', '5', '6', '7', '8', '9', '10', '11', '12', '13', '14', '15-bullseye', '16', '17', '18', '19', 'latest']
     container: silkeh/clang:${{ matrix.compiler }}
     steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
       - name: Install unzip and git
         run: apt-get update ; apt-get install -y unzip git
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@v3.31.0
+        uses: lukka/get-cmake@71b7adfe2603f48bb9ed50d2b01a72499ae94885 # v3.31.0
       - name: Set env FORCE_STDCPPFS_FLAG for clang 7 / 8 / 9 / 10
         run: echo "JSON_FORCED_GLOBAL_COMPILE_OPTIONS=-DJSON_HAS_FILESYSTEM=0;-DJSON_HAS_EXPERIMENTAL_FILESYSTEM=0" >> "$GITHUB_ENV"
         if: ${{ matrix.compiler == '7' || matrix.compiler == '8' || matrix.compiler == '9' || matrix.compiler == '10' }}
@@ -207,9 +262,14 @@ jobs:
       matrix:
         standard: [11, 14, 17, 20, 23]
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@v3.31.0
+        uses: lukka/get-cmake@71b7adfe2603f48bb9ed50d2b01a72499ae94885 # v3.31.0
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
@@ -223,11 +283,16 @@ jobs:
         standard: [11, 14, 17, 20, 23]
         stdlib: [libcxx, libstdcxx]
     steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
       - name: Install git and unzip
         run: apt-get update ; apt-get install -y git unzip
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@v3.31.0
+        uses: lukka/get-cmake@71b7adfe2603f48bb9ed50d2b01a72499ae94885 # v3.31.0
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build with libc++
@@ -241,7 +306,12 @@ jobs:
     runs-on: ubuntu-latest
     container: ghcr.io/nlohmann/json-ci:v2.4.0
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
@@ -251,7 +321,12 @@ jobs:
     runs-on: ubuntu-latest
     container: ghcr.io/nlohmann/json-ci:v2.2.0
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
@@ -262,8 +337,13 @@ jobs:
   ci_reuse_compliance:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/setup-python@0b93645e9fea7318ecaed2b359559ac225c90a2b # v5.3.0
         with:
           python-version: '3.11'
       - name: Install REUSE tool
@@ -277,7 +357,12 @@ jobs:
       matrix:
         target: [ci_test_examples, ci_test_api_documentation]
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Run CMake
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
index 292dea0d2..421043010 100644
--- a/.github/workflows/windows.yml
+++ b/.github/workflows/windows.yml
@@ -24,9 +24,14 @@ jobs:
         architecture: [x64, x86]
 
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Set up MinGW
-        uses: egor-tensin/setup-mingw@v2
+        uses: egor-tensin/setup-mingw@84c781b557efd538dec66bde06988d81cd3138cf # v2.2.0
         with:
           platform: ${{ matrix.architecture }}
           version: 12.2.0 # https://github.com/egor-tensin/setup-mingw/issues/14
@@ -45,7 +50,12 @@ jobs:
         architecture: [Win32, x64]
 
     steps:
-    - uses: actions/checkout@v4
+    - name: Harden Runner
+      uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+      with:
+        egress-policy: audit
+
+    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
     - name: Run CMake
       run: cmake -S . -B build -G "Visual Studio 16 2019" -A ${{ matrix.architecture }} -DJSON_BuildTests=On -DCMAKE_CXX_FLAGS="/W4 /WX"
       if: matrix.build_type == 'Release'
@@ -61,7 +71,12 @@ jobs:
     runs-on: windows-2019
 
     steps:
-    - uses: actions/checkout@v4
+    - name: Harden Runner
+      uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+      with:
+        egress-policy: audit
+
+    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
     - name: Run CMake
       run: cmake -S . -B build -G "Visual Studio 16 2019" -DJSON_BuildTests=On -DCMAKE_CXX_FLAGS="/permissive- /std:c++latest /utf-8 /W4 /WX"
     - name: Build
@@ -77,7 +92,12 @@ jobs:
         architecture: [Win32, x64]
 
     steps:
-    - uses: actions/checkout@v4
+    - name: Harden Runner
+      uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+      with:
+        egress-policy: audit
+
+    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
     - name: Run CMake
       run: cmake -S . -B build -G "Visual Studio 17 2022" -A ${{ matrix.architecture }} -DJSON_BuildTests=On -DCMAKE_CXX_FLAGS="/W4 /WX"
       if: matrix.build_type == 'Release'
@@ -93,7 +113,12 @@ jobs:
     runs-on: windows-2022
 
     steps:
-    - uses: actions/checkout@v4
+    - name: Harden Runner
+      uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+      with:
+        egress-policy: audit
+
+    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
     - name: Run CMake
       run: cmake -S . -B build -G "Visual Studio 17 2022" -DJSON_BuildTests=On -DCMAKE_CXX_FLAGS="/permissive- /std:c++latest /utf-8 /W4 /WX"
     - name: Build
@@ -108,7 +133,12 @@ jobs:
         version: [11, 12, 13, 14, 15]
 
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Install Clang
         run: curl -fsSL -o LLVM${{ matrix.version }}.exe https://github.com/llvm/llvm-project/releases/download/llvmorg-${{ matrix.version }}.0.0/LLVM-${{ matrix.version }}.0.0-win64.exe ; 7z x LLVM${{ matrix.version }}.exe -y -o"C:/Program Files/LLVM"
       - name: Run CMake
@@ -125,7 +155,12 @@ jobs:
         architecture: [Win32, x64]
 
     steps:
-      - uses: actions/checkout@v4
+      - name: Harden Runner
+        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
+        with:
+          egress-policy: audit
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Run CMake
         run: cmake -S . -B build -G "Visual Studio 16 2019" -A ${{ matrix.architecture }} -T ClangCL -DJSON_BuildTests=On
       - name: Build
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
new file mode 100644
index 000000000..f517e8ae2
--- /dev/null
+++ b/.pre-commit-config.yaml
@@ -0,0 +1,18 @@
+repos:
+- repo: https://github.com/gitleaks/gitleaks
+  rev: v8.16.3
+  hooks:
+  - id: gitleaks
+- repo: https://github.com/pocc/pre-commit-hooks
+  rev: v1.3.5
+  hooks:
+  - id: cpplint
+- repo: https://github.com/pre-commit/pre-commit-hooks
+  rev: v4.4.0
+  hooks:
+  - id: end-of-file-fixer
+  - id: trailing-whitespace
+- repo: https://github.com/pylint-dev/pylint
+  rev: v2.17.2
+  hooks:
+  - id: pylint