diff --git a/.github/workflows/check_license.yml b/.github/workflows/check_license.yml
index 2ae3dabb4..0f328f910 100644
--- a/.github/workflows/check_license.yml
+++ b/.github/workflows/check_license.yml
@@ -20,16 +20,21 @@ on:
       - main
   pull_request:
 
+permissions:
+  contents: read
+
 jobs:
   check-license:
     runs-on: ubuntu-latest
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Set up Go
-        uses: actions/setup-go@v6
+        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6
         with:
           go-version: '1.21'
 
diff --git a/.github/workflows/check_private_index.yml b/.github/workflows/check_private_index.yml
index 2061d2b19..45a76c25f 100644
--- a/.github/workflows/check_private_index.yml
+++ b/.github/workflows/check_private_index.yml
@@ -18,12 +18,17 @@ on:
   push:
   pull_request:
 
+permissions:
+  contents: read
+
 jobs:
   check-for-private-index:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
       - name: Search for private index URL in uv.lock files
         run: |
           FORBIDDEN_URL="us-python.pkg.dev"
diff --git a/.github/workflows/composer_build_and_test.yml b/.github/workflows/composer_build_and_test.yml
index 54b4413b7..ad1e04699 100644
--- a/.github/workflows/composer_build_and_test.yml
+++ b/.github/workflows/composer_build_and_test.yml
@@ -24,20 +24,25 @@ on:
       - 'tools/composer/**'
       - '.github/workflows/composer_build_and_test.yml'
 
+permissions:
+  contents: read
+
 jobs:
   build-and-test:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Install pnpm
-        uses: pnpm/action-setup@v4
+        uses: pnpm/action-setup@b906affcce14559ad1aafd4ab0e942779e9f58b1 # v4
         with:
           version: 10
 
       - name: Set up Node.js
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
         with:
           node-version: '20'
           cache: 'pnpm'
diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index 98aee926e..5cef30cdc 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -32,6 +32,9 @@ on:
       - "mkdocs.yml"
       - "docs/**"
 
+permissions:
+  contents: read
+
 jobs:
   build_and_deploy:
     runs-on: ubuntu-latest
@@ -43,7 +46,7 @@ jobs:
 
     steps:
       - name: Checkout Code
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           fetch-depth: 0
@@ -54,12 +57,12 @@ jobs:
           git config --global user.email 41898282+github-actions[bot]@users.noreply.github.com
 
       - name: Setup Python
-        uses: actions/setup-python@v6
+        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6
         with:
           python-version: 3.13
 
       - name: Restore pip cache
-        uses: actions/cache@v5
+        uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5
         with:
           key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements-docs.txt') }}
           path: ~/.cache/pip
diff --git a/.github/workflows/editor_build.yml b/.github/workflows/editor_build.yml
index b60309ff5..468a35912 100644
--- a/.github/workflows/editor_build.yml
+++ b/.github/workflows/editor_build.yml
@@ -28,15 +28,20 @@ on:
       - 'renderers/web_core/**'
       - '.github/workflows/editor_build.yml'
 
+permissions:
+  contents: read
+
 jobs:
   build:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Set up Node.js
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
         with:
           node-version: '20'
 
diff --git a/.github/workflows/inspector_build.yml b/.github/workflows/inspector_build.yml
index e15e22cdd..7d2adf7e3 100644
--- a/.github/workflows/inspector_build.yml
+++ b/.github/workflows/inspector_build.yml
@@ -29,15 +29,20 @@ on:
       - 'renderers/web_core/**'
       - '.github/workflows/inspector_build.yml'
 
+permissions:
+  contents: read
+
 jobs:
   build:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Set up Node.js
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
         with:
           node-version: '20'
 
diff --git a/.github/workflows/java_build_and_test.yml b/.github/workflows/java_build_and_test.yml
index ba55bbdb6..d843b9bb6 100644
--- a/.github/workflows/java_build_and_test.yml
+++ b/.github/workflows/java_build_and_test.yml
@@ -26,6 +26,9 @@ on:
       - 'agent_sdks/java/**'
       - 'specification/**/json/**'
 
+permissions:
+  contents: read
+
 jobs:
   build-and-test:
     name: Build and test Java agent sample
@@ -33,10 +36,12 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Set up JDK
-        uses: actions/setup-java@v5
+        uses: actions/setup-java@be666c2fcd27ec809703dec50e508c2fdc7f6654 # v5
         with:
           java-version: '21'
           distribution: 'temurin'
diff --git a/.github/workflows/lit_build_and_test.yml b/.github/workflows/lit_build_and_test.yml
index 1f9b34fc1..48f07cad5 100644
--- a/.github/workflows/lit_build_and_test.yml
+++ b/.github/workflows/lit_build_and_test.yml
@@ -27,15 +27,20 @@ on:
       - 'renderers/web_core/**'
       - '.github/workflows/lit_build_and_test.yml'
 
+permissions:
+  contents: read
+
 jobs:
   build-and-test:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Set up Node.js
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
         with:
           node-version: '20'
 
diff --git a/.github/workflows/lit_samples_build.yml b/.github/workflows/lit_samples_build.yml
index b46557c9a..dfd9936dd 100644
--- a/.github/workflows/lit_samples_build.yml
+++ b/.github/workflows/lit_samples_build.yml
@@ -23,15 +23,20 @@ on:
     paths-ignore:
       - 'samples/agent/adk/**'
 
+permissions:
+  contents: read
+
 jobs:
   build:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Set up Node.js
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
         with:
           node-version: '20'
 
diff --git a/.github/workflows/ng_build_and_test.yml b/.github/workflows/ng_build_and_test.yml
index 98ff508cb..93864b886 100644
--- a/.github/workflows/ng_build_and_test.yml
+++ b/.github/workflows/ng_build_and_test.yml
@@ -23,15 +23,20 @@ on:
     paths-ignore:
       - 'samples/agent/adk/**'
 
+permissions:
+  contents: read
+
 jobs:
   build-and-test:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Set up Node.js
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
         with:
           node-version: '20'
 
diff --git a/.github/workflows/python_agent_sdk_build_and_test.yml b/.github/workflows/python_agent_sdk_build_and_test.yml
index e2d57f3d1..091e355f8 100644
--- a/.github/workflows/python_agent_sdk_build_and_test.yml
+++ b/.github/workflows/python_agent_sdk_build_and_test.yml
@@ -26,16 +26,21 @@ on:
       - 'agent_sdks/python/**'
       - 'specification/**/json/**'
 
+permissions:
+  contents: read
+
 jobs:
   build-and-test:
     runs-on: ubuntu-latest
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Set up Python
-        uses: actions/setup-python@v6
+        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6
         with:
           python-version: '3.x'
 
diff --git a/.github/workflows/python_samples_build.yml b/.github/workflows/python_samples_build.yml
index ac0fc330b..e871594ce 100644
--- a/.github/workflows/python_samples_build.yml
+++ b/.github/workflows/python_samples_build.yml
@@ -28,6 +28,9 @@ on:
       - 'agent_sdks/python/**'
       - 'specification/**/json/**'
 
+permissions:
+  contents: read
+
 jobs:
   build:
     name: Build samples
@@ -35,10 +38,12 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Set up Python
-        uses: actions/setup-python@v6
+        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6
         with:
           python-version: '3.x'
 
diff --git a/.github/workflows/react_renderer.yml b/.github/workflows/react_renderer.yml
index 50323d3b7..f5889d431 100644
--- a/.github/workflows/react_renderer.yml
+++ b/.github/workflows/react_renderer.yml
@@ -29,15 +29,20 @@ on:
       - 'renderers/lit/**'
       - 'samples/agent/adk/**'
 
+permissions:
+  contents: read
+
 jobs:
   build-and-test:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Set up Node.js
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
         with:
           node-version: '20'
 
@@ -63,10 +68,12 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Set up Node.js
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
         with:
           node-version: '20'
 
@@ -92,10 +99,12 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Set up Node.js
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
         with:
           node-version: '20'
 
diff --git a/.github/workflows/validate_specifications.yml b/.github/workflows/validate_specifications.yml
index 258c84be6..a9212b6d3 100644
--- a/.github/workflows/validate_specifications.yml
+++ b/.github/workflows/validate_specifications.yml
@@ -27,25 +27,30 @@ on:
       - '.github/workflows/validate_specifications.yml'
       - 'specification/scripts/validate.py'
 
+permissions:
+  contents: read
+
 jobs:
   validate:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Install pnpm
-        uses: pnpm/action-setup@v4
+        uses: pnpm/action-setup@b906affcce14559ad1aafd4ab0e942779e9f58b1 # v4
         with:
           version: 10
 
       - name: Set up Node.js
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
         with:
           node-version: '20'
 
       - name: Set up Python
-        uses: actions/setup-python@v6
+        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6
         with:
           python-version: '3.12'
 
diff --git a/.github/workflows/web_build_and_test.yml b/.github/workflows/web_build_and_test.yml
index d80edfd80..f6346f6ce 100644
--- a/.github/workflows/web_build_and_test.yml
+++ b/.github/workflows/web_build_and_test.yml
@@ -25,15 +25,20 @@ on:
       - 'renderers/web_core/**/*'
       - '.github/workflows/web_build_and_test.yml'
 
+permissions:
+  contents: read
+
 jobs:
   build-and-test:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Set up Node.js
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
         with:
           node-version: '20'
 
@@ -50,10 +55,12 @@ jobs:
         run: npm run test
   lint:
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Set up Node.js
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
         with:
           node-version: '20'