diff --git a/.github/workflows/public-quality.yml b/.github/workflows/public-quality.yml
new file mode 100644
index 0000000..6ec28f6
--- /dev/null
+++ b/.github/workflows/public-quality.yml
@@ -0,0 +1,195 @@
+name: Public Quality
+
+on:
+  workflow_call:
+    inputs:
+      profile:
+        description: Public repository quality profile
+        required: true
+        type: string
+
+permissions:
+  contents: read
+
+jobs:
+  typescript:
+    name: TypeScript
+    if: inputs.profile == 'typescript'
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    steps:
+      - name: Checkout
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+
+      - name: Set up pnpm
+        uses: pnpm/action-setup@0ebf47130e4866e96fce0953f49152a61190b271 # v6.0.9
+
+      - name: Set up Node.js
+        uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
+        with:
+          node-version: "24"
+          cache: pnpm
+
+      - name: Install public dependencies
+        run: >-
+          env
+          -u GITHUB_TOKEN
+          -u NODE_AUTH_TOKEN
+          -u NPM_AUTH_TOKEN
+          -u NPM_TOKEN
+          -u PACKAGE_TOKEN
+          -u PACKAGES_TOKEN
+          pnpm install --frozen-lockfile
+
+      - name: Check format
+        run: pnpm run format:check
+
+      - name: Check types
+        run: pnpm run typecheck
+
+      - name: Check lint
+        run: pnpm run lint
+
+      - name: Run tests with coverage
+        run: pnpm run coverage
+
+      - name: Check unused files and dependencies
+        run: pnpm run knip
+
+  python:
+    name: Python ${{ matrix.python-version }}
+    if: inputs.profile == 'python'
+    runs-on: ubuntu-latest
+    timeout-minutes: 45
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.10", "3.11", "3.12", "3.13"]
+    steps:
+      - name: Checkout
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+
+      - name: Set up Python
+        uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Set up uv
+        uses: astral-sh/setup-uv@c771a70e6277c0a99b617c7a806ffedaca235ff9 # v9.0.0
+        with:
+          enable-cache: true
+          cache-dependency-glob: uv.lock
+
+      - name: Install locked dependencies
+        run: uv sync --all-extras --frozen --no-default-groups
+
+      - name: Check format
+        run: uv run --frozen black --check --diff src tests
+
+      - name: Check lint
+        run: >-
+          uv run --frozen flake8 src tests
+          --count
+          --max-complexity=10
+          --max-line-length=88
+          --statistics
+
+      - name: Check types
+        run: uv run --frozen mypy
+
+      - name: Check Python security
+        run: uv run --frozen bandit -r src
+
+      - name: Run tests with coverage
+        run: >-
+          uv run --frozen pytest
+          --cov
+          --cov-branch
+          --cov-fail-under=80
+          --cov-report=term-missing
+          --junitxml=junit.xml
+          -o junit_family=legacy
+
+  metadata:
+    name: Metadata
+    if: inputs.profile == 'metadata'
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - name: Checkout
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+
+      - name: Set up Node.js
+        uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
+        with:
+          node-version: "24"
+
+      - name: Set up Python
+        uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
+        with:
+          python-version: "3.13"
+
+      - name: Install workflow security tool
+        run: python -m pip install "zizmor==1.26.1"
+
+      - name: Check workflow syntax
+        run: npx --yes github-actionlint@1.7.12 -shellcheck ""
+
+      - name: Check workflow security
+        run: >-
+          zizmor
+          --min-severity=medium
+          --min-confidence=medium
+          .github/workflows
+
+      - name: Check format
+        run: npx --yes prettier@3.9.4 --check .
+
+      - name: Build repository context
+        run: npx --yes repomix@1.16.0
+
+  result:
+    name: Quality
+    if: always()
+    needs: [typescript, python, metadata]
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    env:
+      METADATA_RESULT: ${{ needs.metadata.result }}
+      PROFILE: ${{ inputs.profile }}
+      PYTHON_RESULT: ${{ needs.python.result }}
+      TYPESCRIPT_RESULT: ${{ needs.typescript.result }}
+    steps:
+      - name: Validate selected profile
+        shell: bash
+        run: |
+          set -euo pipefail
+
+          case "${PROFILE}" in
+            typescript)
+              selected_result="${TYPESCRIPT_RESULT}"
+              ;;
+            python)
+              selected_result="${PYTHON_RESULT}"
+              ;;
+            metadata)
+              selected_result="${METADATA_RESULT}"
+              ;;
+            *)
+              echo "::error::Unknown public quality profile: ${PROFILE}"
+              exit 1
+              ;;
+          esac
+
+          if [[ "${selected_result}" != "success" ]]; then
+            echo "::error::The ${PROFILE} quality profile ended with ${selected_result}."
+            exit 1
+          fi
+
+          echo "The ${PROFILE} quality profile passed."
diff --git a/.github/workflows/public-token-free-security.yml b/.github/workflows/public-token-free-security.yml
index 1372021..64829f2 100644
--- a/.github/workflows/public-token-free-security.yml
+++ b/.github/workflows/public-token-free-security.yml
@@ -139,6 +139,11 @@ jobs:
               r"^\s*-?\s*['\"]?uses['\"]?\s*:\s*['\"]?([^\s#'\"]+)",
               re.MULTILINE,
           )
+          public_quality_pattern = re.compile(
+              r"MNPPI/\.github/\.github/workflows/"
+              r"public-quality\.yml@[0-9a-f]{40}",
+              re.IGNORECASE,
+          )
           secret_pattern = re.compile(
               r"\$\{\{\s*secrets\.([A-Za-z0-9_]+)", re.IGNORECASE
           )
@@ -185,12 +190,17 @@ jobs:
 
               for match in uses_pattern.finditer(text):
                   target = match.group(1)
-                  if target.casefold().startswith("mnppi/"):
+                  if (
+                      target.casefold().startswith("mnppi/")
+                      and not public_quality_pattern.fullmatch(target)
+                  ):
                       add_error(
                           path,
                           text,
                           match.start(),
-                          "MNPPI actions and reusable workflows are not allowed",
+                          "MNPPI actions and reusable workflows are not allowed "
+                          "unless they call the approved public quality workflow "
+                          "at a full commit SHA",
                       )
 
               for match in secret_pattern.finditer(text):
diff --git a/.github/workflows/quality.yml b/.github/workflows/quality.yml
index a058a4b..d501189 100644
--- a/.github/workflows/quality.yml
+++ b/.github/workflows/quality.yml
@@ -5,6 +5,7 @@ on:
     branches: [main]
   push:
     branches: [main]
+  merge_group:
   workflow_dispatch:
 
 permissions:
@@ -12,29 +13,7 @@ permissions:
 
 jobs:
   quality:
-    name: Quality
-    runs-on: ubuntu-latest
-    timeout-minutes: 10
-    steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
-        with:
-          persist-credentials: false
-
-      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
-        with:
-          node-version: 22
-
-      - name: Install zizmor
-        run: python -m pip install "zizmor==1.26.1"
-
-      - name: actionlint
-        run: npx --yes github-actionlint@1.7.12 -shellcheck ""
-
-      - name: zizmor
-        run: zizmor --min-severity=medium --min-confidence=medium .github/workflows
-
-      - name: Repomix context pack
-        run: npx --yes repomix@1.16.0
-
-      - name: Format check
-        run: npx --yes prettier@3.9.4 --check .
+    name: Public Quality
+    uses: ./.github/workflows/public-quality.yml
+    with:
+      profile: metadata
diff --git a/docs/public-quality.md b/docs/public-quality.md
new file mode 100644
index 0000000..14e2ad1
--- /dev/null
+++ b/docs/public-quality.md
@@ -0,0 +1,62 @@
+# Public Quality
+
+The `public-quality.yml` reusable workflow provides quality checks for public
+MNPPI repositories. It does not use private packages or package credentials.
+
+## Profiles
+
+The workflow has three profiles:
+
+- `typescript` checks format, types, lint, test coverage, and unused files.
+- `python` checks Python 3.10 through 3.13 with a frozen `uv.lock` file.
+- `metadata` checks workflow syntax, workflow security, format, and repository
+  context generation.
+
+Each profile ends with one stable `Quality` job. A repository ruleset can
+require this job after a live pull request proves its exact check name.
+
+## Caller
+
+Each repository stores a small caller workflow:
+
+```yaml
+jobs:
+  quality:
+    permissions:
+      contents: read
+    uses: MNPPI/.github/.github/workflows/public-quality.yml@COMMIT_SHA
+    with:
+      profile: typescript
+```
+
+Replace `COMMIT_SHA` with the full approved commit SHA. Do not use a branch or
+tag.
+
+The caller must not pass secrets. The reusable workflow uses a standard
+GitHub-hosted runner and read-only repository access.
+
+## Profile Requirements
+
+The TypeScript profile requires these package scripts:
+
+- `format:check`
+- `typecheck`
+- `lint`
+- `coverage`
+- `knip`
+
+The repository must commit `pnpm-lock.yaml`.
+
+The Python profile requires the `dev` project extra and these tools:
+
+- Black
+- Flake8
+- mypy
+- Bandit
+- pytest
+- pytest-cov
+
+The repository must commit `uv.lock`.
+
+The metadata profile requires `repomix.config.jsonc`. The repository must
+ignore `.repomix/` and `repomix-output.*`.