diff --git a/.github/actions/mmm-proto-schema-create-version-tag/action.yml b/.github/actions/mmm-proto-schema-create-version-tag/action.yml
new file mode 100644
index 000000000..d9f9c3227
--- /dev/null
+++ b/.github/actions/mmm-proto-schema-create-version-tag/action.yml
@@ -0,0 +1,38 @@
+inputs:
+  new_version:
+    description: The new Meridian semantic version string to create a tag for.
+    required: true
+  tag_prefix:
+    description: The prefix to use for the git tag.
+    required: true
+permissions:
+  contents: write
+runs:
+  using: composite
+  steps:
+    - uses: actions/checkout@v4
+    - name: Create and Push Tag
+      uses: actions/github-script@v6
+      with:
+        script: |
+          const newTag = '${{ inputs.tag_prefix }}${{ inputs.new_version }}';
+          try {
+            await github.rest.git.createTag({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              tag: newTag,
+              message: `Release ${newTag}`,
+              object: context.sha,
+              type: 'commit'
+            });
+            await github.rest.git.createRef({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              ref: `refs/tags/${newTag}`,
+              sha: context.sha
+            });
+            console.log(`Created and pushed new tag: ${newTag}`);
+          } catch (error) {
+            console.error('Error creating tag:', error);
+            core.setFailed(`Failed to create tag: ${error.message}`);
+          }
diff --git a/.github/actions/mmm-proto-schema-version-check/action.yml b/.github/actions/mmm-proto-schema-version-check/action.yml
new file mode 100644
index 000000000..9028bc904
--- /dev/null
+++ b/.github/actions/mmm-proto-schema-version-check/action.yml
@@ -0,0 +1,59 @@
+# Check if version in version_file_path has been incremented. If so, set a `new_version` output.
+inputs:
+  python_version:
+    description: The Python version of the build toolchain to use.
+    required: true
+    default: 3.11
+  version_file_path:
+    description: The path to the file containing the __version__ string.
+    required: true
+  tag_match:
+    description: The git tag pattern to match for version comparison.
+    required: true
+  tag_prefix:
+    description: The prefix to strip from the tag to get the version.
+    required: true
+outputs:
+  new_version:
+    description: The new version if semver was incremented, otherwise an empty string.
+    value: ${{ steps.version_check.outputs.new_version }}
+runs:
+  using: composite
+  steps:
+    - uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+        fetch-tags: true
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: ${{ inputs.python_version }}
+    - shell: bash
+      run: pip install semver
+    - id: version_check
+      name: Check Version
+      shell: bash
+      run: |
+        CURRENT_VERSION=$(python3 -c "import re; print(re.search(r'^__version__\s*=\s*[\'"]([^\'"]*)[\'"]', open('${{ inputs.version_file_path }}').read(), re.M).group(1))")
+        echo "File version: $CURRENT_VERSION"
+        if ! python3 -m semver check "$CURRENT_VERSION"; then
+          echo "Error: Invalid semantic version in file: $CURRENT_VERSION"
+          exit 1
+        fi
+        PREVIOUS_TAG=$(git describe --tags --abbrev=0 --match '${{ inputs.tag_match }}' 2>/dev/null)
+        if [[ -z "$PREVIOUS_TAG" ]]; then
+          echo "No previous tag found matching ${{ inputs.tag_match }}. Using 0.0.0 as previous version."
+          PREVIOUS_VERSION="0.0.0"
+        else
+          echo "Found previous tag: $PREVIOUS_TAG"
+          PREVIOUS_VERSION=$(echo "$PREVIOUS_TAG" | sed 's|^${{ inputs.tag_prefix }}||')
+        fi
+        echo "Comparing $CURRENT_VERSION with $PREVIOUS_VERSION"
+        if [[ $(python3 -m semver compare "$CURRENT_VERSION" "$PREVIOUS_VERSION") -eq 1 ]]; then
+          echo "New version detected: $CURRENT_VERSION"
+          NEW_VERSION=$CURRENT_VERSION
+        else
+          echo "No version increment detected."
+          NEW_VERSION=""
+        fi
+        echo "new_version=$NEW_VERSION" >> $GITHUB_OUTPUT
diff --git a/.github/workflows/publish-mmm-proto-schema.yml b/.github/workflows/publish-mmm-proto-schema.yml
new file mode 100644
index 000000000..ff036c131
--- /dev/null
+++ b/.github/workflows/publish-mmm-proto-schema.yml
@@ -0,0 +1,129 @@
+name: Publish mmm-proto-schema to PyPI  # For tagging and publishing releases.
+
+on:
+  push:
+    branches:
+      - main  # This entire workflow only runs on a push to the `main` branch (i.e. POST SUBMIT).
+    paths:
+      - 'proto/**'
+    tags:
+      - 'mmm-proto-schema/v*'  # Trigger only on pushed tags whose names start with 'v'.
+  workflow_dispatch:  # For triggering publication workflows manually, on demend, from GitHub UI.
+    inputs:
+      publish_proto_schema_to_pypi:  # Creates a boolean `github.event.inputs.publish_proto_schema_to_pypi` variable.
+        description: 'Publish proto schema to PyPI'
+        required: false
+        type: boolean
+        default: false
+      publish_proto_schema_to_testpypi:
+        description: 'Publish proto schema to TestPyPI'
+        required: false
+        type: boolean
+        default: false
+
+env:
+  USE_PYTHON_VERSION: "3.11"
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - uses: ./.github/actions/build
+        with:
+          python_version: ${{ env.USE_PYTHON_VERSION }}
+          src_dir: proto
+          artifact_name: mmm-proto-schema-distributions
+
+  # Check if the current `meridian.__version__` semver has been incremented. If so, set a
+  # `new_version` output.
+  check-version:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    outputs:
+      new_version: ${{ steps.version_check.outputs.new_version }}
+    steps:
+      - uses: actions/checkout@v4
+      - id: version_check
+        uses: ./.github/actions/mmm-proto-schema-version-check
+        with:
+          python_version: ${{ env.USE_PYTHON_VERSION }}
+          version_file_path: proto/__init__.py
+          tag_match: mmm-proto-schema/v*
+          tag_prefix: mmm-proto-schema/v
+
+  create-tag:
+    needs: check-version
+    # Only run if new_version was discovered, and do this only on the main branch.
+    if: >
+      github.ref == 'refs/heads/main'
+      && needs.check-version.outputs.new_version != ''
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write # Allow to create tags
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ./.github/actions/mmm-proto-schema-create-version-tag
+        with:
+          new_version: ${{ needs.check-version.outputs.new_version }}
+          tag_prefix: mmm-proto-schema/v
+
+  publish-proto-schema-to-pypi:
+    name: Publish MMM proto schema to PyPI
+    needs:
+      - build
+      - check-version
+    # Check if it's a tag push, or the `publish_proto_schema_to_pypi` workflow is selected in a manual trigger.
+    # or if a new version was discovered in a push to the `main` branch.
+    if: >
+      github.repository == 'google/meridian' && (
+        (github.ref_type == 'tag' && startsWith(github.ref, 'refs/tags/'))
+        || (github.event_name == 'workflow_dispatch'
+            && github.event.inputs.publish_proto_schema_to_pypi == 'true')
+        || needs.check-version.outputs.new_version != ''
+      )
+    runs-on: ubuntu-latest
+    environment:
+      name: pypi
+      url: https://pypi.org/p/mmm-proto-schema
+    permissions:
+      id-token: write  # IMPORTANT: mandatory for trusted publishing
+    steps:
+      - name: Download all the dists
+        uses: actions/download-artifact@v4
+        with:
+          name: mmm-proto-schema-distributions
+          path: dist/
+      - name: Publish distribution to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          verbose: true
+
+  publish-proto-schema-to-testpypi:
+    name: Publish MMM proto schema to TestPyPI
+    needs:
+      - build
+      - check-version
+    # Check if the `publish_proto_schema_to_testpypi` workflow is selected in a manual trigger.
+    if: >
+      github.repository == 'google/meridian' && (
+        (github.event_name == 'workflow_dispatch'
+            && github.event.inputs.publish_proto_schema_to_testpypi == 'true')
+      )
+    runs-on: ubuntu-latest
+    environment:
+      name: testpypi
+      url: https://test.pypi.org/p/mmm-proto-schema
+    permissions:
+      id-token: write  # IMPORTANT: mandatory for trusted publishing
+    steps:
+      - name: Download all the dists
+        uses: actions/download-artifact@v4
+        with:
+          name: mmm-proto-schema-distributions
+          path: dist/
+      - name: Publish distribution to TestPyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          repository-url: https://test.pypi.org/legacy/
+          verbose: true