diff --git a/.github/workflows/auto-tag.yml b/.github/workflows/auto-tag.yml
new file mode 100644
index 0000000..33446ca
--- /dev/null
+++ b/.github/workflows/auto-tag.yml
@@ -0,0 +1,12 @@
+name: Auto-tag
+on:
+  push:
+    tags:
+      - '*.*.*'
+jobs:
+  auto-tag:
+    name: Auto-tag
+    runs-on: ubuntu-latest
+    steps:
+      - name: Auto-tag
+        uses: silverstripe/gha-auto-tag@main
diff --git a/README.md b/README.md
index 8341a90..ebe5398 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,24 @@
-# gha-update-js
\ No newline at end of file
+# GitHub Actions - Update JS
+
+Update JS dependencies in core Silverstripe modules, create new bundles and create pull-requests
+
+## Usage:
+
+This action has no inputs. It is intended to be [run on a schedule](https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#scheduled-events). You can copy the below example verbatim, and just modify the schedule to suit your use case.
+
+**.github/workflows/update-js.yml**
+```yml
+name: Update JS
+on:
+  # Run on a schedule of once per quarter
+  schedule:
+    - cron: '0 0 1 */3 *'
+  workflow_dispatch:
+jobs:
+  update-js:
+    name: Update JS
+    runs-on: ubuntu-latest
+    steps:
+      - name: Update JS
+        uses: silverstripe/gha-update-js@main
+```
diff --git a/action.yml b/action.yml
new file mode 100644
index 0000000..3cf4831
--- /dev/null
+++ b/action.yml
@@ -0,0 +1,151 @@
+name: Update JS
+description: Updates JS dependencies in Silverstripe core modules
+
+runs:
+  using: composite
+  steps:
+
+    - name: Checkout code
+      uses: actions/checkout@7884fcad6b5d53d10323aee724dc68d8b9096a2e # v2.4.2
+
+    - name: Read .nvmrc
+      id: read-nvm
+      shell: bash
+      run: |
+        echo ::set-output name=version::$(cat .nvmrc)
+
+    - name: Setup node
+      uses: actions/setup-node@eeb10cff27034e7acf239c5d29f62154018672fd # v3.3.0
+      with:
+        node-version: ${{ steps.read-nvm.outputs.version }}
+
+    - name: Install admin JS
+      if: github.event.repository.name != 'silverstripe-admin'
+      shell: bash
+      run: |
+        # Install admin js in sibling directory so shared components are available
+        DIR=$(pwd)
+        cd ..
+        git clone https://github.com/silverstripe/silverstripe-admin.git admin
+        cd admin
+        git checkout 1
+        # yarn comes preinstalled with actions/setup-node
+        yarn install
+        cd $DIR
+
+    # Use `yarn install` rather than `yarn upgrade` to prevent the following error:
+    # "error Outdated lockfile. Please run `yarn install` and try again."
+    - name: Update yarn.lock
+      shell: bash
+      run: |
+        if [[ -f yarn.lock ]]; then
+          rm yarn.lock
+        fi
+        yarn install
+
+    - name: Read package.json
+      id: package-json
+      shell: bash
+      run: |
+        # Read package.json to see if lint and test are runnable scripts
+        LINT="false"
+        TEST="false"
+        if [[ "$(jq .scripts.lint? package.json)" != "null" ]]; then LINT="true"; fi
+        if [[ "$(jq .scripts.test? package.json)" != "null" ]]; then TEST="true"; fi
+        echo "::set-output name=lint::$LINT"
+        echo "::set-output name=test::$TEST"
+        echo "LINT is $LINT"
+        echo "TEST is $TEST"
+
+    # The following 3 steps make up `yarn build`
+    # Splitting apart to make it easier to see where any failures originate from
+    - name: Yarn lint
+      if: steps.package-json.outputs.lint == 'true'
+      shell: bash
+      run: |
+        yarn lint
+
+    - name: Yarn test
+      if: steps.package-json.outputs.test == 'true'
+      shell: bash
+      run: |
+        yarn test
+
+    - name: Build JS with webpack
+      # always run this and subsequent steps even if yarn.lint/yarn.test fails so that pull-request is
+      # created which will result in a red pull-request build so it's easy to see where things are at
+      if: always()
+      shell: bash
+      run: |
+        NODE_ENV=production node_modules/webpack/bin/webpack.js -p --bail --progress
+
+    - name: Remove any old pull-requests
+      if: always()
+      shell: bash
+      env:
+        GITHUB_REPOSITORY: ${{ github.repository }}
+      run: |
+        # https://docs.github.com/en/rest/pulls/pulls#list-pull-requests
+        RESP_CODE=$(curl -w %{http_code} -s -o __response.json \
+        -X GET https://api.github.com/repos/$GITHUB_REPOSITORY/pulls \
+        -H "Accept: application/vnd.github.v3+json")
+        if [[ $RESP_CODE != "200" ]]; then
+          echo "Unable to list pull-requests"
+          exit 1
+        fi
+        JSON=$(cat __response.json)
+        NUMBERS=$(echo $JSON | jq '.[] | select(.title=="DEP Update JS dependencies" and .user.login=="github-actions[bot]") | .number')
+        for NUMBER in $NUMBERS; do
+          # https://docs.github.com/en/rest/pulls/pulls#update-a-pull-request
+          RESP_CODE=$(curl -w %{http_code} -s -o /dev/null \
+          -X PATCH https://api.github.com/repos/$GITHUB_REPOSITORY/pulls/$NUMBER \
+          -H "Accept: application/vnd.github.v3+json" \
+          -H "Authorization: token ${{ github.token }}" \
+          -d @- << EOF
+          {
+            "state": "closed"
+          }
+        EOF
+          )
+          if [[ $RESP_CODE != "200" ]]; then
+            echo "Unable to close pull-request $NUMBER"
+            exit 1
+          fi
+          echo "Closed old pull-request $NUMBER"
+        done
+
+    - name: Remove any old branches
+      if: always()
+      shell: bash
+      env:
+        GITHUB_REPOSITORY: ${{ github.repository }}
+      run: |
+        JSON=$(curl https://api.github.com/repos/$GITHUB_REPOSITORY/branches)
+        BRANCHES=$(echo $JSON | jq -r '.[] | .name | select(.|test("^pulls\/[0-9]\/update-js-[0-9]{10}$"))')
+        for BRANCH in $BRANCHES; do
+          if [[ "$BRANCH" =~ ^pulls/[0-9\.]+/update\-js\-[0-9]+$ ]]; then
+            git push origin --delete "$BRANCH"
+            echo "Deleted old branch $BRANCH"
+          fi
+        done
+
+    - name: Generate branch name
+      if: always()
+      id: generate-branch-name
+      shell: bash
+      env:
+        GITHUB_REF: ${{ github.ref }}
+      run: |
+        # Convert refs/heads/mybranch to mybranch
+        CUT=$(echo $GITHUB_REF | cut -c 12-)
+        # e.g. pulls/1/update-js-1647810133
+        BRANCH=pulls/$CUT/update-js-$(date +%s)
+        echo ::set-output name=branch::$BRANCH
+
+    - name: Git
+      if: always()
+      uses: silverstripe/gha-pull-request@main
+      with:
+        branch: ${{ steps.generate-branch-name.outputs.branch }}
+        title: DEP Update JS dependencies
+        description: Automated yarn upgrade and yarn build