diff --git a/.boundaries-baseline.json b/.boundaries-baseline.json
index 4ca677e4538..95a7a4e2fed 100644
--- a/.boundaries-baseline.json
+++ b/.boundaries-baseline.json
@@ -1,3 +1,3 @@
 {
-  "issues": 163
+  "issues": 152
 }
diff --git a/.github/workflows/util-update-boundaries-baseline.yml b/.github/workflows/util-update-boundaries-baseline.yml
new file mode 100644
index 00000000000..baab13cc3d5
--- /dev/null
+++ b/.github/workflows/util-update-boundaries-baseline.yml
@@ -0,0 +1,108 @@
+name: 'Util: Update Boundaries Baseline'
+
+on:
+  schedule:
+    # Run every day at 03:00 UTC
+    - cron: '0 3 * * *'
+  workflow_dispatch: # Allow manual trigger for testing
+
+permissions: {}
+
+jobs:
+  update-baseline:
+    name: Lower boundaries baseline
+    # Default-branch-only: a dispatch from a feature branch would cut the update
+    # branch from that branch's HEAD and automerge it into master.
+    if: |
+      github.ref_name == github.event.repository.default_branch &&
+      (github.event_name == 'workflow_dispatch' ||
+      (github.event_name == 'schedule' && github.repository == 'n8n-io/n8n'))
+    runs-on: ${{ vars.RUNNER_PROVIDER == 'github' && 'ubuntu-latest' || 'blacksmith-4vcpu-ubuntu-2204' }}
+    # Least-privilege GITHUB_TOKEN: checkout only needs read. The branch push and
+    # the PR use the scoped app token below.
+    permissions:
+      contents: read
+    outputs:
+      pull-request-number: ${{ steps.create-pr.outputs.pull-request-number }}
+    steps:
+      - name: Generate GitHub App Token
+        id: generate-token
+        uses: actions/create-github-app-token@29824e69f54612133e76f7eaac726eef6c875baf # v2.2.1
+        with:
+          app-id: ${{ secrets.N8N_ASSISTANT_APP_ID }}
+          private-key: ${{ secrets.N8N_ASSISTANT_PRIVATE_KEY }}
+          permission-contents: write
+          permission-pull-requests: write
+
+      - name: Checkout repository
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          token: ${{ steps.generate-token.outputs.token }}
+          # create-pull-request pushes with its own token input, not the git remote creds.
+          persist-credentials: false
+
+      # The baseline is the post-build count, so the full build must run first.
+      # See scripts/check-boundaries.mjs.
+      - name: Setup Node.js, install dependencies and build
+        uses: ./.github/actions/setup-nodejs
+
+      # The check script writes the current count as is. The nightly only lowers
+      # the number: a higher count means master regressed, and raising the
+      # baseline would hide that from every PR.
+      - name: Recount boundaries issues
+        id: recount
+        run: |
+          BEFORE="$(node -p 'require("./.boundaries-baseline.json").issues')"
+          pnpm boundaries:baseline
+          AFTER="$(node -p 'require("./.boundaries-baseline.json").issues')"
+          echo "before=$BEFORE" >> "$GITHUB_OUTPUT"
+          echo "after=$AFTER" >> "$GITHUB_OUTPUT"
+          if [ "$AFTER" -gt "$BEFORE" ]; then
+            git checkout -- .boundaries-baseline.json
+            echo "::error::Boundaries issues on master ($AFTER) exceed the baseline ($BEFORE). The baseline is not raised. Fix the regression on master."
+            exit 1
+          fi
+          if [ "$AFTER" -eq "$BEFORE" ]; then
+            echo "Baseline unchanged at $BEFORE issues"
+            echo "has_changes=false" >> "$GITHUB_OUTPUT"
+          else
+            echo "Baseline lowered from $BEFORE to $AFTER issues"
+            echo "has_changes=true" >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Create Pull Request
+        if: steps.recount.outputs.has_changes == 'true'
+        id: create-pr
+        uses: peter-evans/create-pull-request@c0f553fe549906ede9cf27b5156039d195d2ece0 # v8.1.0
+        with:
+          token: ${{ steps.generate-token.outputs.token }}
+          commit-message: 'chore: Lower boundaries baseline (no-changelog)'
+          labels: 'automation:scheduled-update'
+          title: 'chore: Lower boundaries baseline (no-changelog)'
+          body: |
+            This automated PR lowers the `turbo boundaries` ratchet baseline
+            from ${{ steps.recount.outputs.before }} to ${{ steps.recount.outputs.after }} issues.
+
+            Master has fewer undeclared-dependency and reach-in import issues
+            than the committed baseline. This PR locks in the lower count so
+            new violations cannot use the slack.
+
+            The nightly never raises the baseline. A count above the baseline
+            fails the workflow instead.
+
+            _Generated by the nightly boundaries baseline workflow._
+          branch: update-boundaries-baseline
+          base: master
+          delete-branch: true
+          author: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
+          committer: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
+
+  approve-and-automerge:
+    needs: [update-baseline]
+    if: needs.update-baseline.outputs.pull-request-number != ''
+    # The callee's app credentials live on the release environment and cannot
+    # be forwarded as named secrets by the caller.
+    uses: ./.github/workflows/util-approve-and-set-automerge.yml # zizmor: ignore[secrets-inherit]
+    secrets: inherit
+    with:
+      pull-request-number: ${{ needs.update-baseline.outputs.pull-request-number }}
diff --git a/scripts/check-boundaries.mjs b/scripts/check-boundaries.mjs
index be1154c6726..ac36e7226d2 100644
--- a/scripts/check-boundaries.mjs
+++ b/scripts/check-boundaries.mjs
@@ -6,8 +6,10 @@
  * committed baseline — new code stays clean, the backlog burns down over time.
  *
  * Mirrors the incremental-cleanup approach already used by the Playwright
- * janitor (`.janitor-baseline.json`). Baseline is updated manually after real
- * fixes, never automatically.
+ * janitor (`.janitor-baseline.json`). The nightly workflow
+ * `util-update-boundaries-baseline.yml` lowers the baseline when master has
+ * fewer issues. Nothing raises it automatically: a count above the baseline
+ * fails the nightly instead.
  *
  * The baseline is the POST-BUILD count: CI's lint job builds dependencies before
  * this check runs, and built dist trees surface ~8 extra issues that a cold