diff --git a/.github/workflows/sync-feature-branch.yaml b/.github/workflows/sync-feature-branch.yaml
deleted file mode 100644
index 51a8f286..00000000
--- a/.github/workflows/sync-feature-branch.yaml
+++ /dev/null
@@ -1,126 +0,0 @@
-name: Sync feature branch with main
-
-on:
-  push:
-    branches: [main]
-  workflow_dispatch:
-    inputs:
-      target_branch:
-        description: "Feature branch to sync with main"
-        required: true
-        default: "new-resolver-config"
-
-permissions:
-  contents: read
-
-jobs:
-  sync-branch:
-    runs-on: ubuntu-latest
-    if: ${{ github.repository_owner == 'python-wheel-build' }}
-    concurrency:
-      group: sync-${{ inputs.target_branch || 'new-resolver-config' }}
-      cancel-in-progress: false
-    permissions:
-      contents: write
-      issues: write
-    env:
-      TARGET_BRANCH: ${{ inputs.target_branch || 'new-resolver-config' }}
-      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-    steps:
-      - name: Checkout target branch
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
-        with:
-          ref: ${{ env.TARGET_BRANCH }}
-          fetch-depth: 0
-          persist-credentials: false
-
-      - name: Configure git
-        run: |
-          git config user.name "github-actions[bot]"
-          git config user.email "github-actions[bot]@users.noreply.github.com"
-          gh auth setup-git
-
-      - name: Merge main into feature branch
-        id: merge
-        run: |
-          git fetch origin main
-          BEFORE=$(git rev-parse HEAD)
-          if git merge origin/main --no-edit; then
-            AFTER=$(git rev-parse HEAD)
-            if [ "$BEFORE" = "$AFTER" ]; then
-              echo "result=up-to-date" >> "$GITHUB_OUTPUT"
-            else
-              echo "result=merged" >> "$GITHUB_OUTPUT"
-            fi
-          else
-            CONFLICTS=$(git diff --name-only --diff-filter=U)
-            git merge --abort
-            echo "result=conflict" >> "$GITHUB_OUTPUT"
-            echo "conflicts<<DELIM" >> "$GITHUB_OUTPUT"
-            echo "$CONFLICTS" >> "$GITHUB_OUTPUT"
-            echo "DELIM" >> "$GITHUB_OUTPUT"
-          fi
-
-      - name: Push merged changes
-        if: steps.merge.outputs.result == 'merged'
-        run: git push origin "HEAD:${TARGET_BRANCH}"
-
-      - name: Close resolved sync-conflict issues
-        if: steps.merge.outputs.result == 'merged' || steps.merge.outputs.result == 'up-to-date'
-        run: |
-          EXPECTED_TITLE="Sync conflict: ${TARGET_BRANCH} cannot merge main"
-          gh issue list --label "sync-conflict" --state open --json number,title \
-            | jq -r --arg t "$EXPECTED_TITLE" '.[] | select(.title == $t) | .number' \
-            | xargs -rI{} gh issue close {} --comment "Resolved by automated sync."
-
-      - name: Report up-to-date
-        if: steps.merge.outputs.result == 'up-to-date'
-        run: echo "Branch ${TARGET_BRANCH} is already up to date with main."
-
-      - name: Open issue on conflict
-        if: steps.merge.outputs.result == 'conflict'
-        run: |
-          EXPECTED_TITLE="Sync conflict: ${TARGET_BRANCH} cannot merge main"
-
-          EXISTING=$(gh issue list \
-            --label "sync-conflict" \
-            --state open \
-            --json title \
-            | jq --arg expected "$EXPECTED_TITLE" \
-                '[.[] | select(.title == $expected)] | length')
-
-          if [ "$EXISTING" -gt 0 ]; then
-            echo "An open sync-conflict issue for ${TARGET_BRANCH} already exists, skipping."
-            exit 0
-          fi
-
-          gh label create "sync-conflict" \
-            --description "Automated sync with main hit merge conflicts" \
-            --color "D93F0B" \
-            --force
-
-          gh issue create \
-            --title "$EXPECTED_TITLE" \
-            --label "sync-conflict" \
-            --body "$(cat <<EOF
-          The automated sync workflow failed to merge \`main\` into \`${TARGET_BRANCH}\` due to merge conflicts.
-
-          **Conflicting files:**
-          \`\`\`
-          ${{ steps.merge.outputs.conflicts }}
-          \`\`\`
-
-          **Manual resolution required.** To fix:
-
-          \`\`\`bash
-          git checkout ${TARGET_BRANCH}
-          git fetch origin
-          git merge origin/main
-          # resolve conflicts
-          git commit
-          git push
-          \`\`\`
-
-          **Workflow run:** ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
-          EOF
-          )"
diff --git a/.mergify.yml b/.mergify.yml
index 14d9fba3..df484ec1 100644
--- a/.mergify.yml
+++ b/.mergify.yml
@@ -1,4 +1,19 @@
 pull_request_rules:
+  - name: Backport main changes to new-resolver-config
+    conditions:
+      - repository-full-name=python-wheel-build/fromager
+      - base=main
+      - merged
+      # PR #1367 brought the feature branch up to date at this cutoff.
+      - merged-at>2026-10-13T18:55:47Z
+      - head!=new-resolver-config
+    actions:
+      backport:
+        branches:
+          - new-resolver-config
+        ignore_conflicts: true
+        label_conflicts: conflicts
+
   - name: Add CI label
     conditions:
       - or:
@@ -27,6 +42,10 @@ pull_request_rules:
     conditions:
       - and:
           - "-draft"
+          # Maintainers merge resolver backports after reviewing CI and conflicts.
+          - or:
+              - base!=new-resolver-config
+              - -head~=^mergify/bp/new-resolver-config/
 
           # Unit tests
           - check-success=unit (3.12, 1.75, ubuntu-latest)
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 3f9cc005..3181dd6c 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -9,6 +9,7 @@ Fromager thrives on practical, well-tested contributions. This guide summarizes
 - [Quick Start](#quick-start)
 - [Coding Standards](#coding-standards)
 - [Testing](#testing)
+- [Resolver Branch Backports](#resolver-branch-backports)
 - [Commit Guidelines](#commit-guidelines)
 - [Before Submitting](#before-submitting)
 - [Design Patterns Used in Fromager](#design-patterns-used-in-fromager)
@@ -225,6 +226,24 @@ hatch run test:coverage-report                   # Coverage summary
 
 ---
 
+## Resolver Branch Backports
+
+Mergify cherry-picks PRs merged into `main` after the
+[baseline sync #1367](https://github.com/python-wheel-build/fromager/pull/1367)
+into backport PRs for `new-resolver-config`, using its GitHub App without a personal
+token. Maintainers review and manually merge them after applicable CI passes,
+merging dependent backports in source order.
+
+Resolve conflicts and remove the `conflicts` label before merging. To request a
+missing backport, check for an existing PR, then comment
+`@mergifyio backport new-resolver-config` on the merged source PR.
+
+Direct pushes and unsupported merge histories need manual backports. Cherry-picks
+create new commits, so Git may still report the branch as behind `main`. Remove
+the backport rule when the feature branch is retired.
+
+---
+
 ## Commit Guidelines
 
 Fromager follows [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/).