diff --git a/.gitea/workflows/sync.yml b/.gitea/workflows/sync.yml
new file mode 100644
index 0000000..e3cede6
--- /dev/null
+++ b/.gitea/workflows/sync.yml
@@ -0,0 +1,85 @@
+name: Sync blocklists from upstream
+
+on:
+  schedule:
+    - cron: '0 */6 * * *'
+  workflow_dispatch:
+
+jobs:
+  sync:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Fetch and merge upstream files
+        run: |
+          python3 << 'PYEOF'
+          import urllib.request
+          import os
+
+          files = {
+              "blacklist": "https://raw.githubusercontent.com/Cleanuparr/Cleanuparr/main/blacklist",
+              "blacklist_permissive": "https://raw.githubusercontent.com/Cleanuparr/Cleanuparr/main/blacklist_permissive",
+              "whitelist": "https://raw.githubusercontent.com/Cleanuparr/Cleanuparr/main/whitelist",
+              "whitelist_with_subtitles": "https://raw.githubusercontent.com/Cleanuparr/Cleanuparr/main/whitelist_with_subtitles",
+          }
+
+          def merge_blocklist(filename, url):
+              prev_file = f"{filename}.prev"
+
+              # Fetch new upstream
+              with urllib.request.urlopen(url) as r:
+                  upstream_new = set(line.strip() for line in r.read().decode().splitlines() if line.strip())
+
+              # Read previous upstream (empty set if first run)
+              try:
+                  with open(prev_file) as f:
+                      upstream_prev = set(line.strip() for line in f if line.strip())
+              except FileNotFoundError:
+                  upstream_prev = upstream_new.copy()
+
+              # Read current local file
+              try:
+                  with open(filename) as f:
+                      local = set(line.strip() for line in f if line.strip())
+              except FileNotFoundError:
+                  local = set()
+
+              # Three-way merge
+              custom = local - upstream_prev       # your additions
+              result = upstream_new | custom        # new upstream + your custom entries
+
+              print(f"[{filename}] Custom preserved: {sorted(custom)}")
+              print(f"[{filename}] Upstream added: {sorted(upstream_new - upstream_prev)}")
+              print(f"[{filename}] Upstream removed: {sorted(upstream_prev - upstream_new)}")
+
+              # Write merged result sorted
+              with open(filename, "w") as f:
+                  f.write("\n".join(sorted(result)) + "\n")
+
+              # Store new upstream as prev for next run
+              with open(prev_file, "w") as f:
+                  f.write("\n".join(sorted(upstream_new)) + "\n")
+
+          for filename, url in files.items():
+              merge_blocklist(filename, url)
+          PYEOF
+
+      - name: Commit and push if changed
+        run: |
+          git config user.name "gitea-actions"
+          git config user.email "actions@gitea"
+          git add .
+          git diff --staged --quiet || git commit -m "Sync blocklists from upstream"
+          git push
+```
+
+**Step 4 — Trigger manual run**
+
+Go to the Actions tab in your repo and trigger `workflow_dispatch` to verify the first run works and the `.prev` files are created.
+
+**Step 5 — Update Cleanuparr**
+
+Point Cleanuparr's Malware Blocker and Blacklist Sync at your Gitea raw URL:
+```
+https://git.hisp.no/arr/blocklists/raw/branch/main/blacklist_permissive
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