diff --git a/.github/workflows/update-index.yml b/.github/workflows/update-index.yml
index 554097bc71a..1093d95cda5 100644
--- a/.github/workflows/update-index.yml
+++ b/.github/workflows/update-index.yml
@@ -30,7 +30,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/setup-go@v1
+      - uses: actions/setup-go@v5
         with:
           go-version: 1.19
       - uses: actions/checkout@v4
@@ -67,36 +67,61 @@ jobs:
           else
             echo "exists=false" >> $GITHUB_OUTPUT;
           fi
-  
+
   run-linter:
     runs-on: ubuntu-latest
     needs: build
     steps:
-      - name: set up python
-        uses: actions/setup-python@v5
-        with:
-          python-version: '3.12'
       - name: checkout repo
         uses: actions/checkout@v4
         with:
           fetch-depth: 0
           ref: ${{ github.ref }}
-      - name: install pipenv
-        run: |
-          python -m pip install --upgrade pip
-          pip install pipenv
+      - name: set up python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+          cache: 'pipenv'
       - name: install dependencies
         run: |
-          pipenv install --deploy --python 3.12
+          python -m pip install --upgrade pipenv wheel
+          pipenv install --deploy
       - name: hub linter
         run: |
           pipenv run ./hublint defaults > .hublint.toml
           pipenv run ./hublint check --color always --no-warning-details
 
+  run-mkindex:
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: checkout repo
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          ref: ${{ github.ref }}
+      - name: set up python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+          cache: 'pipenv'
+      - name: install dependencies
+        run: |
+          python -m pip install --upgrade pipenv wheel
+          pipenv install --deploy
+      - name: run mkindex
+        run: |
+          jq --sort-keys < .index.json >index.json
+          pipenv run ./mkindex >index-new.json
+          if ! (cmp -s index.json index-new.json); then
+              echo "Error: output from mkindex differs from legacy index builder."
+              diff -u index.json index-new.json
+              exit 1
+          fi
 
   invalidate-cache:
     runs-on: ubuntu-latest
-    needs: 
+    needs:
       - build
       - check-secret
       - run-linter
@@ -124,7 +149,7 @@ jobs:
       - name: Invalidate cache
         run: |
           create_invalidation() {
-            #$1 is not quotted on purpose, so it can be expanded to multiple arguments
+            #$1 is not quoted on purpose, so it can be expanded to multiple arguments
             aws cloudfront create-invalidation --distribution-id ${{ secrets.CF_DISTRIBUTION_ID }} --paths $1
           }
           PATHS="/${{ env.version }}/.index.json"
diff --git a/mkindex b/mkindex
new file mode 100755
index 00000000000..510730eb7ee
--- /dev/null
+++ b/mkindex
@@ -0,0 +1,230 @@
+#!/usr/bin/env python3
+
+import base64
+import decimal
+from dataclasses import dataclass
+import hashlib
+import itertools
+import json
+from pathlib import Path
+from typing import Iterable
+import yaml
+
+
+class HubType(str):
+    pass
+
+
+hubtypes: list[HubType] = [
+    HubType("appsec-configs"),
+    HubType("appsec-rules"),
+    HubType("collections"),
+    HubType("contexts"),
+    HubType("parsers"),
+    HubType("postoverflows"),
+    HubType("scenarios"),
+]
+
+
+class AuthorName(str):
+    pass
+
+
+class ItemName(str):
+    pass
+
+
+class Content(str):
+    pass
+
+
+@dataclass
+class VersionDetail:
+    deprecated: bool
+    digest: str
+
+
+@dataclass
+class Item:
+    path: str
+    author: AuthorName
+    content: Content
+    long_description: str | None
+    version: str
+    versions: dict[str, VersionDetail]
+    labels: dict[str, str] | None = None
+    stage: str | None = None
+    references: list[str] | None = None
+
+    appsec_configs: list[str] | None = None
+    appsec_rules: list[str] | None = None
+    collections: list[str] | None = None
+    contexts: list[str] | None = None
+    parsers: list[str] | None = None
+    postoverflows: list[str] | None = None
+    scenarios: list[str] | None = None
+
+    def set_versions(self, prev_versions: dict):
+        content_hash = hashlib.sha256(base64.b64decode(self.content)).hexdigest()
+
+        last_version = decimal.Decimal('0.0')
+
+        for version_number, detail in prev_versions.items():
+            version_decimal = decimal.Decimal(version_number)
+            if version_decimal > last_version:
+                last_version = version_decimal
+            self.versions[version_number] = VersionDetail(deprecated=detail.get('deprecated', False), digest=detail['digest'])
+            if content_hash == detail['digest']:
+                self.version = version_number
+
+        if self.version == '':
+            last_version += decimal.Decimal('0.1')
+            self.version = str(last_version)
+            self.versions[self.version] = VersionDetail(deprecated=False, digest=content_hash)
+
+
+    def content_as_dicts(self):
+        return yaml.safe_load_all(base64.b64decode(self.content))
+
+    def set_meta_from_content(self):
+        contents = list(self.content_as_dicts())
+        content = contents[0]
+        # XXX: ignore multiple documents after the first one
+        if 'labels' in content:
+            self.labels = content['labels']
+        if 'description' in content:
+            self.description = content['description']
+        if 'references' in content:
+            self.references = content['references']
+
+        if 'appsec-configs' in content:
+            self.appsec_configs = content['appsec-configs']
+        if 'appsec-rules' in content:
+            self.appsec_rules = content['appsec-rules']
+        if 'collections' in content:
+            self.collections = content['collections']
+        if 'contexts' in content:
+            self.contexts = content['contexts']
+        if 'parsers' in content:
+            self.parsers = content['parsers']
+        if 'postoverflows' in content:
+            self.postoverflows = content['postoverflows']
+        if 'scenarios' in content:
+            self.scenarios = content['scenarios']
+
+
+class CustomEncoder(json.JSONEncoder):
+    def default(self, o):
+        if isinstance(o, Item):
+            d = o.__dict__
+            # remove None or ''
+            if 'long_description' in d and not d.get('long_description'):
+                del d['long_description']
+            if 'description' in d and not d.get('description'):
+                del d['description']
+            for key in list(d):
+                if key == 'labels':
+                    # retain None for legacy
+                    continue
+                # remove None from dependency lists
+                if d[key] is None:
+                    del d[key]
+            if 'appsec_configs' in d:
+                d['appsec-configs'] = d.pop('appsec_configs')
+            if 'appsec_rules' in d:
+                d['appsec-rules'] = d.pop('appsec_rules')
+            return d
+        if isinstance(o, VersionDetail):
+            return o.__dict__
+        return super().default(o)
+
+
+type Index = dict[HubType, dict[str, Item]]
+
+
+class IndexUpdater:
+    def __init__(self, index: Index):
+        self.prev_index: dict = index
+        self.new_index = {}
+
+    def parse_dir(self, root: Path):
+        index: Index = {}
+        for hubtype, _, author, name, item in iter_types(root):
+            index.setdefault(hubtype, {})
+            index[hubtype][f"{author}/{name}"] = item
+
+        # copy previous versions from previous index
+        for hubtype, items in index.items():
+            for full_name, item in items.items():
+                prev_versions = {}
+                try:
+                    prev_versions = self.prev_index[hubtype][full_name]['versions']
+                except KeyError:
+                    pass
+
+                item.set_versions(prev_versions)
+                item.set_meta_from_content()
+
+        self.new_index = index
+
+    def index_json(self) -> str:
+        return json.dumps(self.new_index, sort_keys=True, indent=2, cls=CustomEncoder)
+
+
+def iter_items(authordir: Path, stage_name: str | None) -> Iterable[tuple[AuthorName, ItemName, Item]]:
+    for p in itertools.chain(authordir.glob("*/*.yaml"), authordir.glob("*/*.yml")):
+        content = Content(base64.b64encode(p.read_bytes()).decode())
+        author = AuthorName(p.parent.name)
+
+        suffix = ''
+        if p.name.endswith(".yaml"):
+            suffix = ".yaml"
+        elif p.name.endswith(".yml"):
+            suffix = ".yml"
+
+        name = ItemName(p.name.removesuffix(suffix))
+
+        try:
+            long_description = base64.b64encode(p.parent.joinpath(name+'.md').read_bytes()).decode()
+        except FileNotFoundError:
+            long_description = None
+
+        yield author, name, Item(path=p.as_posix(),
+                                 author=author,
+                                 content=content,
+                                 version='',
+                                 versions={},
+                                 long_description=long_description,
+                                 stage=stage_name)
+
+
+def iter_stages(typedir: Path) -> Iterable[tuple[str | None, AuthorName, ItemName, Item]]:
+    hubtype = typedir.name
+    if hubtype in ["parsers", "postoverflows"]:
+        for stage in typedir.iterdir():
+            for author, name, item in iter_items(stage, stage.name):
+                yield stage.name, author, name, item
+    else:
+        for author, name, item in iter_items(typedir, None):
+            yield None, author, name, item
+
+
+def iter_types(root: Path) -> Iterable[tuple[HubType, str | None, AuthorName, ItemName, Item]]:
+    for hubtype in root.iterdir():
+        if hubtype.name not in hubtypes:
+            continue
+        if not hubtype.is_dir():
+            continue
+        for stage_name, author, name, item in iter_stages(hubtype):
+            yield HubType(hubtype.name), stage_name, author, name, item
+
+
+def main():
+    prev_index = json.loads(Path('.index.json').read_text())
+    up = IndexUpdater(prev_index)
+    up.parse_dir(Path('.'))
+    print(up.index_json())
+
+
+if __name__ == "__main__":
+    main()