Simplify the serializer checks

Enforce delete_document too
batch_update for index removal
2026-08-13 22:33:19 +00:00 · 2026-08-13 14:57:05 -07:00 · 2026-08-13 14:57:04 -07:00 · 2026-08-13 14:57:04 -07:00 · 2026-08-13 14:57:04 -07:00 · 2026-08-13 14:57:04 -07:00
64 changed files with 2536 additions and 223 deletions
@@ -299,6 +299,8 @@ optional arguments:
 -sm, --split-manifest
 -z,  --zip
 -zn, --zip-name
+--zip-compression
+--zip-compression-level
 --data-only
 --no-progress-bar
 --passphrase
@@ -361,6 +363,19 @@ If `-z` or `--zip` is provided, the export will be a zip file
 in the target directory, named according to the current local date or the
 value set in `-zn` or `--zip-name`.

+The compression method for the zip can be set with `--zip-compression`
+(`stored`, `deflated` (default), `bzip2`, `lzma`, or `zstd`) and tuned with
+`--zip-compression-level` (deflated: 0–9, bzip2: 1–9, zstd: -22–22; ignored
+for `stored` and `lzma`). Both options require `--zip`.
+
+!!! warning
+
+    `zstd` compression requires Python 3.14 or newer on **both** the machine
+    creating the export and any machine importing it. An archive compressed with
+    `zstd` (or `lzma`/`bzip2` where those modules are unavailable) cannot be
+    imported on a runtime that lacks the codec; the importer will refuse it with
+    a clear error. The default `deflated` is universally readable.
+
 If `--data-only` is provided, only the database will be exported. This option is intended
 to facilitate database upgrades without needing to clean documents and thumbnails from the media directory.

@@ -227,6 +227,7 @@ Version-aware endpoints:
 - `PATCH /api/documents/{id}/`: content updates target the selected version (`?version={version_id}`) or latest version by default; non-content metadata updates target the root document.
 - `GET /api/documents/{id}/download/`, `GET /api/documents/{id}/preview/`, `GET /api/documents/{id}/thumb/`, `GET /api/documents/{id}/metadata/`: accept `?version={version_id}`.
 - `POST /api/documents/{id}/update_version/`: uploads a new version using multipart form field `document` and optional `version_label`.
+- `POST /api/documents/merge_as_versions/`: merges existing top-level documents as versions of a selected root. The JSON body must contain `documents` (at least two document IDs) and `root_document_id` (one of those IDs). When merging one source document, an optional `version_label` may be provided.
 - `PATCH /api/documents/{id}/versions/{version_id}/`: updates the `version_label` of a specific version.
 - `DELETE /api/documents/{root_id}/versions/{version_id}/`: deletes a non-root version.

@@ -99,6 +99,10 @@ Think of versions as **file history** for a document.
 - By default, search and document content use the latest version.
 - In document detail, selecting a version switches the preview, file metadata and content (and download etc buttons) to that version.
 - Deleting a non-root version keeps metadata and falls back to the latest remaining version.
+- From the document list, select two or more documents and choose **Merge as versions** to combine them under one entry. Select the root document whose metadata and permissions should be retained; the other selected documents become file versions. The root may already have versions, but documents being added as versions must not have version histories of their own.
+- From a document's **Versions** menu, choose **Existing** to search for another document and add it as a version of the current document.
+- Documents merged as versions give up their archive serial number. If the root has no ASN of its own it takes the first one, otherwise the ASNs are released and the removal is logged.
+- Merging as versions cannot be undone from the UI, and deleting the root document moves its versions to the trash as well.

 ### Management Lists

@@ -539,7 +539,7 @@
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/common/confirm-dialog/confirm-dialog.component.ts</context>
-          <context context-type="linenumber">47</context>
+          <context context-type="linenumber">54</context>
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/common/edit-dialog/correspondent-edit-dialog/correspondent-edit-dialog.component.html</context>
@@ -3098,15 +3098,15 @@
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">919</context>
+          <context context-type="linenumber">910</context>
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">955</context>
+          <context context-type="linenumber">946</context>
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">978</context>
+          <context context-type="linenumber">969</context>
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/manage/document-attributes/custom-fields/custom-fields.component.ts</context>
@@ -3684,14 +3684,14 @@
        <source>Confirmation</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/common/confirm-dialog/confirm-dialog.component.ts</context>
-          <context context-type="linenumber">23</context>
+          <context context-type="linenumber">30</context>
        </context-group>
      </trans-unit>
      <trans-unit id="9178182467454450952" datatype="html">
        <source>Confirm</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/common/confirm-dialog/confirm-dialog.component.ts</context>
-          <context context-type="linenumber">35</context>
+          <context context-type="linenumber">42</context>
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/common/permissions-dialog/permissions-dialog.component.html</context>
@@ -3703,27 +3703,27 @@
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">556</context>
+          <context context-type="linenumber">547</context>
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">596</context>
+          <context context-type="linenumber">587</context>
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">634</context>
+          <context context-type="linenumber">625</context>
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">672</context>
+          <context context-type="linenumber">663</context>
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">734</context>
+          <context context-type="linenumber">725</context>
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">867</context>
+          <context context-type="linenumber">858</context>
        </context-group>
      </trans-unit>
      <trans-unit id="994016933065248559" datatype="html">
@@ -5743,7 +5743,7 @@
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">871</context>
+          <context context-type="linenumber">862</context>
        </context-group>
      </trans-unit>
      <trans-unit id="4522609911791833187" datatype="html">
@@ -7613,7 +7613,7 @@
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">501</context>
+          <context context-type="linenumber">492</context>
        </context-group>
        <note priority="1" from="description">this string is used to separate processing, failed and added on the file upload widget</note>
      </trans-unit>
@@ -8148,7 +8148,7 @@
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">869</context>
+          <context context-type="linenumber">860</context>
        </context-group>
      </trans-unit>
      <trans-unit id="7295637485862454066" datatype="html">
@@ -8166,7 +8166,7 @@
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">915</context>
+          <context context-type="linenumber">906</context>
        </context-group>
      </trans-unit>
      <trans-unit id="2951161989614003846" datatype="html">
@@ -8523,18 +8523,18 @@
        <source>&quot;<x id="PH" equiv-text="items[0].name"/>&quot;</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">493</context>
+          <context context-type="linenumber">484</context>
        </context-group>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">499</context>
+          <context context-type="linenumber">490</context>
        </context-group>
      </trans-unit>
      <trans-unit id="8639884465898458690" datatype="html">
        <source>&quot;<x id="PH" equiv-text="items[0].name"/>&quot; and &quot;<x id="PH_1" equiv-text="items[1].name"/>&quot;</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">495</context>
+          <context context-type="linenumber">486</context>
        </context-group>
        <note priority="1" from="description">This is for messages like &apos;modify &quot;tag1&quot; and &quot;tag2&quot;&apos;</note>
      </trans-unit>
@@ -8542,7 +8542,7 @@
        <source><x id="PH" equiv-text="list"/> and &quot;<x id="PH_1" equiv-text="items[items.length - 1].name"/>&quot;</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">503,505</context>
+          <context context-type="linenumber">494,496</context>
        </context-group>
        <note priority="1" from="description">this is for messages like &apos;modify &quot;tag1&quot;, &quot;tag2&quot; and &quot;tag3&quot;&apos;</note>
      </trans-unit>
@@ -8550,14 +8550,14 @@
        <source>Confirm tags assignment</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">520</context>
+          <context context-type="linenumber">511</context>
        </context-group>
      </trans-unit>
      <trans-unit id="6619516195038467207" datatype="html">
        <source>This operation will add the tag &quot;<x id="PH" equiv-text="tag.name"/>&quot; to <x id="PH_1" equiv-text="this.getSelectionSize()"/> selected document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">526</context>
+          <context context-type="linenumber">517</context>
        </context-group>
      </trans-unit>
      <trans-unit id="1894412783609570695" datatype="html">
@@ -8566,14 +8566,14 @@
        )"/> to <x id="PH_1" equiv-text="this.getSelectionSize()"/> selected document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">531,533</context>
+          <context context-type="linenumber">522,524</context>
        </context-group>
      </trans-unit>
      <trans-unit id="7181166515756808573" datatype="html">
        <source>This operation will remove the tag &quot;<x id="PH" equiv-text="tag.name"/>&quot; from <x id="PH_1" equiv-text="this.getSelectionSize()"/> selected document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">539</context>
+          <context context-type="linenumber">530</context>
        </context-group>
      </trans-unit>
      <trans-unit id="3819792277998068944" datatype="html">
@@ -8582,7 +8582,7 @@
        )"/> from <x id="PH_1" equiv-text="this.getSelectionSize()"/> selected document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">544,546</context>
+          <context context-type="linenumber">535,537</context>
        </context-group>
      </trans-unit>
      <trans-unit id="2739066218579571288" datatype="html">
@@ -8593,84 +8593,84 @@
        )"/> on <x id="PH_2" equiv-text="this.getSelectionSize()"/> selected document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">548,552</context>
+          <context context-type="linenumber">539,543</context>
        </context-group>
      </trans-unit>
      <trans-unit id="2996713129519325161" datatype="html">
        <source>Confirm correspondent assignment</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">589</context>
+          <context context-type="linenumber">580</context>
        </context-group>
      </trans-unit>
      <trans-unit id="6900893559485781849" datatype="html">
        <source>This operation will assign the correspondent &quot;<x id="PH" equiv-text="correspondent.name"/>&quot; to <x id="PH_1" equiv-text="this.getSelectionSize()"/> selected document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">591</context>
+          <context context-type="linenumber">582</context>
        </context-group>
      </trans-unit>
      <trans-unit id="1257522660364398440" datatype="html">
        <source>This operation will remove the correspondent from <x id="PH" equiv-text="this.getSelectionSize()"/> selected document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">593</context>
+          <context context-type="linenumber">584</context>
        </context-group>
      </trans-unit>
      <trans-unit id="5393409374423140648" datatype="html">
        <source>Confirm document type assignment</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">627</context>
+          <context context-type="linenumber">618</context>
        </context-group>
      </trans-unit>
      <trans-unit id="332180123895325027" datatype="html">
        <source>This operation will assign the document type &quot;<x id="PH" equiv-text="documentType.name"/>&quot; to <x id="PH_1" equiv-text="this.getSelectionSize()"/> selected document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">629</context>
+          <context context-type="linenumber">620</context>
        </context-group>
      </trans-unit>
      <trans-unit id="2236642492594872779" datatype="html">
        <source>This operation will remove the document type from <x id="PH" equiv-text="this.getSelectionSize()"/> selected document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">631</context>
+          <context context-type="linenumber">622</context>
        </context-group>
      </trans-unit>
      <trans-unit id="6386555513013840736" datatype="html">
        <source>Confirm storage path assignment</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">665</context>
+          <context context-type="linenumber">656</context>
        </context-group>
      </trans-unit>
      <trans-unit id="8750527458618415924" datatype="html">
        <source>This operation will assign the storage path &quot;<x id="PH" equiv-text="storagePath.name"/>&quot; to <x id="PH_1" equiv-text="this.getSelectionSize()"/> selected document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">667</context>
+          <context context-type="linenumber">658</context>
        </context-group>
      </trans-unit>
      <trans-unit id="60728365335056946" datatype="html">
        <source>This operation will remove the storage path from <x id="PH" equiv-text="this.getSelectionSize()"/> selected document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">669</context>
+          <context context-type="linenumber">660</context>
        </context-group>
      </trans-unit>
      <trans-unit id="4187352575310415704" datatype="html">
        <source>Confirm custom field assignment</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">698</context>
+          <context context-type="linenumber">689</context>
        </context-group>
      </trans-unit>
      <trans-unit id="7966494636326273856" datatype="html">
        <source>This operation will assign the custom field &quot;<x id="PH" equiv-text="customField.name"/>&quot; to <x id="PH_1" equiv-text="this.getSelectionSize()"/> selected document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">704</context>
+          <context context-type="linenumber">695</context>
        </context-group>
      </trans-unit>
      <trans-unit id="5789455969634598553" datatype="html">
@@ -8679,14 +8679,14 @@
        )"/> to <x id="PH_1" equiv-text="this.getSelectionSize()"/> selected document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">709,711</context>
+          <context context-type="linenumber">700,702</context>
        </context-group>
      </trans-unit>
      <trans-unit id="5648572354333199245" datatype="html">
        <source>This operation will remove the custom field &quot;<x id="PH" equiv-text="customField.name"/>&quot; from <x id="PH_1" equiv-text="this.getSelectionSize()"/> selected document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">717</context>
+          <context context-type="linenumber">708</context>
        </context-group>
      </trans-unit>
      <trans-unit id="6666899594015948817" datatype="html">
@@ -8695,7 +8695,7 @@
        )"/> from <x id="PH_1" equiv-text="this.getSelectionSize()"/> selected document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">722,724</context>
+          <context context-type="linenumber">713,715</context>
        </context-group>
      </trans-unit>
      <trans-unit id="8050047262594964176" datatype="html">
@@ -8706,91 +8706,91 @@
        )"/> on <x id="PH_2" equiv-text="this.getSelectionSize()"/> selected document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">726,730</context>
+          <context context-type="linenumber">717,721</context>
        </context-group>
      </trans-unit>
      <trans-unit id="8615059324209654051" datatype="html">
        <source>Move <x id="PH" equiv-text="this.getSelectionSize()"/> selected document(s) to the trash?</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">868</context>
+          <context context-type="linenumber">859</context>
        </context-group>
      </trans-unit>
      <trans-unit id="8585195717323764335" datatype="html">
        <source>This operation will permanently recreate the archive files for <x id="PH" equiv-text="this.getSelectionSize()"/> selected document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">916</context>
+          <context context-type="linenumber">907</context>
        </context-group>
      </trans-unit>
      <trans-unit id="7366623494074776040" datatype="html">
        <source>The archive files will be re-generated with the current settings.</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">917</context>
+          <context context-type="linenumber">908</context>
        </context-group>
      </trans-unit>
      <trans-unit id="6555329262222566158" datatype="html">
        <source>Rotate confirm</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">952</context>
+          <context context-type="linenumber">943</context>
        </context-group>
      </trans-unit>
      <trans-unit id="5203024009814367559" datatype="html">
        <source>This operation will add rotated versions of the <x id="PH" equiv-text="this.getSelectionSize()"/> document(s).</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">953</context>
+          <context context-type="linenumber">944</context>
        </context-group>
      </trans-unit>
      <trans-unit id="7910756456450124185" datatype="html">
        <source>Merge confirm</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">976</context>
+          <context context-type="linenumber">967</context>
        </context-group>
      </trans-unit>
      <trans-unit id="7643543647233874431" datatype="html">
        <source>This operation will merge <x id="PH" equiv-text="this.getSelectionSize()"/> selected documents into a new document.</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">977</context>
+          <context context-type="linenumber">968</context>
        </context-group>
      </trans-unit>
      <trans-unit id="7869008840945899895" datatype="html">
        <source>Merged document will be queued for consumption.</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">1000</context>
+          <context context-type="linenumber">991</context>
        </context-group>
      </trans-unit>
      <trans-unit id="476913782630693351" datatype="html">
        <source>Custom fields updated.</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">1025</context>
+          <context context-type="linenumber">1016</context>
        </context-group>
      </trans-unit>
      <trans-unit id="3873496751167944011" datatype="html">
        <source>Error updating custom fields.</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">1034</context>
+          <context context-type="linenumber">1025</context>
        </context-group>
      </trans-unit>
      <trans-unit id="6144801143088984138" datatype="html">
        <source>Share link bundle creation requested.</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">1082</context>
+          <context context-type="linenumber">1073</context>
        </context-group>
      </trans-unit>
      <trans-unit id="46019676931295023" datatype="html">
        <source>Share link bundle creation is not available yet.</source>
        <context-group purpose="location">
          <context context-type="sourcefile">src/app/components/document-list/bulk-editor/bulk-editor.component.ts</context>
-          <context context-type="linenumber">1089</context>
+          <context context-type="linenumber">1080</context>
        </context-group>
      </trans-unit>
      <trans-unit id="6307402210351946694" datatype="html">
@@ -576,7 +576,7 @@ describe('TasksComponent', () => {

    expect(dismissSpy).toHaveBeenCalledWith(new Set([tasks[0].id, tasks[1].id]))
    expect(toastSpy).toHaveBeenCalledWith('Error dismissing tasks', error)
-    expect(modal.componentInstance.buttonsEnabled).toBe(true)
+    expect(modal.componentInstance.buttonsEnabled()).toBe(true)
    expect(component.selectedTasks.size).toBe(0)
  })

@@ -642,7 +642,7 @@ describe('TasksComponent', () => {

    expect(dismissSpy).toHaveBeenCalled()
    expect(toastSpy).toHaveBeenCalledWith('Error dismissing tasks', error)
-    expect(modal.componentInstance.buttonsEnabled).toBe(true)
+    expect(modal.componentInstance.buttonsEnabled()).toBe(true)
  })

  it('should dismiss the currently visible scoped and filtered tasks', () => {
@@ -316,7 +316,7 @@ export class TasksComponent
      modal.componentInstance.btnClass = 'btn-warning'
      modal.componentInstance.btnCaption = $localize`Dismiss`
      modal.componentInstance.confirmClicked.pipe(first()).subscribe(() => {
-        modal.componentInstance.buttonsEnabled = false
+        modal.componentInstance.buttonsEnabled.set(false)
        modal.close()
        this.tasksService.dismissTasks(tasks).subscribe({
          next: () => {
@@ -324,7 +324,7 @@ export class TasksComponent
          },
          error: (e) => {
            this.toastService.showError($localize`Error dismissing tasks`, e)
-            modal.componentInstance.buttonsEnabled = true
+            modal.componentInstance.buttonsEnabled.set(true)
          },
        })
        this.clearSelection()
@@ -350,7 +350,7 @@ export class TasksComponent
    modal.componentInstance.btnClass = 'btn-warning'
    modal.componentInstance.btnCaption = $localize`Dismiss`
    modal.componentInstance.confirmClicked.pipe(first()).subscribe(() => {
-      modal.componentInstance.buttonsEnabled = false
+      modal.componentInstance.buttonsEnabled.set(false)
      modal.close()
      this.tasksService.dismissAllTasks().subscribe({
        next: () => {
@@ -358,7 +358,7 @@ export class TasksComponent
        },
        error: (e) => {
          this.toastService.showError($localize`Error dismissing tasks`, e)
-          modal.componentInstance.buttonsEnabled = true
+          modal.componentInstance.buttonsEnabled.set(true)
        },
      })
      this.clearSelection()
@@ -82,7 +82,7 @@ export class TrashComponent
    modal.componentInstance.confirmClicked
      .pipe(takeUntil(this.unsubscribeNotifier))
      .subscribe(() => {
-        modal.componentInstance.buttonsEnabled = false
+        modal.componentInstance.buttonsEnabled.set(false)
        this.trashService.emptyTrash([document.id]).subscribe({
          next: () => {
            this.toastService.showInfo(
@@ -146,7 +146,7 @@ export class UsersAndGroupsComponent
    modal.componentInstance.btnClass = 'btn-danger'
    modal.componentInstance.btnCaption = $localize`Proceed`
    modal.componentInstance.confirmClicked.subscribe(() => {
-      modal.componentInstance.buttonsEnabled = false
+      modal.componentInstance.buttonsEnabled.set(false)
      this.usersService.delete(user).subscribe({
        next: () => {
          modal.close()
@@ -199,7 +199,7 @@ export class UsersAndGroupsComponent
    modal.componentInstance.btnClass = 'btn-danger'
    modal.componentInstance.btnCaption = $localize`Proceed`
    modal.componentInstance.confirmClicked.subscribe(() => {
-      modal.componentInstance.buttonsEnabled = false
+      modal.componentInstance.buttonsEnabled.set(false)
      this.groupsService.delete(group).subscribe({
        next: () => {
          modal.close()
@@ -47,11 +47,12 @@

  .search-container {
    max-height: 4.5rem;
-    overflow: hidden;
+    overflow: visible;
    transition: max-height .2s ease, opacity .2s ease, padding-top .2s ease, padding-bottom .2s ease;

    &.mobile-hidden {
      max-height: 0;
+      overflow: hidden;
      opacity: 0;
      padding-top: 0 !important;
      padding-bottom: 0 !important;
@@ -12,10 +12,10 @@
  }
 </div>
 <div class="modal-footer">
-  <button type="button" class="btn" [class]="cancelBtnClass" (click)="cancel()" [disabled]="!buttonsEnabled">
+  <button type="button" class="btn" [class]="cancelBtnClass" (click)="cancel()" [disabled]="!buttonsEnabled()">
        <span class="d-inline-block" style="padding-bottom: 1px;">{{cancelBtnCaption}}</span>
      </button>
-  <button type="button" class="btn" [class]="btnClass" (click)="confirm()" [disabled]="!confirmButtonEnabled || !buttonsEnabled">
+  <button type="button" class="btn" [class]="btnClass" (click)="confirm()" [disabled]="!confirmButtonEnabled || !buttonsEnabled()">
    <span>
      {{btnCaption}}
      <span class="visually-hidden">{{ seconds | number: '1.0-0' }} seconds</span>
@@ -25,7 +25,7 @@
    }
  </button>
  @if (alternativeBtnCaption) {
-    <button type="button" class="btn" [class]="alternativeBtnClass" (click)="alternative()" [disabled]="!alternativeButtonEnabled || !buttonsEnabled">
+    <button type="button" class="btn" [class]="alternativeBtnClass" (click)="alternative()" [disabled]="!alternativeButtonEnabled || !buttonsEnabled()">
      {{alternativeBtnCaption}}
    </button>
  }
@@ -64,6 +64,22 @@ describe('ConfirmDialogComponent', () => {
    expect(confirmSubjectResult).toBeTruthy()
  })

+  it('should re-render the buttons when they are toggled from outside', async () => {
+    const confirmButton: HTMLButtonElement =
+      fixture.nativeElement.querySelectorAll('.modal-footer button')[1]
+    expect(confirmButton.disabled).toBeFalsy()
+
+    // Deliberately no detectChanges: a request callback toggling this is all
+    // that happens, and nothing else schedules a render for the modal
+    component.buttonsEnabled.set(false)
+    await fixture.whenStable()
+    expect(confirmButton.disabled).toBeTruthy()
+
+    component.buttonsEnabled.set(true)
+    await fixture.whenStable()
+    expect(confirmButton.disabled).toBeFalsy()
+  })
+
  it('should support cancel & close modal', () => {
    let confirmSubjectResult
    const closeModalSpy = jest.spyOn(modal, 'close')
@@ -1,5 +1,12 @@
 import { DecimalPipe } from '@angular/common'
-import { Component, EventEmitter, Input, Output, inject } from '@angular/core'
+import {
+  Component,
+  EventEmitter,
+  Input,
+  Output,
+  inject,
+  signal,
+} from '@angular/core'
 import { NgbActiveModal } from '@ng-bootstrap/ng-bootstrap'
 import { Subject } from 'rxjs'
 import { LoadingComponentWithPermissions } from '../../loading-component/loading.component'
@@ -46,8 +53,7 @@ export class ConfirmDialogComponent extends LoadingComponentWithPermissions {
  @Input()
  cancelBtnCaption = $localize`Cancel`

-  @Input()
-  buttonsEnabled = true
+  readonly buttonsEnabled = signal(true)

  confirmButtonEnabled = true
  alternativeButtonEnabled = true
@@ -0,0 +1,58 @@
+<div class="modal-header">
+  <h4 class="modal-title" id="modal-basic-title">{{title}}</h4>
+  <button type="button" class="btn-close" aria-label="Close" (click)="cancel()"></button>
+</div>
+<div class="modal-body">
+  <p>{{message}}</p>
+  <div class="form-group">
+    <label class="form-label" for="rootDocumentID" i18n>Root document:</label>
+    <select id="rootDocumentID" class="form-select" [ngModel]="rootDocumentID()" (ngModelChange)="rootDocumentID.set($event)">
+      @for (document of documents(); track document.id) {
+        <option [ngValue]="document.id">{{document.title}}</option>
+      }
+    </select>
+  </div>
+  <div class="form-group mt-4">
+    <span class="form-label d-inline-block" i18n>Versions (oldest first):</span>
+    <ul class="list-group"
+        cdkDropList
+        [cdkDropListData]="versionDocumentIDs()"
+        (cdkDropListDropped)="onDrop($event)">
+      @for (documentID of versionDocumentIDs(); track documentID) {
+        @let document = getDocument(documentID);
+        @if (document) {
+          <li class="list-group-item d-flex align-items-center" cdkDrag>
+            <i-bs name="grip-vertical" class="me-2"></i-bs>
+            <div class="d-flex flex-column">
+              <div>
+                @if (document.correspondent) {
+                  <b>{{document.correspondent | correspondentName | async}}: </b>
+                }{{document.title}}
+              </div>
+              <small class="text-muted">
+                {{document.created | customDate:'mediumDate'}}
+                @if (document.page_count) {
+                  | {document.page_count, plural, =1 {One page} other {{{document.page_count}} pages}}
+                }
+              </small>
+            </div>
+            @if ($last) {
+              <span class="badge bg-primary ms-auto" i18n>Current version</span>
+            }
+          </li>
+        }
+      }
+    </ul>
+    @if (versionDocumentIDs().length > 1) {
+      <div class="form-text" i18n>Drag to reorder.</div>
+    }
+  </div>
+</div>
+<div class="modal-footer">
+  <button type="button" class="btn" [class]="cancelBtnClass" (click)="cancel()" [disabled]="!buttonsEnabled()">
+    <span class="d-inline-block" style="padding-bottom: 1px;">{{cancelBtnCaption}}</span>
+  </button>
+  <button type="button" class="btn" [class]="btnClass" (click)="confirm()" [disabled]="!confirmButtonEnabled || !buttonsEnabled()">
+    {{btnCaption}}
+  </button>
+</div>
@@ -0,0 +1,3 @@
+.list-group-item {
+    cursor: move;
+}
@@ -0,0 +1,70 @@
+import { provideHttpClient, withInterceptorsFromDi } from '@angular/common/http'
+import { provideHttpClientTesting } from '@angular/common/http/testing'
+import { ComponentFixture, TestBed } from '@angular/core/testing'
+import { NgbActiveModal } from '@ng-bootstrap/ng-bootstrap'
+import { NgxBootstrapIconsModule, allIcons } from 'ngx-bootstrap-icons'
+import { of } from 'rxjs'
+import { DocumentService } from 'src/app/services/rest/document.service'
+import { MergeAsVersionsConfirmDialogComponent } from './merge-as-versions-confirm-dialog.component'
+
+describe('MergeAsVersionsConfirmDialogComponent', () => {
+  let component: MergeAsVersionsConfirmDialogComponent
+  let fixture: ComponentFixture<MergeAsVersionsConfirmDialogComponent>
+  let documentService: DocumentService
+
+  beforeEach(async () => {
+    await TestBed.configureTestingModule({
+      imports: [
+        NgxBootstrapIconsModule.pick(allIcons),
+        MergeAsVersionsConfirmDialogComponent,
+      ],
+      providers: [
+        NgbActiveModal,
+        provideHttpClient(withInterceptorsFromDi()),
+        provideHttpClientTesting(),
+      ],
+    }).compileComponents()
+
+    fixture = TestBed.createComponent(MergeAsVersionsConfirmDialogComponent)
+    documentService = TestBed.inject(DocumentService)
+    component = fixture.componentInstance
+    fixture.detectChanges()
+  })
+
+  it('should fetch selected documents', () => {
+    const documents = [
+      { id: 1, title: 'Document 1' },
+      { id: 2, title: 'Document 2' },
+    ]
+    jest.spyOn(documentService, 'getFew').mockReturnValue(
+      of({
+        all: [1, 2],
+        count: 2,
+        results: documents,
+      })
+    )
+    component.documentIDs.set([1, 2])
+
+    component.ngOnInit()
+
+    expect(component.documents()).toEqual(documents)
+    expect(documentService.getFew).toHaveBeenCalledWith([1, 2])
+  })
+
+  it('should exclude the root from the draggable documents', () => {
+    component.documentIDs.set([1, 2, 3])
+    component.rootDocumentID.set(2)
+
+    expect(component.versionDocumentIDs()).toEqual([1, 3])
+  })
+
+  it('should move draggable documents while keeping the root fixed', () => {
+    component.documentIDs.set([1, 2, 3])
+    component.rootDocumentID.set(1)
+
+    component.onDrop({ previousIndex: 1, currentIndex: 0 } as any)
+
+    expect(component.documentIDs()).toEqual([1, 3, 2])
+    expect(component.versionDocumentIDs()).toEqual([3, 2])
+  })
+})
@@ -0,0 +1,70 @@
+import {
+  CdkDragDrop,
+  DragDropModule,
+  moveItemInArray,
+} from '@angular/cdk/drag-drop'
+import { AsyncPipe } from '@angular/common'
+import { Component, OnInit, computed, inject, signal } from '@angular/core'
+import { FormsModule } from '@angular/forms'
+import { NgxBootstrapIconsModule } from 'ngx-bootstrap-icons'
+import { takeUntil } from 'rxjs'
+import { Document } from 'src/app/data/document'
+import { CorrespondentNamePipe } from 'src/app/pipes/correspondent-name.pipe'
+import { CustomDatePipe } from 'src/app/pipes/custom-date.pipe'
+import { DocumentService } from 'src/app/services/rest/document.service'
+import { ConfirmDialogComponent } from '../confirm-dialog.component'
+
+@Component({
+  selector: 'pngx-merge-as-versions-confirm-dialog',
+  templateUrl: './merge-as-versions-confirm-dialog.component.html',
+  styleUrl: './merge-as-versions-confirm-dialog.component.scss',
+  imports: [
+    AsyncPipe,
+    CorrespondentNamePipe,
+    CustomDatePipe,
+    DragDropModule,
+    FormsModule,
+    NgxBootstrapIconsModule,
+  ],
+})
+export class MergeAsVersionsConfirmDialogComponent
+  extends ConfirmDialogComponent
+  implements OnInit
+{
+  private readonly documentService = inject(DocumentService)
+
+  readonly documentIDs = signal<number[]>([])
+  readonly documents = signal<Document[]>([])
+  readonly rootDocumentID = signal(-1)
+  readonly versionDocumentIDs = computed(() =>
+    this.documentIDs().filter(
+      (documentID) => documentID !== this.rootDocumentID()
+    )
+  )
+
+  ngOnInit() {
+    this.documentService
+      .getFew(this.documentIDs())
+      .pipe(takeUntil(this.unsubscribeNotifier))
+      .subscribe((response) => this.documents.set(response.results))
+  }
+
+  onDrop(event: CdkDragDrop<number[]>) {
+    const versionDocumentIDs = this.versionDocumentIDs().concat()
+    moveItemInArray(versionDocumentIDs, event.previousIndex, event.currentIndex)
+
+    // The root keeps its place in the list, only the versions move around it
+    let versionIndex = 0
+    this.documentIDs.update((documentIDs) =>
+      documentIDs.map((documentID) =>
+        documentID === this.rootDocumentID()
+          ? documentID
+          : versionDocumentIDs[versionIndex++]
+      )
+    )
+  }
+
+  getDocument(documentID: number): Document | undefined {
+    return this.documents().find((document) => document.id === documentID)
+  }
+}
@@ -36,7 +36,7 @@
        </div>
    <div class="form-group mt-4">
        <label class="form-label" for="metadataDocumentID" i18n>Use metadata from:</label>
-        <select class="form-select" [ngModel]="metadataDocumentID()" (ngModelChange)="metadataDocumentID.set($event)">
+        <select id="metadataDocumentID" class="form-select" [ngModel]="metadataDocumentID()" (ngModelChange)="metadataDocumentID.set($event)">
            <option [ngValue]="-1" i18n>Regenerate all metadata</option>
            @for (document of documents(); track document.id) {
              <option [ngValue]="document.id">{{document.title}}</option>
@@ -56,10 +56,10 @@
    }
 </div>
 <div class="modal-footer">
-    <button type="button" class="btn" [class]="cancelBtnClass" (click)="cancel()" [disabled]="!buttonsEnabled">
+    <button type="button" class="btn" [class]="cancelBtnClass" (click)="cancel()" [disabled]="!buttonsEnabled()">
        <span class="d-inline-block" style="padding-bottom: 1px;">{{cancelBtnCaption}}</span>
    </button>
-    <button type="button" class="btn" [class]="btnClass" (click)="confirm()" [disabled]="!confirmButtonEnabled || !buttonsEnabled">
+    <button type="button" class="btn" [class]="btnClass" (click)="confirm()" [disabled]="!confirmButtonEnabled || !buttonsEnabled()">
        {{btnCaption}}
    </button>
 </div>
@@ -57,7 +57,7 @@
    class="btn"
    [class]="cancelBtnClass"
    (click)="cancel()"
-    [disabled]="!buttonsEnabled"
+    [disabled]="!buttonsEnabled()"
  >
    <span class="d-inline-block" style="padding-bottom: 1px;">
      {{cancelBtnCaption}}
@@ -68,7 +68,7 @@
    class="btn"
    [class]="btnClass"
    (click)="confirm()"
-    [disabled]="!confirmButtonEnabled || !buttonsEnabled"
+    [disabled]="!confirmButtonEnabled || !buttonsEnabled()"
  >
    {{btnCaption}}
  </button>
@@ -34,10 +34,10 @@
          <p class="mb-0 small"><b>{{messageBold}}</b></p>
        }
    </div>
-    <button type="button" class="btn" [class]="cancelBtnClass" (click)="cancel()" [disabled]="!buttonsEnabled">
+    <button type="button" class="btn" [class]="cancelBtnClass" (click)="cancel()" [disabled]="!buttonsEnabled()">
        <span class="d-inline-block" style="padding-bottom: 1px;">{{cancelBtnCaption}}</span>
    </button>
-    <button type="button" class="btn" [class]="btnClass" (click)="confirm()" [disabled]="!confirmButtonEnabled || !buttonsEnabled || degrees === 0">
+    <button type="button" class="btn" [class]="btnClass" (click)="confirm()" [disabled]="!confirmButtonEnabled || !buttonsEnabled() || degrees === 0">
      {{btnCaption}}
      @if (!confirmButtonEnabled) {
          <ngb-progressbar style="height: 1px;" type="dark" [max]="secondsTotal" [value]="seconds"></ngb-progressbar>
@@ -100,7 +100,7 @@
      </div>
    }
    <div class="form-group ms-md-auto">
-      <button type="button" class="btn me-2" [class]="cancelBtnClass" (click)="cancel()" [disabled]="!buttonsEnabled">{{ cancelBtnCaption }}</button>
+      <button type="button" class="btn me-2" [class]="cancelBtnClass" (click)="cancel()" [disabled]="!buttonsEnabled()">{{ cancelBtnCaption }}</button>
      <button type="button" class="btn" [class]="btnClass" (click)="confirm()" [disabled]="pages.length === 0">{{ btnCaption }}</button>
    </div>
  </div>
@@ -119,7 +119,7 @@
        type="button"
        class="btn btn-primary btn-sm d-inline-flex align-items-center gap-2 text-nowrap"
        (click)="submit()"
-        [disabled]="loading() || !buttonsEnabled">
+        [disabled]="loading() || !buttonsEnabled()">
        @if (loading()) {
          <span class="spinner-border spinner-border-sm" role="status" aria-hidden="true"></span>
        }
@@ -69,7 +69,7 @@ describe('ShareLinkBundleDialogComponent', () => {
      file_version: FileVersion.Original,
      expiration_days: 3,
    })
-    expect(component.buttonsEnabled).toBe(false)
+    expect(component.buttonsEnabled()).toBe(false)
    expect(confirmSpy).toHaveBeenCalled()

    component.form.setValue({
@@ -78,7 +78,7 @@ export class ShareLinkBundleDialogComponent extends ConfirmDialogComponent {
        : FileVersion.Original,
      expiration_days: this.form.value.expirationDays,
    }
-    this.buttonsEnabled = false
+    this.buttonsEnabled.set(false)
    super.confirm()
  }

@@ -467,13 +467,6 @@ describe('DocumentDetailComponent', () => {
    const docWithVersions = {
      ...doc,
      versions: [
-        {
-          id: doc.id,
-          added: new Date('2024-01-01T00:00:00Z'),
-          version_label: 'Original',
-          checksum: 'aaaa',
-          is_root: true,
-        },
        {
          id: 10,
          added: new Date('2024-01-02T00:00:00Z'),
@@ -481,6 +474,13 @@ describe('DocumentDetailComponent', () => {
          checksum: 'bbbb',
          is_root: false,
        },
+        {
+          id: doc.id,
+          added: new Date('2024-01-01T00:00:00Z'),
+          version_label: 'Original',
+          checksum: 'aaaa',
+          is_root: true,
+        },
      ],
    } as Document

@@ -1232,8 +1232,8 @@ describe('DocumentDetailComponent', () => {

    metadataSpy.mockClear()
    component.document().versions = [
-      { id: doc.id, is_root: true },
      { id: 10, is_root: false },
+      { id: doc.id, is_root: true },
    ] as any
    jest.spyOn(documentService, 'getPreviewUrl').mockReturnValue('preview-root')
    jest.spyOn(documentService, 'getThumbUrl').mockReturnValue('thumb-root')
@@ -1564,7 +1564,7 @@ describe('DocumentDetailComponent', () => {
    dialog.confirmClicked.next()
    await openModal.result

-    expect(dialog.buttonsEnabled).toBe(false)
+    expect(dialog.buttonsEnabled()).toBe(false)
    expect(reloadSpy).toHaveBeenCalled()
    expect((component as any).incomingUpdateModal).toBeNull()
  })
@@ -1789,7 +1789,7 @@ describe('DocumentDetailComponent', () => {

    expect(errorSpy).toHaveBeenCalled()
    expect(component.networkActive()).toBe(false)
-    expect(dialog.buttonsEnabled).toBe(true)
+    expect(dialog.buttonsEnabled()).toBe(true)
  })

  it('should refresh the document when removing password in update mode', () => {
@@ -1929,8 +1929,8 @@ describe('DocumentDetailComponent', () => {
    component.documentId.set(doc.id)
    component.document.set({ ...doc, versions: [] } as Document)
    const updatedVersions = [
-      { id: doc.id, is_root: true },
      { id: 10, is_root: false },
+      { id: doc.id, is_root: true },
    ] as any
    const openDoc = { ...doc, versions: [] } as Document
    jest.spyOn(openDocumentsService, 'getOpenDocument').mockReturnValue(openDoc)
@@ -2046,8 +2046,8 @@ describe('DocumentDetailComponent', () => {
  it('should include version in download and print only for non-latest selected version', () => {
    initNormally()
    component.document().versions = [
-      { id: doc.id, is_root: true },
      { id: 10, is_root: false },
+      { id: doc.id, is_root: true },
    ] as any

    const getDownloadUrlSpy = jest
@@ -659,7 +659,7 @@ export class DocumentDetailComponent
    modal.componentInstance.cancelBtnCaption = $localize`Dismiss`

    modal.componentInstance.confirmClicked.pipe(first()).subscribe(() => {
-      modal.componentInstance.buttonsEnabled = false
+      modal.componentInstance.buttonsEnabled.set(false)
      modal.close()
      this.reloadRemoteVersion()
    })
@@ -889,13 +889,9 @@ export class DocumentDetailComponent

  updateComponent(doc: Document) {
    this.document.set(doc)
-    // Default selected version is the newest version
+    // Default selected version is the newest version, which the API returns first
    const versions = doc.versions ?? []
-    this.selectedVersionId.set(
-      versions.length
-        ? Math.max(...versions.map((version) => version.id))
-        : doc.id
-    )
+    this.selectedVersionId.set(versions.length ? versions[0].id : doc.id)
    this.previewLoaded.set(false)
    this.requiresPassword = false
    this.updateFormForCustomFields()
@@ -1374,7 +1370,7 @@ export class DocumentDetailComponent
    modal.componentInstance.confirmClicked
      .pipe(
        switchMap(() => {
-          modal.componentInstance.buttonsEnabled = false
+          modal.componentInstance.buttonsEnabled.set(false)
          return this.documentsService.delete(this.document())
        })
      )
@@ -1386,7 +1382,7 @@ export class DocumentDetailComponent
        },
        error: (error) => {
          this.toastService.showError($localize`Error deleting document`, error)
-          modal.componentInstance.buttonsEnabled = true
+          modal.componentInstance.buttonsEnabled.set(true)
          this.subscribeModalDelete(modal)
        },
      })
@@ -1411,7 +1407,7 @@ export class DocumentDetailComponent
    modal.componentInstance.btnClass = 'btn-danger'
    modal.componentInstance.btnCaption = $localize`Proceed`
    modal.componentInstance.confirmClicked.subscribe(() => {
-      modal.componentInstance.buttonsEnabled = false
+      modal.componentInstance.buttonsEnabled.set(false)
      this.documentsService
        .reprocessDocuments({ documents: [this.document().id] })
        .subscribe({
@@ -1425,7 +1421,7 @@ export class DocumentDetailComponent
          },
          error: (error) => {
            if (modal) {
-              modal.componentInstance.buttonsEnabled = true
+              modal.componentInstance.buttonsEnabled.set(true)
            }
            this.toastService.showError(
              $localize`Error executing operation`,
@@ -1441,7 +1437,8 @@ export class DocumentDetailComponent
    if (!versions.length || !this.selectedVersionId()) {
      return null
    }
-    const latestVersionId = Math.max(...versions.map((version) => version.id))
+    // The API returns versions newest first
+    const latestVersionId = versions[0].id
    return this.selectedVersionId() === latestVersionId
      ? null
      : this.selectedVersionId()
@@ -1798,7 +1795,7 @@ export class DocumentDetailComponent
    modal.componentInstance.confirmClicked
      .pipe(takeUntil(this.unsubscribeNotifier))
      .subscribe(() => {
-        modal.componentInstance.buttonsEnabled = false
+        modal.componentInstance.buttonsEnabled.set(false)
        this.documentsService
          .editPdfDocuments([sourceDocumentId], {
            operations: modal.componentInstance.getOperations(),
@@ -1821,7 +1818,7 @@ export class DocumentDetailComponent
            },
            error: (error) => {
              if (modal) {
-                modal.componentInstance.buttonsEnabled = true
+                modal.componentInstance.buttonsEnabled.set(true)
              }
              this.toastService.showError(
                $localize`Error executing PDF edit operation`,
@@ -1855,7 +1852,7 @@ export class DocumentDetailComponent
        const sourceDocumentId = this.selectedVersionId() ?? this.document().id
        const dialog =
          modal.componentInstance as PasswordRemovalConfirmDialogComponent
-        dialog.buttonsEnabled = false
+        dialog.buttonsEnabled.set(false)
        this.networkActive.set(true)
        this.documentsService
          .removePasswordDocuments([sourceDocumentId], {
@@ -1880,7 +1877,7 @@ export class DocumentDetailComponent
              }
            },
            error: (error) => {
-              dialog.buttonsEnabled = true
+              dialog.buttonsEnabled.set(true)
              this.networkActive.set(false)
              this.toastService.showError(
                $localize`Error executing password removal operation`,
@@ -0,0 +1,18 @@
+<div class="modal-header">
+  <h4 class="modal-title" i18n>Add existing document as version</h4>
+  <button type="button" class="btn-close" aria-label="Close" (click)="cancel()"></button>
+</div>
+<div class="modal-body">
+  <pngx-input-document-link
+    [(ngModel)]="selectedDocumentIDs"
+    [parentDocumentID]="rootDocumentID"
+    [minimal]="true"
+    placeholder="Search for a document"
+    i18n-placeholder
+  ></pngx-input-document-link>
+  <div class="form-text mt-2" i18n>Select one document to add as a version.</div>
+</div>
+<div class="modal-footer">
+  <button type="button" class="btn btn-outline-secondary" (click)="cancel()" [disabled]="!buttonsEnabled()" i18n>Cancel</button>
+  <button type="button" class="btn btn-primary" (click)="confirm()" [disabled]="!buttonsEnabled() || selectedDocumentIDs.length !== 1" i18n>Add version</button>
+</div>
@@ -0,0 +1,73 @@
+import { ComponentFixture, TestBed } from '@angular/core/testing'
+import { NgbActiveModal } from '@ng-bootstrap/ng-bootstrap'
+import { DocumentService } from 'src/app/services/rest/document.service'
+import { AddExistingDocumentVersionDialogComponent } from './add-existing-document-version-dialog.component'
+
+describe('AddExistingDocumentVersionDialogComponent', () => {
+  let component: AddExistingDocumentVersionDialogComponent
+  let fixture: ComponentFixture<AddExistingDocumentVersionDialogComponent>
+  let activeModal: jest.Mocked<Pick<NgbActiveModal, 'dismiss'>>
+
+  beforeEach(async () => {
+    activeModal = { dismiss: jest.fn() }
+    await TestBed.configureTestingModule({
+      imports: [AddExistingDocumentVersionDialogComponent],
+      providers: [
+        {
+          provide: NgbActiveModal,
+          useValue: activeModal,
+        },
+        {
+          provide: DocumentService,
+          useValue: {},
+        },
+      ],
+    }).compileComponents()
+
+    fixture = TestBed.createComponent(AddExistingDocumentVersionDialogComponent)
+    component = fixture.componentInstance
+    component.rootDocumentID = 3
+    fixture.detectChanges()
+  })
+
+  it('should emit the single selected document', () => {
+    const emitSpy = jest.spyOn(component.confirmClicked, 'emit')
+    component.selectedDocumentIDs = [20]
+
+    component.confirm()
+
+    expect(emitSpy).toHaveBeenCalledWith(20)
+  })
+
+  it('should require exactly one selected document', () => {
+    const emitSpy = jest.spyOn(component.confirmClicked, 'emit')
+    component.selectedDocumentIDs = [20, 21]
+
+    component.confirm()
+
+    expect(emitSpy).not.toHaveBeenCalled()
+  })
+
+  it('should dismiss on cancel', () => {
+    component.cancel()
+
+    expect(activeModal.dismiss).toHaveBeenCalled()
+  })
+
+  it('should re-render the buttons when they are toggled from outside', async () => {
+    const cancelButton: HTMLButtonElement = fixture.nativeElement.querySelector(
+      '.modal-footer button'
+    )
+    expect(cancelButton.disabled).toBeFalsy()
+
+    // No detectChanges: the dropdown toggling this from a request callback is
+    // all that happens, and nothing else schedules a render for the modal
+    component.buttonsEnabled.set(false)
+    await fixture.whenStable()
+    expect(cancelButton.disabled).toBeTruthy()
+
+    component.buttonsEnabled.set(true)
+    await fixture.whenStable()
+    expect(cancelButton.disabled).toBeFalsy()
+  })
+})
@@ -0,0 +1,35 @@
+import {
+  Component,
+  EventEmitter,
+  Input,
+  Output,
+  inject,
+  signal,
+} from '@angular/core'
+import { FormsModule } from '@angular/forms'
+import { NgbActiveModal } from '@ng-bootstrap/ng-bootstrap'
+import { DocumentLinkComponent } from 'src/app/components/common/input/document-link/document-link.component'
+
+@Component({
+  selector: 'pngx-add-existing-document-version-dialog',
+  templateUrl: './add-existing-document-version-dialog.component.html',
+  imports: [DocumentLinkComponent, FormsModule],
+})
+export class AddExistingDocumentVersionDialogComponent {
+  private readonly activeModal = inject(NgbActiveModal)
+
+  @Input() rootDocumentID: number
+  @Output() confirmClicked = new EventEmitter<number>()
+
+  selectedDocumentIDs: number[] = []
+  readonly buttonsEnabled = signal(true)
+
+  confirm(): void {
+    if (this.selectedDocumentIDs.length !== 1) return
+    this.confirmClicked.emit(this.selectedDocumentIDs[0])
+  }
+
+  cancel(): void {
+    this.activeModal.dismiss()
+  }
+}
@@ -24,13 +24,26 @@
          class="visually-hidden"
          (change)="onVersionFileSelected($event)"
        />
-        <button
-          class="btn btn-sm btn-outline-secondary w-100"
-          (click)="versionFileInput.click()"
-          [disabled]="!userIsOwner || !userCanEdit"
-        >
-          <i-bs name="file-earmark-plus"></i-bs><span class="ps-1" i18n>Add new version</span>
-        </button>
+        <div class="btn-group btn-group-sm w-100">
+          <button
+            class="btn btn-sm btn-outline-secondary w-100"
+            (click)="versionFileInput.click()"
+            [disabled]="!userIsOwner || !userCanEdit"
+            title="Upload a new version"
+            i18n-title
+          >
+            <i-bs name="file-earmark-plus"></i-bs><span class="ps-1" i18n>Upload</span>
+          </button>
+          <button
+            class="btn btn-sm btn-outline-secondary w-100"
+            (click)="addExistingDocumentAsVersion()"
+            [disabled]="!userIsOwner || !userCanEdit"
+            title="Use an existing document"
+            i18n-title
+          >
+            <i-bs name="file-earmark"></i-bs><span class="ps-1" i18n>Existing</span>
+          </button>
+        </div>
      } @else {
        @switch (versionUploadState()) {
          @case (UploadState.Uploading) {
@@ -1,6 +1,7 @@
 import { DatePipe } from '@angular/common'
-import { SimpleChange } from '@angular/core'
+import { SimpleChange, signal } from '@angular/core'
 import { ComponentFixture, TestBed } from '@angular/core/testing'
+import { NgbModal } from '@ng-bootstrap/ng-bootstrap'
 import { NgxBootstrapIconsModule, allIcons } from 'ngx-bootstrap-icons'
 import { Subject, of, throwError } from 'rxjs'
 import { DocumentVersionInfo } from 'src/app/data/document'
@@ -19,12 +20,17 @@ describe('DocumentVersionDropdownComponent', () => {
  let documentService: jest.Mocked<
    Pick<
      DocumentService,
-      'deleteVersion' | 'getVersions' | 'uploadVersion' | 'updateVersionLabel'
+      | 'deleteVersion'
+      | 'getVersions'
+      | 'mergeDocumentsAsVersions'
+      | 'uploadVersion'
+      | 'updateVersionLabel'
    >
  >
  let toastService: jest.Mocked<Pick<ToastService, 'showError' | 'showInfo'>>
  let finished$: Subject<{ taskId: string }>
  let failed$: Subject<{ taskId: string; message?: string }>
+  let modalService: jest.Mocked<Pick<NgbModal, 'open'>>

  beforeEach(async () => {
    finished$ = new Subject<{ taskId: string }>()
@@ -32,9 +38,11 @@ describe('DocumentVersionDropdownComponent', () => {
    documentService = {
      deleteVersion: jest.fn(),
      getVersions: jest.fn(),
+      mergeDocumentsAsVersions: jest.fn(),
      uploadVersion: jest.fn(),
      updateVersionLabel: jest.fn(),
    }
+    modalService = { open: jest.fn() }
    toastService = {
      showError: jest.fn(),
      showInfo: jest.fn(),
@@ -61,6 +69,10 @@ describe('DocumentVersionDropdownComponent', () => {
          provide: ToastService,
          useValue: toastService,
        },
+        {
+          provide: NgbModal,
+          useValue: modalService,
+        },
        {
          provide: WebsocketStatusService,
          useValue: {
@@ -222,9 +234,10 @@ describe('DocumentVersionDropdownComponent', () => {
  })

  it('onVersionFileSelected should upload and update versions after websocket success', () => {
+    // Newest first, as the API returns them
    const versions: DocumentVersionInfo[] = [
-      { id: 3, is_root: true, checksum: 'aaaa' },
      { id: 20, is_root: false, checksum: 'cccc' },
+      { id: 3, is_root: true, checksum: 'aaaa' },
    ]
    const file = new File(['test'], 'new-version.pdf', {
      type: 'application/pdf',
@@ -323,4 +336,45 @@ describe('DocumentVersionDropdownComponent', () => {
    expect(component.editingVersionId).toBeNull()
    expect(component.versionLabelDraft).toEqual('')
  })
+
+  it('addExistingDocumentAsVersion should merge with a label and refresh versions', () => {
+    const confirmClicked = new Subject<number>()
+    const modal = {
+      componentInstance: {
+        rootDocumentID: null,
+        buttonsEnabled: signal(true),
+        confirmClicked,
+      },
+      close: jest.fn(),
+    }
+    modalService.open.mockReturnValue(modal as any)
+    documentService.mergeDocumentsAsVersions.mockReturnValue(of({} as any))
+    // Newest first, as the API returns them. The merged document has a lower id
+    // than the root, which is the whole point of merging an existing document.
+    const versions: DocumentVersionInfo[] = [
+      { id: 2, is_root: false, checksum: 'cccc' },
+      { id: 3, is_root: true, checksum: 'aaaa' },
+    ]
+    documentService.getVersions.mockReturnValue(of({ id: 3, versions } as any))
+    component.newVersionLabel = '  Imported  '
+    const versionsEmitSpy = jest.spyOn(component.versionsUpdated, 'emit')
+    const selectedEmitSpy = jest.spyOn(component.versionSelected, 'emit')
+
+    component.addExistingDocumentAsVersion()
+    expect(modal.componentInstance.rootDocumentID).toEqual(3)
+    confirmClicked.next(2)
+
+    expect(documentService.mergeDocumentsAsVersions).toHaveBeenCalledWith(
+      [3, 2],
+      3,
+      'Imported'
+    )
+    expect(documentService.updateVersionLabel).not.toHaveBeenCalled()
+    expect(documentService.getVersions).toHaveBeenCalledWith(3)
+    expect(versionsEmitSpy).toHaveBeenCalledWith(versions)
+    expect(selectedEmitSpy).toHaveBeenCalledWith(2)
+    expect(component.newVersionLabel).toEqual('')
+    expect(modal.close).toHaveBeenCalled()
+    expect(toastService.showInfo).toHaveBeenCalled()
+  })
 })
@@ -11,7 +11,7 @@ import {
  SimpleChanges,
 } from '@angular/core'
 import { FormsModule } from '@angular/forms'
-import { NgbDropdownModule } from '@ng-bootstrap/ng-bootstrap'
+import { NgbDropdownModule, NgbModal } from '@ng-bootstrap/ng-bootstrap'
 import { NgxBootstrapIconsModule } from 'ngx-bootstrap-icons'
 import { merge, of, Subject } from 'rxjs'
 import {
@@ -33,6 +33,7 @@ import {
  WebsocketStatusService,
 } from 'src/app/services/websocket-status.service'
 import { ConfirmButtonComponent } from '../../common/confirm-button/confirm-button.component'
+import { AddExistingDocumentVersionDialogComponent } from './add-existing-document-version-dialog/add-existing-document-version-dialog.component'

@Component({
  selector: 'pngx-document-version-dropdown',
@@ -69,6 +70,7 @@ export class DocumentVersionDropdownComponent implements OnChanges, OnDestroy {
  private readonly documentsService = inject(DocumentService)
  private readonly toastService = inject(ToastService)
  private readonly websocketStatusService = inject(WebsocketStatusService)
+  private readonly modalService = inject(NgbModal)
  private readonly destroy$ = new Subject<void>()
  private readonly documentChange$ = new Subject<void>()

@@ -256,11 +258,10 @@ export class DocumentVersionDropdownComponent implements OnChanges, OnDestroy {
      .subscribe({
        next: (doc) => {
          if (uploadDocumentId !== this.documentId) return
-          if (doc?.versions) {
+          if (doc?.versions?.length) {
            this.versionsUpdated.emit(doc.versions)
-            this.versionSelected.emit(
-              Math.max(...doc.versions.map((version) => version.id))
-            )
+            // The API returns versions newest first
+            this.versionSelected.emit(doc.versions[0].id)
            this.clearVersionUploadStatus()
          }
        },
@@ -278,6 +279,55 @@ export class DocumentVersionDropdownComponent implements OnChanges, OnDestroy {
      })
  }

+  addExistingDocumentAsVersion(): void {
+    const modal = this.modalService.open(
+      AddExistingDocumentVersionDialogComponent,
+      { backdrop: 'static' }
+    )
+    const dialog =
+      modal.componentInstance as AddExistingDocumentVersionDialogComponent
+    dialog.rootDocumentID = this.documentId
+    dialog.confirmClicked
+      .pipe(takeUntil(this.destroy$), takeUntil(this.documentChange$))
+      .subscribe((existingDocumentID) => {
+        dialog.buttonsEnabled.set(false)
+        const versionLabel = this.newVersionLabel?.trim()
+        this.documentsService
+          .mergeDocumentsAsVersions(
+            [this.documentId, existingDocumentID],
+            this.documentId,
+            versionLabel
+          )
+          .pipe(
+            switchMap(() => this.documentsService.getVersions(this.documentId)),
+            first(),
+            finalize(() => dialog.buttonsEnabled.set(true)),
+            takeUntil(this.destroy$),
+            takeUntil(this.documentChange$)
+          )
+          .subscribe({
+            next: (document) => {
+              if (document?.versions?.length) {
+                this.versionsUpdated.emit(document.versions)
+                // The API returns versions newest first
+                this.versionSelected.emit(document.versions[0].id)
+              }
+              this.newVersionLabel = ''
+              modal.close()
+              this.toastService.showInfo(
+                $localize`Existing document added as a version.`
+              )
+            },
+            error: (error) => {
+              this.toastService.showError(
+                $localize`Error adding existing document as a version`,
+                error
+              )
+            },
+          })
+      })
+  }
+
  clearVersionUploadStatus(): void {
    this.versionUploadState.set(UploadState.Idle)
    this.versionUploadError.set(null)
@@ -95,6 +95,9 @@
          <button ngbDropdownItem (click)="mergeSelected()" [disabled]="!userCanAdd || list.allSelected || list.selectedCount < 2">
            <i-bs name="journals" class="me-1"></i-bs><ng-container i18n>Merge</ng-container>
          </button>
+          <button ngbDropdownItem (click)="mergeSelectedAsVersions()" [disabled]="!userOwnsAll || !userCanEditAll || !userCanDelete || list.allSelected || list.selectedCount < 2">
+            <i-bs name="journal-bookmark-fill" class="me-1"></i-bs><ng-container i18n>Merge as versions</ng-container>
+          </button>
        </div>
      </div>
    </div>
@@ -1248,6 +1248,89 @@ describe('BulkEditorComponent', () => {
    expect(documentListViewService.selected.size).toEqual(0)
  })

+  it('should support merging documents as versions', () => {
+    let modal: NgbModalRef
+    modalService.activeInstances.subscribe((m) => (modal = m[0]))
+    jest.spyOn(permissionsService, 'currentUserCan').mockReturnValue(true)
+    jest
+      .spyOn(documentListViewService, 'documents', 'get')
+      .mockReturnValue([{ id: 3 }, { id: 4 }])
+    jest.spyOn(documentService, 'getFew').mockReturnValue(
+      of({
+        all: [3, 4],
+        count: 2,
+        results: [
+          { id: 3, title: 'Document 3' },
+          { id: 4, title: 'Document 4' },
+        ],
+      })
+    )
+    jest
+      .spyOn(documentListViewService, 'selected', 'get')
+      .mockReturnValue(new Set([3, 4]))
+    jest
+      .spyOn(permissionsService, 'currentUserHasObjectPermissions')
+      .mockReturnValue(true)
+    jest
+      .spyOn(permissionsService, 'currentUserOwnsObject')
+      .mockReturnValue(true)
+    const mergeAsVersionsSpy = jest
+      .spyOn(documentService, 'mergeDocumentsAsVersions')
+      .mockReturnValue(of(true))
+    const toastInfoSpy = jest.spyOn(toastService, 'showInfo')
+    fixture.detectChanges()
+
+    component.mergeSelectedAsVersions()
+    expect(modal).not.toBeUndefined()
+    modal.componentInstance.rootDocumentID.set(4)
+    modal.componentInstance.confirm()
+
+    expect(mergeAsVersionsSpy).toHaveBeenCalledWith([3, 4], 4)
+    httpTestingController.match(
+      `${environment.apiBaseUrl}documents/?page=1&page_size=50&ordering=-created&truncate_content=true&include_selection_data=true`
+    )
+    httpTestingController.match(
+      `${environment.apiBaseUrl}documents/?page=1&page_size=100000&fields=id`
+    )
+    expect(documentListViewService.selected.size).toEqual(0)
+    expect(toastInfoSpy).toHaveBeenCalledWith('Documents merged as versions.')
+  })
+
+  it('should not report success when merging documents as versions fails', () => {
+    let modal: NgbModalRef
+    modalService.activeInstances.subscribe((m) => (modal = m[0]))
+    jest.spyOn(permissionsService, 'currentUserCan').mockReturnValue(true)
+    jest
+      .spyOn(documentListViewService, 'documents', 'get')
+      .mockReturnValue([{ id: 3 }, { id: 4 }])
+    jest.spyOn(documentService, 'getFew').mockReturnValue(
+      of({
+        all: [3, 4],
+        count: 2,
+        results: [
+          { id: 3, title: 'Document 3' },
+          { id: 4, title: 'Document 4' },
+        ],
+      })
+    )
+    jest
+      .spyOn(documentListViewService, 'selected', 'get')
+      .mockReturnValue(new Set([3, 4]))
+    jest
+      .spyOn(documentService, 'mergeDocumentsAsVersions')
+      .mockReturnValue(throwError(() => new Error('failed')))
+    const toastInfoSpy = jest.spyOn(toastService, 'showInfo')
+    const toastErrorSpy = jest.spyOn(toastService, 'showError')
+    fixture.detectChanges()
+
+    component.mergeSelectedAsVersions()
+    modal.componentInstance.rootDocumentID.set(4)
+    modal.componentInstance.confirm()
+
+    expect(toastErrorSpy).toHaveBeenCalled()
+    expect(toastInfoSpy).not.toHaveBeenCalled()
+  })
+
  it('should support bulk download with archive, originals or both and file formatting', () => {
    jest.spyOn(permissionsService, 'currentUserCan').mockReturnValue(true)
    jest
@@ -1683,7 +1766,7 @@ describe('BulkEditorComponent', () => {
          expiration_days: 7,
        },
        loading: signal(false),
-        buttonsEnabled: true,
+        buttonsEnabled: signal(true),
        copied: signal(false),
      },
    }
@@ -1715,7 +1798,7 @@ describe('BulkEditorComponent', () => {
      expiration_days: 7,
    })
    expect(dialogInstance.loading()).toBe(false)
-    expect(dialogInstance.buttonsEnabled).toBe(false)
+    expect(dialogInstance.buttonsEnabled()).toBe(false)
    expect(dialogInstance.createdBundle).toEqual({ id: 42 })
    expect(typeof dialogInstance.onOpenManage).toBe('function')
    expect(toastInfoSpy).toHaveBeenCalledWith(
@@ -1755,7 +1838,7 @@ describe('BulkEditorComponent', () => {
          expiration_days: null,
        },
        loading: signal(false),
-        buttonsEnabled: true,
+        buttonsEnabled: signal(true),
      },
    }

@@ -1777,7 +1860,7 @@ describe('BulkEditorComponent', () => {
      expect.any(Error)
    )
    expect(dialogInstance.loading()).toBe(false)
-    expect(dialogInstance.buttonsEnabled).toBe(true)
+    expect(dialogInstance.buttonsEnabled()).toBe(true)
    openSpy.mockRestore()
  })

@@ -50,6 +50,7 @@ import { SettingsService } from 'src/app/services/settings.service'
 import { ToastService } from 'src/app/services/toast.service'
 import { flattenTags } from 'src/app/utils/flatten-tags'
 import { queryParamsFromFilterRules } from 'src/app/utils/query-params'
+import { MergeAsVersionsConfirmDialogComponent } from '../../common/confirm-dialog/merge-as-versions-confirm-dialog/merge-as-versions-confirm-dialog.component'
 import { MergeConfirmDialogComponent } from '../../common/confirm-dialog/merge-confirm-dialog/merge-confirm-dialog.component'
 import { RotateConfirmDialogComponent } from '../../common/confirm-dialog/rotate-confirm-dialog/rotate-confirm-dialog.component'
 import { CorrespondentEditDialogComponent } from '../../common/edit-dialog/correspondent-edit-dialog/correspondent-edit-dialog.component'
@@ -171,6 +172,13 @@ export class BulkEditorComponent
    )
  }

+  get userCanDelete(): boolean {
+    return this.permissionService.currentUserCan(
+      PermissionAction.Delete,
+      PermissionType.Document
+    )
+  }
+
  ngOnInit() {
    if (
      this.permissionService.currentUserCan(
@@ -273,7 +281,7 @@ export class BulkEditorComponent
    overrideSelection?: DocumentSelectionQuery
  ) {
    if (modal) {
-      this.setModalButtonsEnabled(modal, false)
+      modal.componentInstance.buttonsEnabled.set(false)
    }
    this.documentService
      .bulkEdit(overrideSelection ?? this.getSelectionQuery(), method, args)
@@ -287,14 +295,17 @@ export class BulkEditorComponent
  private executeDocumentAction(
    modal: NgbModalRef,
    request: Observable<any>,
-    options: { deleteOriginals?: boolean } = {}
+    options: { clearSelection?: boolean; successMessage?: string } = {}
  ) {
    if (modal) {
-      this.setModalButtonsEnabled(modal, false)
+      modal.componentInstance.buttonsEnabled.set(false)
    }
    request.pipe(first()).subscribe({
      next: () => {
-        this.handleOperationSuccess(modal, options.deleteOriginals ?? false)
+        this.handleOperationSuccess(modal, options.clearSelection ?? false)
+        if (options.successMessage) {
+          this.toastService.showInfo(options.successMessage)
+        }
      },
      error: (error) => this.handleOperationError(modal, error),
    })
@@ -320,7 +331,7 @@ export class BulkEditorComponent

  private handleOperationError(modal: NgbModalRef, error: any) {
    if (modal) {
-      this.setModalButtonsEnabled(modal, true)
+      modal.componentInstance.buttonsEnabled.set(true)
    }
    this.toastService.showError(
      $localize`Error executing bulk operation`,
@@ -328,15 +339,6 @@ export class BulkEditorComponent
    )
  }

-  private setModalButtonsEnabled(modal: NgbModalRef, enabled: boolean) {
-    const buttonsEnabled = modal.componentInstance.buttonsEnabled
-    if (typeof buttonsEnabled?.set === 'function') {
-      buttonsEnabled.set(enabled)
-    } else {
-      modal.componentInstance.buttonsEnabled = enabled
-    }
-  }
-
  private applySelectionData(
    items: SelectionDataItem[],
    selectionModel: FilterableDropdownSelectionModel
@@ -872,7 +874,7 @@ export class BulkEditorComponent
      modal.componentInstance.confirmClicked
        .pipe(takeUntil(this.unsubscribeNotifier))
        .subscribe(() => {
-          modal.componentInstance.buttonsEnabled = false
+          modal.componentInstance.buttonsEnabled.set(false)
          this.executeDocumentAction(
            modal,
            this.documentService.deleteDocuments(this.getSelectionQuery())
@@ -920,7 +922,7 @@ export class BulkEditorComponent
    modal.componentInstance.confirmClicked
      .pipe(takeUntil(this.unsubscribeNotifier))
      .subscribe(() => {
-        modal.componentInstance.buttonsEnabled = false
+        modal.componentInstance.buttonsEnabled.set(false)
        this.executeDocumentAction(
          modal,
          this.documentService.reprocessDocuments(this.getSelectionQuery())
@@ -957,7 +959,7 @@ export class BulkEditorComponent
    rotateDialog.confirmClicked
      .pipe(takeUntil(this.unsubscribeNotifier))
      .subscribe(() => {
-        rotateDialog.buttonsEnabled = false
+        rotateDialog.buttonsEnabled.set(false)
        this.executeDocumentAction(
          modal,
          this.documentService.rotateDocuments(
@@ -990,11 +992,11 @@ export class BulkEditorComponent
        if (mergeDialog.archiveFallback()) {
          args.archive_fallback = true
        }
-        mergeDialog.buttonsEnabled = false
+        mergeDialog.buttonsEnabled.set(false)
        this.executeDocumentAction(
          modal,
          this.documentService.mergeDocuments(mergeDialog.documentIDs(), args),
-          { deleteOriginals: !!args.delete_originals }
+          { clearSelection: !!args.delete_originals }
        )
        this.toastService.showInfo(
          $localize`Merged document will be queued for consumption.`
@@ -1002,6 +1004,35 @@ export class BulkEditorComponent
      })
  }

+  mergeSelectedAsVersions() {
+    let modal = this.modalService.open(MergeAsVersionsConfirmDialogComponent, {
+      backdrop: 'static',
+    })
+    const mergeDialog =
+      modal.componentInstance as MergeAsVersionsConfirmDialogComponent
+    const documentIDs = Array.from(this.list.selected)
+    mergeDialog.title = $localize`Merge as versions`
+    mergeDialog.message = $localize`The selected documents will become versions of the root document.`
+    mergeDialog.btnCaption = $localize`Proceed`
+    mergeDialog.documentIDs.set(documentIDs)
+    mergeDialog.rootDocumentID.set(documentIDs[0])
+    mergeDialog.confirmClicked
+      .pipe(takeUntil(this.unsubscribeNotifier))
+      .subscribe(() => {
+        this.executeDocumentAction(
+          modal,
+          this.documentService.mergeDocumentsAsVersions(
+            mergeDialog.documentIDs(),
+            mergeDialog.rootDocumentID()
+          ),
+          {
+            clearSelection: true,
+            successMessage: $localize`Documents merged as versions.`,
+          }
+        )
+      })
+  }
+
  public setCustomFieldValues(changedCustomFields: ChangedItems) {
    const modal = this.modalService.open(CustomFieldsBulkEditDialogComponent, {
      backdrop: 'static',
@@ -1063,14 +1094,14 @@ export class BulkEditorComponent
      .pipe(takeUntil(this.unsubscribeNotifier))
      .subscribe(() => {
        dialog.loading.set(true)
-        dialog.buttonsEnabled = false
+        dialog.buttonsEnabled.set(false)
        this.shareLinkBundleService
          .createBundle(dialog.payload)
          .pipe(first())
          .subscribe({
            next: (result) => {
              dialog.loading.set(false)
-              dialog.buttonsEnabled = false
+              dialog.buttonsEnabled.set(false)
              dialog.createdBundle = result
              dialog.copied.set(false)
              dialog.payload = null
@@ -1084,7 +1115,7 @@ export class BulkEditorComponent
            },
            error: (error) => {
              dialog.loading.set(false)
-              dialog.buttonsEnabled = true
+              dialog.buttonsEnabled.set(true)
              this.toastService.showError(
                $localize`Share link bundle creation is not available yet.`,
                error
@@ -105,7 +105,7 @@ export class CustomFieldsComponent
    modal.componentInstance.btnClass = 'btn-danger'
    modal.componentInstance.btnCaption = $localize`Proceed`
    modal.componentInstance.confirmClicked.subscribe(() => {
-      modal.componentInstance.buttonsEnabled = false
+      modal.componentInstance.buttonsEnabled.set(false)
      this.customFieldsService.delete(field).subscribe({
        next: () => {
          modal.close()
@@ -274,7 +274,7 @@ export abstract class ManagementListComponent<T extends MatchingModel>
    activeModal.componentInstance.btnClass = 'btn-danger'
    activeModal.componentInstance.btnCaption = $localize`Delete`
    activeModal.componentInstance.confirmClicked.subscribe(() => {
-      activeModal.componentInstance.buttonsEnabled = false
+      activeModal.componentInstance.buttonsEnabled.set(false)
      this.service
        .delete(object)
        .pipe(takeUntil(this.unsubscribeNotifier))
@@ -284,7 +284,7 @@ export abstract class ManagementListComponent<T extends MatchingModel>
            this.reloadData()
          },
          error: (error) => {
-            activeModal.componentInstance.buttonsEnabled = true
+            activeModal.componentInstance.buttonsEnabled.set(true)
            this.toastService.showError(
              $localize`Error while deleting element`,
              error
@@ -455,7 +455,7 @@ export abstract class ManagementListComponent<T extends MatchingModel>
    modal.componentInstance.btnClass = 'btn-danger'
    modal.componentInstance.btnCaption = $localize`Proceed`
    modal.componentInstance.confirmClicked.subscribe(() => {
-      modal.componentInstance.buttonsEnabled = false
+      modal.componentInstance.buttonsEnabled.set(false)
      this.service
        .bulk_edit_objects(
          this.allSelectionActive ? [] : Array.from(this.selectedObjects),
@@ -472,7 +472,7 @@ export abstract class ManagementListComponent<T extends MatchingModel>
            this.reloadData()
          },
          error: (error) => {
-            modal.componentInstance.buttonsEnabled = true
+            modal.componentInstance.buttonsEnabled.set(true)
            this.toastService.showError(
              $localize`Error deleting objects`,
              error
@@ -196,7 +196,7 @@ export class MailComponent
    modal.componentInstance.btnClass = 'btn-danger'
    modal.componentInstance.btnCaption = $localize`Proceed`
    modal.componentInstance.confirmClicked.subscribe(() => {
-      modal.componentInstance.buttonsEnabled = false
+      modal.componentInstance.buttonsEnabled.set(false)
      this.mailAccountService.delete(account).subscribe({
        next: () => {
          modal.close()
@@ -298,7 +298,7 @@ export class MailComponent
    modal.componentInstance.btnClass = 'btn-danger'
    modal.componentInstance.btnCaption = $localize`Proceed`
    modal.componentInstance.confirmClicked.subscribe(() => {
-      modal.componentInstance.buttonsEnabled = false
+      modal.componentInstance.buttonsEnabled.set(false)
      this.mailRuleService.delete(rule).subscribe({
        next: () => {
          modal.close()
@@ -134,7 +134,7 @@ export class WorkflowsComponent
    modal.componentInstance.btnClass = 'btn-danger'
    modal.componentInstance.btnCaption = $localize`Proceed`
    modal.componentInstance.confirmClicked.subscribe(() => {
-      modal.componentInstance.buttonsEnabled = false
+      modal.componentInstance.buttonsEnabled.set(false)
      this.workflowService.delete(workflow).subscribe({
        next: () => {
          modal.close()
@@ -18,7 +18,7 @@ export class DirtyFormGuard extends DirtyCheckGuard {
    modal.componentInstance.btnClass = 'btn-warning'
    modal.componentInstance.btnCaption = $localize`Leave page`
    modal.componentInstance.confirmClicked.subscribe(() => {
-      modal.componentInstance.buttonsEnabled = false
+      modal.componentInstance.buttonsEnabled.set(false)
      modal.close()
    })
    const subject = new Subject<boolean>()
@@ -36,12 +36,12 @@ export class DirtySavedViewGuard {
    modal.componentInstance.alternativeBtnClass = 'btn-primary'
    modal.componentInstance.alternativeBtnCaption = $localize`Save and close`
    modal.componentInstance.alternativeClicked.pipe(first()).subscribe(() => {
-      modal.componentInstance.buttonsEnabled = false
+      modal.componentInstance.buttonsEnabled.set(false)
      component.saveViewConfig()
      modal.close()
    })
    modal.componentInstance.confirmClicked.pipe(first()).subscribe(() => {
-      modal.componentInstance.buttonsEnabled = false
+      modal.componentInstance.buttonsEnabled.set(false)
      modal.close()
    })

@@ -142,7 +142,7 @@ export class OpenDocumentsService {
      modal.componentInstance.btnClass = 'btn-warning'
      modal.componentInstance.btnCaption = $localize`Close document`
      modal.componentInstance.confirmClicked.pipe(first()).subscribe(() => {
-        modal.componentInstance.buttonsEnabled = false
+        modal.componentInstance.buttonsEnabled.set(false)
        modal.close()
        this.openDocuments.splice(index, 1)
        this.dirtyDocuments.delete(doc.id)
@@ -165,7 +165,7 @@ export class OpenDocumentsService {
      modal.componentInstance.btnClass = 'btn-warning'
      modal.componentInstance.btnCaption = $localize`Close documents`
      modal.componentInstance.confirmClicked.pipe(first()).subscribe(() => {
-        modal.componentInstance.buttonsEnabled = false
+        modal.componentInstance.buttonsEnabled.set(false)
        modal.close()
        this.openDocuments.splice(0, this.openDocuments.length)
        this.dirtyDocuments.clear()
@@ -316,6 +316,34 @@ describe(`DocumentService`, () => {
    })
  })

+  it('should call appropriate api endpoint for merging documents as versions', () => {
+    const ids = [1, 2, 3]
+    subscription = service.mergeDocumentsAsVersions(ids, 2).subscribe()
+    const req = httpTestingController.expectOne(
+      `${environment.apiBaseUrl}${endpoint}/merge_as_versions/`
+    )
+    expect(req.request.method).toEqual('POST')
+    expect(req.request.body).toEqual({
+      documents: ids,
+      root_document_id: 2,
+    })
+  })
+
+  it('should include an optional label when merging one document as a version', () => {
+    const ids = [1, 2]
+    subscription = service
+      .mergeDocumentsAsVersions(ids, 2, 'Imported')
+      .subscribe()
+    const req = httpTestingController.expectOne(
+      `${environment.apiBaseUrl}${endpoint}/merge_as_versions/`
+    )
+    expect(req.request.body).toEqual({
+      documents: ids,
+      root_document_id: 2,
+      version_label: 'Imported',
+    })
+  })
+
  it('should call appropriate api endpoint for edit pdf', () => {
    const ids = [1]
    const args = { operations: [{ page: 1, rotate: 90, doc: 0 }] }
@@ -374,6 +374,18 @@ export class DocumentService extends AbstractPaperlessService<Document> {
    })
  }

+  mergeDocumentsAsVersions(
+    ids: number[],
+    rootDocumentId: number,
+    versionLabel?: string
+  ) {
+    return this.http.post(this.getResourceUrl(null, 'merge_as_versions'), {
+      documents: ids,
+      root_document_id: rootDocumentId,
+      ...(versionLabel ? { version_label: versionLabel } : {}),
+    })
+  }
+
  editPdfDocuments(ids: number[], request: EditPdfDocumentsRequest) {
    return this.http.post(this.getResourceUrl(null, 'edit_pdf'), {
      documents: ids,
@@ -115,6 +115,7 @@ import {
  house,
  inbox,
  infoCircle,
+  journalBookmarkFill,
  journals,
  link,
  listNested,
@@ -361,6 +362,7 @@ const icons = {
  house,
  inbox,
  infoCircle,
+  journalBookmarkFill,
  journals,
  link,
  listNested,
@@ -12,6 +12,7 @@ from celery import group
 from celery import shared_task
 from django.conf import settings
 from django.db import transaction
+from django.db.models import Max
 from django.db.models import Q
 from django.utils import timezone

@@ -30,6 +31,7 @@ from documents.permissions import set_permissions_for_object
 from documents.plugins.helpers import DocumentsStatusManager
 from documents.tasks import bulk_update_documents
 from documents.tasks import consume_file
+from documents.tasks import remove_document_from_index
 from documents.tasks import update_document_content_maybe_archive_file
 from documents.versioning import get_latest_version_for_root
 from documents.versioning import get_root_document
@@ -39,6 +41,9 @@ if TYPE_CHECKING:

    from django.contrib.auth.models import User

+if settings.AUDIT_LOG_ENABLED:
+    from auditlog.models import LogEntry
+
 logger: logging.Logger = logging.getLogger("paperless.bulk_edit")

 SourceMode = Literal["latest_version", "explicit_selection"]
@@ -612,6 +617,113 @@ def merge(
    return "OK"


+def merge_as_versions(
+    doc_ids: list[int],
+    *,
+    root_document_id: int,
+    version_label: str | None = None,
+    user: User | None = None,
+) -> Literal["OK"]:
+    with transaction.atomic():
+        documents = list(
+            Document.objects.select_for_update()
+            .filter(id__in=doc_ids)
+            .defer("content"),
+        )
+        documents_by_id = {document.id: document for document in documents}
+
+        source_ids = [doc_id for doc_id in doc_ids if doc_id != root_document_id]
+        root_document = documents_by_id[root_document_id]
+        next_version_index = (
+            Document.global_objects.filter(
+                root_document_id=root_document_id,
+            ).aggregate(max_index=Max("version_index"))["max_index"]
+            or 0
+        )
+
+        # A version gives up its ASN
+        source_asns = [
+            documents_by_id[source_id].archive_serial_number
+            for source_id in source_ids
+            if documents_by_id[source_id].archive_serial_number is not None
+        ]
+
+        updated_fields = ["root_document", "version_index", "archive_serial_number"]
+        if version_label is not None:
+            updated_fields.append("version_label")
+
+        for source_id in source_ids:
+            next_version_index += 1
+            source_document = documents_by_id[source_id]
+            source_document.root_document_id = root_document.pk
+            source_document.version_index = next_version_index
+            source_document.archive_serial_number = None
+            if version_label is not None:
+                source_document.version_label = version_label
+
+        # bulk_update and not save() to avoid post_save now
+        Document.objects.bulk_update(
+            [documents_by_id[source_id] for source_id in source_ids],
+            updated_fields,
+        )
+
+        root_updates = {"modified": timezone.now()}
+        if source_asns and root_document.archive_serial_number is None:
+            # If a version had one, hand the ASN over, the same as merge() does
+            root_updates["archive_serial_number"] = source_asns.pop(0)
+            logger.info(
+                f"Document {root_document.id} took archive serial number "
+                f"{root_updates['archive_serial_number']} from a document merged into it",
+            )
+        if source_asns:
+            logger.warning(
+                f"Archive serial number(s) {source_asns} were removed by merging "
+                f"those documents as versions of document {root_document.id}",
+            )
+
+        Document.objects.filter(pk=root_document.pk).update(**root_updates)
+
+        if settings.AUDIT_LOG_ENABLED:
+            # update() doesn't fire auditlog signals, so manual
+            LogEntry.objects.log_create(
+                instance=root_document,
+                changes={"Merged As Versions": ["None", source_ids]},
+                action=LogEntry.Action.UPDATE,
+                actor=user,
+                additional_data={
+                    "reason": "Merged as versions",
+                    "version_ids": source_ids,
+                },
+            )
+
+    # One batch rather than a task each
+    from documents.search import SearchIndexLockError
+    from documents.search import get_backend
+
+    try:
+        with get_backend().batch_update() as batch:
+            for source_id in source_ids:
+                batch.remove(source_id)
+    except SearchIndexLockError:
+        logger.error(
+            f"Search index lock exhausted removing {source_ids}, "
+            f"scheduling deferred index removal",
+        )
+        for source_id in source_ids:
+            remove_document_from_index.apply_async(args=[source_id], countdown=60)
+
+    bulk_update_documents.apply_async(
+        kwargs={"document_ids": [root_document_id]},
+        headers={"trigger_source": PaperlessTask.TriggerSource.SYSTEM},
+    )
+
+    # And as far as the frontend is concerned, they're deleted
+    status_mgr = DocumentsStatusManager()
+    status_mgr.send_documents_deleted(source_ids)
+
+    return "OK"
+
+
 def split(
    doc_ids: list[int],
    pages: list[list[int]],
@@ -0,0 +1,106 @@
+from __future__ import annotations
+
+import importlib
+import zipfile
+
+# ZIP_ZSTANDARD exists only on Python 3.14+ (PEP 784). None elsewhere.
+ZSTD: int | None = getattr(zipfile, "ZIP_ZSTANDARD", None)
+
+# CLI choices are fixed across runtimes so argparse never hides zstd; runtime
+# availability is enforced separately in compression_available().
+COMPRESSION_CHOICES: tuple[str, ...] = (
+    "stored",
+    "deflated",
+    "bzip2",
+    "lzma",
+    "zstd",
+)
+
+# Method name -> zipfile compression constant (zstd only when supported).
+COMPRESSION_METHODS: dict[str, int] = {
+    "stored": zipfile.ZIP_STORED,
+    "deflated": zipfile.ZIP_DEFLATED,
+    "bzip2": zipfile.ZIP_BZIP2,
+    "lzma": zipfile.ZIP_LZMA,
+}
+if ZSTD is not None:
+    COMPRESSION_METHODS["zstd"] = ZSTD
+
+# Inclusive (min, max) level bounds per method; None => level not applicable.
+# Verified on CPython 3.14.3.
+#
+# zstd's raw library bounds are (-131072, 22)
+# (compression.zstd.CompressionParameter.compression_level.bounds()) — the
+# minimum is an internal implementation constant (-ZSTD_TARGETLENGTH_MAX),
+# not a meaningful distinct "level"; deeper negative values than -22 buy
+# nothing over -22 in practice. We expose the conventional zstd CLI range
+# instead of the raw library bounds.
+LEVEL_BOUNDS: dict[str, tuple[int, int] | None] = {
+    "stored": None,
+    "deflated": (0, 9),
+    "bzip2": (1, 9),
+    "lzma": None,
+    "zstd": (-22, 22),
+}
+
+# zipfile compress_type id -> method name.
+_COMPRESS_TYPE_TO_METHOD: dict[int, str] = {
+    zipfile.ZIP_STORED: "stored",
+    zipfile.ZIP_DEFLATED: "deflated",
+    zipfile.ZIP_BZIP2: "bzip2",
+    zipfile.ZIP_LZMA: "lzma",
+    93: "zstd",
+}
+
+
+def compression_available(method: str) -> bool:
+    """Whether the running interpreter can actually use the given method."""
+    if method in ("stored", "deflated"):
+        # zlib is a hard CPython dependency; stored needs nothing.
+        return True
+    if method == "bzip2":
+        return _module_importable("bz2")
+    if method == "lzma":
+        return _module_importable("lzma")
+    if method == "zstd":
+        return ZSTD is not None and _module_importable("compression.zstd")
+    return False  # pragma: no cover -- method is always one of COMPRESSION_CHOICES
+
+
+def _module_importable(name: str) -> bool:
+    try:
+        importlib.import_module(name)
+    except ImportError:
+        return False
+    return True
+
+
+def level_error(method: str, level: int | None) -> str | None:
+    """Return a human message if (method, level) is invalid, else None."""
+    if level is None:
+        return None
+    bounds = LEVEL_BOUNDS[method]
+    if bounds is None:
+        return f"--zip-compression-level has no effect for '{method}'"
+    low, high = bounds
+    if not (low <= level <= high):
+        return (
+            f"--zip-compression-level for '{method}' must be between {low} and {high}"
+        )
+    return None
+
+
+def compress_type_readable(compress_type: int) -> bool:
+    """Whether this interpreter can decompress an entry of the given type."""
+    method = _COMPRESS_TYPE_TO_METHOD.get(compress_type)
+    if method is None:
+        return False
+    return compression_available(method)
+
+
+def unreadable_method_names(compress_types: set[int]) -> set[str]:
+    """Map a set of compress_type ids to human method names for error messages."""
+    names: set[str] = set()
+    for ct in compress_types:
+        names.add(_COMPRESS_TYPE_TO_METHOD.get(ct, f"method {ct}"))
+    return names
@@ -243,11 +243,21 @@ class ZipExportSink(ExportSink):
    added as an entry at finalize (a zip entry cannot be interleaved with others).
    """

-    def __init__(self, target: Path, zip_name: str, *, delete: bool = False) -> None:
+    def __init__(
+        self,
+        target: Path,
+        zip_name: str,
+        *,
+        delete: bool = False,
+        compression: int = zipfile.ZIP_DEFLATED,
+        compresslevel: int | None = None,
+    ) -> None:
        self._target = target.resolve()
        self._zip_path = (self._target / zip_name).with_suffix(".zip")
        self._tmp_path = self._zip_path.with_name(self._zip_path.name + ".tmp")
        self._delete = delete
+        self._compression = compression
+        self._compresslevel = compresslevel
        self._zip: zipfile.ZipFile | None = None
        self._dirs: set[str] = set()
        self._pending_manifest: tuple[Path, str] | None = None
@@ -258,7 +268,8 @@ class ZipExportSink(ExportSink):
        self._zip = zipfile.ZipFile(
            self._tmp_path,
            "w",
-            compression=zipfile.ZIP_DEFLATED,
+            compression=self._compression,
+            compresslevel=self._compresslevel,
            allowZip64=True,
        )

@@ -29,6 +29,11 @@ if TYPE_CHECKING:
 if settings.AUDIT_LOG_ENABLED:
    from auditlog.models import LogEntry

+from documents.export.compression import COMPRESSION_CHOICES
+from documents.export.compression import COMPRESSION_METHODS
+from documents.export.compression import ZSTD
+from documents.export.compression import compression_available
+from documents.export.compression import level_error
 from documents.export.sinks import DirectoryExportSink
 from documents.export.sinks import ExportSink
 from documents.export.sinks import StreamingManifestWriter
@@ -192,6 +197,28 @@ class Command(CryptMixin, PaperlessCommand):
            help="Sets the export zip file name",
        )

+        parser.add_argument(
+            "--zip-compression",
+            choices=COMPRESSION_CHOICES,
+            default=None,
+            help=(
+                "Compression method for the export zip (requires --zip). "
+                "Default: deflated. 'zstd' requires Python 3.14+ on both the "
+                "exporting and importing machine."
+            ),
+        )
+
+        parser.add_argument(
+            "--zip-compression-level",
+            type=int,
+            default=None,
+            help=(
+                "Compression level for the export zip (requires --zip). "
+                "deflated: 0-9, bzip2: 1-9, zstd: -22..22; ignored for "
+                "stored/lzma."
+            ),
+        )
+
        parser.add_argument(
            "--data-only",
            default=False,
@@ -247,12 +274,39 @@ class Command(CryptMixin, PaperlessCommand):
        if not os.access(self.target, os.W_OK):
            raise CommandError("That path doesn't appear to be writable")

+        zip_compression: str | None = options["zip_compression"]
+        zip_compression_level: int | None = options["zip_compression_level"]
+
+        if not self.zip_export and (
+            zip_compression is not None or zip_compression_level is not None
+        ):
+            raise CommandError(
+                "--zip-compression and --zip-compression-level require --zip",
+            )
+
+        compression_method = zip_compression or "deflated"
+        if self.zip_export:
+            if not compression_available(compression_method):
+                if compression_method == "zstd" and ZSTD is None:
+                    raise CommandError(
+                        "zstd compression requires Python 3.14 or newer",
+                    )
+                raise CommandError(
+                    f"Compression method '{compression_method}' is not "
+                    f"available on this Python runtime",
+                )
+            level_msg = level_error(compression_method, zip_compression_level)
+            if level_msg is not None:
+                raise CommandError(level_msg)
+
        sink: ExportSink
        if self.zip_export:
            sink = ZipExportSink(
                self.target,
                options["zip_name"],
                delete=self.delete,
+                compression=COMPRESSION_METHODS[compression_method],
+                compresslevel=zip_compression_level,
            )
        else:
            sink = DirectoryExportSink(
@@ -32,6 +32,8 @@ from django.db.models.signals import post_save
 from filelock import FileLock
 from guardian.shortcuts import clear_ct_cache

+from documents.export.compression import compress_type_readable
+from documents.export.compression import unreadable_method_names
 from documents.file_handling import create_source_path_directory
 from documents.management.commands.base import PaperlessCommand
 from documents.management.commands.mixins import CryptMixin
@@ -460,6 +462,20 @@ class Command(CryptMixin, PaperlessCommand):
        with tempfile.TemporaryDirectory() as tmp_dir:
            if is_zipfile(self.source):
                with ZipFile(self.source) as zf:
+                    unsupported = {
+                        info.compress_type
+                        for info in zf.infolist()
+                        if not compress_type_readable(info.compress_type)
+                    }
+                    if unsupported:
+                        names = sorted(unreadable_method_names(unsupported))
+                        message = (
+                            f"This archive uses compression this Python version cannot "
+                            f"read ({', '.join(names)})."
+                        )
+                        if "zstd" in names:
+                            message += " zstd archives require Python 3.14+."
+                        raise CommandError(message)
                    zf.extractall(tmp_dir)
                self.source = Path(tmp_dir)
            self._run_import()
@@ -372,6 +372,10 @@ class Document(SoftDeleteModel, ModelWithOwner):  # type: ignore[django-manager-
        For version documents, this is always the document's own content.
        If the queryset already annotated ``effective_content``, that value is used.
        """
+        # Here to avoid circular import
+        from documents.versioning import sort_versions_newest_first
+        from documents.versioning import versions_newest_first
+
        if hasattr(self, "effective_content"):
            return getattr(self, "effective_content")

@@ -388,12 +392,10 @@ class Document(SoftDeleteModel, ModelWithOwner):  # type: ignore[django-manager-
            # Empty list means prefetch ran and found no versions — use own content.
            if not prefetched_versions:
                return self.content
-            latest_prefetched = max(prefetched_versions, key=lambda doc: doc.id)
-            return latest_prefetched.content
+            return sort_versions_newest_first(prefetched_versions)[0].content

        latest_version_content = (
-            Document.objects.filter(root_document=self)
-            .order_by("-id")
+            versions_newest_first(Document.objects.filter(root_document=self))
            .values_list("content", flat=True)
            .first()
        )
@@ -85,8 +85,10 @@ from documents.permissions import set_permissions_for_object
 from documents.regex import validate_regex_pattern
 from documents.templating.filepath import validate_filepath_template_and_render
 from documents.templating.utils import convert_format_str_to_template_format
+from documents.templating.workflows import validate_workflow_template
 from documents.validators import uri_validator
 from documents.validators import url_validator
+from documents.versioning import sort_versions_newest_first

 if TYPE_CHECKING:
    from collections.abc import Iterable
@@ -1115,9 +1117,13 @@ class DocumentSerializer(
                "added",
                "checksum",
                "version_label",
+                "root_document_id",
+                "version_index",
            )
            versions = [*versions_qs, root_doc]

+        versions = sort_versions_newest_first(versions)
+
        def build_info(doc: Document) -> _DocumentVersionInfo:
            return {
                "id": doc.id,
@@ -1127,9 +1133,7 @@ class DocumentSerializer(
                "is_root": doc.id == root_doc.id,
            }

-        info = [build_info(doc) for doc in versions]
-        info.sort(key=lambda item: item["id"], reverse=True)
-        return info
+        return [build_info(doc) for doc in versions]

    def get_original_file_name(self, obj) -> str | None:
        return obj.original_filename
@@ -1676,6 +1680,52 @@ class MergeDocumentsSerializer(DocumentListSerializer, SourceModeValidationMixin
    from_webui = serializers.BooleanField(required=False, default=False)


+class MergeDocumentsAsVersionsSerializer(DocumentListSerializer):
+    root_document_id = serializers.IntegerField(required=True)
+    version_label = serializers.CharField(
+        required=False,
+        allow_blank=True,
+        allow_null=True,
+        max_length=64,
+    )
+
+    def validate_version_label(self, value):
+        if value is None:
+            return None
+        normalized = value.strip()
+        return normalized or None
+
+    def validate(self, attrs):
+        documents = attrs["documents"]
+        if len(documents) < 2:
+            raise serializers.ValidationError(
+                "At least two documents are required.",
+            )
+        if attrs.get("version_label") is not None and len(documents) != 2:
+            raise serializers.ValidationError(
+                "version_label can only be used when merging one source document.",
+            )
+        if attrs["root_document_id"] not in documents:
+            raise serializers.ValidationError(
+                "root_document_id must be one of the selected documents.",
+            )
+
+        selected_documents = Document.objects.filter(id__in=documents)
+        if selected_documents.filter(root_document__isnull=False).exists():
+            raise serializers.ValidationError(
+                "Only top-level documents can be merged as versions.",
+            )
+
+        source_document_ids = set(documents) - {attrs["root_document_id"]}
+        if Document.global_objects.filter(
+            root_document_id__in=source_document_ids,
+        ).exists():
+            raise serializers.ValidationError(
+                "Documents with existing versions cannot be merged into another document.",
+            )
+        return attrs
+
+
 class EditPdfDocumentsSerializer(DocumentListSerializer, SourceModeValidationMixin):
    operations = serializers.ListField(required=True)
    delete_original = serializers.BooleanField(required=False, default=False)
@@ -3185,33 +3235,10 @@ class WorkflowActionSerializer(serializers.ModelSerializer[WorkflowAction]):
                attrs["assign_title"] = None
            else:
                try:
-                    # test against all placeholders, see consumer.py `parse_doc_title_w_placeholders`
-                    attrs["assign_title"].format(
-                        correspondent="",
-                        document_type="",
-                        added="",
-                        added_year="",
-                        added_year_short="",
-                        added_month="",
-                        added_month_name="",
-                        added_month_name_short="",
-                        added_day="",
-                        added_time="",
-                        owner_username="",
-                        original_filename="",
-                        filename="",
-                        created="",
-                        created_year="",
-                        created_year_short="",
-                        created_month="",
-                        created_month_name="",
-                        created_month_name_short="",
-                        created_day="",
-                        created_time="",
-                    )
+                    validate_workflow_template(attrs["assign_title"])
                except (ValueError, KeyError) as e:
                    raise serializers.ValidationError(
-                        {"assign_title": f'Invalid f-string detected: "{e.args[0]}"'},
+                        {"assign_title": f"{e.args[0]}"},
                    )

        if attrs.get("assign_custom_fields_values"):
@@ -6,9 +6,11 @@ from pathlib import Path
 from django.utils.text import slugify as django_slugify
 from jinja2 import StrictUndefined
 from jinja2 import Template
+from jinja2 import TemplateAssertionError
 from jinja2 import TemplateSyntaxError
 from jinja2 import UndefinedError
 from jinja2 import make_logging_undefined
+from jinja2.meta import find_undeclared_variables
 from jinja2.sandbox import SecurityError

 from documents.templating.environment import _template_environment
@@ -29,6 +31,49 @@ _template_environment.filters["slugify"] = django_slugify
 _template_environment.filters["localize_date"] = localize_date


+_known_placeholder_names = {
+    "correspondent",
+    "document_type",
+    "added",
+    "added_year",
+    "added_year_short",
+    "added_month",
+    "added_month_name",
+    "added_month_name_short",
+    "added_day",
+    "added_time",
+    "owner_username",
+    "original_filename",
+    "filename",
+    "created",
+    "created_year",
+    "created_year_short",
+    "created_month",
+    "created_month_name",
+    "created_month_name_short",
+    "created_day",
+    "created_time",
+    "doc_title",
+    "doc_url",
+    "doc_id",
+}
+
+
+def validate_workflow_template(text: str) -> None:
+    try:
+        ast = _template_environment.parse(text)
+        undeclared_vars = find_undeclared_variables(ast)
+    except TemplateAssertionError as e:
+        raise ValueError(f"Template assertion error: {e}")
+    except TemplateSyntaxError as e:
+        raise ValueError(f"Template syntax error: {e}")
+    unknown_vars = undeclared_vars - _known_placeholder_names
+    if unknown_vars:
+        raise KeyError(
+            f"Template references unknown placeholders: {', '.join(unknown_vars)}",
+        )
+
+
 def parse_w_workflow_placeholders(
    text: str,
    correspondent_name: str,
@@ -0,0 +1,208 @@
+import sys
+import zipfile
+
+import pytest
+import pytest_mock
+
+from documents.export import compression
+
+
+class TestCompressionMethods:
+    def test_choices_always_include_zstd(self) -> None:
+        """
+        GIVEN:
+            - The compression policy module's CLI choices list
+        WHEN:
+            - Read on any runtime
+        THEN:
+            - zstd is always present; availability is checked separately so
+              argparse never hides it based on the current Python version
+        """
+        assert compression.COMPRESSION_CHOICES == (
+            "stored",
+            "deflated",
+            "bzip2",
+            "lzma",
+            "zstd",
+        )
+
+    @pytest.mark.parametrize(
+        ("name", "constant"),
+        [
+            ("stored", zipfile.ZIP_STORED),
+            ("deflated", zipfile.ZIP_DEFLATED),
+            ("bzip2", zipfile.ZIP_BZIP2),
+            ("lzma", zipfile.ZIP_LZMA),
+        ],
+    )
+    def test_method_maps_to_zipfile_constant(self, name: str, constant: int) -> None:
+        """
+        GIVEN:
+            - A compression method name
+        WHEN:
+            - Looked up in COMPRESSION_METHODS
+        THEN:
+            - It maps to the matching zipfile compression constant
+        """
+        assert compression.COMPRESSION_METHODS[name] == constant
+
+    def test_stored_and_deflated_always_available(self) -> None:
+        """
+        GIVEN:
+            - The stored and deflated compression methods
+        WHEN:
+            - Checked with compression_available()
+        THEN:
+            - Both are always available (zlib is a hard CPython dependency)
+        """
+        assert compression.compression_available("stored")
+        assert compression.compression_available("deflated")
+
+    def test_zstd_availability_tracks_runtime(self) -> None:
+        """
+        GIVEN:
+            - The zstd compression method
+        WHEN:
+            - Checked with compression_available() on this runtime
+        THEN:
+            - Availability matches whether Python is 3.14+
+        """
+        expected: bool = sys.version_info >= (3, 14)
+        assert compression.compression_available("zstd") == expected
+
+    def test_unimportable_module_reports_unavailable(
+        self,
+        mocker: pytest_mock.MockerFixture,
+    ) -> None:
+        """
+        GIVEN:
+            - A compression method whose backing module fails to import
+              (e.g. a minimal Python build without bz2/lzma compiled in)
+        WHEN:
+            - Checked with compression_available()
+        THEN:
+            - False is returned rather than the ImportError propagating
+        """
+        mocker.patch(
+            "documents.export.compression.importlib.import_module",
+            side_effect=ImportError,
+        )
+        assert not compression.compression_available("bzip2")
+
+
+class TestLevelError:
+    @pytest.mark.parametrize(
+        ("method", "level"),
+        [
+            ("deflated", 0),
+            ("deflated", 9),
+            ("bzip2", 1),
+            ("bzip2", 9),
+            ("zstd", -22),
+            ("zstd", 22),
+            ("deflated", None),
+            ("stored", None),
+        ],
+    )
+    def test_valid_levels_return_none(self, method: str, level: int | None) -> None:
+        """
+        GIVEN:
+            - A method and a level within its valid bounds (or no level)
+        WHEN:
+            - Checked with level_error()
+        THEN:
+            - No error message is returned
+        """
+        assert compression.level_error(method, level) is None
+
+    @pytest.mark.parametrize(
+        ("method", "level"),
+        [
+            ("deflated", 10),
+            ("deflated", -1),
+            ("bzip2", 0),
+            ("bzip2", 10),
+            ("zstd", -23),
+            ("zstd", 23),
+        ],
+    )
+    def test_out_of_range_levels_return_message(
+        self,
+        method: str,
+        level: int,
+    ) -> None:
+        """
+        GIVEN:
+            - A method and a level outside its valid bounds
+        WHEN:
+            - Checked with level_error()
+        THEN:
+            - An error message naming the valid range is returned
+        """
+        msg: str | None = compression.level_error(method, level)
+        assert msg is not None
+        assert "between" in msg
+
+    @pytest.mark.parametrize("method", ["stored", "lzma"])
+    def test_level_on_levelless_method_is_rejected(self, method: str) -> None:
+        """
+        GIVEN:
+            - A method that ignores compression level (stored, lzma)
+        WHEN:
+            - A level is passed to level_error() anyway
+        THEN:
+            - An error message noting the level has no effect is returned
+        """
+        msg: str | None = compression.level_error(method, 5)
+        assert msg is not None
+        assert "no effect" in msg
+
+
+class TestCompressTypeReadable:
+    @pytest.mark.parametrize("ct", [zipfile.ZIP_STORED, zipfile.ZIP_DEFLATED])
+    def test_stored_and_deflated_always_readable(self, ct: int) -> None:
+        """
+        GIVEN:
+            - A stored or deflated compress_type id
+        WHEN:
+            - Checked with compress_type_readable()
+        THEN:
+            - It is always readable
+        """
+        assert compression.compress_type_readable(ct)
+
+    def test_zstd_compress_type_readability_tracks_runtime(self) -> None:
+        """
+        GIVEN:
+            - The zstd compress_type id (93, ZIP_ZSTANDARD)
+        WHEN:
+            - Checked with compress_type_readable() on this runtime
+        THEN:
+            - Readability matches whether Python is 3.14+
+        """
+        expected: bool = sys.version_info >= (3, 14)
+        assert compression.compress_type_readable(93) == expected
+
+    def test_unknown_compress_type_is_unreadable(self) -> None:
+        """
+        GIVEN:
+            - An unrecognized compress_type id
+        WHEN:
+            - Checked with compress_type_readable()
+        THEN:
+            - It is reported as unreadable
+        """
+        assert not compression.compress_type_readable(9999)
+
+    def test_unreadable_method_names_lists_methods(self) -> None:
+        """
+        GIVEN:
+            - A set containing an unknown compress_type id
+        WHEN:
+            - Passed to unreadable_method_names()
+        THEN:
+            - It is reported generically as "method <id>"
+        """
+        # An unknown method id maps to no name and is reported generically.
+        names: set[str] = compression.unreadable_method_names({9999})
+        assert names == {"method 9999"}
@@ -5,6 +5,7 @@ import zipfile
 from pathlib import Path

 import pytest
+import pytest_mock
 from pytest_django.fixtures import SettingsWrapper

 from documents.export.sinks import DirectoryExportSink
@@ -305,6 +306,48 @@ class TestZipExportSink:
        assert not (target / "export.zip").exists()


+class TestZipExportSinkCompression:
+    @pytest.mark.parametrize(
+        ("method", "constant"),
+        [
+            ("stored", zipfile.ZIP_STORED),
+            ("deflated", zipfile.ZIP_DEFLATED),
+            ("bzip2", zipfile.ZIP_BZIP2),
+            ("lzma", zipfile.ZIP_LZMA),
+        ],
+    )
+    def test_compression_and_level_forwarded_to_zipfile(
+        self,
+        mocker: pytest_mock.MockerFixture,
+        tmp_path: Path,
+        method: str,
+        constant: int,
+    ) -> None:
+        """
+        GIVEN:
+            - A ZipExportSink constructed with a compression method and level
+        WHEN:
+            - The sink is opened
+        THEN:
+            - zipfile.ZipFile is constructed with those values forwarded
+              unchanged (whether ZipFile actually compresses is Python's own
+              contract, not ours, so this checks the call args, not a real
+              archive)
+        """
+        target: Path = tmp_path / "out"
+        target.mkdir()
+        zip_cls = mocker.patch("documents.export.sinks.zipfile.ZipFile")
+        sink = ZipExportSink(target, "export", compression=constant, compresslevel=5)
+        sink._open()
+        zip_cls.assert_called_once_with(
+            mocker.ANY,
+            "w",
+            compression=constant,
+            compresslevel=5,
+            allowZip64=True,
+        )
+
+
 class TestStreamContract:
    @pytest.fixture(params=["dir", "zip"])
    def sink(self, request: pytest.FixtureRequest, tmp_path: Path) -> ExportSink:
@@ -827,6 +827,67 @@ class TestDocumentVersioningApi(DirectoriesMixin, APITestCase):
        self.assertEqual(resp.status_code, status.HTTP_200_OK)
        self.assertEqual(resp.data["content"], "v1-content")

+    def _make_root_with_out_of_order_versions(self) -> tuple[Document, ...]:
+        """
+        A root whose newest version has a *lower* id than an older one, which is
+        what merging an existing document in as a version produces.
+        """
+        root = Document.objects.create(
+            title="root",
+            checksum="root",
+            mime_type="application/pdf",
+            content="root-content",
+        )
+        newest = Document.objects.create(
+            title="newest",
+            checksum="newest",
+            mime_type="application/pdf",
+            content="newest-content",
+        )
+        older = Document.objects.create(
+            title="older",
+            checksum="older",
+            mime_type="application/pdf",
+            root_document=root,
+            version_index=1,
+            content="older-content",
+        )
+        # Assigned last, so `newest` has the lower id despite being the later version
+        newest.root_document = root
+        newest.version_index = 2
+        newest.save()
+        return root, newest, older
+
+    def test_retrieve_uses_version_index_not_id_for_latest(self) -> None:
+        root, _, _ = self._make_root_with_out_of_order_versions()
+
+        resp = self.client.get(f"/api/documents/{root.id}/")
+
+        self.assertEqual(resp.status_code, status.HTTP_200_OK)
+        self.assertEqual(resp.data["content"], "newest-content")
+
+    def test_list_uses_version_index_not_id_for_latest(self) -> None:
+        self._make_root_with_out_of_order_versions()
+
+        resp = self.client.get("/api/documents/?fields=id,content")
+
+        self.assertEqual(resp.status_code, status.HTTP_200_OK)
+        self.assertEqual(
+            [doc["content"] for doc in resp.data["results"]],
+            ["newest-content"],
+        )
+
+    def test_versions_are_listed_newest_first_with_root_last(self) -> None:
+        root, newest, older = self._make_root_with_out_of_order_versions()
+
+        resp = self.client.get(f"/api/documents/{root.id}/")
+
+        self.assertEqual(resp.status_code, status.HTTP_200_OK)
+        self.assertEqual(
+            [(version["id"], version["is_root"]) for version in resp.data["versions"]],
+            [(newest.id, False), (older.id, False), (root.id, True)],
+        )
+

 class TestVersionAwareFilters(TestCase):
    def test_title_content_filter_falls_back_to_content(self) -> None:
@@ -48,6 +48,7 @@ class TestApiSchema(APITestCase):
        self.assertIn("/api/documents/reprocess/", paths)
        self.assertIn("/api/documents/rotate/", paths)
        self.assertIn("/api/documents/merge/", paths)
+        self.assertIn("/api/documents/merge_as_versions/", paths)
        self.assertIn("/api/documents/edit_pdf/", paths)
        self.assertIn("/api/documents/remove_password/", paths)

@@ -351,11 +351,45 @@ class TestApiWorkflows(DirectoriesMixin, APITestCase):

        self.assertEqual(WorkflowTrigger.objects.count(), 1)

-    def test_api_create_invalid_assign_title(self) -> None:
+    def test_api_create_complex_assign_title(self) -> None:
        """
        GIVEN:
            - API request to create a workflow
-            - Invalid f-string for assign_title
+            - Template using Jinja flow control statements
+        WHEN:
+            - API is called
+        THEN:
+            - Workflow is created
+        """
+        response = self.client.post(
+            self.ENDPOINT,
+            json.dumps(
+                {
+                    "name": "Workflow 2",
+                    "order": 1,
+                    "triggers": [
+                        {
+                            "type": WorkflowTrigger.WorkflowTriggerType.DOCUMENT_UPDATED,
+                        },
+                    ],
+                    "actions": [
+                        {
+                            "assign_title": '{# this is a comment #}foo{% if created_year < 2000 %}bar{% endif %}{{ "{:04d}".format(42) }}',
+                        },
+                    ],
+                },
+            ),
+            content_type="application/json",
+        )
+        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+
+        self.assertEqual(Workflow.objects.count(), 2)
+
+    def test_api_create_invalid_assign_title_syntax_error(self) -> None:
+        """
+        GIVEN:
+            - API request to create a workflow
+            - Invalid template for assign_title
        WHEN:
            - API is called
        THEN:
@@ -366,7 +400,7 @@ class TestApiWorkflows(DirectoriesMixin, APITestCase):
            self.ENDPOINT,
            json.dumps(
                {
-                    "name": "Workflow 1",
+                    "name": "Workflow 2",
                    "order": 1,
                    "triggers": [
                        {
@@ -375,7 +409,7 @@ class TestApiWorkflows(DirectoriesMixin, APITestCase):
                    ],
                    "actions": [
                        {
-                            "assign_title": "{created_year]",
+                            "assign_title": "{{created_year}",
                        },
                    ],
                },
@@ -384,7 +418,89 @@ class TestApiWorkflows(DirectoriesMixin, APITestCase):
        )
        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
        self.assertIn(
-            "Invalid f-string detected",
+            "Template syntax error",
+            response.data["actions"][0]["assign_title"][0],
+        )
+
+        self.assertEqual(Workflow.objects.count(), 1)
+
+    def test_api_create_invalid_assign_title_assertion_error(self) -> None:
+        """
+        GIVEN:
+            - API request to create a workflow
+            - Template using unknown filters for assign_title
+        WHEN:
+            - API is called
+        THEN:
+            - Correct HTTP 400 response
+            - No objects are created
+        """
+        response = self.client.post(
+            self.ENDPOINT,
+            json.dumps(
+                {
+                    "name": "Workflow 2",
+                    "order": 1,
+                    "triggers": [
+                        {
+                            "type": WorkflowTrigger.WorkflowTriggerType.DOCUMENT_UPDATED,
+                        },
+                    ],
+                    "actions": [
+                        {
+                            "assign_title": "{{ created_year | foo }}",
+                        },
+                    ],
+                },
+            ),
+            content_type="application/json",
+        )
+        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
+        self.assertIn(
+            "Template assertion error",
+            response.data["actions"][0]["assign_title"][0],
+        )
+
+        self.assertEqual(Workflow.objects.count(), 1)
+
+    def test_api_create_invalid_assign_title_unknown_placeholder(self) -> None:
+        """
+        GIVEN:
+            - API request to create a workflow
+            - Template with unknown placeholders for assign_title
+        WHEN:
+            - API is called
+        THEN:
+            - Correct HTTP 400 response
+            - No objects are created
+        """
+        response = self.client.post(
+            self.ENDPOINT,
+            json.dumps(
+                {
+                    "name": "Workflow 2",
+                    "order": 1,
+                    "triggers": [
+                        {
+                            "type": WorkflowTrigger.WorkflowTriggerType.DOCUMENT_UPDATED,
+                        },
+                    ],
+                    "actions": [
+                        {
+                            "assign_title": "{{creation_year}}",
+                        },
+                    ],
+                },
+            ),
+            content_type="application/json",
+        )
+        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
+        self.assertIn(
+            "Template references unknown placeholders",
+            response.data["actions"][0]["assign_title"][0],
+        )
+        self.assertIn(
+            "creation_year",
            response.data["actions"][0]["assign_title"][0],
        )

@@ -6,6 +6,8 @@ from datetime import timedelta
 from io import StringIO
 from pathlib import Path
 from unittest import mock
+from zipfile import ZIP_DEFLATED
+from zipfile import ZIP_LZMA
 from zipfile import ZipFile

 import pytest
@@ -1078,6 +1080,197 @@ class TestExportImport(
                        skip_checks=True,
                    )

+    def test_compression_flags_require_zip(self) -> None:
+        """
+        GIVEN:
+            - A request to export without --zip
+        WHEN:
+            - --zip-compression or --zip-compression-level is passed anyway
+        THEN:
+            - A CommandError is raised (the flags are meaningless without --zip)
+        """
+        cases = {
+            "zip-compression": ["--zip-compression", "lzma"],
+            "zip-compression-level": ["--zip-compression-level", "5"],
+        }
+        for case_id, args in cases.items():
+            with self.subTest(case_id), self.assertRaises(CommandError):
+                call_command(
+                    "document_exporter",
+                    self.target,
+                    *args,
+                    skip_checks=True,
+                )
+
+    def test_zip_compression_level_out_of_range_raises(self) -> None:
+        """
+        GIVEN:
+            - A request to export to a zip file
+        WHEN:
+            - --zip-compression-level is outside the chosen method's valid range
+        THEN:
+            - A CommandError is raised
+        """
+        with self.assertRaises(CommandError):
+            call_command(
+                "document_exporter",
+                self.target,
+                "--zip",
+                "--zip-compression",
+                "deflated",
+                "--zip-compression-level",
+                "99",
+                skip_checks=True,
+            )
+
+    def test_zip_compression_level_rejected_for_levelless_method(self) -> None:
+        """
+        GIVEN:
+            - A request to export to a zip file with a compression method
+              that ignores level entirely (stored, lzma)
+        WHEN:
+            - --zip-compression-level is also passed
+        THEN:
+            - A CommandError is raised
+        """
+        for method in ("stored", "lzma"):
+            with self.subTest(method), self.assertRaises(CommandError):
+                call_command(
+                    "document_exporter",
+                    self.target,
+                    "--zip",
+                    "--zip-compression",
+                    method,
+                    "--zip-compression-level",
+                    "5",
+                    skip_checks=True,
+                )
+
+    def test_zstd_unavailable_raises_friendly_error(self) -> None:
+        """
+        GIVEN:
+            - A Python runtime without zstd support (< 3.14)
+        WHEN:
+            - --zip-compression zstd is requested
+        THEN:
+            - A CommandError naming the Python version requirement is raised
+
+        zstd availability is mocked rather than relying on the actual
+        runtime: on a Python 3.14+ CI leg, ZSTD is not None, so without the
+        mock this check is skipped and the command falls through into the
+        real export, which fails on missing document files instead of
+        raising the expected CommandError.
+        """
+        with (
+            mock.patch(
+                "documents.management.commands.document_exporter.ZSTD",
+                None,
+            ),
+            mock.patch(
+                "documents.management.commands.document_exporter.compression_available",
+                return_value=False,
+            ),
+            self.assertRaises(CommandError) as e,
+        ):
+            call_command(
+                "document_exporter",
+                self.target,
+                "--zip",
+                "--zip-compression",
+                "zstd",
+                skip_checks=True,
+            )
+        self.assertIn("3.14", str(e.exception))
+
+    def test_non_zstd_unavailable_raises_generic_error(self) -> None:
+        """
+        GIVEN:
+            - A Python runtime missing the module backing a non-zstd method
+              (e.g. bz2/lzma not compiled in on a minimal build)
+        WHEN:
+            - That method is requested via --zip-compression
+        THEN:
+            - A CommandError is raised naming the method, not the
+              zstd-specific "requires 3.14" message
+        """
+        with (
+            mock.patch(
+                "documents.management.commands.document_exporter.compression_available",
+                return_value=False,
+            ),
+            self.assertRaises(CommandError) as e,
+        ):
+            call_command(
+                "document_exporter",
+                self.target,
+                "--zip",
+                "--zip-compression",
+                "bzip2",
+                skip_checks=True,
+            )
+        self.assertIn("bzip2", str(e.exception))
+        self.assertNotIn("3.14", str(e.exception))
+
+    def test_zip_compression_flag_resolves_to_sink_constant(self) -> None:
+        """
+        GIVEN:
+            - A request to export to a zip file with --zip-compression lzma
+        WHEN:
+            - The export runs
+        THEN:
+            - ZipExportSink is constructed with the resolved ZIP_LZMA constant
+              (whether zipfile actually compresses with the chosen method is
+              Python's own contract, and ZipExportSink's own tests already
+              cover the forwarding; what this command owns is resolving the
+              CLI string to the right constant, so assert that resolution
+              directly)
+        """
+        with mock.patch(
+            "documents.management.commands.document_exporter.ZipExportSink",
+        ) as sink_cls:
+            call_command(
+                "document_exporter",
+                self.target,
+                "--zip",
+                "--zip-compression",
+                "lzma",
+                skip_checks=True,
+            )
+        sink_cls.assert_called_once_with(
+            mock.ANY,
+            mock.ANY,
+            delete=False,
+            compression=ZIP_LZMA,
+            compresslevel=None,
+        )
+
+    def test_default_zip_compression_resolves_to_deflate(self) -> None:
+        """
+        GIVEN:
+            - A request to export to a zip file with no --zip-compression flag
+        WHEN:
+            - The export runs
+        THEN:
+            - ZipExportSink is constructed with the default ZIP_DEFLATED
+              constant and compresslevel=None, matching pre-existing behavior
+        """
+        with mock.patch(
+            "documents.management.commands.document_exporter.ZipExportSink",
+        ) as sink_cls:
+            call_command(
+                "document_exporter",
+                self.target,
+                "--zip",
+                skip_checks=True,
+            )
+        sink_cls.assert_called_once_with(
+            mock.ANY,
+            mock.ANY,
+            delete=False,
+            compression=ZIP_DEFLATED,
+            compresslevel=None,
+        )
+

@pytest.mark.management
 class TestCryptExportImport(
@@ -525,6 +525,71 @@ class TestCommandImport(
        self.assertEqual(doc.tags.count(), 1)
        self.assertEqual(doc.tags.first().name, "batch-flush-tag")

+    def test_import_rejects_unreadable_compression(self) -> None:
+        """
+        GIVEN:
+            - A zip archive with an entry whose compression this Python can't read
+        WHEN:
+            - Import is attempted
+        THEN:
+            - A CommandError naming the issue is raised, before extraction
+        """
+        import zipfile
+        from unittest import mock
+
+        archive = Path(self.dirs.scratch_dir) / "export.zip"
+        with zipfile.ZipFile(archive, "w") as zf:
+            zf.writestr("manifest.json", "[]")
+
+        with mock.patch(
+            "documents.management.commands.document_importer.compress_type_readable",
+            return_value=False,
+        ):
+            with self.assertRaises(CommandError) as e:
+                call_command(
+                    "document_importer",
+                    str(archive),
+                    "--no-progress-bar",
+                    skip_checks=True,
+                )
+        self.assertIn("compression", str(e.exception))
+
+    def test_import_rejects_unreadable_zstd_with_version_hint(self) -> None:
+        """
+        GIVEN:
+            - A zip archive with an entry compressed with zstd
+        WHEN:
+            - Import is attempted on a Python runtime that can't read zstd
+        THEN:
+            - The CommandError names the 3.14+ requirement, not just the
+              generic "can't read" message
+        """
+        import zipfile
+        from unittest import mock
+
+        archive = Path(self.dirs.scratch_dir) / "export.zip"
+        with zipfile.ZipFile(archive, "w") as zf:
+            zf.writestr("manifest.json", "[]")
+
+        with (
+            mock.patch(
+                "documents.management.commands.document_importer.compress_type_readable",
+                return_value=False,
+            ),
+            mock.patch(
+                "documents.management.commands.document_importer.unreadable_method_names",
+                return_value={"zstd"},
+            ),
+        ):
+            with self.assertRaises(CommandError) as e:
+                call_command(
+                    "document_importer",
+                    str(archive),
+                    "--no-progress-bar",
+                    skip_checks=True,
+                )
+        self.assertIn("3.14", str(e.exception))
+

@pytest.mark.management
@pytest.mark.django_db
@@ -0,0 +1,546 @@
+import json
+from unittest import mock
+
+from auditlog.models import LogEntry
+from django.contrib.auth.models import Permission
+from django.contrib.auth.models import User
+from django.contrib.contenttypes.models import ContentType
+from django.test import TestCase
+from rest_framework import status
+from rest_framework.test import APITestCase
+
+from documents.bulk_edit import merge_as_versions
+from documents.models import Document
+from documents.serialisers import MergeDocumentsAsVersionsSerializer
+
+
+class TestMergeDocumentsAsVersionsSerializer(TestCase):
+    def setUp(self) -> None:
+        self.doc1 = Document.objects.create(checksum="A", title="A")
+        self.doc2 = Document.objects.create(checksum="B", title="B")
+        self.doc3 = Document.objects.create(checksum="C", title="C")
+
+    def test_accepts_selected_root_document(self) -> None:
+        serializer = MergeDocumentsAsVersionsSerializer(
+            data={
+                "documents": [self.doc1.id, self.doc2.id, self.doc3.id],
+                "root_document_id": self.doc2.id,
+            },
+        )
+
+        self.assertTrue(serializer.is_valid(), serializer.errors)
+        self.assertEqual(
+            serializer.validated_data,
+            {
+                "documents": [self.doc1.id, self.doc2.id, self.doc3.id],
+                "root_document_id": self.doc2.id,
+            },
+        )
+
+    def test_requires_at_least_two_documents(self) -> None:
+        serializer = MergeDocumentsAsVersionsSerializer(
+            data={
+                "documents": [self.doc1.id],
+                "root_document_id": self.doc1.id,
+            },
+        )
+
+        self.assertFalse(serializer.is_valid())
+        self.assertEqual(
+            serializer.errors["non_field_errors"][0],
+            "At least two documents are required.",
+        )
+
+    def test_accepts_version_label_for_one_source_document(self) -> None:
+        serializer = MergeDocumentsAsVersionsSerializer(
+            data={
+                "documents": [self.doc1.id, self.doc2.id],
+                "root_document_id": self.doc1.id,
+                "version_label": "  Imported  ",
+            },
+        )
+
+        self.assertTrue(serializer.is_valid(), serializer.errors)
+        self.assertEqual(serializer.validated_data["version_label"], "Imported")
+
+    def test_rejects_version_label_for_multiple_source_documents(self) -> None:
+        serializer = MergeDocumentsAsVersionsSerializer(
+            data={
+                "documents": [self.doc1.id, self.doc2.id, self.doc3.id],
+                "root_document_id": self.doc1.id,
+                "version_label": "Imported",
+            },
+        )
+
+        self.assertFalse(serializer.is_valid())
+        self.assertEqual(
+            serializer.errors["non_field_errors"][0],
+            "version_label can only be used when merging one source document.",
+        )
+
+    def test_requires_root_document_to_be_selected(self) -> None:
+        serializer = MergeDocumentsAsVersionsSerializer(
+            data={
+                "documents": [self.doc1.id, self.doc2.id],
+                "root_document_id": self.doc3.id,
+            },
+        )
+
+        self.assertFalse(serializer.is_valid())
+        self.assertEqual(
+            serializer.errors["non_field_errors"][0],
+            "root_document_id must be one of the selected documents.",
+        )
+
+    def test_rejects_duplicate_documents(self) -> None:
+        serializer = MergeDocumentsAsVersionsSerializer(
+            data={
+                "documents": [self.doc1.id, self.doc1.id],
+                "root_document_id": self.doc1.id,
+            },
+        )
+
+        self.assertFalse(serializer.is_valid())
+        self.assertIn("documents", serializer.errors)
+
+    def test_rejects_selected_version(self) -> None:
+        version = Document.objects.create(
+            checksum="D",
+            title="D",
+            root_document=self.doc1,
+            version_index=1,
+        )
+        serializer = MergeDocumentsAsVersionsSerializer(
+            data={
+                "documents": [version.id, self.doc2.id],
+                "root_document_id": self.doc2.id,
+            },
+        )
+
+        self.assertFalse(serializer.is_valid())
+        self.assertEqual(
+            serializer.errors["non_field_errors"][0],
+            "Only top-level documents can be merged as versions.",
+        )
+
+    def test_rejects_source_document_with_versions(self) -> None:
+        Document.objects.create(
+            checksum="D",
+            title="D",
+            root_document=self.doc1,
+            version_index=1,
+        )
+        serializer = MergeDocumentsAsVersionsSerializer(
+            data={
+                "documents": [self.doc1.id, self.doc2.id],
+                "root_document_id": self.doc2.id,
+            },
+        )
+
+        self.assertFalse(serializer.is_valid())
+        self.assertEqual(
+            serializer.errors["non_field_errors"][0],
+            "Documents with existing versions cannot be merged into another document.",
+        )
+
+    def test_rejects_source_document_with_trashed_versions(self) -> None:
+        version = Document.objects.create(
+            checksum="D",
+            title="D",
+            root_document=self.doc1,
+            version_index=1,
+        )
+        version.delete()  # trashed, but still points at doc1
+        serializer = MergeDocumentsAsVersionsSerializer(
+            data={
+                "documents": [self.doc1.id, self.doc2.id],
+                "root_document_id": self.doc2.id,
+            },
+        )
+
+        self.assertFalse(serializer.is_valid())
+        self.assertEqual(
+            serializer.errors["non_field_errors"][0],
+            "Documents with existing versions cannot be merged into another document.",
+        )
+
+    def test_allows_root_document_with_versions(self) -> None:
+        Document.objects.create(
+            checksum="D",
+            title="D",
+            root_document=self.doc1,
+            version_index=1,
+        )
+        serializer = MergeDocumentsAsVersionsSerializer(
+            data={
+                "documents": [self.doc1.id, self.doc2.id],
+                "root_document_id": self.doc1.id,
+            },
+        )
+
+        self.assertTrue(serializer.is_valid(), serializer.errors)
+
+
+class TestMergeDocumentsAsVersions(TestCase):
+    @mock.patch("documents.bulk_edit.DocumentsStatusManager")
+    @mock.patch("documents.bulk_edit.bulk_update_documents.apply_async")
+    @mock.patch("documents.search.get_backend")
+    def test_merges_documents_in_selection_order(
+        self,
+        get_backend_mock,
+        bulk_update_mock,
+        status_manager_mock,
+    ) -> None:
+        root = Document.objects.create(checksum="A", title="Root")
+        existing_version = Document.objects.create(
+            checksum="B",
+            title="Existing version",
+            root_document=root,
+            version_index=3,
+        )
+        source1 = Document.objects.create(
+            checksum="C",
+            title="Source 1",
+            archive_serial_number=1,
+        )
+        source2 = Document.objects.create(
+            checksum="D",
+            title="Source 2",
+            archive_serial_number=2,
+        )
+        original_modified = root.modified
+
+        result = merge_as_versions(
+            [source2.id, root.id, source1.id],
+            root_document_id=root.id,
+        )
+
+        self.assertEqual(result, "OK")
+        source1.refresh_from_db()
+        source2.refresh_from_db()
+        root.refresh_from_db()
+        # source2 was selected first, so it becomes the older of the two versions
+        self.assertEqual(source2.root_document_id, root.id)
+        self.assertEqual(source2.version_index, 4)
+        self.assertEqual(source1.root_document_id, root.id)
+        self.assertEqual(source1.version_index, 5)
+        self.assertIsNone(source1.archive_serial_number)
+        self.assertIsNone(source2.archive_serial_number)
+        # The root had no ASN of its own, so it takes the first one
+        self.assertEqual(root.archive_serial_number, 2)
+        self.assertGreater(root.modified, original_modified)
+        self.assertEqual(existing_version.root_document_id, root.id)
+
+        batch = get_backend_mock.return_value.batch_update.return_value.__enter__.return_value
+        self.assertEqual(
+            [call.args[0] for call in batch.remove.call_args_list],
+            [source2.id, source1.id],
+        )
+        bulk_update_mock.assert_called_once_with(
+            kwargs={"document_ids": [root.id]},
+            headers={"trigger_source": "system"},
+        )
+        status_manager_mock.return_value.send_documents_deleted.assert_called_once_with(
+            [source2.id, source1.id],
+        )
+
+    @mock.patch("documents.bulk_edit.DocumentsStatusManager")
+    @mock.patch("documents.bulk_edit.bulk_update_documents.apply_async")
+    @mock.patch("documents.search.get_backend")
+    def test_root_keeps_its_own_archive_serial_number(self, *_mocks) -> None:
+        root = Document.objects.create(
+            checksum="A",
+            title="Root",
+            archive_serial_number=1,
+        )
+        source = Document.objects.create(
+            checksum="B",
+            title="Source",
+            archive_serial_number=2,
+        )
+
+        with self.assertLogs("paperless.bulk_edit", level="WARNING") as logs:
+            merge_as_versions([root.id, source.id], root_document_id=root.id)
+
+        root.refresh_from_db()
+        source.refresh_from_db()
+        self.assertEqual(root.archive_serial_number, 1)
+        self.assertIsNone(source.archive_serial_number)
+        # Dropping an ASN is not silent
+        self.assertIn("[2]", logs.output[0])
+
+    @mock.patch("documents.bulk_edit.DocumentsStatusManager")
+    @mock.patch("documents.bulk_edit.bulk_update_documents.apply_async")
+    @mock.patch("documents.search.get_backend")
+    def test_root_without_asn_takes_the_source_archive_serial_number(
+        self,
+        *_mocks,
+    ) -> None:
+        root = Document.objects.create(checksum="A", title="Root")
+        source = Document.objects.create(
+            checksum="B",
+            title="Source",
+            archive_serial_number=7,
+        )
+
+        merge_as_versions([root.id, source.id], root_document_id=root.id)
+
+        root.refresh_from_db()
+        source.refresh_from_db()
+        self.assertEqual(root.archive_serial_number, 7)
+        self.assertIsNone(source.archive_serial_number)
+
+    @mock.patch("documents.bulk_edit.DocumentsStatusManager")
+    @mock.patch("documents.bulk_edit.bulk_update_documents.apply_async")
+    @mock.patch("documents.search.get_backend")
+    def test_writes_audit_log_entry(self, *_mocks) -> None:
+        user = User.objects.create_user(username="merger")
+        root = Document.objects.create(checksum="A", title="Root")
+        source = Document.objects.create(checksum="B", title="Source")
+        LogEntry.objects.all().delete()
+
+        merge_as_versions([root.id, source.id], root_document_id=root.id, user=user)
+
+        entry = LogEntry.objects.filter(
+            content_type=ContentType.objects.get_for_model(Document),
+            object_id=root.id,
+        ).first()
+        self.assertIsNotNone(entry)
+        self.assertEqual(entry.actor, user)
+        self.assertEqual(entry.action, LogEntry.Action.UPDATE)
+        self.assertEqual(entry.changes, {"Merged As Versions": ["None", [source.id]]})
+        self.assertEqual(entry.additional_data["version_ids"], [source.id])
+
+    @mock.patch("documents.bulk_edit.DocumentsStatusManager")
+    @mock.patch("documents.bulk_edit.bulk_update_documents.apply_async")
+    @mock.patch("documents.search.get_backend")
+    def test_sets_version_label_for_one_source_document(
+        self,
+        _get_backend_mock,
+        _bulk_update_mock,
+        _status_manager_mock,
+    ) -> None:
+        root = Document.objects.create(checksum="A", title="Root")
+        source = Document.objects.create(checksum="B", title="Source")
+
+        merge_as_versions(
+            [root.id, source.id],
+            root_document_id=root.id,
+            version_label="Imported",
+        )
+
+        source.refresh_from_db()
+        self.assertEqual(source.version_label, "Imported")
+
+
+class TestMergeDocumentsAsVersionsAPI(APITestCase):
+    def setUp(self) -> None:
+        self.user = User.objects.create_user(username="user")
+        self.user.user_permissions.add(
+            Permission.objects.get(codename="change_document"),
+            Permission.objects.get(codename="view_document"),
+            Permission.objects.get(codename="delete_document"),
+        )
+        self.doc1 = Document.objects.create(
+            checksum="A",
+            title="A",
+            owner=self.user,
+        )
+        self.doc2 = Document.objects.create(
+            checksum="B",
+            title="B",
+            owner=self.user,
+        )
+        self.client.force_authenticate(user=self.user)
+
+    @mock.patch("documents.views.bulk_edit.merge_as_versions")
+    def test_merges_documents_as_versions(self, merge_mock) -> None:
+        merge_mock.return_value = "OK"
+        merge_mock.__name__ = "merge_as_versions"
+
+        response = self.client.post(
+            "/api/documents/merge_as_versions/",
+            json.dumps(
+                {
+                    "documents": [self.doc1.id, self.doc2.id],
+                    "root_document_id": self.doc2.id,
+                    "version_label": "Imported",
+                },
+            ),
+            content_type="application/json",
+        )
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.assertEqual(response.data, {"result": "OK"})
+        merge_mock.assert_called_once_with(
+            [self.doc1.id, self.doc2.id],
+            root_document_id=self.doc2.id,
+            version_label="Imported",
+            user=self.user,
+        )
+
+    @mock.patch("documents.views.bulk_edit.merge_as_versions")
+    def test_requires_change_permission(self, merge_mock) -> None:
+        merge_mock.__name__ = "merge_as_versions"
+        user = User.objects.create_user(username="no-change")
+        self.doc1.owner = user
+        self.doc1.save()
+        self.doc2.owner = user
+        self.doc2.save()
+        self.client.force_authenticate(user=user)
+
+        response = self.client.post(
+            "/api/documents/merge_as_versions/",
+            {
+                "documents": [self.doc1.id, self.doc2.id],
+                "root_document_id": self.doc1.id,
+            },
+            format="json",
+        )
+
+        self.assertEqual(response.status_code, status.HTTP_403_FORBIDDEN)
+        merge_mock.assert_not_called()
+
+    @mock.patch("documents.views.bulk_edit.merge_as_versions")
+    def test_requires_delete_permission(self, merge_mock) -> None:
+        merge_mock.__name__ = "merge_as_versions"
+        # Owns them and may change them, but may not make them stop being documents
+        user = User.objects.create_user(username="no-delete")
+        user.user_permissions.add(
+            Permission.objects.get(codename="change_document"),
+            Permission.objects.get(codename="view_document"),
+        )
+        for doc in (self.doc1, self.doc2):
+            doc.owner = user
+            doc.save()
+        self.client.force_authenticate(user=user)
+
+        response = self.client.post(
+            "/api/documents/merge_as_versions/",
+            {
+                "documents": [self.doc1.id, self.doc2.id],
+                "root_document_id": self.doc1.id,
+            },
+            format="json",
+        )
+
+        self.assertEqual(response.status_code, status.HTTP_403_FORBIDDEN)
+        merge_mock.assert_not_called()
+
+    @mock.patch("documents.views.bulk_edit.merge_as_versions")
+    def test_rejects_unselected_root(self, merge_mock) -> None:
+        doc3 = Document.objects.create(
+            checksum="C",
+            title="C",
+            owner=self.user,
+        )
+
+        response = self.client.post(
+            "/api/documents/merge_as_versions/",
+            {
+                "documents": [self.doc1.id, self.doc2.id],
+                "root_document_id": doc3.id,
+            },
+            format="json",
+        )
+
+        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
+        merge_mock.assert_not_called()
+
+    @mock.patch("documents.views.bulk_edit.merge_as_versions")
+    def test_rejects_source_document_with_versions(self, merge_mock) -> None:
+        Document.objects.create(
+            checksum="C",
+            title="C",
+            root_document=self.doc1,
+            version_index=1,
+            owner=self.user,
+        )
+
+        response = self.client.post(
+            "/api/documents/merge_as_versions/",
+            {
+                "documents": [self.doc1.id, self.doc2.id],
+                "root_document_id": self.doc2.id,
+            },
+            format="json",
+        )
+
+        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
+        merge_mock.assert_not_called()
+        self.doc1.refresh_from_db()
+        self.assertIsNone(self.doc1.root_document_id)
+
+    @mock.patch("documents.bulk_edit.DocumentsStatusManager")
+    @mock.patch("documents.bulk_edit.bulk_update_documents.apply_async")
+    @mock.patch("documents.search.get_backend")
+    def test_merges_and_returns_documents_as_versions(
+        self,
+        get_backend_mock,
+        bulk_update_mock,
+        status_manager_mock,
+    ) -> None:
+        response = self.client.post(
+            "/api/documents/merge_as_versions/",
+            {
+                "documents": [self.doc1.id, self.doc2.id],
+                "root_document_id": self.doc2.id,
+                "version_label": "Imported",
+            },
+            format="json",
+        )
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.doc1.refresh_from_db()
+        self.assertEqual(self.doc1.root_document_id, self.doc2.id)
+        self.assertEqual(self.doc1.version_label, "Imported")
+
+        detail_response = self.client.get(
+            f"/api/documents/{self.doc2.id}/?fields=id,versions",
+        )
+        self.assertEqual(detail_response.status_code, status.HTTP_200_OK)
+        versions = detail_response.data["versions"]
+        self.assertEqual(
+            {version["id"] for version in versions},
+            {self.doc1.id, self.doc2.id},
+        )
+        self.assertEqual(
+            [version["id"] for version in versions if version["is_root"]],
+            [self.doc2.id],
+        )
+        batch = get_backend_mock.return_value.batch_update.return_value.__enter__.return_value
+        batch.remove.assert_called_once_with(self.doc1.id)
+        bulk_update_mock.assert_called_once_with(
+            kwargs={"document_ids": [self.doc2.id]},
+            headers={"trigger_source": "system"},
+        )
+        status_manager_mock.return_value.send_documents_deleted.assert_called_once_with(
+            [self.doc1.id],
+        )
+
+    @mock.patch("documents.bulk_edit.DocumentsStatusManager")
+    @mock.patch("documents.bulk_edit.bulk_update_documents.apply_async")
+    @mock.patch("documents.search.get_backend")
+    def test_chosen_order_survives_to_the_versions_list(self, *_mocks) -> None:
+        doc3 = Document.objects.create(checksum="C", title="C", owner=self.user)
+        # Deliberately not in id order, as dragging the dialog rows produces
+        ordered = [doc3.id, self.doc1.id]
+
+        response = self.client.post(
+            "/api/documents/merge_as_versions/",
+            {
+                "documents": [*ordered, self.doc2.id],
+                "root_document_id": self.doc2.id,
+            },
+            format="json",
+        )
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        detail_response = self.client.get(
+            f"/api/documents/{self.doc2.id}/?fields=id,versions",
+        )
+        # Newest first, so the reverse of the order they were merged in
+        self.assertEqual(
+            [version["id"] for version in detail_response.data["versions"]],
+            [self.doc1.id, doc3.id, self.doc2.id],
+        )
@@ -5,12 +5,34 @@ from enum import StrEnum
 from typing import TYPE_CHECKING
 from typing import Any

+from django.db.models import F
+from django.db.models import QuerySet
+
 from documents.models import Document

 if TYPE_CHECKING:
    from rest_framework.request import Request


+def versions_newest_first(documents: QuerySet[Document]) -> QuerySet[Document]:
+    """
+    Sorts versions so the newest one comes first using version_index and not on id,
+    because an existing document can be merged in as a version
+    """
+    return documents.order_by(F("version_index").desc(nulls_last=True), "-id")
+
+
+def sort_versions_newest_first(documents: list[Document]) -> list[Document]:
+    """
+    Same sorting as versions_newest_first()
+    """
+    return sorted(
+        documents,
+        key=lambda doc: (doc.version_index or 0, doc.id),
+        reverse=True,
+    )
+
+
 class VersionResolutionError(StrEnum):
    INVALID = "invalid"
    NOT_FOUND = "not_found"
@@ -51,7 +73,7 @@ def get_latest_version_for_root(
    include_deleted: bool = False,
 ) -> Document:
    manager = _document_manager(include_deleted=include_deleted)
-    latest = manager.filter(root_document=root_doc).order_by("-id").first()
+    latest = versions_newest_first(manager.filter(root_document=root_doc)).first()
    return latest or root_doc


@@ -195,6 +195,7 @@ from documents.serialisers import DocumentVersionLabelSerializer
 from documents.serialisers import DocumentVersionSerializer
 from documents.serialisers import EditPdfDocumentsSerializer
 from documents.serialisers import EmailSerializer
+from documents.serialisers import MergeDocumentsAsVersionsSerializer
 from documents.serialisers import MergeDocumentsSerializer
 from documents.serialisers import NotesSerializer
 from documents.serialisers import PostDocumentSerializer
@@ -232,6 +233,7 @@ from documents.versioning import get_latest_version_for_root
 from documents.versioning import get_request_version_param
 from documents.versioning import get_root_document
 from documents.versioning import resolve_requested_version_for_root
+from documents.versioning import versions_newest_first
 from paperless import version
 from paperless.celery import app as celery_app
 from paperless.config import AIConfig
@@ -1075,9 +1077,9 @@ class DocumentViewSet(

    def get_queryset(self):
        latest_version_content = Subquery(
-            Document.objects.filter(root_document=OuterRef("pk"))
-            .order_by("-id")
-            .values("content")[:1],
+            versions_newest_first(
+                Document.objects.filter(root_document=OuterRef("pk")),
+            ).values("content")[:1],
        )
        # A correlated subquery avoids the LEFT JOIN + Count() this used to
        # be, which forced a GROUP BY aggregate over every matching document
@@ -1113,6 +1115,7 @@ class DocumentViewSet(
                        "checksum",
                        "version_label",
                        "root_document_id",
+                        "version_index",
                    ),
                ),
                "tags",
@@ -2133,11 +2136,9 @@ class DocumentViewSet(
                },
            )

-        current = (
-            Document.objects.filter(Q(id=root_doc.id) | Q(root_document=root_doc))
-            .order_by("-id")
-            .first()
-        )
+        current = versions_newest_first(
+            Document.objects.filter(Q(id=root_doc.id) | Q(root_document=root_doc)),
+        ).first()

        document_updated.send(
            sender=self.__class__,
@@ -2765,8 +2766,12 @@ class DocumentOperationPermissionMixin(PassUserMixin, DocumentSelectionMixin):
        "delete_pages",
        "edit_pdf",
        "remove_password",
+        "merge_as_versions",
+    }
+    # merge_as_versions doesn't queue any consume tasks
+    METHOD_NAMES_REQUIRING_TRIGGER_SOURCE = METHOD_NAMES_REQUIRING_USER - {
+        "merge_as_versions",
    }
-    METHOD_NAMES_REQUIRING_TRIGGER_SOURCE = METHOD_NAMES_REQUIRING_USER

    def _has_document_permissions(
        self,
@@ -2807,6 +2812,7 @@ class DocumentOperationPermissionMixin(PassUserMixin, DocumentSelectionMixin):
                    bulk_edit.rotate,
                    bulk_edit.delete_pages,
                    bulk_edit.edit_pdf,
+                    bulk_edit.merge_as_versions,
                    bulk_edit.remove_password,
                ]
            )
@@ -2837,6 +2843,9 @@ class DocumentOperationPermissionMixin(PassUserMixin, DocumentSelectionMixin):
            has_perms
            and (
                method == bulk_edit.delete
+                # Sources stop being documents of their own, and removing one
+                # again afterwards needs delete_document
+                or method == bulk_edit.merge_as_versions
                or (
                    method in [bulk_edit.merge, bulk_edit.split]
                    and parameters.get("delete_originals")
@@ -3093,6 +3102,33 @@ class MergeDocumentsView(DocumentOperationPermissionMixin):
        )


+@extend_schema_view(
+    post=extend_schema(
+        operation_id="documents_merge_as_versions",
+        description="Merge selected documents as versions of a chosen root document",
+        responses={
+            200: inline_serializer(
+                name="MergeDocumentsAsVersionsResult",
+                fields={
+                    "result": serializers.CharField(),
+                },
+            ),
+        },
+    ),
+)
+class MergeDocumentsAsVersionsView(DocumentOperationPermissionMixin):
+    serializer_class = MergeDocumentsAsVersionsSerializer
+
+    def post(self, request, *args, **kwargs):
+        serializer = self.get_serializer(data=request.data)
+        serializer.is_valid(raise_exception=True)
+        return self._execute_document_action(
+            method=bulk_edit.merge_as_versions,
+            validated_data=serializer.validated_data,
+            operation_label="document merge as versions",
+        )
+
+
@extend_schema_view(
    post=extend_schema(
        operation_id="documents_delete",
@@ -2,7 +2,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: paperless-ngx\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2026-08-12 19:04+0000\n"
+"POT-Creation-Date: 2026-08-13 19:47+0000\n"
 "PO-Revision-Date: 2022-02-17 04:17\n"
 "Last-Translator: \n"
 "Language-Team: English\n"
@@ -1575,49 +1575,49 @@ msgstr ""
 msgid "workflow runs"
 msgstr ""

-#: documents/serialisers.py:521 documents/serialisers.py:873
-#: documents/serialisers.py:2768 documents/views.py:299 documents/views.py:2555
+#: documents/serialisers.py:522 documents/serialisers.py:874
+#: documents/serialisers.py:2769 documents/views.py:299 documents/views.py:2555
 #: paperless_mail/serialisers.py:155
 msgid "Insufficient permissions."
 msgstr ""

-#: documents/serialisers.py:709
+#: documents/serialisers.py:710
 msgid "Invalid color."
 msgstr ""

-#: documents/serialisers.py:2245
+#: documents/serialisers.py:2246
 #, python-format
 msgid "File type %(type)s not supported"
 msgstr ""

-#: documents/serialisers.py:2289
+#: documents/serialisers.py:2290
 #, python-format
 msgid "Custom field id must be an integer: %(id)s"
 msgstr ""

-#: documents/serialisers.py:2296
+#: documents/serialisers.py:2297
 #, python-format
 msgid "Custom field with id %(id)s does not exist"
 msgstr ""

-#: documents/serialisers.py:2313 documents/serialisers.py:2323
+#: documents/serialisers.py:2314 documents/serialisers.py:2324
 msgid ""
 "Custom fields must be a list of integers or an object mapping ids to values."
 msgstr ""

-#: documents/serialisers.py:2318
+#: documents/serialisers.py:2319
 msgid "Some custom fields don't exist or were specified twice."
 msgstr ""

-#: documents/serialisers.py:2465
+#: documents/serialisers.py:2466
 msgid "Invalid variable detected."
 msgstr ""

-#: documents/serialisers.py:2824
+#: documents/serialisers.py:2825
 msgid "Duplicate document identifiers are not allowed."
 msgstr ""

-#: documents/serialisers.py:2854 documents/views.py:4509
+#: documents/serialisers.py:2855 documents/views.py:4509
 #, python-format
 msgid "Documents not found: %(ids)s"
 msgstr ""
@@ -27,6 +27,7 @@ from documents.views import EditPdfDocumentsView
 from documents.views import GlobalSearchView
 from documents.views import IndexView
 from documents.views import LogViewSet
+from documents.views import MergeDocumentsAsVersionsView
 from documents.views import MergeDocumentsView
 from documents.views import PostDocumentView
 from documents.views import RemoteVersionView
@@ -172,6 +173,11 @@ urlpatterns = [
                                MergeDocumentsView.as_view(),
                                name="merge_documents",
                            ),
+                            re_path(
+                                "^merge_as_versions/",
+                                MergeDocumentsAsVersionsView.as_view(),
+                                name="merge_documents_as_versions",
+                            ),
                            re_path(
                                "^edit_pdf/",
                                EditPdfDocumentsView.as_view(),
Author	SHA1	Message	Date
shamoon	e4a7cd31c1	Simplify the serializer checks	2026-08-13 14:57:05 -07:00
shamoon	ad86ea01af	Enforce delete_document too	2026-08-13 14:57:04 -07:00
shamoon	2f4eed1bd9	batch_update for index removal	2026-08-13 14:57:04 -07:00
shamoon	cb9cac7b54	Do this as a bulk_update	2026-08-13 14:57:04 -07:00
shamoon	a3341021c0	use root_document_id	2026-08-13 14:57:04 -07:00
shamoon	1b43d53dbf	defer content	2026-08-13 14:57:03 -07:00
shamoon	6b12756c2b	Bring the buttonsEnabled stuff into here	2026-08-13 14:57:03 -07:00
shamoon	2ec7ff7369	Update merge-as-versions-confirm-dialog.component.ts	2026-08-13 14:57:03 -07:00
shamoon	f9895b528a	Update main.ts	2026-08-13 14:57:03 -07:00
shamoon	906e961d66	The ol empty string fun	2026-08-13 14:57:02 -07:00
shamoon	24c0e648a4	Avoid double popup when the request actually failed	2026-08-13 14:57:02 -07:00
shamoon	081d53617c	Rework the dialog to be less confusing	2026-08-13 14:57:02 -07:00
shamoon	d3131d51b8	Sheesh, now we can bring back ordering	2026-08-13 14:57:02 -07:00
shamoon	6c7505586c	Audit log stuff: need a user, avoid post_save signals etc	2026-08-13 14:57:02 -07:00
shamoon	3cc2f30780	Bah, deal with ASNs	2026-08-13 14:57:01 -07:00
shamoon	0f88a3173a	We need to use global objects here	2026-08-13 14:57:01 -07:00
shamoon	bfe1aaaa79	Frontend can always just do versions[0]	2026-08-13 14:57:01 -07:00
shamoon	13382c2a91	Add some tests for this new version doesnt follow id	2026-08-13 14:57:01 -07:00
shamoon	1030e8ca27	use the helpers	2026-08-13 14:57:00 -07:00
shamoon	e195dff291	Add helpers for versioning by version_index	2026-08-13 14:57:00 -07:00
shamoon	16e38c58c8	Sonar	2026-08-13 14:57:00 -07:00
shamoon	dfb20f1eef	Use the task for remove from index	2026-08-13 14:57:00 -07:00
shamoon	57efd7e423	Also support choosing a doc as a version from detail view See https://github.com/paperless-ngx/paperless-ngx/discussions/13467	2026-08-13 14:56:59 -07:00
shamoon	4b57503151	Support optional label with one doc	2026-08-13 14:56:59 -07:00
shamoon	adc1b75512	Derp, no re-ordering	2026-08-13 14:56:59 -07:00
shamoon	c2c58e1be5	Docs	2026-08-13 14:56:59 -07:00
shamoon	15476d4123	API docs, add to schema test Update api.md	2026-08-13 14:56:58 -07:00
shamoon	8795eae6f1	Actually at this point lets split the dialogs	2026-08-13 14:56:58 -07:00
shamoon	102259b505	Dont show root in the list (and remove it from the sortable list)	2026-08-13 14:56:58 -07:00
shamoon	45d093bea4	Basic merge dialog	2026-08-13 14:56:58 -07:00
shamoon	4145b99562	Forgot to import the icon	2026-08-13 14:56:57 -07:00
shamoon	4e1097261f	Frondend bulk edit stuff	2026-08-13 14:56:57 -07:00
shamoon	dfc13d0d07	Ok frontend service	2026-08-13 14:56:57 -07:00
shamoon	826b0650fd	Tests for API view	2026-08-13 14:56:57 -07:00
shamoon	986ca01670	API view	2026-08-13 14:56:57 -07:00
shamoon	d61c51277d	Backend operation, also delete from search and notify the frontend	2026-08-13 14:56:56 -07:00
shamoon	c1171ef9a8	Basic merge as versions view	2026-08-13 14:56:56 -07:00
GitHub Actions	01c12d9ea4	Auto translate strings	2026-08-13 19:48:40 +00:00
Max TruxaandGitHub	f5c0d118f7	Fix: fix validation of workflow title assignment (#13659 )	2026-08-13 12:46:57 -07:00
Trenton H GitHub shamoon	ff13847d0a	Feature: Allow selection of compression type and and level during export (#13661 ) * Feature: Allow configuring the compression type and compression levels during export Building on the zip export improvements, this now allows users to further configure the zip to fit their needs. A simple stored zip for speed, or a high compression zstd for the smallest archive. Full validation of the method and levels at the command line Co-authored-by: shamoon <4887959+shamoon@users.noreply.github.com>	2026-08-13 18:29:33 +00:00
shamoonandGitHub	634f803872	Fix: dont clip search dropdown on mobile (#13675 )	2026-08-13 10:57:16 -07:00
GitHub Actions	639d566a7c	Auto translate strings	2026-08-13 16:50:00 +00:00
shamoonandGitHub	0a94f8f0d4	Fix: use proper signal for modal buttonsEnabled (#13672 )	2026-08-13 09:48:23 -07:00