diff --git a/TESTING.md b/TESTING.md
index 54eba39e..6e9cba4f 100644
--- a/TESTING.md
+++ b/TESTING.md
@@ -4510,7 +4510,11 @@ category; without one it shows the category its link supplies.
   - 409 `source-changed`: a stale `root_scope`;
   - 413: a body over 1 MiB.
   Any invalid item fails the whole request before a write. Targets that fold to one
-  key are written and counted once.
+  key are written and counted once. Instead of `items` a request may send `filter`,
+  the Images listing's own query ("Select all N matching", #392, keys as in
+  `parse_listing_filter`), resolved now: over 500 matches is a 400
+  `too-many-images` ("Select at most 500 images."), a renumbered source a 409
+  `source-changed`.
 - PUT writes only files the source's listing holds and counts the rest in
   `not_found`; when none is listed it answers 404 `files-not-found` and writes
   nothing. A file that already has the value counts as `unchanged` and keeps its
diff --git a/py/api/image_categories.py b/py/api/image_categories.py
index 381b6059..0b497bae 100644
--- a/py/api/image_categories.py
+++ b/py/api/image_categories.py
@@ -6,6 +6,8 @@ category can still be removed); ``GET /prompt_manager/images/categories``
 lists the own-category values of files the sources list. Targets are the
 Images listing identity (``{root_index, root_scope, path}``, checked by
 ``media_target``) of an output source; LoRA folders are not sources here.
+Instead of ``items`` a request may name ``filter``, the Images listing's own
+query ("Select all N matching", #392), resolved now up to 500 images.
 Each file is stored under its file key (``images.image_category_key``).
 These routes never read or write prompts, recipes or image links.
 """
@@ -33,8 +35,9 @@ except ImportError:
     from utils.validators import validate_category
 
 CATEGORY_MEDIA_MESSAGE = "Only media files can have a category"
-_PUT_FIELDS = frozenset({"items", "category"})
-_DELETE_FIELDS = frozenset({"items"})
+_PUT_FIELDS = frozenset({"category"})
+_DELETE_FIELDS = frozenset()
+TOO_MANY = f"Select at most {MAX_JOB_TARGETS} images."
 SOURCE_CHANGED_MESSAGE = "The sources changed. Refresh the images and try again."
 WRITE_FAILED = "The category could not be changed."
 READ_FAILED = "Image categories could not be read."
@@ -196,20 +199,53 @@ class ImageCategoryRoutesMixin:
 
     # -- writing ---------------------------------------------------------------
 
+    async def _filter_targets(self, raw):
+        """``(targets, None)`` for an Images listing filter, else ``(None, error)``.
+
+        "Select all N matching" (#392) sends the listing's own query; it is
+        resolved now, up to 500 images (a 400 ``too-many-images`` above).
+        """
+        from .images import ListingSourceChanged, parse_listing_filter
+
+        try:
+            selection = await self.resolve_listing_filter(
+                parse_listing_filter(raw), MAX_JOB_TARGETS
+            )
+        except ListingSourceChanged:
+            return None, _coded(409, "source-changed", SOURCE_CHANGED_MESSAGE)
+        except ValueError as exc:
+            return None, bad_request(str(exc))
+        if selection.truncated:
+            return None, _coded(400, "too-many-images", TOO_MANY)
+        return tuple(selection.targets), None
+
     async def _category_request(self, request, fields: frozenset):
-        """``(data, targets, roots, None)`` or ``(None, None, None, error)``."""
+        """``(data, targets, roots, None)`` or ``(None, None, None, error)``.
+
+        The images are ``items`` (1 to 500 targets) or ``filter`` (all images
+        an Images listing filter admits), besides *fields*.
+        """
         data, error = await _json_body_or_error(request)
         if error is not None:
             return None, None, None, error
-        if set(data) != fields:
+        names = set(data) - fields
+        if set(data) & fields != fields or names not in ({"items"}, {"filter"}):
             return (
                 None,
                 None,
                 None,
                 bad_request(
-                    "Request must contain exactly " + ", ".join(sorted(fields))
+                    "Request must contain "
+                    + ", ".join(sorted(fields))
+                    + (" and " if fields else "")
+                    + "either items or filter"
                 ),
             )
+        if "filter" in data:
+            targets, error = await self._filter_targets(data["filter"])
+            if error is not None:
+                return None, None, None, error
+            return data, targets, list(self._get_all_output_dirs()), None
         items = data["items"]
         if not isinstance(items, list) or not 1 <= len(items) <= MAX_JOB_TARGETS:
             return (
diff --git a/tests/test_api_image_categories.py b/tests/test_api_image_categories.py
index 5e06368a..02905267 100644
--- a/tests/test_api_image_categories.py
+++ b/tests/test_api_image_categories.py
@@ -322,3 +322,54 @@ class TestCategoryList(ImageCategoryTestCase):
             data = await self.listed(status=500)
         self.assertEqual(data["error"], "Image categories could not be read.")
         self.assertNotIn("secret", json.dumps(data))
+
+
+class TestAllMatchingFilter(ImageCategoryTestCase):
+    """#392 "Select all N matching": the listing filter, resolved now."""
+
+    async def test_filter_sets_and_clears_every_match(self):
+        for name in ("bulk/a.png", "bulk/b.png", "other/c.png"):
+            make_png(self.output_dir / name)
+        data = await self.send(
+            "PUT", {"filter": {"subfolder": "bulk"}, "category": "Scans"}
+        )
+        self.assertEqual((data["updated"], data["not_found"]), (2, 0))
+        self.assertEqual(
+            sorted(row[1] for row in self.rows()), ["bulk/a.png", "bulk/b.png"]
+        )
+        data = await self.send("DELETE", {"filter": {"subfolder": "bulk"}})
+        self.assertEqual(data["cleared"], 2)
+        data = await self.send(
+            "PUT", {"filter": {"subfolder": "none"}, "category": "Scans"}, 404
+        )
+        self.assertEqual(data["code"], "files-not-found")
+        self.assertEqual(
+            (await self.send("DELETE", {"filter": {"q": "zz"}}))["cleared"], 0
+        )
+
+    async def test_filter_refusals(self):
+        make_png(self.output_dir / "a.png")
+        item = self.target("a.png")
+        for body in (
+            {"filter": {}, "items": [item], "category": "x"},
+            {"filter": {"unknown": "1"}, "category": "x"},
+            {"filter": "q=a", "category": "x"},
+            {"filter": {"root": "0", "root_scope": "nothex"}, "category": "x"},
+        ):
+            with self.subTest(body=body):
+                await self.send("PUT", body, 400)
+        data = await self.send(
+            "PUT",
+            {"filter": {"root": "0", "root_scope": "0" * 64}, "category": "x"},
+            409,
+        )
+        self.assertEqual(data["code"], "source-changed")
+        self.assertEqual(self.rows(), [])
+
+    async def test_more_than_500_matching_is_refused(self):
+        for number in range(501):
+            make_png(self.output_dir / f"many/{number:03}.png", size=(1, 1))
+        data = await self.send("PUT", {"filter": {}, "category": "x"}, 400)
+        self.assertEqual(data["code"], "too-many-images")
+        self.assertEqual(data["error"], "Select at most 500 images.")
+        self.assertEqual(self.rows(), [])