From a313f075710cb2e3f9c72888bcaa1058a09d2e82 Mon Sep 17 00:00:00 2001
From: Peter Pinch <pdpinch@mit.edu>
Date: Thu, 10 Sep 2026 08:25:36 -0400
Subject: [PATCH 1/9] Update certificate description in Product Page
 CertificateTrackCard (#3924)

The Institute has strict guidelines around the use of the MIT name
---
 .../src/app-pages/ProductPages/CertificateTrackCard.test.tsx    | 2 +-
 .../main/src/app-pages/ProductPages/CertificateTrackCard.tsx    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/frontends/main/src/app-pages/ProductPages/CertificateTrackCard.test.tsx b/frontends/main/src/app-pages/ProductPages/CertificateTrackCard.test.tsx
index f5f91fe2a4..d336183032 100644
--- a/frontends/main/src/app-pages/ProductPages/CertificateTrackCard.test.tsx
+++ b/frontends/main/src/app-pages/ProductPages/CertificateTrackCard.test.tsx
@@ -31,7 +31,7 @@ describe("CertificateTrackCard", () => {
     ).toBeInTheDocument()
     expect(screen.getByText("Graded assignments & exams")).toBeInTheDocument()
     expect(
-      screen.getByText("MIT certificate on completion"),
+      screen.getByText("MIT Open Learning certificate of completion"),
     ).toBeInTheDocument()
   })
 
diff --git a/frontends/main/src/app-pages/ProductPages/CertificateTrackCard.tsx b/frontends/main/src/app-pages/ProductPages/CertificateTrackCard.tsx
index f8e5529f56..85cee2b0ac 100644
--- a/frontends/main/src/app-pages/ProductPages/CertificateTrackCard.tsx
+++ b/frontends/main/src/app-pages/ProductPages/CertificateTrackCard.tsx
@@ -92,7 +92,7 @@ const CertificateTrackCard: React.FC<CertificateTrackCardProps> = ({
       </FeatureRow>
       <FeatureRow>
         <FeatureIcon aria-hidden="true" />
-        <span>MIT certificate on completion</span>
+        <span>MIT Open Learning certificate of completion</span>
       </FeatureRow>
     </TrackCard>
   )

From 743bb2a17cb7c7cf212981d649551476a086a6d3 Mon Sep 17 00:00:00 2001
From: Matt Bertrand <mrbertrand@gmail.com>
Date: Thu, 10 Sep 2026 09:14:58 -0400
Subject: [PATCH 2/9] Skip staff-only OLX content when ingesting edX course
 archives (#3909)

---
 learning_resources/etl/edx_shared.py          |  70 +++++++-
 learning_resources/etl/edx_shared_test.py     | 156 ++++++++++++++++++
 learning_resources/etl/utils.py               |  66 +++++++-
 learning_resources/etl/utils_test.py          | 130 +++++++++++++++
 .../commands/unpublish_staff_only_files.py    |  69 ++++++++
 learning_resources/tasks.py                   |  66 ++++++--
 learning_resources/tasks_test.py              |  37 +++++
 main/celery.py                                |   2 +
 8 files changed, 574 insertions(+), 22 deletions(-)
 create mode 100644 learning_resources/management/commands/unpublish_staff_only_files.py

diff --git a/learning_resources/etl/edx_shared.py b/learning_resources/etl/edx_shared.py
index b5666ff9d1..71fff4dbf3 100644
--- a/learning_resources/etl/edx_shared.py
+++ b/learning_resources/etl/edx_shared.py
@@ -1,11 +1,12 @@
 """Shared functions for EdX sites"""
 
 import logging
+import tarfile
 from itertools import chain
 from pathlib import Path
-from tarfile import ReadError
 from tempfile import TemporaryDirectory
 
+from defusedxml import ElementTree
 from django.conf import settings
 from django.core.cache import caches
 from django.db.models import Prefetch, Q
@@ -15,10 +16,12 @@
 from learning_resources.etl.utils import (
     calc_checksum,
     get_bucket_by_name,
+    get_edx_module_id,
     get_s3_prefix_for_source,
+    staff_only_olx_paths,
     transform_content_files,
 )
-from learning_resources.models import LearningResourceRun
+from learning_resources.models import ContentFile, LearningResourceRun
 
 log = logging.getLogger(__name__)
 
@@ -138,7 +141,7 @@ def process_course_archive(
         bucket.download_file(key, course_tarpath)
         try:
             checksum = calc_checksum(course_tarpath)
-        except ReadError:
+        except tarfile.ReadError:
             log.exception("Error reading tar file %s, skipping", course_tarpath)
             return True
         if run.checksum == checksum and not overwrite:
@@ -364,3 +367,64 @@ def sync_edx_course_files(
         skipped,
         processed,
     )
+
+
+def unpublish_staff_only_content_files(
+    etl_source: str, ids: list[int], keys: list[str]
+) -> int:
+    """
+    Unpublish (and deindex) content files under staff-only OLX subtrees for the
+    runs matching the given archive keys, without re-extracting anything.
+
+    Args:
+        etl_source(str): The edx ETL source
+        ids(list of int): list of course ids to process
+        keys(list[str]): list of S3 archive keys to search through
+
+    Returns:
+        int: number of content files unpublished
+    """
+    from learning_resources_search import tasks as search_tasks
+    from vector_search import tasks as vector_tasks
+
+    bucket = get_bucket_by_name(settings.COURSE_ARCHIVE_BUCKET_NAME)
+    run_lookup = build_run_lookup(etl_source, ids)
+    total = 0
+    for key in keys:
+        matching_runs = run_lookup.get(extract_run_id_from_key(etl_source, key))
+        if not matching_runs:
+            continue
+        run = matching_runs[0]
+        with TemporaryDirectory() as tempdir:
+            tarpath = Path(tempdir, key.rsplit("/", maxsplit=1)[-1])
+            bucket.download_file(key, tarpath)
+            try:
+                with tarfile.open(tarpath) as tar:
+                    tar.extractall(tempdir, filter="data")
+            except tarfile.ReadError:
+                log.exception("Error extracting %s, skipping", key)
+                continue
+            olx_path = next((p for p in Path(tempdir).iterdir() if p.is_dir()), None)
+            if olx_path is None:
+                continue
+            try:
+                hidden_paths = staff_only_olx_paths(olx_path)
+            except ElementTree.ParseError:
+                log.exception("Malformed OLX in %s, skipping", key)
+                continue
+            hidden_keys = {get_edx_module_id(str(path), run) for path in hidden_paths}
+        if not hidden_keys:
+            continue
+        # scoped to this run: keys embed the run_id, but never rely on that alone
+        hidden_files = ContentFile.objects.filter(run=run, key__in=hidden_keys)
+        unpublished = hidden_files.filter(published=True).update(published=False)
+        total += unpublished
+        log.info(
+            "Unpublished %d staff-only content files for %s", unpublished, run.run_id
+        )
+        # dispatched whenever hidden rows exist, not only when this call flipped
+        # them, so a re-run after a failed deindex task cleans up the indexes
+        if hidden_files.exists():
+            search_tasks.deindex_run_content_files.delay(run.id, unpublished_only=True)
+            vector_tasks.remove_unpublished_run_content_files.delay(run.id)
+    return total
diff --git a/learning_resources/etl/edx_shared_test.py b/learning_resources/etl/edx_shared_test.py
index e0a8bc8a5c..1d9cc34aa6 100644
--- a/learning_resources/etl/edx_shared_test.py
+++ b/learning_resources/etl/edx_shared_test.py
@@ -4,9 +4,11 @@
 import tarfile
 from datetime import datetime
 from pathlib import Path
+from types import SimpleNamespace
 from zoneinfo import ZoneInfo
 
 import pytest
+from defusedxml import ElementTree
 
 from learning_resources.constants import PlatformType
 from learning_resources.etl.constants import ETLSource
@@ -17,6 +19,7 @@
     normalize_run_id,
     process_course_archive,
     sync_edx_course_files,
+    unpublish_staff_only_content_files,
 )
 from learning_resources.etl.utils import get_edx_module_id, get_s3_prefix_for_source
 from learning_resources.factories import (
@@ -1647,3 +1650,156 @@ def test_process_course_archive_all_failures_not_marked_empty(mocker, tmp_path):
     run.refresh_from_db()
     assert run.archive_key is None
     assert run.checksum is None
+
+
+def _staff_only_archive(tmp_path) -> Path:
+    """Build a tar.gz OLX export with one visible and one staff-only chapter"""
+    olx = tmp_path / "course"
+    files = {
+        "course.xml": '<course url_name="run" org="MITx" course="1"/>',
+        "course/run.xml": '<course><chapter url_name="ok"/><chapter url_name="staff"/></course>',
+        "chapter/ok.xml": '<chapter><sequential url_name="seq_ok"/></chapter>',
+        "sequential/seq_ok.xml": '<sequential><vertical url_name="v_ok"/></sequential>',
+        "vertical/v_ok.xml": '<vertical><html url_name="h_ok"/></vertical>',
+        "html/h_ok.xml": '<html filename="h_ok"/>',
+        "html/h_ok.html": "<p>ok</p>",
+        "chapter/staff.xml": (
+            '<chapter visible_to_staff_only="true"><sequential url_name="seq_staff"/></chapter>'
+        ),
+        "sequential/seq_staff.xml": '<sequential><vertical url_name="v_staff"/></sequential>',
+        "vertical/v_staff.xml": '<vertical><html url_name="h_staff"/></vertical>',
+        "html/h_staff.xml": '<html filename="h_staff"/>',
+        "html/h_staff.html": "<p>staff</p>",
+    }
+    for rel, text in files.items():
+        (olx / rel).parent.mkdir(parents=True, exist_ok=True)
+        (olx / rel).write_text(text)
+    tarpath = tmp_path / "course.tar.gz"
+    with tarfile.open(tarpath, "w:gz") as tar:
+        tar.add(olx, arcname="course")
+    return tarpath
+
+
+@pytest.fixture
+def staff_only_run(mock_course_archive_bucket, mocker, tmp_path):
+    """Create a mitxonline run whose mock-bucket archive has a staff-only chapter"""
+    mocker.patch(
+        "learning_resources.etl.edx_shared.get_bucket_by_name",
+        return_value=mock_course_archive_bucket.bucket,
+    )
+    source = ETLSource.mitxonline.name
+    course = LearningResourceFactory.create(
+        etl_source=source, is_course=True, published=True, create_runs=False
+    )
+    run = LearningResourceRunFactory.create(learning_resource=course, published=True)
+    key = f"{get_s3_prefix_for_source(source)}/{run.run_id}/foo.tar.gz"
+    mock_course_archive_bucket.bucket.put_object(
+        Key=key, Body=_staff_only_archive(tmp_path).read_bytes()
+    )
+    return SimpleNamespace(source=source, course=course, run=run, key=key)
+
+
+@pytest.fixture
+def mock_deindex_tasks(mocker):
+    """Mock the OpenSearch and Qdrant deindex task dispatchers"""
+    return SimpleNamespace(
+        opensearch=mocker.patch(
+            "learning_resources_search.tasks.deindex_run_content_files.delay"
+        ),
+        qdrant=mocker.patch(
+            "vector_search.tasks.remove_unpublished_run_content_files.delay"
+        ),
+    )
+
+
+def test_unpublish_staff_only_content_files(staff_only_run, mock_deindex_tasks):
+    """Only the matching run's staff-only content files are unpublished and deindexed"""
+    run = staff_only_run.run
+    other_run = LearningResourceRunFactory.create(
+        learning_resource=staff_only_run.course, published=True
+    )
+    run_keys = {
+        name: get_edx_module_id(f"course/{name}", run)
+        for name in ("html/h_ok.xml", "html/h_staff.xml")
+    }
+    for cf_key in run_keys.values():
+        ContentFileFactory.create(run=run, key=cf_key, published=True)
+    # same key strings on another run must not be touched
+    for cf_key in run_keys.values():
+        ContentFileFactory.create(run=other_run, key=cf_key, published=True)
+
+    unpublished = unpublish_staff_only_content_files(
+        staff_only_run.source, [staff_only_run.course.id], [staff_only_run.key]
+    )
+
+    assert unpublished == 1
+    assert not ContentFile.objects.filter(
+        run=run, key=run_keys["html/h_staff.xml"], published=True
+    ).exists()
+    assert ContentFile.objects.filter(
+        run=run, key=run_keys["html/h_ok.xml"], published=True
+    ).exists()
+    assert ContentFile.objects.filter(run=other_run, published=True).count() == 2
+    mock_deindex_tasks.opensearch.assert_called_once_with(run.id, unpublished_only=True)
+    mock_deindex_tasks.qdrant.assert_called_once_with(run.id)
+
+
+def test_unpublish_staff_only_content_files_nothing_hidden(
+    staff_only_run, mock_deindex_tasks
+):
+    """No deindex tasks are queued when a run has no staff-only content files"""
+    run = staff_only_run.run
+    ContentFileFactory.create(
+        run=run, key=get_edx_module_id("course/html/h_ok.xml", run), published=True
+    )
+
+    assert (
+        unpublish_staff_only_content_files(
+            staff_only_run.source, [staff_only_run.course.id], [staff_only_run.key]
+        )
+        == 0
+    )
+    mock_deindex_tasks.opensearch.assert_not_called()
+
+
+def test_unpublish_staff_only_content_files_malformed_archive(
+    staff_only_run, mock_deindex_tasks, mocker
+):
+    """A malformed archive is skipped without touching its content files"""
+    mocker.patch(
+        "learning_resources.etl.edx_shared.staff_only_olx_paths",
+        side_effect=ElementTree.ParseError("bad"),
+    )
+    ContentFileFactory.create(
+        run=staff_only_run.run,
+        key=get_edx_module_id("course/html/h_staff.xml", staff_only_run.run),
+        published=True,
+    )
+
+    assert (
+        unpublish_staff_only_content_files(
+            staff_only_run.source, [staff_only_run.course.id], [staff_only_run.key]
+        )
+        == 0
+    )
+    assert ContentFile.objects.filter(run=staff_only_run.run, published=True).exists()
+    mock_deindex_tasks.opensearch.assert_not_called()
+
+
+def test_unpublish_staff_only_content_files_rerun_redeindexes(
+    staff_only_run, mock_deindex_tasks
+):
+    """A re-run with already-unpublished hidden files still queues the deindex tasks"""
+    run = staff_only_run.run
+    ContentFileFactory.create(
+        run=run, key=get_edx_module_id("course/html/h_staff.xml", run), published=False
+    )
+
+    assert (
+        unpublish_staff_only_content_files(
+            staff_only_run.source, [staff_only_run.course.id], [staff_only_run.key]
+        )
+        == 0
+    )
+    mock_deindex_tasks.opensearch.assert_called_once_with(run.id, unpublished_only=True)
+    mock_deindex_tasks.qdrant.assert_called_once_with(run.id)
diff --git a/learning_resources/etl/utils.py b/learning_resources/etl/utils.py
index 2dd4a5be21..bd2a76eb41 100644
--- a/learning_resources/etl/utils.py
+++ b/learning_resources/etl/utils.py
@@ -319,11 +319,72 @@ def parse_dates(date_string, hour=12):
     return None
 
 
+def _hidden_block_files(root: Path, tag: str, url_name: str, element) -> set[Path]:
+    """Files belonging to one hidden block: its own files, html body, transcripts"""
+    files = set(root.glob(f"{tag}/{url_name}.*"))
+    if tag == "html" and element.get("filename"):
+        files.update(root.glob(f"html/{element.get('filename')}.*"))
+    if tag == "video":
+        files.update(
+            root / "static" / transcript.get("src")
+            for transcript in element.iter("transcript")
+            if transcript.get("src")
+        )
+    return files
+
+
+def _parse_olx_block(root: Path, tag: str, url_name: str):
+    """
+    Parse <tag>/<url_name>.xml, returning None if missing. Malformed XML raises
+    so a course is never ingested with unverified staff-only status.
+    """
+    try:
+        return ElementTree.parse(root / tag / f"{url_name}.xml").getroot()
+    except (FileNotFoundError, NotADirectoryError):
+        return None
+
+
+def staff_only_olx_paths(olx_path: str | Path) -> set[Path]:
+    """
+    Return the files under visible_to_staff_only="true" subtrees of an OLX
+    course tree, including transcripts of hidden videos. Empty when olx_path
+    is not an OLX export (no course.xml). Blocks may be pointers to
+    <tag>/<url_name>.xml or hold their children inline; both are walked.
+    """
+    root = Path(olx_path)
+    course = _parse_olx_block(root, "", "course")
+    if course is None:
+        return set()
+    hidden: set[Path] = set()
+    seen: set[tuple[str, str]] = set()
+    stack = [(course, "course", course.get("url_name"), False)]
+    while stack:
+        pointer, tag, url_name, staff_only = stack.pop()
+        if url_name:
+            if (tag, url_name) in seen:
+                continue
+            seen.add((tag, url_name))
+        # pointer file wins when present; otherwise the element is the block itself
+        element = _parse_olx_block(root, tag, url_name) if url_name else None
+        if element is None:
+            element = pointer
+        staff_only = staff_only or "true" in (
+            pointer.get("visible_to_staff_only"),
+            element.get("visible_to_staff_only"),
+        )
+        if staff_only and url_name:
+            hidden.update(_hidden_block_files(root, tag, url_name, element))
+        stack.extend(
+            (child, child.tag, child.get("url_name"), staff_only) for child in element
+        )
+    return hidden
+
+
 def documents_from_olx(
     olx_path: str, valid_file_types: list[str] = VALID_TEXT_FILE_TYPES
 ) -> Generator[tuple, None, None]:
     """
-    Extract text from OLX directory
+    Extract text from OLX directory, skipping staff-only content
 
     Args:
         olx_path (str): The path to the directory with the OLX data
@@ -331,11 +392,14 @@ def documents_from_olx(
     Yields:
         tuple: A list of (bytes of content, metadata)
     """
+    staff_only = staff_only_olx_paths(olx_path)
     for root, _, files in os.walk(olx_path):
         path = "/".join(root.split("/")[3:])
         for filename in files:
             extension_lower = Path(filename).suffix.lower()
 
+            if Path(root, filename) in staff_only:
+                continue
             if extension_lower in valid_file_types and "draft" not in root:
                 with Path.open(Path(root, filename), "rb") as f:
                     filebytes = f.read()
diff --git a/learning_resources/etl/utils_test.py b/learning_resources/etl/utils_test.py
index 805c714a56..3b68b15abf 100644
--- a/learning_resources/etl/utils_test.py
+++ b/learning_resources/etl/utils_test.py
@@ -8,6 +8,7 @@
 
 import pypdf
 import pytest
+from defusedxml import ElementTree
 
 from learning_resources.constants import (
     CONTENT_TYPE_FILE,
@@ -294,6 +295,135 @@ def test_documents_from_olx():
     assert formula2do[1]["mime_type"].endswith("/xml")
 
 
+def _write_olx(root, rel, text):
+    path = root / rel
+    path.parent.mkdir(parents=True, exist_ok=True)
+    path.write_text(text)
+
+
+def test_documents_from_olx_skips_staff_only_subtrees(tmp_path):
+    """Files under visible_to_staff_only subtrees (and their transcripts) are skipped"""
+    olx = tmp_path / "course"
+    _write_olx(olx, "course.xml", '<course url_name="run" org="MITx" course="1"/>')
+    _write_olx(
+        olx,
+        "course/run.xml",
+        '<course><chapter url_name="ch_ok"/><chapter url_name="ch_staff"/></course>',
+    )
+    _write_olx(
+        olx, "chapter/ch_ok.xml", '<chapter><sequential url_name="seq_ok"/></chapter>'
+    )
+    _write_olx(
+        olx,
+        "sequential/seq_ok.xml",
+        '<sequential><vertical url_name="v_ok"/><vertical url_name="v_staff"/></sequential>',
+    )
+    _write_olx(olx, "vertical/v_ok.xml", '<vertical><html url_name="h_ok"/></vertical>')
+    _write_olx(olx, "html/h_ok.xml", '<html filename="h_ok"/>')
+    _write_olx(olx, "html/h_ok.html", "<p>visible</p>")
+    _write_olx(
+        olx,
+        "vertical/v_staff.xml",
+        '<vertical visible_to_staff_only="true"><problem url_name="p_staff"/></vertical>',
+    )
+    _write_olx(olx, "problem/p_staff.xml", "<problem/>")
+    _write_olx(
+        olx,
+        "chapter/ch_staff.xml",
+        '<chapter visible_to_staff_only="true"><sequential url_name="seq_staff"/></chapter>',
+    )
+    _write_olx(
+        olx,
+        "sequential/seq_staff.xml",
+        '<sequential><vertical url_name="v_hidden"/></sequential>',
+    )
+    _write_olx(
+        olx,
+        "vertical/v_hidden.xml",
+        '<vertical><html url_name="h_hidden"/><video url_name="vid_hidden"/></vertical>',
+    )
+    _write_olx(olx, "html/h_hidden.xml", '<html filename="h_hidden_file"/>')
+    _write_olx(olx, "html/h_hidden_file.html", "<p>hidden</p>")
+    _write_olx(
+        olx,
+        "video/vid_hidden.xml",
+        '<video url_name="vid_hidden"><transcript language="en" src="hidden.srt"/></video>',
+    )
+    _write_olx(olx, "static/hidden.srt", "1\n00:00:00,000 --> 00:00:01,000\nhidden\n")
+    _write_olx(olx, "static/visible.srt", "1\n00:00:00,000 --> 00:00:01,000\nvisible\n")
+    _write_olx(olx, "tabs/syllabus.html", "<p>tab</p>")
+
+    prefix = "/".join(str(olx).split("/")[3:]) + "/"
+    paths = sorted(
+        meta["source_path"].removeprefix(prefix)
+        for _, meta in utils.documents_from_olx(str(olx))
+    )
+    assert paths == [
+        "chapter/ch_ok.xml",
+        "course.xml",
+        "course/run.xml",
+        "html/h_ok.html",
+        "html/h_ok.xml",
+        "sequential/seq_ok.xml",
+        "static/visible.srt",
+        "tabs/syllabus.html",
+        "vertical/v_ok.xml",
+    ]
+
+
+def test_documents_from_olx_skips_staff_only_inline_structure(tmp_path):
+    """Structure held inline in course.xml (no pointer files) is still filtered"""
+    olx = tmp_path / "course"
+    _write_olx(
+        olx,
+        "course.xml",
+        '<course org="MITx" course="1">'
+        '<chapter display_name="ok"><vertical><html url_name="h_ok"/></vertical></chapter>'
+        '<chapter visible_to_staff_only="true"><vertical>'
+        '<html url_name="h_staff"/><video url_name="vid_staff"/>'
+        "</vertical></chapter>"
+        "</course>",
+    )
+    _write_olx(olx, "html/h_ok.xml", '<html filename="h_ok"/>')
+    _write_olx(olx, "html/h_ok.html", "<p>visible</p>")
+    _write_olx(olx, "html/h_staff.xml", '<html filename="h_staff"/>')
+    _write_olx(olx, "html/h_staff.html", "<p>hidden</p>")
+    _write_olx(
+        olx,
+        "video/vid_staff.xml",
+        '<video url_name="vid_staff"><transcript language="en" src="hidden.srt"/></video>',
+    )
+    _write_olx(olx, "static/hidden.srt", "1\n00:00:00,000 --> 00:00:01,000\nhidden\n")
+
+    prefix = "/".join(str(olx).split("/")[3:]) + "/"
+    paths = sorted(
+        meta["source_path"].removeprefix(prefix)
+        for _, meta in utils.documents_from_olx(str(olx))
+    )
+    assert paths == ["course.xml", "html/h_ok.html", "html/h_ok.xml"]
+
+
+@pytest.mark.parametrize("bad_file", ["course.xml", "chapter/a.xml"])
+def test_documents_from_olx_malformed_block_fails_closed(tmp_path, bad_file):
+    """A malformed block raises rather than ingesting files with unchecked visibility"""
+    olx = tmp_path / "course"
+    _write_olx(olx, "course.xml", '<course url_name="run"/>')
+    _write_olx(olx, "course/run.xml", '<course><chapter url_name="a"/></course>')
+    _write_olx(olx, "chapter/a.xml", '<chapter visible_to_staff_only="true"/>')
+    _write_olx(olx, bad_file, "<broken")
+    with pytest.raises(ElementTree.ParseError):
+        list(utils.documents_from_olx(str(olx)))
+
+
+def test_documents_from_olx_without_course_xml_yields_everything(tmp_path):
+    """Non-OLX trees (canvas, tutor problem sets) are not filtered"""
+    olx = tmp_path / "course"
+    _write_olx(olx, "chapter/a.xml", '<chapter visible_to_staff_only="true"/>')
+    _write_olx(olx, "web_resources/b.html", "<p>b</p>")
+    paths = [meta["source_path"] for _, meta in utils.documents_from_olx(str(olx))]
+    assert len(paths) == 2
+
+
 @pytest.mark.parametrize(
     ("etl_source", "expected_setting"),
     [
diff --git a/learning_resources/management/commands/unpublish_staff_only_files.py b/learning_resources/management/commands/unpublish_staff_only_files.py
new file mode 100644
index 0000000000..a03e57d2c8
--- /dev/null
+++ b/learning_resources/management/commands/unpublish_staff_only_files.py
@@ -0,0 +1,69 @@
+"""Unpublish edX content files that sit under staff-only OLX subtrees"""
+
+from django.core.management import BaseCommand
+
+from learning_resources.etl.constants import ETLSource
+from learning_resources.tasks import unpublish_all_staff_only_files
+from main import settings
+from main.utils import now_in_utc
+
+EDX_SOURCES = [
+    ETLSource.mitxonline.name,
+    ETLSource.mit_edx.name,
+    ETLSource.xpro.name,
+    ETLSource.oll.name,
+]
+
+
+class Command(BaseCommand):
+    """
+    Walk each course's current archive and unpublish content files under
+    visible_to_staff_only subtrees, then deindex them. Nothing is re-extracted
+    or re-embedded.
+    """
+
+    help = "Unpublish staff-only edX content files from existing archives"
+
+    def add_arguments(self, parser):
+        parser.add_argument(
+            "--source",
+            dest="sources",
+            action="append",
+            choices=EDX_SOURCES,
+            help="ETL source to process (repeatable). Default: all edX sources",
+        )
+        parser.add_argument(
+            "-c",
+            "--chunk-size",
+            dest="chunk_size",
+            default=settings.LEARNING_COURSE_ITERATOR_CHUNK_SIZE,
+            type=int,
+            help="Chunk size for batch task",
+        )
+        parser.add_argument(
+            "--resource-ids",
+            dest="learning_resource_ids",
+            required=False,
+            help="If set, only process the learning resources with these ids",
+        )
+
+    def handle(self, *args, **options):  # noqa: ARG002
+        """Run the unpublish tasks"""
+        resource_ids = (
+            options["learning_resource_ids"].split(",")
+            if options["learning_resource_ids"]
+            else None
+        )
+        start = now_in_utc()
+        for source in options["sources"] or EDX_SOURCES:
+            task = unpublish_all_staff_only_files.delay(
+                etl_source=source,
+                chunk_size=options["chunk_size"],
+                learning_resource_ids=resource_ids,
+            )
+            self.stdout.write(f"Started task {task} for {source}, waiting...")
+            results = task.get()
+            total = sum(count or 0 for count in results or [])
+            self.stdout.write(f"{source}: unpublished {total} content files")
+        total_seconds = (now_in_utc() - start).total_seconds()
+        self.stdout.write(f"Finished in {total_seconds} seconds")
diff --git a/learning_resources/tasks.py b/learning_resources/tasks.py
index 7f4f824b17..7cc3a6df4f 100644
--- a/learning_resources/tasks.py
+++ b/learning_resources/tasks.py
@@ -29,6 +29,7 @@
     get_most_recent_course_archives,
     sync_edx_archive,
     sync_edx_course_files,
+    unpublish_staff_only_content_files,
 )
 from learning_resources.etl.loaders import (
     load_learning_materials,
@@ -197,25 +198,8 @@ def get_content_tasks(
     if chunk_size is None:
         chunk_size = settings.LEARNING_COURSE_ITERATOR_CHUNK_SIZE
 
-    blocklisted_ids = load_course_blocklist()
     archive_keys = get_most_recent_course_archives(etl_source)
-
-    if learning_resource_ids:
-        learning_resources = (
-            LearningResource.objects.filter(
-                id__in=learning_resource_ids, etl_source=etl_source
-            )
-            .order_by("-id")
-            .values_list("id", flat=True)
-        )
-    else:
-        learning_resources = (
-            LearningResource.objects.filter(Q(published=True) | Q(test_mode=True))
-            .filter(course__isnull=False, etl_source=etl_source)
-            .exclude(readable_id__in=blocklisted_ids)
-            .order_by("-id")
-            .values_list("id", flat=True)
-        )
+    learning_resources = _content_file_resource_ids(etl_source, learning_resource_ids)
 
     return celery.group(
         [
@@ -228,6 +212,52 @@ def get_content_tasks(
     )
 
 
+def _content_file_resource_ids(etl_source: str, learning_resource_ids):
+    """Course ids whose archives should be processed for an edX source"""
+    if learning_resource_ids:
+        return (
+            LearningResource.objects.filter(
+                id__in=learning_resource_ids, etl_source=etl_source
+            )
+            .order_by("-id")
+            .values_list("id", flat=True)
+        )
+    return (
+        LearningResource.objects.filter(Q(published=True) | Q(test_mode=True))
+        .filter(course__isnull=False, etl_source=etl_source)
+        .exclude(readable_id__in=load_course_blocklist())
+        .order_by("-id")
+        .values_list("id", flat=True)
+    )
+
+
+@app.task(acks_late=True, reject_on_worker_lost=True)
+def unpublish_staff_only_files(ids: list[int], etl_source: str, keys: list[str]):
+    """Unpublish staff-only content files for a chunk of courses"""
+    return unpublish_staff_only_content_files(etl_source, ids, keys)
+
+
+@app.task(bind=True)
+def unpublish_all_staff_only_files(
+    self, *, etl_source, chunk_size=None, learning_resource_ids=None
+):
+    """Fan out unpublish_staff_only_files over an edX source's current archives"""
+    if chunk_size is None:
+        chunk_size = settings.LEARNING_COURSE_ITERATOR_CHUNK_SIZE
+    archive_keys = get_most_recent_course_archives(etl_source)
+    return self.replace(
+        celery.group(
+            [
+                unpublish_staff_only_files.si(ids, etl_source, archive_keys)
+                for ids in chunks(
+                    _content_file_resource_ids(etl_source, learning_resource_ids),
+                    chunk_size=chunk_size,
+                )
+            ]
+        )
+    )
+
+
 @app.task(bind=True)
 def import_all_mit_edx_files(
     self, *, chunk_size=None, overwrite=False, learning_resource_ids=None
diff --git a/learning_resources/tasks_test.py b/learning_resources/tasks_test.py
index 13a005f872..5ac6ca66ad 100644
--- a/learning_resources/tasks_test.py
+++ b/learning_resources/tasks_test.py
@@ -1551,3 +1551,40 @@ def test_get_podcast_transcripts(mocker):
     mock_etl_podcast.get_podcast_transcripts.assert_called_once_with(
         mock_etl_podcast.get_podcast_episodes_for_transcripts_job.return_value
     )
+
+
+@mock_aws
+def test_unpublish_all_staff_only_files(
+    settings, mocker, mocked_celery, mock_course_archive_bucket
+):
+    """unpublish_all_staff_only_files fans out one task per chunk of course ids"""
+    mock_task = mocker.patch("learning_resources.tasks.unpublish_staff_only_files.si")
+    mocker.patch("learning_resources.tasks.load_course_blocklist", return_value=[])
+    mocker.patch(
+        "learning_resources.tasks.get_most_recent_course_archives",
+        return_value=["foo.tar.gz"],
+    )
+    setup_s3(settings)
+    etl_source = ETLSource.mitxonline.name
+    courses = factories.CourseFactory.create_batch(
+        3, etl_source=etl_source, platform=PlatformType.mitxonline.name
+    )
+    with pytest.raises(mocked_celery.replace_exception_class):
+        tasks.unpublish_all_staff_only_files.delay(
+            etl_source=etl_source, chunk_size=2, learning_resource_ids=None
+        )
+    assert mock_task.call_count == 2
+    called_ids = sorted(
+        rid for call in mock_task.call_args_list for rid in call.args[0]
+    )
+    assert called_ids == sorted(c.learning_resource_id for c in courses)
+    mock_task.assert_any_call(ANY, etl_source, ["foo.tar.gz"])
+
+
+def test_unpublish_staff_only_files_task(mocker):
+    """unpublish_staff_only_files task delegates to edx_shared"""
+    mock_fn = mocker.patch(
+        "learning_resources.tasks.unpublish_staff_only_content_files", return_value=3
+    )
+    assert tasks.unpublish_staff_only_files([1, 2], "mitxonline", ["k"]) == 3
+    mock_fn.assert_called_once_with("mitxonline", [1, 2], ["k"])
diff --git a/main/celery.py b/main/celery.py
index f1fb14c339..6a83648815 100644
--- a/main/celery.py
+++ b/main/celery.py
@@ -30,6 +30,8 @@
     "learning_resources.tasks.import_all_xpro_files": {"queue": "edx_content"},
     "learning_resources.tasks.import_all_mit_edx_files": {"queue": "edx_content"},
     "learning_resources.tasks.import_all_mitxonline_files": {"queue": "edx_content"},
+    "learning_resources.tasks.unpublish_staff_only_files": {"queue": "edx_content"},
+    "learning_resources.tasks.unpublish_all_staff_only_files": {"queue": "edx_content"},
     "learning_resources_search.tasks.index_run_content_files": {"queue": "edx_content"},
     "learning_resources_search.tasks.deindex_run_content_files": {
         "queue": "edx_content"

From 56fbdc75a0447bc50af30762f65c4b00b48a7bc0 Mon Sep 17 00:00:00 2001
From: "renovate[bot]" <29139614+renovate[bot]@users.noreply.github.com>
Date: Thu, 10 Sep 2026 13:24:50 -0400
Subject: [PATCH 3/9] Update dependency sharp to v0.35.4 [SECURITY] (#3917)

---
 frontends/main/package.json |   2 +-
 yarn.lock                   | 253 ++++++++++++++++++------------------
 2 files changed, 129 insertions(+), 126 deletions(-)

diff --git a/frontends/main/package.json b/frontends/main/package.json
index cb33fd70b4..f98729719f 100644
--- a/frontends/main/package.json
+++ b/frontends/main/package.json
@@ -72,7 +72,7 @@
     "react-hotkeys-hook": "^5.2.1",
     "react-markdown": "^10.0.0",
     "react-slick": "^0.31.0",
-    "sharp": "0.35.0",
+    "sharp": "0.35.4",
     "slick-carousel": "^1.8.1",
     "tiny-invariant": "^1.3.3",
     "video.js": "^8.23.7",
diff --git a/yarn.lock b/yarn.lock
index 9dfb70c47c..9b36ffbb49 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2024,7 +2024,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@emnapi/runtime@npm:^1.11.0":
+"@emnapi/runtime@npm:^1.11.3":
   version: 1.11.3
   resolution: "@emnapi/runtime@npm:1.11.3"
   dependencies:
@@ -2646,11 +2646,11 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-darwin-arm64@npm:0.35.0":
-  version: 0.35.0
-  resolution: "@img/sharp-darwin-arm64@npm:0.35.0"
+"@img/sharp-darwin-arm64@npm:0.35.4":
+  version: 0.35.4
+  resolution: "@img/sharp-darwin-arm64@npm:0.35.4"
   dependencies:
-    "@img/sharp-libvips-darwin-arm64": "npm:1.3.0"
+    "@img/sharp-libvips-darwin-arm64": "npm:1.3.3"
   dependenciesMeta:
     "@img/sharp-libvips-darwin-arm64":
       optional: true
@@ -2670,11 +2670,11 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-darwin-x64@npm:0.35.0":
-  version: 0.35.0
-  resolution: "@img/sharp-darwin-x64@npm:0.35.0"
+"@img/sharp-darwin-x64@npm:0.35.4":
+  version: 0.35.4
+  resolution: "@img/sharp-darwin-x64@npm:0.35.4"
   dependencies:
-    "@img/sharp-libvips-darwin-x64": "npm:1.3.0"
+    "@img/sharp-libvips-darwin-x64": "npm:1.3.3"
   dependenciesMeta:
     "@img/sharp-libvips-darwin-x64":
       optional: true
@@ -2682,11 +2682,11 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-freebsd-wasm32@npm:0.35.0":
-  version: 0.35.0
-  resolution: "@img/sharp-freebsd-wasm32@npm:0.35.0"
+"@img/sharp-freebsd-wasm32@npm:0.35.4":
+  version: 0.35.4
+  resolution: "@img/sharp-freebsd-wasm32@npm:0.35.4"
   dependencies:
-    "@img/sharp-wasm32": "npm:0.35.0"
+    "@img/sharp-wasm32": "npm:0.35.4"
   conditions: os=freebsd
   languageName: node
   linkType: hard
@@ -2698,9 +2698,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-libvips-darwin-arm64@npm:1.3.0":
-  version: 1.3.0
-  resolution: "@img/sharp-libvips-darwin-arm64@npm:1.3.0"
+"@img/sharp-libvips-darwin-arm64@npm:1.3.3":
+  version: 1.3.3
+  resolution: "@img/sharp-libvips-darwin-arm64@npm:1.3.3"
   conditions: os=darwin & cpu=arm64
   languageName: node
   linkType: hard
@@ -2712,9 +2712,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-libvips-darwin-x64@npm:1.3.0":
-  version: 1.3.0
-  resolution: "@img/sharp-libvips-darwin-x64@npm:1.3.0"
+"@img/sharp-libvips-darwin-x64@npm:1.3.3":
+  version: 1.3.3
+  resolution: "@img/sharp-libvips-darwin-x64@npm:1.3.3"
   conditions: os=darwin & cpu=x64
   languageName: node
   linkType: hard
@@ -2726,9 +2726,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-libvips-linux-arm64@npm:1.3.0":
-  version: 1.3.0
-  resolution: "@img/sharp-libvips-linux-arm64@npm:1.3.0"
+"@img/sharp-libvips-linux-arm64@npm:1.3.3":
+  version: 1.3.3
+  resolution: "@img/sharp-libvips-linux-arm64@npm:1.3.3"
   conditions: os=linux & cpu=arm64 & libc=glibc
   languageName: node
   linkType: hard
@@ -2740,9 +2740,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-libvips-linux-arm@npm:1.3.0":
-  version: 1.3.0
-  resolution: "@img/sharp-libvips-linux-arm@npm:1.3.0"
+"@img/sharp-libvips-linux-arm@npm:1.3.3":
+  version: 1.3.3
+  resolution: "@img/sharp-libvips-linux-arm@npm:1.3.3"
   conditions: os=linux & cpu=arm & libc=glibc
   languageName: node
   linkType: hard
@@ -2754,9 +2754,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-libvips-linux-ppc64@npm:1.3.0":
-  version: 1.3.0
-  resolution: "@img/sharp-libvips-linux-ppc64@npm:1.3.0"
+"@img/sharp-libvips-linux-ppc64@npm:1.3.3":
+  version: 1.3.3
+  resolution: "@img/sharp-libvips-linux-ppc64@npm:1.3.3"
   conditions: os=linux & cpu=ppc64 & libc=glibc
   languageName: node
   linkType: hard
@@ -2768,9 +2768,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-libvips-linux-riscv64@npm:1.3.0":
-  version: 1.3.0
-  resolution: "@img/sharp-libvips-linux-riscv64@npm:1.3.0"
+"@img/sharp-libvips-linux-riscv64@npm:1.3.3":
+  version: 1.3.3
+  resolution: "@img/sharp-libvips-linux-riscv64@npm:1.3.3"
   conditions: os=linux & cpu=riscv64 & libc=glibc
   languageName: node
   linkType: hard
@@ -2782,9 +2782,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-libvips-linux-s390x@npm:1.3.0":
-  version: 1.3.0
-  resolution: "@img/sharp-libvips-linux-s390x@npm:1.3.0"
+"@img/sharp-libvips-linux-s390x@npm:1.3.3":
+  version: 1.3.3
+  resolution: "@img/sharp-libvips-linux-s390x@npm:1.3.3"
   conditions: os=linux & cpu=s390x & libc=glibc
   languageName: node
   linkType: hard
@@ -2796,9 +2796,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-libvips-linux-x64@npm:1.3.0":
-  version: 1.3.0
-  resolution: "@img/sharp-libvips-linux-x64@npm:1.3.0"
+"@img/sharp-libvips-linux-x64@npm:1.3.3":
+  version: 1.3.3
+  resolution: "@img/sharp-libvips-linux-x64@npm:1.3.3"
   conditions: os=linux & cpu=x64 & libc=glibc
   languageName: node
   linkType: hard
@@ -2810,9 +2810,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-libvips-linuxmusl-arm64@npm:1.3.0":
-  version: 1.3.0
-  resolution: "@img/sharp-libvips-linuxmusl-arm64@npm:1.3.0"
+"@img/sharp-libvips-linuxmusl-arm64@npm:1.3.3":
+  version: 1.3.3
+  resolution: "@img/sharp-libvips-linuxmusl-arm64@npm:1.3.3"
   conditions: os=linux & cpu=arm64 & libc=musl
   languageName: node
   linkType: hard
@@ -2824,9 +2824,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-libvips-linuxmusl-x64@npm:1.3.0":
-  version: 1.3.0
-  resolution: "@img/sharp-libvips-linuxmusl-x64@npm:1.3.0"
+"@img/sharp-libvips-linuxmusl-x64@npm:1.3.3":
+  version: 1.3.3
+  resolution: "@img/sharp-libvips-linuxmusl-x64@npm:1.3.3"
   conditions: os=linux & cpu=x64 & libc=musl
   languageName: node
   linkType: hard
@@ -2843,11 +2843,11 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-linux-arm64@npm:0.35.0":
-  version: 0.35.0
-  resolution: "@img/sharp-linux-arm64@npm:0.35.0"
+"@img/sharp-linux-arm64@npm:0.35.4":
+  version: 0.35.4
+  resolution: "@img/sharp-linux-arm64@npm:0.35.4"
   dependencies:
-    "@img/sharp-libvips-linux-arm64": "npm:1.3.0"
+    "@img/sharp-libvips-linux-arm64": "npm:1.3.3"
   dependenciesMeta:
     "@img/sharp-libvips-linux-arm64":
       optional: true
@@ -2867,11 +2867,11 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-linux-arm@npm:0.35.0":
-  version: 0.35.0
-  resolution: "@img/sharp-linux-arm@npm:0.35.0"
+"@img/sharp-linux-arm@npm:0.35.4":
+  version: 0.35.4
+  resolution: "@img/sharp-linux-arm@npm:0.35.4"
   dependencies:
-    "@img/sharp-libvips-linux-arm": "npm:1.3.0"
+    "@img/sharp-libvips-linux-arm": "npm:1.3.3"
   dependenciesMeta:
     "@img/sharp-libvips-linux-arm":
       optional: true
@@ -2891,11 +2891,11 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-linux-ppc64@npm:0.35.0":
-  version: 0.35.0
-  resolution: "@img/sharp-linux-ppc64@npm:0.35.0"
+"@img/sharp-linux-ppc64@npm:0.35.4":
+  version: 0.35.4
+  resolution: "@img/sharp-linux-ppc64@npm:0.35.4"
   dependencies:
-    "@img/sharp-libvips-linux-ppc64": "npm:1.3.0"
+    "@img/sharp-libvips-linux-ppc64": "npm:1.3.3"
   dependenciesMeta:
     "@img/sharp-libvips-linux-ppc64":
       optional: true
@@ -2915,11 +2915,11 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-linux-riscv64@npm:0.35.0":
-  version: 0.35.0
-  resolution: "@img/sharp-linux-riscv64@npm:0.35.0"
+"@img/sharp-linux-riscv64@npm:0.35.4":
+  version: 0.35.4
+  resolution: "@img/sharp-linux-riscv64@npm:0.35.4"
   dependencies:
-    "@img/sharp-libvips-linux-riscv64": "npm:1.3.0"
+    "@img/sharp-libvips-linux-riscv64": "npm:1.3.3"
   dependenciesMeta:
     "@img/sharp-libvips-linux-riscv64":
       optional: true
@@ -2939,11 +2939,11 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-linux-s390x@npm:0.35.0":
-  version: 0.35.0
-  resolution: "@img/sharp-linux-s390x@npm:0.35.0"
+"@img/sharp-linux-s390x@npm:0.35.4":
+  version: 0.35.4
+  resolution: "@img/sharp-linux-s390x@npm:0.35.4"
   dependencies:
-    "@img/sharp-libvips-linux-s390x": "npm:1.3.0"
+    "@img/sharp-libvips-linux-s390x": "npm:1.3.3"
   dependenciesMeta:
     "@img/sharp-libvips-linux-s390x":
       optional: true
@@ -2963,11 +2963,11 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-linux-x64@npm:0.35.0":
-  version: 0.35.0
-  resolution: "@img/sharp-linux-x64@npm:0.35.0"
+"@img/sharp-linux-x64@npm:0.35.4":
+  version: 0.35.4
+  resolution: "@img/sharp-linux-x64@npm:0.35.4"
   dependencies:
-    "@img/sharp-libvips-linux-x64": "npm:1.3.0"
+    "@img/sharp-libvips-linux-x64": "npm:1.3.3"
   dependenciesMeta:
     "@img/sharp-libvips-linux-x64":
       optional: true
@@ -2987,11 +2987,11 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-linuxmusl-arm64@npm:0.35.0":
-  version: 0.35.0
-  resolution: "@img/sharp-linuxmusl-arm64@npm:0.35.0"
+"@img/sharp-linuxmusl-arm64@npm:0.35.4":
+  version: 0.35.4
+  resolution: "@img/sharp-linuxmusl-arm64@npm:0.35.4"
   dependencies:
-    "@img/sharp-libvips-linuxmusl-arm64": "npm:1.3.0"
+    "@img/sharp-libvips-linuxmusl-arm64": "npm:1.3.3"
   dependenciesMeta:
     "@img/sharp-libvips-linuxmusl-arm64":
       optional: true
@@ -3011,11 +3011,11 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-linuxmusl-x64@npm:0.35.0":
-  version: 0.35.0
-  resolution: "@img/sharp-linuxmusl-x64@npm:0.35.0"
+"@img/sharp-linuxmusl-x64@npm:0.35.4":
+  version: 0.35.4
+  resolution: "@img/sharp-linuxmusl-x64@npm:0.35.4"
   dependencies:
-    "@img/sharp-libvips-linuxmusl-x64": "npm:1.3.0"
+    "@img/sharp-libvips-linuxmusl-x64": "npm:1.3.3"
   dependenciesMeta:
     "@img/sharp-libvips-linuxmusl-x64":
       optional: true
@@ -3032,20 +3032,20 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-wasm32@npm:0.35.0":
-  version: 0.35.0
-  resolution: "@img/sharp-wasm32@npm:0.35.0"
+"@img/sharp-wasm32@npm:0.35.4":
+  version: 0.35.4
+  resolution: "@img/sharp-wasm32@npm:0.35.4"
   dependencies:
-    "@emnapi/runtime": "npm:^1.11.0"
-  checksum: 10/58173a1b3a596b4a450cc23561413aca76741ea9e03534daaea907c9d1438a3f765273216876fe3e03372cfd8a5b72506228f3a20d5eccb6aec1f3b7cdb0c710
+    "@emnapi/runtime": "npm:^1.11.3"
+  checksum: 10/24250d2a5c1e681577c97a1774fd8785fc237066146badb9d25f8512dfd09771838b6d76fb0912baa0b29a0d7a564282dfc562062e747486aee832cc98941210
   languageName: node
   linkType: hard
 
-"@img/sharp-webcontainers-wasm32@npm:0.35.0":
-  version: 0.35.0
-  resolution: "@img/sharp-webcontainers-wasm32@npm:0.35.0"
+"@img/sharp-webcontainers-wasm32@npm:0.35.4":
+  version: 0.35.4
+  resolution: "@img/sharp-webcontainers-wasm32@npm:0.35.4"
   dependencies:
-    "@img/sharp-wasm32": "npm:0.35.0"
+    "@img/sharp-wasm32": "npm:0.35.4"
   conditions: cpu=wasm32
   languageName: node
   linkType: hard
@@ -3057,9 +3057,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-win32-arm64@npm:0.35.0":
-  version: 0.35.0
-  resolution: "@img/sharp-win32-arm64@npm:0.35.0"
+"@img/sharp-win32-arm64@npm:0.35.4":
+  version: 0.35.4
+  resolution: "@img/sharp-win32-arm64@npm:0.35.4"
   conditions: os=win32 & cpu=arm64
   languageName: node
   linkType: hard
@@ -3071,9 +3071,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-win32-ia32@npm:0.35.0":
-  version: 0.35.0
-  resolution: "@img/sharp-win32-ia32@npm:0.35.0"
+"@img/sharp-win32-ia32@npm:0.35.4":
+  version: 0.35.4
+  resolution: "@img/sharp-win32-ia32@npm:0.35.4"
   conditions: os=win32 & cpu=ia32
   languageName: node
   linkType: hard
@@ -3085,9 +3085,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@img/sharp-win32-x64@npm:0.35.0":
-  version: 0.35.0
-  resolution: "@img/sharp-win32-x64@npm:0.35.0"
+"@img/sharp-win32-x64@npm:0.35.4":
+  version: 0.35.4
+  resolution: "@img/sharp-win32-x64@npm:0.35.4"
   conditions: os=win32 & cpu=x64
   languageName: node
   linkType: hard
@@ -16982,7 +16982,7 @@ __metadata:
     react-hotkeys-hook: "npm:^5.2.1"
     react-markdown: "npm:^10.0.0"
     react-slick: "npm:^0.31.0"
-    sharp: "npm:0.35.0"
+    sharp: "npm:0.35.4"
     slick-carousel: "npm:^1.8.1"
     tiny-invariant: "npm:^1.3.3"
     ts-jest: "npm:^29.2.4"
@@ -21206,7 +21206,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"semver@npm:^7.8.4":
+"semver@npm:^7.8.5":
   version: 7.8.5
   resolution: "semver@npm:7.8.5"
   bin:
@@ -21281,38 +21281,38 @@ __metadata:
   languageName: node
   linkType: hard
 
-"sharp@npm:0.35.0":
-  version: 0.35.0
-  resolution: "sharp@npm:0.35.0"
+"sharp@npm:0.35.4":
+  version: 0.35.4
+  resolution: "sharp@npm:0.35.4"
   dependencies:
     "@img/colour": "npm:^1.1.0"
-    "@img/sharp-darwin-arm64": "npm:0.35.0"
-    "@img/sharp-darwin-x64": "npm:0.35.0"
-    "@img/sharp-freebsd-wasm32": "npm:0.35.0"
-    "@img/sharp-libvips-darwin-arm64": "npm:1.3.0"
-    "@img/sharp-libvips-darwin-x64": "npm:1.3.0"
-    "@img/sharp-libvips-linux-arm": "npm:1.3.0"
-    "@img/sharp-libvips-linux-arm64": "npm:1.3.0"
-    "@img/sharp-libvips-linux-ppc64": "npm:1.3.0"
-    "@img/sharp-libvips-linux-riscv64": "npm:1.3.0"
-    "@img/sharp-libvips-linux-s390x": "npm:1.3.0"
-    "@img/sharp-libvips-linux-x64": "npm:1.3.0"
-    "@img/sharp-libvips-linuxmusl-arm64": "npm:1.3.0"
-    "@img/sharp-libvips-linuxmusl-x64": "npm:1.3.0"
-    "@img/sharp-linux-arm": "npm:0.35.0"
-    "@img/sharp-linux-arm64": "npm:0.35.0"
-    "@img/sharp-linux-ppc64": "npm:0.35.0"
-    "@img/sharp-linux-riscv64": "npm:0.35.0"
-    "@img/sharp-linux-s390x": "npm:0.35.0"
-    "@img/sharp-linux-x64": "npm:0.35.0"
-    "@img/sharp-linuxmusl-arm64": "npm:0.35.0"
-    "@img/sharp-linuxmusl-x64": "npm:0.35.0"
-    "@img/sharp-webcontainers-wasm32": "npm:0.35.0"
-    "@img/sharp-win32-arm64": "npm:0.35.0"
-    "@img/sharp-win32-ia32": "npm:0.35.0"
-    "@img/sharp-win32-x64": "npm:0.35.0"
+    "@img/sharp-darwin-arm64": "npm:0.35.4"
+    "@img/sharp-darwin-x64": "npm:0.35.4"
+    "@img/sharp-freebsd-wasm32": "npm:0.35.4"
+    "@img/sharp-libvips-darwin-arm64": "npm:1.3.3"
+    "@img/sharp-libvips-darwin-x64": "npm:1.3.3"
+    "@img/sharp-libvips-linux-arm": "npm:1.3.3"
+    "@img/sharp-libvips-linux-arm64": "npm:1.3.3"
+    "@img/sharp-libvips-linux-ppc64": "npm:1.3.3"
+    "@img/sharp-libvips-linux-riscv64": "npm:1.3.3"
+    "@img/sharp-libvips-linux-s390x": "npm:1.3.3"
+    "@img/sharp-libvips-linux-x64": "npm:1.3.3"
+    "@img/sharp-libvips-linuxmusl-arm64": "npm:1.3.3"
+    "@img/sharp-libvips-linuxmusl-x64": "npm:1.3.3"
+    "@img/sharp-linux-arm": "npm:0.35.4"
+    "@img/sharp-linux-arm64": "npm:0.35.4"
+    "@img/sharp-linux-ppc64": "npm:0.35.4"
+    "@img/sharp-linux-riscv64": "npm:0.35.4"
+    "@img/sharp-linux-s390x": "npm:0.35.4"
+    "@img/sharp-linux-x64": "npm:0.35.4"
+    "@img/sharp-linuxmusl-arm64": "npm:0.35.4"
+    "@img/sharp-linuxmusl-x64": "npm:0.35.4"
+    "@img/sharp-webcontainers-wasm32": "npm:0.35.4"
+    "@img/sharp-win32-arm64": "npm:0.35.4"
+    "@img/sharp-win32-ia32": "npm:0.35.4"
+    "@img/sharp-win32-x64": "npm:0.35.4"
     detect-libc: "npm:^2.1.2"
-    semver: "npm:^7.8.4"
+    semver: "npm:^7.8.5"
   dependenciesMeta:
     "@img/sharp-darwin-arm64":
       optional: true
@@ -21364,7 +21364,10 @@ __metadata:
       optional: true
     "@img/sharp-win32-x64":
       optional: true
-  checksum: 10/391d1212df0a8ac61c4bdf3b745a8530b050ff71c198038ece5eccfa013cbb5bc0735dba71d47aeeb4f82a86d2bc4dc212e44b397cbb6afa285624a6bd069516
+  peerDependenciesMeta:
+    "@types/node":
+      optional: true
+  checksum: 10/f3130f6f126e532d67560b808b95d7c235e669b7f4dd68e0d464feed9a70d52c356ac53867eb44ec877788176a15a3bdffc8ac777a9ed777fc4b63cc99582cb2
   languageName: node
   linkType: hard
 

From 2e275f4f265cc4287eedd90840789ac5a6b278e8 Mon Sep 17 00:00:00 2001
From: Ahtesham Quraish <ahtesham-quraish@users.noreply.github.com>
Date: Fri, 11 Sep 2026 14:16:17 +0500
Subject: [PATCH 4/9] Build internal resource links from learn_url (#3885)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

* Build internal resource links from learn_url

Eleven components built links to related resources from (id, parent, title),
slugifying each title locally: the podcast and video listings, the "more from
this playlist" and "up next" rails, the series navigation, and the drawer's
call-to-action. They now read the resource's learn_url, so the backend is the
only thing that decides how a URL is spelled.

Where a link is scoped by context rather than by the resource — a video in the
playlist you are browsing, an episode under the podcast you arrived from — only
the slug comes from learn_url and the parent segment stays as given. Podcasts
and playlists have no such parent and use learn_url whole. Share URLs use it
whole too, so sharing hands out the URL that owns the content rather than the
context it was found in.

The call-to-action keeps its membership guards: a video outside any playlist, or
an episode with no podcast, still falls through to the source URL rather than to
a Learn page.

`PodcastEpisodeParentSerializer` gains learn_url. The episode page names its
series in a breadcrumb and in its PodcastEpisode JSON-LD, and the embedded
parent carried only an id, so `partOfSeries.url` would otherwise have to name a
URL that redirects. `parent` is already select_related by the `_podcasts`
prefetch, so this costs no extra query.

With those callers converted, pathSlug and the four title-based path builders
are unused and removed. slugify remains only for the drawer's cosmetic
`resource_title`, which the backend cannot supply per-resource: a resource with
a dedicated page has no resource_title in its learn_url.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* Document the slug contract these path helpers actually have

The block described a `title` argument that no helper takes, and attributed the
"resource" fallback to the frontend when the backend owns it. State what the
helpers do: take an already-derived slug, emit the bare redirecting path when
it is undefined, and in generateVideoPlaylistPath's case return that bare form
unconditionally.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* Assert the episode row hrefs on the podcast page

The fixture set each episode's parent ids but left its own learn_url
drawer-shaped, so learnUrlSlug yielded "search" and every row rendered
/podcast/<id>/podcast_episode/<id>/search. Nothing asserted the href, so the
malformed link was invisible.

Give episodes a dedicated-page learn_url, and pin the hrefs in the list test so
a drawer-shaped fixture cannot quietly return.

Add a case where the episode's canonical learn_url names a different parent —
an episode in several podcasts is viewable under any of them — proving the row
keeps the podcast being viewed as context and borrows only the slug.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* Assert the "More from" row hrefs on the episode page

The section's tests only checked that titles rendered, and the factory left each
episode's learn_url drawer-shaped, so learnUrlSlug yielded "search" and every
row rendered /podcast/<context>/podcast_episode/<id>/search undetected.

Give factory episodes a dedicated-page learn_url scoped to a deliberately
different canonical parent, so every row exercises the case an episode in
several podcasts presents. Assert the hrefs by role: the context segment is the
podcast being viewed, the slug comes from learn_url.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* Assert the remaining context-plus-slug hrefs

Two more rails read their slug from learn_url while keeping their own context,
and neither had an href pinned: the latest-episodes list on /podcasts, and the
"more from this playlist" rows on the video page. Both fixtures kept the
factory's drawer-shaped learn_url, so each row rendered a "/search" slug with
no test failing.

Scope both fixtures' learn_url to a deliberately different canonical parent, so
every row exercises the multi-parent case, and assert the hrefs by role.

In VideoDetailPage the fixture default is applied only when a caller has not
overridden learn_url, so the share-URL test still names its own value.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* Stop justifying learn_url by naming the UI that reads it

A fixture that explains a field by pointing at a breadcrumb and a JSON-LD block
goes stale the moment either changes, and nobody returns to a fixture comment to
notice. Drop it from both factories.

The serializer docstring loses the same sentence but keeps what a reader cannot
infer from the code: why the parent list is empty, and that `parent` is already
select_related so the field costs no query.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* Return a resource's URL slug as a top-level API field

Consumers that build a resource page path need the slug segment, and the
only way to get it today is to parse it back out of learn_url. Serve it
directly as url_slug.

* Consume url_slug; keep context for UI and share, canonical for crawlers

Replaces the fifteen `learnUrlSlug(learn_url)` call sites with the
resource's `url_slug` and drops both `learnUrlSlug` and `learnUrlPath`:
Next treats an absolute same-origin href the same as a path, and the
redirect pages now build their canonical from the slug directly.

Splits the three uses of a resource URL the way the review asks:

- HTML UI (breadcrumbs, carousels, "view all") keeps parent context
- Share keeps parent context too, as `main` did — a video shared from
  the xTalk playlist should not land on a different series
- JSON-LD is canonical throughout. `buildPodcastEpisodeStructuredData`
  now takes the canonical parent from the episode itself, so `url` and
  `partOfSeries` can no longer name two different podcasts.

* Pass a playlist id as the string the API declares

`VideoResource.playlists` is Array<string>, unlike an episode's
`podcasts`, which is Array<number>.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Build the episode share URL with absoluteUrl

Matches the two video pages and drops the file's only use of env().

* Let the podcast fixture keep the factory's learn_url

The href assertion compares against the fixture's own value, so a
hand-written URL asserted nothing. The factory's drawer-shaped default
makes it fail if the component builds the path instead of using learn_url.

* Compare both sides of a canonical redirect with the same builder

The incoming path was written out by hand at all four [slug] pages, so it
repeated what the builder already knows and could drift from it. It also
escaped the id segment differently: the builder runs ids through
generatePath, the hand-written copy did not.

videoDetailPath now takes a string id and playlist so the video page can
pass its route params straight in.

* Drop a String() on a value already typed string

podcastEpisodePath takes both ids as strings, unlike the builders that
accept number | string and need the conversion.

---------

Co-authored-by: Ahtesham Quraish <ahtesham.quraish@arbisoft.com>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
Co-authored-by: Ahtesham Quraish <ahtesham.quraish@192.168.1.215>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
---
 frontends/api/src/generated/v0/api.ts         |   4 +
 frontends/api/src/generated/v1/api.ts         |   4 +
 .../test-utils/factories/learningResources.ts |   1 +
 .../PodcastPage/PodcastDetailPage.test.tsx    |  35 +++++-
 .../PodcastPage/PodcastDetailPage.tsx         |   6 +-
 .../PodcastEpisodeDetailPage.test.tsx         |  95 +++++++++++++--
 .../PodcastPage/PodcastEpisodeDetailPage.tsx  |  31 ++---
 .../LatestEpisodesSection.test.tsx            |  38 +++++-
 .../LatestEpisodesSection.tsx                 |   6 +-
 .../PodcastSection.test.tsx                   |   4 +-
 .../PodcastsListingPage/PodcastSection.tsx    |  12 +-
 .../PodcastsListingPage/helpers.test.ts       |  36 +++++-
 .../podcastEpisodeStructuredData.test.ts      |  60 +++++-----
 .../podcastEpisodeStructuredData.ts           |  26 ++---
 .../MoreFromPlaylist.tsx                      |  11 +-
 .../RelatedPlaylist.tsx                       |   9 +-
 .../VideoDetailPage.test.tsx                  |  49 +++++---
 .../VideoDetailPage.tsx                       |  31 ++---
 .../VideoPlaylistCollectionPage.test.tsx      |  11 +-
 .../VideoPlaylistCollectionPage.tsx           |   4 +-
 .../VideoSeriesDetailPage.test.tsx            |  16 +--
 .../VideoSeriesDetailPage.tsx                 |  30 ++---
 .../useSeriesNavigation.ts                    |   4 +-
 .../podcast/[podcastId]/[slug]/page.test.tsx  |   5 +-
 .../podcast/[podcastId]/[slug]/page.tsx       |  10 +-
 .../(site)/podcast/[podcastId]/page.test.tsx  |   7 +-
 .../app/(site)/podcast/[podcastId]/page.tsx   |   4 +-
 .../[episodeId]/[slug]/page.test.tsx          |   5 +-
 .../[episodeId]/[slug]/page.tsx               |  12 +-
 .../podcast_episode/[episodeId]/page.test.tsx |   3 +-
 .../podcast_episode/[episodeId]/page.tsx      |   8 +-
 .../video-playlist/[id]/[slug]/page.test.tsx  |   2 +-
 .../video-playlist/[id]/[slug]/page.tsx       |   6 +-
 .../(site)/video-playlist/[id]/page.test.tsx  |   3 +-
 .../app/(site)/video-playlist/[id]/page.tsx   |   4 +-
 .../(site)/video/[id]/[slug]/page.test.tsx    |  21 +++-
 .../src/app/(site)/video/[id]/[slug]/page.tsx |   9 +-
 .../src/app/(site)/video/[id]/page.test.tsx   |   4 +-
 .../main/src/app/(site)/video/[id]/page.tsx   |   8 +-
 frontends/main/src/common/urls.test.ts        | 100 +++++++---------
 frontends/main/src/common/urls.ts             | 109 +++++-------------
 .../CallToActionSection.test.tsx              |  85 ++++++++++++++
 .../CallToActionSection.tsx                   |  29 +++--
 .../LearningResourceExpanded.test.tsx         |  11 +-
 .../LearningResourcePaste.test.ts             |  25 ++--
 learning_resources/serializers.py             |  13 +++
 learning_resources/serializers_test.py        |   3 +-
 learning_resources/utils.py                   |   7 +-
 openapi/specs/v0.yaml                         |   5 +
 openapi/specs/v1.yaml                         |   5 +
 50 files changed, 613 insertions(+), 413 deletions(-)

diff --git a/frontends/api/src/generated/v0/api.ts b/frontends/api/src/generated/v0/api.ts
index 886e79590a..a39b59a902 100644
--- a/frontends/api/src/generated/v0/api.ts
+++ b/frontends/api/src/generated/v0/api.ts
@@ -1579,6 +1579,10 @@ export interface PodcastEpisodeParent {
   id: number
   title: string
   readable_id: string
+  /**
+   * Where this podcast lives within Learn
+   */
+  learn_url: string
 }
 /**
  * Serializer for podcast episode resources
diff --git a/frontends/api/src/generated/v1/api.ts b/frontends/api/src/generated/v1/api.ts
index b851ec7b93..fa2b4a73ed 100644
--- a/frontends/api/src/generated/v1/api.ts
+++ b/frontends/api/src/generated/v1/api.ts
@@ -2540,6 +2540,10 @@ export interface PodcastEpisodeParent {
   id: number
   title: string
   readable_id: string
+  /**
+   * Where this podcast lives within Learn
+   */
+  learn_url: string
 }
 /**
  * Serializer for PodcastEpisode
diff --git a/frontends/api/src/test-utils/factories/learningResources.ts b/frontends/api/src/test-utils/factories/learningResources.ts
index 5d9174f0f3..53305df828 100644
--- a/frontends/api/src/test-utils/factories/learningResources.ts
+++ b/frontends/api/src/test-utils/factories/learningResources.ts
@@ -655,6 +655,7 @@ const podcastEpisode: LearningResourceFactory<PodcastEpisodeResource> = (
             id: parentPodcastId,
             title: faker.lorem.words(3),
             readable_id: faker.string.uuid(),
+            learn_url: `${TEST_APP_ORIGIN}/podcast/${parentPodcastId}/podcast`,
           },
         ],
         duration: faker.helpers.arrayElement(["PT1H13M44S", "PT2H30M", "PT1M"]),
diff --git a/frontends/main/src/app-pages/PodcastPage/PodcastDetailPage.test.tsx b/frontends/main/src/app-pages/PodcastPage/PodcastDetailPage.test.tsx
index 2a43638a36..12e48bb365 100644
--- a/frontends/main/src/app-pages/PodcastPage/PodcastDetailPage.test.tsx
+++ b/frontends/main/src/app-pages/PodcastPage/PodcastDetailPage.test.tsx
@@ -3,6 +3,7 @@ import { factories, setMockResponse, urls } from "api/test-utils"
 import { ResourceTypeEnum } from "api/v1"
 import type { LearningResource, PodcastEpisodeResource } from "api/v1"
 import { renderWithProviders, screen, user } from "@/test-utils"
+import { podcastEpisodePath } from "@/common/urls"
 import { PodcastDetailPage } from "./PodcastDetailPage"
 
 jest.mock(
@@ -67,6 +68,7 @@ const setupApis = ({
             id: podcast.id,
             title: podcast.title!,
             readable_id: podcast.readable_id,
+            learn_url: podcast.learn_url,
           },
         ]
       }
@@ -98,6 +100,28 @@ const setupApis = ({
 }
 
 describe("PodcastDetailPage", () => {
+  test("episode rows keep this podcast as context and take only the backend slug", async () => {
+    // The episode's canonical parent is a *different* podcast — an episode in
+    // several podcasts is viewable under any of them. The row href must keep the
+    // podcast being viewed and borrow only the slug.
+    const episodes = makePodcastEpisodes(1)
+    const { podcast } = setupApis({ episodesPage1: episodes })
+    const episode = episodes[0]
+    episode.podcast_episode!.podcasts = [podcast.id + 1, podcast.id]
+
+    renderWithProviders(<PodcastDetailPage podcastId={String(podcast.id)} />)
+
+    const title = await screen.findByText(episode.title!)
+    expect(title.closest("a")).toHaveAttribute(
+      "href",
+      podcastEpisodePath(
+        String(episode.id),
+        String(podcast.id),
+        episode.url_slug,
+      ),
+    )
+  })
+
   test("renders initial episode list", async () => {
     const episodes = makePodcastEpisodes(3)
     const { podcast } = setupApis({ episodesPage1: episodes })
@@ -106,7 +130,16 @@ describe("PodcastDetailPage", () => {
 
     await screen.findByText(episodes[0].title!)
     for (const episode of episodes) {
-      expect(screen.getByText(episode.title!)).toBeInTheDocument()
+      const title = screen.getByText(episode.title!)
+      expect(title).toBeInTheDocument()
+      expect(title.closest("a")).toHaveAttribute(
+        "href",
+        podcastEpisodePath(
+          String(episode.id),
+          String(podcast.id),
+          episode.url_slug,
+        ),
+      )
     }
   })
 
diff --git a/frontends/main/src/app-pages/PodcastPage/PodcastDetailPage.tsx b/frontends/main/src/app-pages/PodcastPage/PodcastDetailPage.tsx
index d4d0e9c2ee..026ca3438f 100644
--- a/frontends/main/src/app-pages/PodcastPage/PodcastDetailPage.tsx
+++ b/frontends/main/src/app-pages/PodcastPage/PodcastDetailPage.tsx
@@ -11,7 +11,7 @@ import {
 import { ResourceTypeEnum } from "api/v1"
 import type { LearningResource } from "api/v1"
 import { formatDate } from "ol-utilities"
-import { HOME, podcastEpisodePageView } from "@/common/urls"
+import { HOME, podcastEpisodePath } from "@/common/urls"
 import { addExternalLinkTargets } from "@/common/utils"
 import PodcastContainer from "./PodcastContainer"
 import PodcastBreadcrumbs from "./PodcastBreadcrumbs"
@@ -406,10 +406,10 @@ export const PodcastDetailPage: React.FC<PodcastDetailPageProps> = ({
                       key={episode.id}
                       isMobile={isMobile}
                       episode={episode}
-                      href={podcastEpisodePageView(
+                      href={podcastEpisodePath(
                         String(episode.id),
                         String(id),
-                        episode.title,
+                        episode.url_slug,
                       )}
                       onPlayClick={handlePlayClick}
                       onPauseClick={pause}
diff --git a/frontends/main/src/app-pages/PodcastPage/PodcastEpisodeDetailPage.test.tsx b/frontends/main/src/app-pages/PodcastPage/PodcastEpisodeDetailPage.test.tsx
index 5f25f8c595..8b0d74b244 100644
--- a/frontends/main/src/app-pages/PodcastPage/PodcastEpisodeDetailPage.test.tsx
+++ b/frontends/main/src/app-pages/PodcastPage/PodcastEpisodeDetailPage.test.tsx
@@ -1,5 +1,6 @@
 import React from "react"
 import { factories, setMockResponse, urls } from "api/test-utils"
+import { absoluteUrl, podcastEpisodePath } from "@/common/urls"
 import { ResourceTypeEnum } from "api/v1"
 import type { LearningResource, PodcastEpisodeResource } from "api/v1"
 import { renderWithProviders, screen, user, waitFor } from "@/test-utils"
@@ -77,6 +78,7 @@ const setupApis = ({
           id: podcast.id,
           title: podcast.title!,
           readable_id: podcast.readable_id,
+          learn_url: podcast.learn_url,
         },
       ],
       has_transcript:
@@ -171,6 +173,18 @@ describe("PodcastEpisodeDetailPage", () => {
 
     await screen.findByText(moreEpisodes[0].title!)
     expect(screen.getByText(moreEpisodes[1].title!)).toBeInTheDocument()
+
+    // Each row keeps the podcast being viewed as the context segment and takes
+    // only the slug from the episode.
+    for (const more of moreEpisodes) {
+      const link = screen.getByRole("link", {
+        name: new RegExp(more.title!, "i"),
+      })
+      expect(link).toHaveAttribute(
+        "href",
+        podcastEpisodePath(String(more.id), String(podcast.id), more.url_slug),
+      )
+    }
   })
 
   test("play button is present and enabled when episode has an audio URL", async () => {
@@ -247,6 +261,7 @@ describe("PodcastEpisodeDetailPage", () => {
         id: podcast.id,
         title: podcast.title!,
         readable_id: podcast.readable_id,
+        learn_url: podcast.learn_url,
       },
     ]
 
@@ -316,7 +331,63 @@ describe("PodcastEpisodeDetailPage", () => {
     expect(internalLink).not.toHaveAttribute("target")
   })
 
-  test("names the URL's podcast (not the first parent) for a multi-parent episode", async () => {
+  test("Share link keeps the podcast the episode is viewed under", async () => {
+    // Sharing hands out the page in front of the user, parent podcast included,
+    // even when that is not the canonical parent: the recommendation is usually
+    // about the series it was found in.
+    const episode = makePodcastEpisode()
+    const canonical = makePodcast({ title: "Canonical Podcast" })
+    const viewed = makePodcast({ title: "Viewed Podcast" })
+    episode.podcast_episode.podcasts = [canonical.id, viewed.id]
+    episode.podcast_episode.parent_podcasts = [
+      {
+        id: canonical.id,
+        title: canonical.title!,
+        readable_id: canonical.readable_id,
+        learn_url: canonical.learn_url,
+      },
+      {
+        id: viewed.id,
+        title: viewed.title!,
+        readable_id: viewed.readable_id,
+        learn_url: viewed.learn_url,
+      },
+    ]
+
+    setMockResponse.get(
+      urls.learningResources.details({ id: episode.id }),
+      episode,
+    )
+    setMockResponse.get(
+      urls.learningResources.details({ id: viewed.id }),
+      viewed,
+    )
+    setMockResponse.get(
+      `${urls.learningResources.items({ id: viewed.id })}?limit=${EPISODES_PAGE_SIZE}`,
+      makeItemsResponse([episode]),
+    )
+
+    renderWithProviders(
+      <PodcastEpisodeDetailPage
+        episodeId={String(episode.id)}
+        podcastId={String(viewed.id)}
+      />,
+    )
+
+    await user.click(await screen.findByRole("button", { name: /share/i }))
+
+    expect(screen.getByRole("textbox")).toHaveValue(
+      absoluteUrl(
+        podcastEpisodePath(
+          String(episode.id),
+          String(viewed.id),
+          episode.url_slug,
+        ),
+      ),
+    )
+  })
+
+  test("shows the viewed podcast but publishes the canonical one", async () => {
     const episode = makePodcastEpisode()
     episode.podcast_episode.audio_url = "https://example.com/ep.mp3"
     // The resource factory leaves last_modified unset, and the JSON-LD is
@@ -331,11 +402,13 @@ describe("PodcastEpisodeDetailPage", () => {
         id: podcastA.id,
         title: "Podcast A",
         readable_id: podcastA.readable_id,
+        learn_url: podcastA.learn_url,
       },
       {
         id: podcastB.id,
         title: "Podcast B",
         readable_id: podcastB.readable_id,
+        learn_url: podcastB.learn_url,
       },
     ]
 
@@ -363,24 +436,22 @@ describe("PodcastEpisodeDetailPage", () => {
       await screen.findByRole("button", { name: /play episode/i }),
     )
 
-    // The header/breadcrumb and the player bar must agree on Podcast B.
+    // The header/breadcrumb and the player bar follow the route: Podcast B.
     expect(screen.getByTestId("player-podcast-name")).toHaveTextContent(
       "Podcast B",
     )
 
-    // So must the JSON-LD: partOfSeries takes its url from the podcast in the
-    // current route, so taking the name from parent_podcasts[0] instead would
-    // publish Podcast A's name against Podcast B's url.
+    // The JSON-LD does not. It is read by crawlers, so both its url and its
+    // series name the canonical parent — A — and never the route's.
     const jsonLd = JSON.parse(
       document.querySelector('script[type="application/ld+json"]')!.innerHTML,
     )
-    expect(jsonLd.partOfSeries).toEqual(
-      expect.objectContaining({
-        "@type": "PodcastSeries",
-        name: "Podcast B",
-        url: expect.stringContaining(`/podcast/${podcastB.id}/`),
-      }),
-    )
+    expect(jsonLd.url).toBe(episode.learn_url)
+    expect(jsonLd.partOfSeries).toEqual({
+      "@type": "PodcastSeries",
+      name: "Podcast A",
+      url: podcastA.learn_url,
+    })
   })
 
   test("escapes every < in the JSON-LD, not just </", async () => {
diff --git a/frontends/main/src/app-pages/PodcastPage/PodcastEpisodeDetailPage.tsx b/frontends/main/src/app-pages/PodcastPage/PodcastEpisodeDetailPage.tsx
index bc93c78c5a..74a8a06c7c 100644
--- a/frontends/main/src/app-pages/PodcastPage/PodcastEpisodeDetailPage.tsx
+++ b/frontends/main/src/app-pages/PodcastPage/PodcastEpisodeDetailPage.tsx
@@ -13,7 +13,7 @@ import { useQuery } from "@tanstack/react-query"
 import { ResourceTypeEnum } from "api/v1"
 import type { PodcastEpisodeResource } from "api/v1"
 import { formatDate } from "ol-utilities"
-import { HOME, podcastPageView, podcastEpisodePageView } from "@/common/urls"
+import { HOME, absoluteUrl, podcastEpisodePath } from "@/common/urls"
 import { addExternalLinkTargets } from "@/common/utils"
 import { EpisodeItem } from "./PodcastsListingPage/EpisodeItem"
 import PodcastContainer from "./PodcastContainer"
@@ -37,9 +37,6 @@ import PodcastShareButton from "./PodcastShareButton"
 import EpisodeContentTabs from "./EpisodeContentTabs"
 import type { TranscriptState } from "./EpisodeContentTabs"
 import { buildPodcastEpisodeStructuredData } from "./podcastEpisodeStructuredData"
-import { env } from "@/env"
-
-const NEXT_PUBLIC_ORIGIN = env("NEXT_PUBLIC_ORIGIN")
 
 /* ── Layout ── */
 
@@ -259,13 +256,17 @@ export const PodcastEpisodeDetailPage: React.FC<
     toggle(episode, Number(podcastId))
   }
 
-  const podcastHref = podcastId
-    ? podcastPageView(podcastId, parentPodcast?.title)
-    : "/"
+  // A podcast has a single page, so its `learn_url` is that page.
+  const podcastHref = parentPodcast?.learn_url ?? "/"
 
+  // Shares the page in front of the user, parent podcast included: an episode
+  // in several podcasts is viewable under any of them, and a recommendation is
+  // usually about the series it was found in.
   const sharePageUrl =
     episode && podcastId
-      ? `${NEXT_PUBLIC_ORIGIN}${podcastEpisodePageView(String(episode.id), podcastId, episode.title)}`
+      ? absoluteUrl(
+          podcastEpisodePath(String(episode.id), podcastId, episode.url_slug),
+        )
       : ""
 
   // Episode descriptions are sanitized on the backend with nh3 during ETL
@@ -285,15 +286,7 @@ export const PodcastEpisodeDetailPage: React.FC<
   // tag so crawlers can read it without executing any additional JS.
   // See: https://schema.org/PodcastEpisode
   const structuredData = !episodeLoading
-    ? buildPodcastEpisodeStructuredData(episode as PodcastEpisodeResource, {
-        url: sharePageUrl || undefined,
-        // The same parent the breadcrumb and podcastHref use, so partOfSeries'
-        // name and url always describe one series.
-        series: parentPodcast,
-        seriesUrl: podcastId
-          ? `${NEXT_PUBLIC_ORIGIN}${podcastHref}`
-          : undefined,
-      })
+    ? buildPodcastEpisodeStructuredData(episode as PodcastEpisodeResource)
     : null
 
   return (
@@ -398,10 +391,10 @@ export const PodcastEpisodeDetailPage: React.FC<
                   episode={episode}
                   href={
                     podcastId
-                      ? podcastEpisodePageView(
+                      ? podcastEpisodePath(
                           String(episode.id),
                           podcastId,
-                          episode.title,
+                          episode.url_slug,
                         )
                       : ""
                   }
diff --git a/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/LatestEpisodesSection.test.tsx b/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/LatestEpisodesSection.test.tsx
index 7243dd776c..773413b2b6 100644
--- a/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/LatestEpisodesSection.test.tsx
+++ b/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/LatestEpisodesSection.test.tsx
@@ -1,17 +1,21 @@
 import React from "react"
+import { faker } from "@faker-js/faker/locale/en"
 import { factories } from "api/test-utils"
 import type { LearningResource } from "api/v1"
-import { SEARCH_PODCAST_EPISODES } from "@/common/urls"
+import { SEARCH_PODCAST_EPISODES, podcastEpisodePath } from "@/common/urls"
 import { renderWithProviders, screen, user } from "@/test-utils"
 import LatestEpisodesSection from "./LatestEpisodesSection"
 
+/** The podcast the rows are scoped to, taken from the episode's `podcasts[0]`. */
+const CONTEXT_PODCAST_ID = faker.number.int({ min: 1, max: 1e6 })
+
 const makeEpisodes = (count: number): LearningResource[] =>
   Array.from({ length: count }, (_, i) =>
     factories.learningResources.podcastEpisode({
       title: `Episode ${i + 1}`,
       podcast_episode: {
         id: i + 1,
-        podcasts: [1],
+        podcasts: [CONTEXT_PODCAST_ID],
         duration: "PT1M",
         audio_url: "https://example.com/audio.mp3",
         episode_link: "https://example.com/link",
@@ -36,6 +40,36 @@ describe("LatestEpisodesSection", () => {
     expect(screen.getByText("All episodes")).toBeInTheDocument()
   })
 
+  it("keeps each episode's podcast context and takes only the backend slug", () => {
+    const episodes = makeEpisodes(2)
+    renderWithProviders(
+      <LatestEpisodesSection
+        episodes={episodes}
+        isMobile={false}
+        isAudioPlaying={false}
+        onPlayClick={jest.fn()}
+        onPauseClick={jest.fn()}
+        hasMoreEpisodes={false}
+        isPlayable={() => true}
+      />,
+    )
+
+    // Each row is an anchor given role="listitem", so query by that role.
+    const rows = screen.getAllByRole("listitem")
+    expect(rows).toHaveLength(episodes.length)
+    episodes.forEach((episode, i) => {
+      expect(rows[i]).toHaveTextContent(episode.title!)
+      expect(rows[i]).toHaveAttribute(
+        "href",
+        podcastEpisodePath(
+          String(episode.id),
+          String(CONTEXT_PODCAST_ID),
+          episode.url_slug,
+        ),
+      )
+    })
+  })
+
   it("renders all provided episodes", () => {
     const episodes = makeEpisodes(3)
     renderWithProviders(
diff --git a/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/LatestEpisodesSection.tsx b/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/LatestEpisodesSection.tsx
index b36633c8e4..4817ee59e1 100644
--- a/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/LatestEpisodesSection.tsx
+++ b/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/LatestEpisodesSection.tsx
@@ -2,7 +2,7 @@ import React from "react"
 import { Link, Skeleton, styled } from "ol-components"
 import { ButtonLink } from "@mitodl/smoot-design"
 import type { LearningResource, PodcastEpisodeResource } from "api/v1"
-import { SEARCH_PODCAST_EPISODES, podcastEpisodePageView } from "@/common/urls"
+import { SEARCH_PODCAST_EPISODES, podcastEpisodePath } from "@/common/urls"
 import {
   Section,
   SectionHeader,
@@ -130,10 +130,10 @@ const LatestEpisodesSection: React.FC<LatestEpisodesSectionProps> = ({
                 overline={overline}
                 href={
                   parentPodcastId
-                    ? podcastEpisodePageView(
+                    ? podcastEpisodePath(
                         String(episode.id),
                         String(parentPodcastId),
-                        episode.title,
+                        episode.url_slug,
                       )
                     : SEARCH_PODCAST_EPISODES
                 }
diff --git a/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/PodcastSection.test.tsx b/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/PodcastSection.test.tsx
index 51317c7f6f..7c175b8228 100644
--- a/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/PodcastSection.test.tsx
+++ b/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/PodcastSection.test.tsx
@@ -1,7 +1,7 @@
 import React from "react"
 import { factories } from "api/test-utils"
 import type { LearningResource } from "api/v1"
-import { SEARCH_PODCASTS, podcastPageView } from "@/common/urls"
+import { SEARCH_PODCASTS } from "@/common/urls"
 import { renderWithProviders, screen } from "@/test-utils"
 import PodcastSection from "./PodcastSection"
 
@@ -67,7 +67,7 @@ describe("PodcastSection", () => {
     expect(screen.getByText(/Updated May 3/)).toBeInTheDocument()
     expect(screen.getByRole("link", { name: /Chalk Radio/ })).toHaveAttribute(
       "href",
-      podcastPageView("1", "Chalk Radio"),
+      series.learn_url,
     )
   })
 
diff --git a/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/PodcastSection.tsx b/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/PodcastSection.tsx
index c5c3d5e4a9..1723d5b687 100644
--- a/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/PodcastSection.tsx
+++ b/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/PodcastSection.tsx
@@ -7,7 +7,7 @@ import { RiArrowRightLine, RiArrowRightSLine } from "@remixicon/react"
 import DOMPurify from "isomorphic-dompurify"
 import { formatDate } from "ol-utilities"
 import type { LearningResource } from "api/v1"
-import { SEARCH_PODCASTS, podcastPageView } from "@/common/urls"
+import { SEARCH_PODCASTS } from "@/common/urls"
 import { stripAnchorTags } from "@/common/utils"
 import {
   Section,
@@ -316,10 +316,7 @@ const PodcastSection: React.FC<PodcastSectionProps> = ({
                     ? formatDate(item.last_modified, "MMM D")
                     : null
                   return (
-                    <FeaturedPodcastCard
-                      key={item.id}
-                      href={podcastPageView(String(item.id), item.title)}
-                    >
+                    <FeaturedPodcastCard key={item.id} href={item.learn_url}>
                       <FeaturedPodcastHeader>
                         {item.image?.url && (
                           <FeaturedPodcastImage
@@ -392,10 +389,7 @@ const PodcastSection: React.FC<PodcastSectionProps> = ({
                 ? formatDate(item.last_modified, "MMM D")
                 : null
               return (
-                <MorePodcastRow
-                  key={item.id}
-                  href={podcastPageView(String(item.id), item.title)}
-                >
+                <MorePodcastRow key={item.id} href={item.learn_url}>
                   <MorePodcastLeft>
                     <MorePodcastTitle
                       className="series-row-title"
diff --git a/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/helpers.test.ts b/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/helpers.test.ts
index 165bf39e56..37ac485718 100644
--- a/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/helpers.test.ts
+++ b/frontends/main/src/app-pages/PodcastPage/PodcastsListingPage/helpers.test.ts
@@ -200,7 +200,12 @@ describe("getEpisodeParentPodcastName", () => {
         id: 1,
         podcasts: [42],
         parent_podcasts: [
-          { id: 42, title: "The Show Name", readable_id: "the-show" },
+          {
+            id: 42,
+            title: "The Show Name",
+            readable_id: "the-show",
+            learn_url: "http://test.learn.odl.local:8062/podcast/42/the-show",
+          },
         ],
         duration: "PT1M",
         audio_url: "https://example.com/audio.mp3",
@@ -230,8 +235,18 @@ describe("getEpisodeParentPodcastName", () => {
         id: 1,
         podcasts: [1, 2],
         parent_podcasts: [
-          { id: 1, title: "Podcast A", readable_id: "podcast-a" },
-          { id: 2, title: "Podcast B", readable_id: "podcast-b" },
+          {
+            id: 1,
+            title: "Podcast A",
+            readable_id: "podcast-a",
+            learn_url: "http://test.learn.odl.local:8062/podcast/1/podcast-a",
+          },
+          {
+            id: 2,
+            title: "Podcast B",
+            readable_id: "podcast-b",
+            learn_url: "http://test.learn.odl.local:8062/podcast/2/podcast-b",
+          },
         ],
         duration: "PT1M",
         audio_url: "https://example.com/audio.mp3",
@@ -263,8 +278,18 @@ describe("getEpisodeParentPodcast", () => {
       id: 1,
       podcasts: [1, 2],
       parent_podcasts: [
-        { id: 1, title: "Podcast A", readable_id: "podcast-a" },
-        { id: 2, title: "Podcast B", readable_id: "podcast-b" },
+        {
+          id: 1,
+          title: "Podcast A",
+          readable_id: "podcast-a",
+          learn_url: "http://test.learn.odl.local:8062/podcast/1/podcast-a",
+        },
+        {
+          id: 2,
+          title: "Podcast B",
+          readable_id: "podcast-b",
+          learn_url: "http://test.learn.odl.local:8062/podcast/2/podcast-b",
+        },
       ],
       duration: "PT1M",
       audio_url: "https://example.com/audio.mp3",
@@ -284,6 +309,7 @@ describe("getEpisodeParentPodcast", () => {
       id: 2,
       title: "Podcast B",
       readable_id: "podcast-b",
+      learn_url: "http://test.learn.odl.local:8062/podcast/2/podcast-b",
     })
   })
 
diff --git a/frontends/main/src/app-pages/PodcastPage/podcastEpisodeStructuredData.test.ts b/frontends/main/src/app-pages/PodcastPage/podcastEpisodeStructuredData.test.ts
index cb7653b442..a87b574c32 100644
--- a/frontends/main/src/app-pages/PodcastPage/podcastEpisodeStructuredData.test.ts
+++ b/frontends/main/src/app-pages/PodcastPage/podcastEpisodeStructuredData.test.ts
@@ -1,5 +1,6 @@
+import { faker } from "@faker-js/faker/locale/en"
 import { factories } from "api/test-utils"
-import type { PodcastEpisodeResource } from "api/v1"
+import type { PodcastEpisodeParent, PodcastEpisodeResource } from "api/v1"
 import { buildPodcastEpisodeStructuredData } from "./podcastEpisodeStructuredData"
 
 const makeEpisode = (
@@ -12,24 +13,29 @@ const makeEpisode = (
     podcast_episode: podcastEpisode,
   })
 
+const makeParent = (): PodcastEpisodeParent => {
+  const id = faker.number.int({ min: 1, max: 1e6 })
+  const slug = faker.lorem.slug()
+  return {
+    id,
+    title: faker.lorem.words(3),
+    readable_id: faker.lorem.slug(),
+    learn_url: `http://test.learn.odl.local:8062/podcast/${id}/${slug}`,
+  }
+}
+
 test("omits the payload entirely without a last_modified date", () => {
   const episode = factories.learningResources.podcastEpisode({
     last_modified: null,
   })
-  expect(
-    buildPodcastEpisodeStructuredData(episode, { series: null }),
-  ).toBeNull()
-  expect(
-    buildPodcastEpisodeStructuredData(undefined, { series: null }),
-  ).toBeNull()
+  expect(buildPodcastEpisodeStructuredData(episode)).toBeNull()
+  expect(buildPodcastEpisodeStructuredData(undefined)).toBeNull()
 })
 
 test.each(["PT17M16S", "PT0S", "PT1H13M44S", "P1D", "P1Y2M3DT4H5M6.7S"])(
   "keeps the valid ISO-8601 duration %s",
   (duration) => {
-    const built = buildPodcastEpisodeStructuredData(makeEpisode({ duration }), {
-      series: null,
-    })
+    const built = buildPodcastEpisodeStructuredData(makeEpisode({ duration }))
     expect(built).toHaveProperty("duration", duration)
   },
 )
@@ -39,27 +45,29 @@ test.each(["PT17M16S", "PT0S", "PT1H13M44S", "P1D", "P1Y2M3DT4H5M6.7S"])(
 test.each(["P", "PT", "P1DT", "17 minutes", "1:13:44", ""])(
   "drops the invalid duration %p rather than publishing it",
   (duration) => {
-    const built = buildPodcastEpisodeStructuredData(makeEpisode({ duration }), {
-      series: null,
-    })
+    const built = buildPodcastEpisodeStructuredData(makeEpisode({ duration }))
     expect(built).not.toHaveProperty("duration")
   },
 )
 
-test("names the series it is given, not one it picks itself", () => {
-  const episode = makeEpisode({
-    parent_podcasts: [
-      { id: 1, title: "Podcast A", readable_id: "a" },
-      { id: 2, title: "Podcast B", readable_id: "b" },
-    ],
-  })
-  const built = buildPodcastEpisodeStructuredData(episode, {
-    series: { id: 2, title: "Podcast B", readable_id: "b" },
-    seriesUrl: "https://learn.mit.edu/podcast/2/podcast-b",
-  })
+test("names the canonical series, not a later parent", () => {
+  const canonical = makeParent()
+  const other = makeParent()
+  const episode = makeEpisode({ parent_podcasts: [canonical, other] })
+
+  const built = buildPodcastEpisodeStructuredData(episode)
+
+  expect(built).toHaveProperty("url", episode.learn_url)
   expect(built).toHaveProperty("partOfSeries", {
     "@type": "PodcastSeries",
-    name: "Podcast B",
-    url: "https://learn.mit.edu/podcast/2/podcast-b",
+    name: canonical.title,
+    url: canonical.learn_url,
   })
 })
+
+test("omits partOfSeries for an episode with no parent podcast", () => {
+  const built = buildPodcastEpisodeStructuredData(
+    makeEpisode({ parent_podcasts: [] }),
+  )
+  expect(built).not.toHaveProperty("partOfSeries")
+})
diff --git a/frontends/main/src/app-pages/PodcastPage/podcastEpisodeStructuredData.ts b/frontends/main/src/app-pages/PodcastPage/podcastEpisodeStructuredData.ts
index f7481b0f87..3252ac3e9f 100644
--- a/frontends/main/src/app-pages/PodcastPage/podcastEpisodeStructuredData.ts
+++ b/frontends/main/src/app-pages/PodcastPage/podcastEpisodeStructuredData.ts
@@ -7,24 +7,14 @@ import type { PodcastEpisodeParent, PodcastEpisodeResource } from "api/v1"
 const ISO_8601_DURATION_RE =
   /^P(?!$)(?:\d+Y)?(?:\d+M)?(?:\d+W)?(?:\d+D)?(?:T(?!$)(?:\d+H)?(?:\d+M)?(?:\d+(?:\.\d+)?S)?)?$/
 
-type BuildOptions = {
-  /** Absolute canonical url of the episode page */
-  url?: string
-  /**
-   * The parent podcast series the episode is being viewed under, as resolved
-   * by `getEpisodeParentPodcast`. Required rather than picked from
-   * `parent_podcasts[0]` here: an episode can belong to several series, and
-   * choosing one independently of the caller would pair that series' name with
-   * `seriesUrl`, which the caller builds from the parent in the current url.
-   */
-  series: PodcastEpisodeParent | null
-  /** Absolute canonical url of the parent podcast page */
-  seriesUrl?: string
-}
-
 /**
  * Builds a schema.org PodcastEpisode structured-data payload.
  *
+ * Every URL here is canonical, taken from the episode rather than from the page
+ * rendering it. An episode in several podcasts is viewable under any of them, so
+ * a page that passed in its own parent would pair one series' name with another
+ * series' `url`. `parent_podcasts[0]` is the parent `learn_url` was built from.
+ *
  * The transcript text itself is deliberately not included. `schema.org`'s
  * `transcript` property has a `domainIncludes` of `AudioObject` and
  * `VideoObject` only -- it is not a `PodcastEpisode` property -- and no Google
@@ -38,11 +28,11 @@ type BuildOptions = {
  */
 export function buildPodcastEpisodeStructuredData(
   episode: PodcastEpisodeResource | undefined,
-  { url, series, seriesUrl }: BuildOptions,
 ): Record<string, unknown> | null {
   if (!episode || !episode.last_modified) return null
 
   const details = episode.podcast_episode
+  const series: PodcastEpisodeParent | undefined = details?.parent_podcasts?.[0]
 
   const durationIso =
     details?.duration && ISO_8601_DURATION_RE.test(details.duration)
@@ -54,7 +44,7 @@ export function buildPodcastEpisodeStructuredData(
     "@type": "PodcastEpisode",
     name: episode.title,
     ...(episode.description ? { description: episode.description } : {}),
-    ...(url ? { url } : {}),
+    url: episode.learn_url,
     datePublished: episode.last_modified,
     ...(episode.image?.url ? { image: episode.image.url } : {}),
     ...(durationIso ? { duration: durationIso } : {}),
@@ -71,7 +61,7 @@ export function buildPodcastEpisodeStructuredData(
           partOfSeries: {
             "@type": "PodcastSeries",
             name: series.title,
-            ...(seriesUrl ? { url: seriesUrl } : {}),
+            url: series.learn_url,
           },
         }
       : {}),
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/MoreFromPlaylist.tsx b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/MoreFromPlaylist.tsx
index 8a51b0dfc8..6c90c54e5f 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/MoreFromPlaylist.tsx
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/MoreFromPlaylist.tsx
@@ -3,14 +3,15 @@ import Image from "next/image"
 import { Skeleton } from "ol-components"
 import { formatDurationClockTime } from "ol-utilities"
 import type { VideoResource } from "api/v1"
-import { videoDetailPageView, videoPlaylistPageView } from "@/common/urls"
+import { videoDetailPath } from "@/common/urls"
 import * as Styled from "./VideoDetailPage.styled"
 
 type MoreFromPlaylistProps = {
   playlistId: number
   /** Display name of the playlist, used in headings and labels. */
   playlistLabel: string
-  playlistTitle?: string
+  /** The playlist's own page, for the "see all" link. */
+  playlistHref: string
   /** Sibling videos to list, already filtered and capped by the caller. */
   videos: VideoResource[]
   /** Total videos in the playlist, used to decide whether to link to the rest. */
@@ -34,7 +35,7 @@ const MoreFromPlaylistItem: React.FC<{
 
   return (
     <Styled.MoreFromItem
-      href={videoDetailPageView(video.id, playlistId, video.title)}
+      href={videoDetailPath(video.id, playlistId, video.url_slug)}
       aria-label={`Open video ${video.title}`}
     >
       <Styled.ThumbnailWrapper>
@@ -75,7 +76,7 @@ const MoreFromPlaylistItem: React.FC<{
 const MoreFromPlaylist: React.FC<MoreFromPlaylistProps> = ({
   playlistId,
   playlistLabel,
-  playlistTitle,
+  playlistHref,
   videos,
   totalVideos,
   isLoading,
@@ -121,7 +122,7 @@ const MoreFromPlaylist: React.FC<MoreFromPlaylistProps> = ({
       </Styled.MoreFromList>
       {hasMore && (
         <Styled.SeeAllLink
-          href={videoPlaylistPageView(String(playlistId), playlistTitle)}
+          href={playlistHref}
           aria-label={`View all videos in ${playlistLabel}`}
         >
           View all in {playlistLabel} →
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/RelatedPlaylist.tsx b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/RelatedPlaylist.tsx
index 8d8602effa..51dce2304a 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/RelatedPlaylist.tsx
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/RelatedPlaylist.tsx
@@ -4,7 +4,6 @@ import { Skeleton, Typography, styled, theme } from "ol-components"
 import VideoContainer from "./VideoContainer"
 import type { VideoPlaylistResource } from "api/v1"
 import { formatDurationHuman } from "ol-utilities"
-import { videoPlaylistPageView } from "@/common/urls"
 
 const Section = styled.section(({ theme }) => ({
   padding: "80px 0",
@@ -140,13 +139,7 @@ const RelatedPlaylist: React.FC<RelatedCollectionsProps> = ({
                 </div>
               ))
             : collections.map((collection) => (
-                <CollectionLink
-                  href={videoPlaylistPageView(
-                    String(collection.id),
-                    collection.title,
-                  )}
-                  key={collection.id}
-                >
+                <CollectionLink href={collection.learn_url} key={collection.id}>
                   <CollectionType>
                     {collectionTypeLabel(collection)}
                   </CollectionType>
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoDetailPage.test.tsx b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoDetailPage.test.tsx
index c82af78d12..6733edf605 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoDetailPage.test.tsx
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoDetailPage.test.tsx
@@ -1,6 +1,7 @@
 import React from "react"
 import user from "@testing-library/user-event"
 import { setMockResponse, urls, factories } from "api/test-utils"
+import { absoluteUrl, videoDetailPath } from "@/common/urls"
 import { renderWithProviders, screen } from "@/test-utils"
 import { useFeatureFlagEnabled } from "posthog-js/react"
 import { useFeatureFlagsLoaded } from "@/common/useFeatureFlagsLoaded"
@@ -103,6 +104,24 @@ describe("VideoDetailPage", () => {
     mockedUseFeatureFlagsLoaded.mockReturnValue(true)
   })
 
+  test("'more from this playlist' rows keep the browsed playlist and take only the backend slug", async () => {
+    const current = makeVideo({ title: "Current Video" })
+    const sibling = makeVideo({ title: "Sibling Video" })
+    renderPage({
+      video: current,
+      playlistId: 99,
+      playlistItems: [current, sibling],
+    })
+
+    const row = await screen.findByRole("link", {
+      name: `Open video ${sibling.title}`,
+    })
+    expect(row).toHaveAttribute(
+      "href",
+      videoDetailPath(sibling.id, 99, sibling.url_slug),
+    )
+  })
+
   test("renders the video title once data is loaded", async () => {
     const video = makeVideo({ title: "Introduction to Machine Learning" })
     renderPage({ video })
@@ -112,29 +131,23 @@ describe("VideoDetailPage", () => {
     })
   })
 
-  // Share URL is the slugged canonical form, and carries the playlist only
-  // when present (no `?playlist=null` when the video is viewed without one).
-  test.each([
-    {
-      playlistId: 99,
-      expected:
-        "http://test.learn.odl.local:8062/video/720/intro-to-machine-learning?playlist=99",
-    },
-    {
-      playlistId: null,
-      expected:
-        "http://test.learn.odl.local:8062/video/720/intro-to-machine-learning",
-    },
-  ])(
-    "Share link is the slugged canonical URL (playlistId=$playlistId)",
-    async ({ playlistId, expected }) => {
-      const video = makeVideo({ id: 720, title: "Intro to Machine Learning" })
+  // Sharing keeps the playlist the video is being watched in, even when that
+  // is not the canonical one: the recommendation is usually about the series.
+  // A video watched outside any playlist gets the bare form, not `playlist=null`.
+  test.each([{ playlistId: 99 }, { playlistId: null }])(
+    "Share link keeps the browsed playlist (playlistId=$playlistId)",
+    async ({ playlistId }) => {
+      const video = makeVideo({ title: "Intro to Machine Learning" })
       renderPage({ video, playlistId })
 
       await screen.findByRole("heading", { name: video.title })
       await user.click(screen.getByRole("button", { name: /share/i }))
 
-      expect(screen.getByRole("textbox")).toHaveValue(expected)
+      expect(screen.getByRole("textbox")).toHaveValue(
+        absoluteUrl(
+          videoDetailPath(video.id, playlistId ?? undefined, video.url_slug),
+        ),
+      )
     },
   )
 
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoDetailPage.tsx b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoDetailPage.tsx
index 2be1d42088..2547e2edf0 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoDetailPage.tsx
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoDetailPage.tsx
@@ -1,6 +1,5 @@
 "use client"
 
-import { env } from "@/env"
 import React, { useEffect, useRef } from "react"
 import { Skeleton, SkipLink } from "ol-components"
 import VideoContainer from "./VideoContainer"
@@ -14,13 +13,11 @@ import {
 import type { VideoResource, VideoPlaylistResource } from "api/v1"
 import { VideoResourceResourceTypeEnum } from "api/v1"
 import { formatDurationClockTime } from "ol-utilities"
-import { videoDetailPageView, videoPlaylistPageView } from "@/common/urls"
+import { absoluteUrl, videoDetailPath, videoPlaylistPath } from "@/common/urls"
 import { buildVideoStructuredData } from "./videoStructuredData"
 import type { VideoPlayerHandle } from "@/page-components/VideoPlayer/VideoResourcePlayer"
 import * as Styled from "./VideoDetailPage.styled"
 
-const NEXT_PUBLIC_ORIGIN = env("NEXT_PUBLIC_ORIGIN")
-
 /** How many sibling videos the "More from" list shows at most. */
 const MORE_FROM_LIMIT = 5
 
@@ -144,10 +141,7 @@ const VideoDetailPage: React.FC<VideoDetailPageProps> = ({
               ...(playlist
                 ? [
                     {
-                      href: videoPlaylistPageView(
-                        String(playlist.id),
-                        playlist.title,
-                      ),
+                      href: playlist.learn_url,
                       label: playlistLabel,
                     },
                   ]
@@ -163,9 +157,7 @@ const VideoDetailPage: React.FC<VideoDetailPageProps> = ({
           {isLoading ? (
             <Skeleton width={120} height={18} style={{ marginBottom: 8 }} />
           ) : playlist ? (
-            <Styled.CategoryLabel
-              href={videoPlaylistPageView(String(playlist.id), playlist.title)}
-            >
+            <Styled.CategoryLabel href={playlist.learn_url}>
               {playlistLabel}
             </Styled.CategoryLabel>
           ) : null}
@@ -197,7 +189,16 @@ const VideoDetailPage: React.FC<VideoDetailPageProps> = ({
               <VideoShareButton
                 video={video}
                 title={video.title ?? "video"}
-                pageUrl={`${NEXT_PUBLIC_ORIGIN}${videoDetailPageView(video.id, playlistId ?? undefined, video.title)}`}
+                // Shares the page in front of the user, playlist included: a
+                // video in several playlists is viewable in any of them, and a
+                // recommendation is usually about the series it was found in.
+                pageUrl={absoluteUrl(
+                  videoDetailPath(
+                    video.id,
+                    playlistId ?? undefined,
+                    video.url_slug,
+                  ),
+                )}
                 playerRef={playerRef}
               />
             )}
@@ -232,7 +233,11 @@ const VideoDetailPage: React.FC<VideoDetailPageProps> = ({
               <MoreFromPlaylist
                 playlistId={playlistId}
                 playlistLabel={playlistLabel}
-                playlistTitle={playlist?.title}
+                playlistHref={
+                  playlist
+                    ? playlist.learn_url
+                    : videoPlaylistPath(playlistId, undefined)
+                }
                 videos={otherVideos}
                 totalVideos={totalPlaylistVideos}
                 isLoading={itemsLoading}
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoPlaylistCollectionPage.test.tsx b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoPlaylistCollectionPage.test.tsx
index fbee2629c7..168bdb3bd0 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoPlaylistCollectionPage.test.tsx
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoPlaylistCollectionPage.test.tsx
@@ -1,5 +1,6 @@
 import React from "react"
 import { setMockResponse, urls, factories } from "api/test-utils"
+import { videoDetailPath } from "@/common/urls"
 import { renderWithProviders, screen } from "@/test-utils"
 import VideoPage from "./VideoPlaylistCollectionPage"
 import { ResourceTypeEnum } from "api/v1"
@@ -21,7 +22,7 @@ const makeSeriesPlaylist = () =>
     offered_by: { code: "ocw", name: "OCW", channel_url: null },
   })
 
-const makeVideo = (overrides = {}) =>
+const makeVideo = (overrides: { title?: string } = {}) =>
   factories.learningResources.resource({
     resource_type: ResourceTypeEnum.Video,
     ...overrides,
@@ -212,7 +213,7 @@ describe("VideoPage", () => {
       const titleEl = await screen.findByText(collection.title)
       expect(titleEl.closest("a")).toHaveAttribute(
         "href",
-        `/video/${collection.id}/collection-video?playlist=${playlist.id}`,
+        videoDetailPath(collection.id, playlist.id, collection.url_slug),
       )
     })
 
@@ -230,7 +231,7 @@ describe("VideoPage", () => {
       const titleEls = await screen.findAllByText(featured.title)
       expect(titleEls[0].closest("a")).toHaveAttribute(
         "href",
-        `/video/${featured.id}/quantum-computing-and-the-future?playlist=${playlist.id}`,
+        videoDetailPath(featured.id, playlist.id, featured.url_slug),
       )
     })
   })
@@ -304,13 +305,13 @@ describe("VideoPage", () => {
       const ep1Title = await screen.findByText(ep1.title)
       expect(ep1Title.closest("a")).toHaveAttribute(
         "href",
-        `/video/${ep1.id}/episode-alpha?playlist=${playlist.id}`,
+        videoDetailPath(ep1.id, playlist.id, ep1.url_slug),
       )
 
       const ep2Title = screen.getByText(ep2.title)
       expect(ep2Title.closest("a")).toHaveAttribute(
         "href",
-        `/video/${ep2.id}/episode-beta?playlist=${playlist.id}`,
+        videoDetailPath(ep2.id, playlist.id, ep2.url_slug),
       )
     })
   })
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoPlaylistCollectionPage.tsx b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoPlaylistCollectionPage.tsx
index 69871a12df..cea8f4ba34 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoPlaylistCollectionPage.tsx
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoPlaylistCollectionPage.tsx
@@ -12,7 +12,7 @@ import {
 } from "api/hooks/learningResources"
 import { formatDurationHuman } from "ol-utilities"
 import { isOcwPlaylist } from "@/common/utils"
-import { videoDetailPageView } from "@/common/urls"
+import { videoDetailPath } from "@/common/urls"
 import type { VideoResource, VideoPlaylistResource } from "api/v1"
 import { ResourceTypeEnum, VideoResourceResourceTypeEnum } from "api/v1"
 import { EpisodeItem } from "./SeriesVideoList"
@@ -65,7 +65,7 @@ const VideoPlaylistCollectionPage: React.FC<
   VideoPlaylistCollectionPageProps
 > = ({ playlistId }) => {
   const getVideoHref = (resource: VideoResource) =>
-    videoDetailPageView(resource.id, playlistId, resource.title)
+    videoDetailPath(resource.id, playlistId, resource.url_slug)
 
   const {
     data: playlist,
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoSeriesDetailPage.test.tsx b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoSeriesDetailPage.test.tsx
index ad4adeb3ee..4e4253edee 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoSeriesDetailPage.test.tsx
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoSeriesDetailPage.test.tsx
@@ -1,5 +1,6 @@
 import React from "react"
 import { setMockResponse, urls, factories } from "api/test-utils"
+import { absoluteUrl, videoDetailPath } from "@/common/urls"
 import { renderWithProviders, screen, user } from "@/test-utils"
 import VideoSeriesDetailPage from "./VideoSeriesDetailPage"
 import { ResourceTypeEnum } from "api/v1"
@@ -130,10 +131,7 @@ describe("VideoSeriesDetailPage", () => {
         name: "Neural Networks Series",
       })
       expect(playlistLinks.length).toBeGreaterThanOrEqual(1)
-      expect(playlistLinks[0]).toHaveAttribute(
-        "href",
-        `/video-playlist/${playlist.id}/neural-networks-series`,
-      )
+      expect(playlistLinks[0]).toHaveAttribute("href", playlist.learn_url)
     })
 
     test("does not include a playlist breadcrumb when no playlistId", async () => {
@@ -206,7 +204,7 @@ describe("VideoSeriesDetailPage", () => {
       })
       expect(prevLink).toHaveAttribute(
         "href",
-        `/video/${prev.id}/part-1?playlist=${playlist.id}`,
+        videoDetailPath(prev.id, playlist.id, prev.url_slug),
       )
     })
 
@@ -226,7 +224,7 @@ describe("VideoSeriesDetailPage", () => {
       })
       expect(nextLink).toHaveAttribute(
         "href",
-        `/video/${next.id}/part-2?playlist=${playlist.id}`,
+        videoDetailPath(next.id, playlist.id, next.url_slug),
       )
     })
 
@@ -291,7 +289,7 @@ describe("VideoSeriesDetailPage", () => {
       ).not.toBeInTheDocument()
     })
 
-    test("share URL uses the slugged canonical form with playlist param", async () => {
+    test("share URL keeps the playlist the video is watched in", async () => {
       const playlist = makePlaylist({ id: 99 })
       const current = makeVideo({ id: 720, title: "Intro to Machine Learning" })
       const next = makeVideo({ title: "Next Lecture" })
@@ -308,8 +306,10 @@ describe("VideoSeriesDetailPage", () => {
           name: /share intro to machine learning/i,
         }),
       )
+      // Sharing hands out the page in front of the user, playlist included,
+      // even when that is not the canonical playlist.
       expect(screen.getByRole("textbox")).toHaveValue(
-        "http://test.learn.odl.local:8062/video/720/intro-to-machine-learning?playlist=99",
+        absoluteUrl(videoDetailPath(current.id, playlist.id, current.url_slug)),
       )
     })
 
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoSeriesDetailPage.tsx b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoSeriesDetailPage.tsx
index 3d14cef071..8df08dff2b 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoSeriesDetailPage.tsx
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoSeriesDetailPage.tsx
@@ -7,19 +7,16 @@ import { useLearningResourcesDetail } from "api/hooks/learningResources"
 import type { VideoResource, VideoPlaylistResource } from "api/v1"
 import { formatDurationClockTime } from "ol-utilities"
 import { useSeriesNavigation } from "./useSeriesNavigation"
-import { videoDetailPageView, videoPlaylistPageView } from "@/common/urls"
+import { absoluteUrl, videoDetailPath, videoPlaylistPath } from "@/common/urls"
 import SeriesNavBar from "./SeriesNavBar"
 import UpNextSection from "./UpNextSection"
 import * as Styled from "./VideoSeriesDetailPage.styled"
-import { env } from "@/env"
 import { buildVideoStructuredData } from "./videoStructuredData"
 import VideoResourcePlayer from "@/page-components/VideoPlayer/VideoResourcePlayer"
 import type { VideoPlayerHandle } from "@/page-components/VideoPlayer/VideoResourcePlayer"
 
 import VideoShareButton from "./VideoShareButton"
 
-const NEXT_PUBLIC_ORIGIN = env("NEXT_PUBLIC_ORIGIN")
-
 const StyledVideoResourcePlayer = styled(VideoResourcePlayer)(({ theme }) => ({
   borderBottom: `3px solid ${theme.custom.colors.darkGray2}`,
 }))
@@ -122,10 +119,7 @@ const VideoSeriesDetailPage: React.FC<VideoSeriesDetailPageProps> = ({
               ...(playlist && playlistId
                 ? [
                     {
-                      href: videoPlaylistPageView(
-                        String(playlist.id),
-                        playlist.title,
-                      ),
+                      href: playlist.learn_url,
                       label: playlistLabel,
                     },
                   ]
@@ -139,10 +133,11 @@ const VideoSeriesDetailPage: React.FC<VideoSeriesDetailPageProps> = ({
       {/* Series navigation bar */}
       {playlistId && (
         <SeriesNavBar
-          playlistHref={videoPlaylistPageView(
-            String(playlistId),
-            playlist?.title,
-          )}
+          playlistHref={
+            playlist
+              ? playlist.learn_url
+              : videoPlaylistPath(playlistId, undefined)
+          }
           playlistLabel={playlistLabel}
           videoId={videoId}
           isLoading={isLoading}
@@ -179,7 +174,16 @@ const VideoSeriesDetailPage: React.FC<VideoSeriesDetailPageProps> = ({
               <VideoShareButton
                 video={video}
                 title={video?.title ?? ""}
-                pageUrl={`${NEXT_PUBLIC_ORIGIN}${videoDetailPageView(video.id, playlistId ?? undefined, video.title)}`}
+                // Shares the page in front of the user, playlist included: a
+                // video in several playlists is viewable in any of them, and a
+                // recommendation is usually about the series it was found in.
+                pageUrl={absoluteUrl(
+                  videoDetailPath(
+                    video.id,
+                    playlistId ?? undefined,
+                    video.url_slug,
+                  ),
+                )}
                 playerRef={playerRef}
               />
             )}
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/useSeriesNavigation.ts b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/useSeriesNavigation.ts
index 02448816a7..b953858b37 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/useSeriesNavigation.ts
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/useSeriesNavigation.ts
@@ -3,7 +3,7 @@ import { useQuery } from "@tanstack/react-query"
 import { learningResourceQueries } from "api/hooks/learningResources"
 import type { VideoResource } from "api/v1"
 import { VideoResourceResourceTypeEnum } from "api/v1"
-import { videoDetailPageView } from "@/common/urls"
+import { videoDetailPath } from "@/common/urls"
 
 export type SeriesNavigation = {
   videoItems: VideoResource[]
@@ -44,7 +44,7 @@ export function useSeriesNavigation(
   const videoPosition = currentIndex >= 0 ? currentIndex + 1 : null
 
   const getVideoHref = (v: VideoResource) =>
-    videoDetailPageView(v.id, playlistId ?? undefined, v.title)
+    videoDetailPath(v.id, playlistId ?? undefined, v.url_slug)
 
   return {
     videoItems,
diff --git a/frontends/main/src/app/(site)/podcast/[podcastId]/[slug]/page.test.tsx b/frontends/main/src/app/(site)/podcast/[podcastId]/[slug]/page.test.tsx
index f912c0545f..b961423e4d 100644
--- a/frontends/main/src/app/(site)/podcast/[podcastId]/[slug]/page.test.tsx
+++ b/frontends/main/src/app/(site)/podcast/[podcastId]/[slug]/page.test.tsx
@@ -27,15 +27,12 @@ beforeEach(() => {
 
 const ORIGIN = "http://test.learn.odl.local:8062"
 
-/**
- * The backend names the canonical URL, so a test asserting on it must say what
- * the backend returned. `slug` is the segment learn_url carries.
- */
 const mockPodcast = (slug = "beyond-biology") => {
   const id = 1234
   const podcast = factories.learningResources.podcast({
     id,
     title: "Beyond Biology",
+    url_slug: slug,
     learn_url: `${ORIGIN}/podcast/${id}/${slug}`,
   })
   setMockResponse.get(
diff --git a/frontends/main/src/app/(site)/podcast/[podcastId]/[slug]/page.tsx b/frontends/main/src/app/(site)/podcast/[podcastId]/[slug]/page.tsx
index ad19747cd1..7b39e0cd9d 100644
--- a/frontends/main/src/app/(site)/podcast/[podcastId]/[slug]/page.tsx
+++ b/frontends/main/src/app/(site)/podcast/[podcastId]/[slug]/page.tsx
@@ -12,7 +12,7 @@ import {
 import { learningResourceQueries } from "api/hooks/learningResources"
 import { notFound, redirect } from "next/navigation"
 import { parseResourceId } from "@/common/slugs"
-import { carrySearchParams, learnUrlPath } from "@/common/urls"
+import { carrySearchParams, podcastPath } from "@/common/urls"
 
 type Props = AppPageProps<"/podcast/[podcastId]/[slug]">
 
@@ -57,10 +57,10 @@ const Page: React.FC<Props> = async (props) => {
     notFound()
   }
 
-  // The backend names the canonical URL; redirect if we're not on it (stale or
-  // uppercase slug, or a non-normalized id segment).
-  const canonical = learnUrlPath(resource.learn_url)
-  if (`/podcast/${podcastId}/${slug}` !== canonical) {
+  // The backend names the slug; redirect if we're not on the canonical form
+  // (stale or uppercase slug, or a non-normalized id segment).
+  const canonical = podcastPath(id, resource.url_slug)
+  if (podcastPath(podcastId, slug) !== canonical) {
     redirect(carrySearchParams(canonical, await props.searchParams))
   }
 
diff --git a/frontends/main/src/app/(site)/podcast/[podcastId]/page.test.tsx b/frontends/main/src/app/(site)/podcast/[podcastId]/page.test.tsx
index 1d43ee65ff..d3825de307 100644
--- a/frontends/main/src/app/(site)/podcast/[podcastId]/page.test.tsx
+++ b/frontends/main/src/app/(site)/podcast/[podcastId]/page.test.tsx
@@ -26,16 +26,11 @@ const pageProps = (
   searchParams: Promise.resolve(searchParams),
 })
 
-/**
- * The backend names the canonical URL, so a test that asserts on it must say
- * what the backend returned. The factory default is a drawer URL, which is what
- * a resource with no page of its own gets.
- */
 const podcastWithPage = (id: number, slug: string) =>
   factories.learningResources.podcast({
     id,
     title: "Beyond Biology",
-    learn_url: `http://test.learn.odl.local:8062/podcast/${id}/${slug}`,
+    url_slug: slug,
   })
 
 test("bare podcast id redirects to the slugged canonical", async () => {
diff --git a/frontends/main/src/app/(site)/podcast/[podcastId]/page.tsx b/frontends/main/src/app/(site)/podcast/[podcastId]/page.tsx
index 9c6cedc079..66548b37ae 100644
--- a/frontends/main/src/app/(site)/podcast/[podcastId]/page.tsx
+++ b/frontends/main/src/app/(site)/podcast/[podcastId]/page.tsx
@@ -4,7 +4,7 @@ import { ResourceTypeEnum } from "api"
 import { learningResourceQueries } from "api/hooks/learningResources"
 import { notFound, redirect } from "next/navigation"
 import { parseResourceId } from "@/common/slugs"
-import { carrySearchParams, learnUrlPath } from "@/common/urls"
+import { carrySearchParams, podcastPath } from "@/common/urls"
 
 /** Bare /podcast/{id} is never canonical → 307-redirect to the slugged form. */
 const Page = async (props: AppPageProps<"/podcast/[podcastId]">) => {
@@ -22,7 +22,7 @@ const Page = async (props: AppPageProps<"/podcast/[podcastId]">) => {
   }
   redirect(
     carrySearchParams(
-      learnUrlPath(resource.learn_url),
+      podcastPath(id, resource.url_slug),
       await props.searchParams,
     ),
   )
diff --git a/frontends/main/src/app/(site)/podcast/[podcastId]/podcast_episode/[episodeId]/[slug]/page.test.tsx b/frontends/main/src/app/(site)/podcast/[podcastId]/podcast_episode/[episodeId]/[slug]/page.test.tsx
index f90a76a2d7..63cf822e8d 100644
--- a/frontends/main/src/app/(site)/podcast/[podcastId]/podcast_episode/[episodeId]/[slug]/page.test.tsx
+++ b/frontends/main/src/app/(site)/podcast/[podcastId]/podcast_episode/[episodeId]/[slug]/page.test.tsx
@@ -38,9 +38,10 @@ const mockEpisode = (
   const episode = factories.learningResources.podcastEpisode({
     id,
     title: "Episode One",
+    url_slug: slug,
     podcast_episode: { podcasts: parentIds, has_transcript: hasTranscript },
-    // The backend names the slug, always under the canonical parent; the page
-    // resolves the parent segment against the request.
+    // learn_url is always scoped to the canonical parent; the page resolves the
+    // parent segment against the request instead.
     learn_url: `http://test.learn.odl.local:8062/podcast/${parentIds[0]}/podcast_episode/${id}/${slug}`,
   })
   setMockResponse.get(
diff --git a/frontends/main/src/app/(site)/podcast/[podcastId]/podcast_episode/[episodeId]/[slug]/page.tsx b/frontends/main/src/app/(site)/podcast/[podcastId]/podcast_episode/[episodeId]/[slug]/page.tsx
index b68f9be800..fc912478c4 100644
--- a/frontends/main/src/app/(site)/podcast/[podcastId]/podcast_episode/[episodeId]/[slug]/page.tsx
+++ b/frontends/main/src/app/(site)/podcast/[podcastId]/podcast_episode/[episodeId]/[slug]/page.tsx
@@ -19,11 +19,7 @@ import {
   parseResourceId,
   resolveEpisodeParent,
 } from "@/common/slugs"
-import {
-  carrySearchParams,
-  learnUrlSlug,
-  podcastEpisodePath,
-} from "@/common/urls"
+import { carrySearchParams, podcastEpisodePath } from "@/common/urls"
 
 type Props =
   AppPageProps<"/podcast/[podcastId]/podcast_episode/[episodeId]/[slug]">
@@ -88,11 +84,9 @@ const Page: React.FC<Props> = async (props) => {
   const canonical = podcastEpisodePath(
     String(epId),
     String(canonicalPodcastId),
-    learnUrlSlug(episode.learn_url),
+    episode.url_slug,
   )
-  if (
-    `/podcast/${podcastId}/podcast_episode/${episodeId}/${slug}` !== canonical
-  ) {
+  if (podcastEpisodePath(episodeId, podcastId, slug) !== canonical) {
     redirect(carrySearchParams(canonical, await props.searchParams))
   }
 
diff --git a/frontends/main/src/app/(site)/podcast/[podcastId]/podcast_episode/[episodeId]/page.test.tsx b/frontends/main/src/app/(site)/podcast/[podcastId]/podcast_episode/[episodeId]/page.test.tsx
index 5a0d3986a2..3a81ed2e6a 100644
--- a/frontends/main/src/app/(site)/podcast/[podcastId]/podcast_episode/[episodeId]/page.test.tsx
+++ b/frontends/main/src/app/(site)/podcast/[podcastId]/podcast_episode/[episodeId]/page.test.tsx
@@ -19,9 +19,8 @@ test("bare episode URL redirects to the slugged canonical with corrected parent"
   const episode = factories.learningResources.podcastEpisode({
     id,
     title: "Episode One",
+    url_slug: "episode-one",
     podcast_episode: { podcasts: [10] },
-    // The backend names the slug; the factory default is a drawer URL.
-    learn_url: `http://test.learn.odl.local:8062/podcast/10/podcast_episode/${id}/episode-one`,
   })
   setMockResponse.get(
     urls.learningResources.details({ id: episode.id }),
diff --git a/frontends/main/src/app/(site)/podcast/[podcastId]/podcast_episode/[episodeId]/page.tsx b/frontends/main/src/app/(site)/podcast/[podcastId]/podcast_episode/[episodeId]/page.tsx
index 7b0f410c5b..b75db277a6 100644
--- a/frontends/main/src/app/(site)/podcast/[podcastId]/podcast_episode/[episodeId]/page.tsx
+++ b/frontends/main/src/app/(site)/podcast/[podcastId]/podcast_episode/[episodeId]/page.tsx
@@ -8,11 +8,7 @@ import {
   parseResourceId,
   resolveEpisodeParent,
 } from "@/common/slugs"
-import {
-  carrySearchParams,
-  learnUrlSlug,
-  podcastEpisodePath,
-} from "@/common/urls"
+import { carrySearchParams, podcastEpisodePath } from "@/common/urls"
 
 /**
  * Bare /podcast/{podcastId}/podcast_episode/{episodeId} is never canonical →
@@ -46,7 +42,7 @@ const Page = async (
       podcastEpisodePath(
         String(epId),
         String(canonicalPodcastId),
-        learnUrlSlug(episode.learn_url),
+        episode.url_slug,
       ),
       await props.searchParams,
     ),
diff --git a/frontends/main/src/app/(site)/video-playlist/[id]/[slug]/page.test.tsx b/frontends/main/src/app/(site)/video-playlist/[id]/[slug]/page.test.tsx
index 88b290056c..ae5b45e625 100644
--- a/frontends/main/src/app/(site)/video-playlist/[id]/[slug]/page.test.tsx
+++ b/frontends/main/src/app/(site)/video-playlist/[id]/[slug]/page.test.tsx
@@ -26,12 +26,12 @@ beforeEach(() => {
   })
 })
 
-/** The backend names the canonical URL; `slug` is the segment it carries. */
 const mockPlaylist = (slug = "great-talks") => {
   const id = 4242
   const playlist = factories.learningResources.videoPlaylist({
     id,
     title: "Great Talks",
+    url_slug: slug,
     learn_url: `http://test.learn.odl.local:8062/video-playlist/${id}/${slug}`,
   })
   // Playlist detail is a different endpoint from learningResources.details.
diff --git a/frontends/main/src/app/(site)/video-playlist/[id]/[slug]/page.tsx b/frontends/main/src/app/(site)/video-playlist/[id]/[slug]/page.tsx
index 98b4b7ff20..8416be32d9 100644
--- a/frontends/main/src/app/(site)/video-playlist/[id]/[slug]/page.tsx
+++ b/frontends/main/src/app/(site)/video-playlist/[id]/[slug]/page.tsx
@@ -10,7 +10,7 @@ import { getQueryClient } from "@/app/getQueryClient"
 import VideoPlaylistCollectionPage from "@/app-pages/VideoPlaylistCollectionPage/VideoPlaylistCollectionPage"
 import { notFound, redirect } from "next/navigation"
 import { parseResourceId } from "@/common/slugs"
-import { carrySearchParams, learnUrlPath } from "@/common/urls"
+import { carrySearchParams, videoPlaylistPath } from "@/common/urls"
 
 type Props = AppPageProps<"/video-playlist/[id]/[slug]">
 
@@ -63,8 +63,8 @@ const Page: React.FC<Props> = async ({ params, searchParams }) => {
     videoPlaylistQueries.detail(playlistId),
   )
 
-  const canonical = learnUrlPath(playlist.learn_url)
-  if (`/video-playlist/${id}/${slug}` !== canonical) {
+  const canonical = videoPlaylistPath(playlistId, playlist.url_slug)
+  if (videoPlaylistPath(id, slug) !== canonical) {
     redirect(carrySearchParams(canonical, await searchParams))
   }
 
diff --git a/frontends/main/src/app/(site)/video-playlist/[id]/page.test.tsx b/frontends/main/src/app/(site)/video-playlist/[id]/page.test.tsx
index 4821edbf36..a4c5b82ea2 100644
--- a/frontends/main/src/app/(site)/video-playlist/[id]/page.test.tsx
+++ b/frontends/main/src/app/(site)/video-playlist/[id]/page.test.tsx
@@ -19,8 +19,7 @@ test("bare /video-playlist/{id} redirects to the slugged canonical", async () =>
   const playlist = factories.learningResources.videoPlaylist({
     id,
     title: "Great Talks",
-    // The backend names the canonical URL; the factory default is a drawer URL.
-    learn_url: `http://test.learn.odl.local:8062/video-playlist/${id}/great-talks`,
+    url_slug: "great-talks",
   })
   setMockResponse.get(
     urls.videoPlaylists.details({ id: playlist.id }),
diff --git a/frontends/main/src/app/(site)/video-playlist/[id]/page.tsx b/frontends/main/src/app/(site)/video-playlist/[id]/page.tsx
index f305baa27a..5992c3d95c 100644
--- a/frontends/main/src/app/(site)/video-playlist/[id]/page.tsx
+++ b/frontends/main/src/app/(site)/video-playlist/[id]/page.tsx
@@ -3,7 +3,7 @@ import { videoPlaylistQueries } from "api/hooks/learningResources"
 import { getQueryClient } from "@/app/getQueryClient"
 import { notFound, redirect } from "next/navigation"
 import { parseResourceId } from "@/common/slugs"
-import { carrySearchParams, learnUrlPath } from "@/common/urls"
+import { carrySearchParams, videoPlaylistPath } from "@/common/urls"
 
 /** Bare /video-playlist/{id} is never canonical → 307-redirect to slugged form. */
 const Page = async (props: AppPageProps<"/video-playlist/[id]">) => {
@@ -18,7 +18,7 @@ const Page = async (props: AppPageProps<"/video-playlist/[id]">) => {
   )
   redirect(
     carrySearchParams(
-      learnUrlPath(playlist.learn_url),
+      videoPlaylistPath(playlistId, playlist.url_slug),
       await props.searchParams,
     ),
   )
diff --git a/frontends/main/src/app/(site)/video/[id]/[slug]/page.test.tsx b/frontends/main/src/app/(site)/video/[id]/[slug]/page.test.tsx
index 522489a6de..0bac1efa86 100644
--- a/frontends/main/src/app/(site)/video/[id]/[slug]/page.test.tsx
+++ b/frontends/main/src/app/(site)/video/[id]/[slug]/page.test.tsx
@@ -33,8 +33,9 @@ const mockVideo = (playlists: string[], slug = "beyond-biology") => {
   const id = 777
   const video = factories.learningResources.video({
     id,
-    // The backend names the slug, always under the canonical playlist; the page
-    // resolves ?playlist against the request.
+    url_slug: slug,
+    // learn_url is always scoped to the canonical playlist; the page resolves
+    // ?playlist against the request instead.
     learn_url: `http://test.learn.odl.local:8062/video/${id}/${slug}?playlist=${playlists[0]}`,
     title: "Beyond Biology",
     playlists,
@@ -90,6 +91,22 @@ test("generateMetadata canonical is the same URL in every playlist context", asy
   )
 })
 
+test("redirects a non-normalized ?playlist to its canonical spelling", async () => {
+  // Both sides of the compare come from videoDetailPath, so the incoming value
+  // has to survive verbatim: "007" resolves to playlist 7, whose canonical form
+  // is ?playlist=7.
+  const video = mockVideo(["7", "66"])
+  await expect(
+    Page({
+      params: Promise.resolve({ id: String(video.id), slug: "beyond-biology" }),
+      searchParams: Promise.resolve({ playlist: "007" }),
+    }),
+  ).rejects.toThrow("NEXT_REDIRECT")
+  expect(mockRedirect).toHaveBeenCalledWith(
+    `/video/${video.id}/beyond-biology?playlist=7`,
+  )
+})
+
 test("notFound for a resource that is not a video", async () => {
   const course = factories.learningResources.course()
   setMockResponse.get(urls.learningResources.details({ id: course.id }), course)
diff --git a/frontends/main/src/app/(site)/video/[id]/[slug]/page.tsx b/frontends/main/src/app/(site)/video/[id]/[slug]/page.tsx
index 56bdab3bfc..432663162a 100644
--- a/frontends/main/src/app/(site)/video/[id]/[slug]/page.tsx
+++ b/frontends/main/src/app/(site)/video/[id]/[slug]/page.tsx
@@ -19,7 +19,7 @@ import {
   resolveVideoPlaylist,
   videoPlaylistIds,
 } from "@/common/slugs"
-import { carrySearchParams, learnUrlSlug, videoDetailPath } from "@/common/urls"
+import { carrySearchParams, videoDetailPath } from "@/common/urls"
 
 type Props = AppPageProps<"/video/[id]/[slug]">
 
@@ -75,16 +75,13 @@ const Page: React.FC<Props> = async ({ params, searchParams }) => {
   const canonical = videoDetailPath(
     videoId,
     playlistId ?? undefined,
-    learnUrlSlug(video.learn_url),
+    video.url_slug,
   )
-  const incomingBase = `/video/${id}/${slug}`
   // A repeated ?playlist (array) resolves as no-playlist but is never the
   // canonical form, so it always redirects (which strips it).
   const incoming = Array.isArray(rawPlaylist)
     ? null
-    : typeof rawPlaylist === "string"
-      ? `${incomingBase}?playlist=${rawPlaylist}`
-      : incomingBase
+    : videoDetailPath(id, rawPlaylist, slug)
   if (incoming !== canonical) {
     redirect(carrySearchParams(canonical, resolvedSearchParams, ["playlist"]))
   }
diff --git a/frontends/main/src/app/(site)/video/[id]/page.test.tsx b/frontends/main/src/app/(site)/video/[id]/page.test.tsx
index 3fb2aeed42..4e762878e2 100644
--- a/frontends/main/src/app/(site)/video/[id]/page.test.tsx
+++ b/frontends/main/src/app/(site)/video/[id]/page.test.tsx
@@ -18,9 +18,7 @@ test("bare /video/{id} redirects to the slug + first playlist", async () => {
   const id = 777
   const video = factories.learningResources.video({
     id,
-    // The backend names the slug; the page resolves ?playlist against the
-    // request, so learn_url carries the canonical playlist.
-    learn_url: `http://test.learn.odl.local:8062/video/${id}/beyond-biology?playlist=55`,
+    url_slug: "beyond-biology",
     title: "Beyond Biology",
     playlists: ["55", "66"],
   })
diff --git a/frontends/main/src/app/(site)/video/[id]/page.tsx b/frontends/main/src/app/(site)/video/[id]/page.tsx
index d097173a75..b97deb73ea 100644
--- a/frontends/main/src/app/(site)/video/[id]/page.tsx
+++ b/frontends/main/src/app/(site)/video/[id]/page.tsx
@@ -8,7 +8,7 @@ import {
   resolveVideoPlaylist,
   videoPlaylistIds,
 } from "@/common/slugs"
-import { carrySearchParams, learnUrlSlug, videoDetailPath } from "@/common/urls"
+import { carrySearchParams, videoDetailPath } from "@/common/urls"
 
 /** Bare /video/{id} is never canonical → 307-redirect to slug + resolved playlist. */
 const Page = async ({ params, searchParams }: AppPageProps<"/video/[id]">) => {
@@ -31,11 +31,7 @@ const Page = async ({ params, searchParams }: AppPageProps<"/video/[id]">) => {
   )
   redirect(
     carrySearchParams(
-      videoDetailPath(
-        videoId,
-        playlistId ?? undefined,
-        learnUrlSlug(video.learn_url),
-      ),
+      videoDetailPath(videoId, playlistId ?? undefined, video.url_slug),
       resolvedSearchParams,
       ["playlist"],
     ),
diff --git a/frontends/main/src/common/urls.test.ts b/frontends/main/src/common/urls.test.ts
index d9966a6f91..82228af4c2 100644
--- a/frontends/main/src/common/urls.test.ts
+++ b/frontends/main/src/common/urls.test.ts
@@ -6,10 +6,10 @@ import {
   coursePageView,
   ocwLearnPageView,
   programPageView,
-  podcastPageView,
-  podcastEpisodePageView,
-  videoDetailPageView,
-  videoPlaylistPageView,
+  podcastEpisodePath,
+  videoDetailPath,
+  podcastPath,
+  videoPlaylistPath,
   canonicalResourceDrawerUrl,
   carrySearchParams,
   resourceDrawerSearch,
@@ -179,50 +179,6 @@ test.each([
   expect(ocwLearnPageView(input)).toBe(expected)
 })
 
-describe("slug-aware path builders", () => {
-  test("podcastPageView appends a slug segment; blank → 'resource'; no title → bare", () => {
-    expect(podcastPageView("123", "Beyond Biology")).toBe(
-      "/podcast/123/beyond-biology",
-    )
-    expect(podcastPageView("123", "2024")).toBe("/podcast/123/resource") // blank slug
-    // explicit undefined title → bare (redirects)
-    expect(podcastPageView("123", undefined)).toBe("/podcast/123")
-  })
-
-  test("podcastEpisodePageView slugs the episode, keeps podcast id bare", () => {
-    expect(podcastEpisodePageView("55", "123", "Episode One")).toBe(
-      "/podcast/123/podcast_episode/55/episode-one",
-    )
-    expect(podcastEpisodePageView("55", "123", "你好")).toBe(
-      "/podcast/123/podcast_episode/55/resource",
-    )
-  })
-
-  test("videoDetailPageView slugs the video and keeps ?playlist", () => {
-    expect(videoDetailPageView(16765, 13798, "Beyond Biology")).toBe(
-      "/video/16765/beyond-biology?playlist=13798",
-    )
-    expect(videoDetailPageView(16765, undefined, "Beyond Biology")).toBe(
-      "/video/16765/beyond-biology",
-    )
-    expect(videoDetailPageView(16765, 13798, undefined)).toBe(
-      "/video/16765?playlist=13798",
-    )
-  })
-
-  test("videoDetailPageView allows a slug equal to 'embed' (embed route moved out)", () => {
-    expect(videoDetailPageView(16765, undefined, "Embed")).toBe(
-      "/video/16765/embed",
-    )
-  })
-
-  test("videoPlaylistPageView appends a slug segment", () => {
-    expect(videoPlaylistPageView("13798", "Great Talks")).toBe(
-      "/video-playlist/13798/great-talks",
-    )
-  })
-})
-
 describe("separate-param drawer builders", () => {
   test("resourceDrawerSearch emits resource + optional resource_title (relative)", () => {
     expect(resourceDrawerSearch(114927, "Beyond Biology")).toBe(
@@ -244,17 +200,43 @@ describe("separate-param drawer builders", () => {
   })
 })
 
-test("INVARIANT: canonical paths round-trip URL decoding byte-identically", () => {
-  // The [slug] pages compare Next's *decoded* route params against builder
-  // output; if a builder ever emits a percent-encodable character, a URL
-  // could redirect to a spelling of itself and loop. See pathSlug in urls.ts.
-  const paths = [
-    podcastPageView("123", "Beyond Biology!"),
-    podcastEpisodePageView("55", "123", "Épisode #1"),
-    videoDetailPageView(16765, 13798, "你好"),
-    videoPlaylistPageView("9", "a".repeat(70)),
-  ]
-  paths.forEach((p) => expect(decodeURIComponent(p)).toBe(p))
+describe("resource page paths", () => {
+  test("podcastEpisodePath places the episode under the given podcast", () => {
+    expect(podcastEpisodePath("55", "123", "episode-one")).toBe(
+      "/podcast/123/podcast_episode/55/episode-one",
+    )
+    // No slug → bare, which redirects to the canonical form.
+    expect(podcastEpisodePath("55", "123", undefined)).toBe(
+      "/podcast/123/podcast_episode/55",
+    )
+  })
+
+  test("videoDetailPath keeps ?playlist alongside the slug", () => {
+    expect(videoDetailPath(16765, 13798, "beyond-biology")).toBe(
+      "/video/16765/beyond-biology?playlist=13798",
+    )
+    expect(videoDetailPath(16765, undefined, "beyond-biology")).toBe(
+      "/video/16765/beyond-biology",
+    )
+    expect(videoDetailPath(16765, 13798, undefined)).toBe(
+      "/video/16765?playlist=13798",
+    )
+  })
+
+  test("videoPlaylistPath appends the slug when there is one", () => {
+    expect(videoPlaylistPath(13798, "xtalks")).toBe(
+      "/video-playlist/13798/xtalks",
+    )
+    // No slug → bare, which redirects to the canonical form.
+    expect(videoPlaylistPath(13798, undefined)).toBe("/video-playlist/13798")
+  })
+
+  test("podcastPath appends the slug when there is one", () => {
+    expect(podcastPath(123, "beyond-biology")).toBe(
+      "/podcast/123/beyond-biology",
+    )
+    expect(podcastPath(123, undefined)).toBe("/podcast/123")
+  })
 })
 
 describe("carrySearchParams", () => {
diff --git a/frontends/main/src/common/urls.ts b/frontends/main/src/common/urls.ts
index dca3cb939b..17b4219f9a 100644
--- a/frontends/main/src/common/urls.ts
+++ b/frontends/main/src/common/urls.ts
@@ -160,19 +160,6 @@ export const RESOURCE_DRAWER_PARAMS = {
   syllabusOnly: "syllabus_only",
 } as const
 
-/**
- * Path slug segment from a title: the slug, or the literal "resource" when the
- * slug is blank (the canonical path's slug segment is mandatory — see the
- * readable-URLs spec, mitodl/hq#11210). The slug is cosmetic and ignored on
- * lookup.
- *
- * INVARIANT: canonical paths must round-trip Next's URL decoding
- * byte-identically — keep the slug charset to [a-z0-9-] and ids numeric, or
- * the [slug] pages' incoming-vs-canonical string compares could redirect a
- * URL to a spelling of itself and loop.
- */
-const pathSlug = (title: string): string => slugify(title) || "resource"
-
 /** Prefix a same-origin path with the public origin (for canonical tags). */
 export const absoluteUrl = (path: string): string =>
   `${requiredEnv("NEXT_PUBLIC_ORIGIN")}${path}`
@@ -371,34 +358,37 @@ export const LINKEDIN_ADD_TO_PROFILE_BASE_URL =
 export const COURSE_PAGE_VIEW = "/courses/[readableId]"
 export const coursePageView = (readableId: string) =>
   generatePath(COURSE_PAGE_VIEW, { readableId })
-// Each page-view builder appends a mandatory slug segment when a title is given
-// (the slug, or the literal "resource" when blank). With an undefined title it
-// emits the bare path, which still resolves and 307-redirects to canonical.
-// `title` is required-but-undefinable so a call site can't silently omit it —
-// passing undefined (e.g. a title still in flight) is a visible opt-in to the
-// redirecting bare form. Id and slug are separate segments; the slug is
-// cosmetic and ignored on lookup.
+// The resource page builders below take the resource's `url_slug`. `slug` is
+// required-but-undefinable so a call site can't silently omit it; passing
+// undefined emits the bare path, which resolves and 307-redirects to the
+// slugged canonical.
 export const VIDEO_PLAYLIST_PAGE_VIEW = "/video-playlist/[id]"
-export const videoPlaylistPageView = (
-  id: string,
-  title: string | undefined,
+export const videoPlaylistPath = (
+  id: number | string,
+  slug: string | undefined,
 ) => {
-  const base = generatePath(VIDEO_PLAYLIST_PAGE_VIEW, { id })
-  return title === undefined ? base : `${base}/${pathSlug(title)}`
+  const base = generatePath(VIDEO_PLAYLIST_PAGE_VIEW, { id: String(id) })
+  return slug === undefined ? base : `${base}/${slug}`
 }
 export const PODCASTS_PAGE_VIEW = "/podcasts"
 
 export const PODCAST_PAGE_VIEW = "/podcast/[podcastId]"
-export const podcastPageView = (id: string, title: string | undefined) => {
-  const base = generatePath(PODCAST_PAGE_VIEW, { podcastId: id })
-  return title === undefined ? base : `${base}/${pathSlug(title)}`
+export const podcastPath = (
+  podcastId: number | string,
+  slug: string | undefined,
+) => {
+  const base = generatePath(PODCAST_PAGE_VIEW, {
+    podcastId: String(podcastId),
+  })
+  return slug === undefined ? base : `${base}/${slug}`
 }
+
 export const PODCAST_EPISODE_PAGE_VIEW =
   "/podcast/[podcastId]/podcast_episode/[episodeId]"
 /**
- * An episode's path from an already-known slug. The episode pages read the slug
- * from the resource's `learn_url` but resolve the parent podcast against the
- * request, since an episode in several podcasts is viewable under any of them.
+ * An episode's path. The parent podcast is the caller's to choose: an episode in
+ * several podcasts is viewable under any of them, so a page passes the podcast
+ * it is being viewed under rather than the canonical one.
  */
 export const podcastEpisodePath = (
   id: string,
@@ -406,31 +396,21 @@ export const podcastEpisodePath = (
   slug: string | undefined,
 ) => {
   const base = generatePath(PODCAST_EPISODE_PAGE_VIEW, {
-    podcastId: String(podcastId), // bare context id
-    episodeId: String(id),
+    podcastId, // bare context id
+    episodeId: id,
   })
   return slug === undefined ? base : `${base}/${slug}`
 }
 
-export const podcastEpisodePageView = (
-  id: string,
-  podcastId: string,
-  title: string | undefined,
-) =>
-  podcastEpisodePath(
-    id,
-    podcastId,
-    title === undefined ? undefined : pathSlug(title),
-  )
 export const VIDEO_DETAIL_PAGE_VIEW = "/video/[videoId]"
 /**
- * A video's path from an already-known slug. The video pages read the slug from
- * the resource's `learn_url` but resolve `?playlist` against the request, since
- * a video in several playlists is legitimately viewable in any of them.
+ * A video's path. `?playlist` is the caller's to choose: a video in several
+ * playlists is viewable in any of them, so a page passes the playlist it is
+ * being viewed in rather than the canonical one.
  */
 export const videoDetailPath = (
-  videoId: number,
-  playlistId: number | undefined,
+  videoId: number | string,
+  playlistId: number | string | undefined,
   slug: string | undefined,
 ) => {
   const path = generatePath(VIDEO_DETAIL_PAGE_VIEW, {
@@ -444,39 +424,6 @@ export const videoDetailPath = (
   return base
 }
 
-export const videoDetailPageView = (
-  videoId: number,
-  playlistId: number | undefined,
-  title: string | undefined,
-) => {
-  return videoDetailPath(
-    videoId,
-    playlistId,
-    title === undefined ? undefined : pathSlug(title),
-  )
-}
-/**
- * The path and query of a resource's `learn_url`.
- *
- * `learn_url` is absolute; redirect targets and the [slug] pages' canonical
- * comparisons are same-origin paths. Parsing rather than string-slicing keeps
- * the readable-id characters that are legal unescaped in a path — an MITx
- * Online id such as `course-v1:MITxT+14.100x` survives intact.
- */
-export const learnUrlPath = (learnUrl: string): string => {
-  const { pathname, search } = new URL(learnUrl)
-  return `${pathname}${search}`
-}
-
-/**
- * The slug segment of a dedicated-page `learn_url`, i.e. its final path
- * segment. Used where a page owns part of the URL the backend does not — a
- * video's `?playlist`, which is resolved against the incoming request rather
- * than fixed to the canonical parent.
- */
-export const learnUrlSlug = (learnUrl: string): string =>
-  new URL(learnUrl).pathname.split("/").filter(Boolean).at(-1) ?? ""
-
 /**
  * Append a request's incoming search params to a canonical URL so redirects
  * preserve tracking params (e.g. utm_*). Params the canonical already sets
diff --git a/frontends/main/src/page-components/LearningResourceExpanded/CallToActionSection.test.tsx b/frontends/main/src/page-components/LearningResourceExpanded/CallToActionSection.test.tsx
index 05ffadb86c..54eea7a44f 100644
--- a/frontends/main/src/page-components/LearningResourceExpanded/CallToActionSection.test.tsx
+++ b/frontends/main/src/page-components/LearningResourceExpanded/CallToActionSection.test.tsx
@@ -1,7 +1,9 @@
 import React from "react"
 import { screen, fireEvent } from "@testing-library/react"
 import { renderWithProviders } from "@/test-utils"
+import { faker } from "@faker-js/faker/locale/en"
 import { factories } from "api/test-utils"
+import type { LearningResource } from "api"
 import { DEFAULT_RESOURCE_IMG } from "ol-utilities"
 import { getByImageSrc } from "ol-test-utilities"
 import { PlatformEnum, ResourceTypeEnum } from "api"
@@ -123,6 +125,89 @@ describe("CallToActionSection", () => {
     )
   })
 
+  describe("resources whose canonical home is on Learn", () => {
+    const render = (resource: LearningResource) =>
+      renderWithProviders(
+        <CallToActionSection
+          imgConfig={IMG_CONFIG}
+          resource={resource}
+          shareUrl="https://learn.mit.edu/test"
+        />,
+      )
+
+    it.each([
+      {
+        label: "a video playlist",
+        resource: () =>
+          factories.learningResources.videoPlaylist({
+            resource_category: "Video Playlist",
+          }),
+        cta: "Learn More",
+      },
+      {
+        label: "a video in a playlist",
+        resource: () =>
+          factories.learningResources.video({
+            resource_category: "Video",
+            playlists: [String(faker.number.int({ min: 1, max: 1e6 }))],
+          }),
+        cta: "Watch Video",
+      },
+      {
+        label: "a podcast",
+        resource: () =>
+          factories.learningResources.podcast({
+            resource_category: "Podcast",
+          }),
+        cta: "Listen to Podcast",
+      },
+      {
+        label: "an episode with a parent podcast",
+        resource: () =>
+          factories.learningResources.podcastEpisode({
+            resource_category: "Podcast Episode",
+            podcast_episode: {
+              podcasts: [faker.number.int({ min: 1, max: 1e6 })],
+            },
+          }),
+        cta: "Listen to Podcast",
+      },
+    ])("sends $label to its learn_url", ({ resource: make, cta }) => {
+      const resource = make() as LearningResource
+      render(resource)
+      expect(screen.getByRole("link", { name: cta })).toHaveAttribute(
+        "href",
+        resource.learn_url,
+      )
+    })
+
+    it("sends an episode with no parent podcast to the source instead", () => {
+      // Its learn_url is this very drawer, so linking there would be circular.
+      const episode = factories.learningResources.podcastEpisode({
+        resource_category: "Podcast Episode",
+        url: "https://example.com/episode.mp3",
+        podcast_episode: { podcasts: [] },
+      }) as LearningResource
+      render(episode)
+      expect(
+        screen.getByRole("link", { name: "Listen to Podcast" }),
+      ).toHaveAttribute("href", expect.stringContaining("example.com/episode"))
+    })
+
+    it("sends a video outside every playlist to the source instead", () => {
+      const video = factories.learningResources.video({
+        resource_category: "Video",
+        url: "https://youtube.com/watch?v=abc",
+        playlists: [],
+      }) as LearningResource
+      render(video)
+      expect(screen.getByRole("link", { name: "Watch Video" })).toHaveAttribute(
+        "href",
+        expect.stringContaining("youtube.com/watch"),
+      )
+    })
+  })
+
   describe("UTM parameters", () => {
     it("adds UTM params to external URLs", () => {
       const resource = factories.learningResources.resource({
diff --git a/frontends/main/src/page-components/LearningResourceExpanded/CallToActionSection.tsx b/frontends/main/src/page-components/LearningResourceExpanded/CallToActionSection.tsx
index aaeac27c1d..73843aa1f3 100644
--- a/frontends/main/src/page-components/LearningResourceExpanded/CallToActionSection.tsx
+++ b/frontends/main/src/page-components/LearningResourceExpanded/CallToActionSection.tsx
@@ -43,10 +43,6 @@ import {
   FACEBOOK_SHARE_BASE_URL,
   TWITTER_SHARE_BASE_URL,
   LINKEDIN_SHARE_BASE_URL,
-  videoDetailPageView,
-  videoPlaylistPageView,
-  podcastPageView,
-  podcastEpisodePageView,
   ocwLearnPageView,
 } from "@/common/urls"
 import { parentPodcastIds, videoPlaylistIds } from "@/common/slugs"
@@ -321,27 +317,30 @@ const getResourceUrl = (
     ocwProductPages?: boolean
   },
 ) => {
-  if (resource.resource_type === ResourceTypeEnum.VideoPlaylist) {
-    return videoPlaylistPageView(resource.id.toString(), resource.title)
+  if (
+    resource.resource_type === ResourceTypeEnum.VideoPlaylist ||
+    resource.resource_type === ResourceTypeEnum.Podcast
+  ) {
+    return resource.learn_url
   }
+
+  // A video outside every playlist does have a Learn page, but a context-free
+  // one. The fallthrough below reaches the OCW product page, which frames the
+  // video in its course.
   if (resource.resource_type === ResourceTypeEnum.Video) {
     const [firstPlaylist] = videoPlaylistIds(resource)
     if (firstPlaylist !== undefined) {
-      return videoDetailPageView(resource.id, firstPlaylist, resource.title)
+      return resource.learn_url
     }
   }
 
-  if (resource.resource_type === ResourceTypeEnum.Podcast) {
-    return podcastPageView(resource.id.toString(), resource.title)
-  }
+  // An episode with no parent podcast has no page of its own, so its
+  // `learn_url` is the drawer this button sits in. The fallthrough sends those
+  // to the source rather than linking the drawer to itself.
   if (resource.resource_type === ResourceTypeEnum.PodcastEpisode) {
     const [parentPodcastId] = parentPodcastIds(resource)
     if (parentPodcastId !== undefined) {
-      return podcastEpisodePageView(
-        resource.id.toString(),
-        String(parentPodcastId),
-        resource.title,
-      )
+      return resource.learn_url
     }
   }
 
diff --git a/frontends/main/src/page-components/LearningResourceExpanded/LearningResourceExpanded.test.tsx b/frontends/main/src/page-components/LearningResourceExpanded/LearningResourceExpanded.test.tsx
index d2e892de8c..1f41c330a0 100644
--- a/frontends/main/src/page-components/LearningResourceExpanded/LearningResourceExpanded.test.tsx
+++ b/frontends/main/src/page-components/LearningResourceExpanded/LearningResourceExpanded.test.tsx
@@ -12,7 +12,6 @@ import { renderWithProviders } from "@/test-utils"
 import { useFeatureFlagEnabled } from "posthog-js/react"
 import { kebabCase } from "lodash"
 import { faker } from "@faker-js/faker/locale/en"
-import { podcastEpisodePageView } from "@/common/urls"
 import { parentPodcastIds } from "@/common/slugs"
 
 jest.mock("posthog-js/react")
@@ -177,14 +176,10 @@ describe("Learning Resource Expanded", () => {
       const [parentPodcastId] = parentPodcastIds(
         resource as Parameters<typeof parentPodcastIds>[0],
       )
+      // With a parent podcast the CTA points at the episode's own page, which
+      // the backend names; without one it falls through to the source URL.
       const expectedHref =
-        parentPodcastId !== undefined
-          ? podcastEpisodePageView(
-              String(resource.id),
-              String(parentPodcastId),
-              resource.title,
-            )
-          : resource.url
+        parentPodcastId !== undefined ? resource.learn_url : resource.url
       expect(link.href).toContain(expectedHref || "")
     },
   )
diff --git a/frontends/main/src/page-components/TiptapEditor/extensions/node/LearningResource/LearningResourcePaste.test.ts b/frontends/main/src/page-components/TiptapEditor/extensions/node/LearningResource/LearningResourcePaste.test.ts
index c9fafcc362..41f2e8497e 100644
--- a/frontends/main/src/page-components/TiptapEditor/extensions/node/LearningResource/LearningResourcePaste.test.ts
+++ b/frontends/main/src/page-components/TiptapEditor/extensions/node/LearningResource/LearningResourcePaste.test.ts
@@ -1,35 +1,34 @@
 import {
-  videoDetailPageView,
-  podcastPageView,
-  podcastEpisodePageView,
+  videoDetailPath,
+  podcastEpisodePath,
+  podcastPath,
   resourceDrawerSearch,
 } from "@/common/urls"
 import { extractResourceId } from "./LearningResourcePaste"
 
-// The paste handler must recover the resource id from the *canonical* URLs our
-// builders emit — including the cosmetic slug segment they now append. Building
-// inputs from the real constructors (rather than hand-written strings) keeps
-// this contract pinned if the URL shape ever changes.
+// The paste handler must recover the resource id from the URLs our path
+// builders emit, cosmetic slug segment included. Every input here comes from a
+// real builder, so a change to a URL shape reaches this test on its own.
 describe("extractResourceId", () => {
   test("recovers the video id from a canonical video URL", () => {
-    const url = videoDetailPageView(135366, 128974, "Intro to Machine Learning")
+    const url = videoDetailPath(135366, 128974, "intro-to-machine-learning")
     expect(extractResourceId(url)).toBe(135366)
   })
 
   test("recovers the episode id (not the podcast id) from an episode URL", () => {
-    const url = podcastEpisodePageView("137277", "136068", "Episode One")
+    const url = podcastEpisodePath("137277", "136068", "episode-one")
     expect(extractResourceId(url)).toBe(137277)
   })
 
   test("recovers the podcast id from a canonical podcast URL", () => {
-    const url = podcastPageView("136068", "Beyond Biology")
+    const url = podcastPath(136068, "beyond-biology")
     expect(extractResourceId(url)).toBe(136068)
   })
 
   test("recovers the id from a bare (no-slug) canonical URL", () => {
-    // Builders emit the bare path when title is undefined; the id sits at the
-    // end of the string, exercising the `$` arm of the `(?:[/?#]|$)` boundary.
-    const url = podcastPageView("136068", undefined)
+    // The id sits at the end of the string, exercising the `$` arm of the
+    // `(?:[/?#]|$)` boundary.
+    const url = podcastPath(136068, undefined)
     expect(extractResourceId(url)).toBe(136068)
   })
 
diff --git a/learning_resources/serializers.py b/learning_resources/serializers.py
index 5610e6ce29..685339788f 100644
--- a/learning_resources/serializers.py
+++ b/learning_resources/serializers.py
@@ -458,6 +458,19 @@ class PodcastEpisodeParentSerializer(serializers.Serializer):
     id = serializers.IntegerField(source="parent_id")
     title = serializers.CharField(source="parent.title")
     readable_id = serializers.CharField(source="parent.readable_id")
+    learn_url = serializers.SerializerMethodField(
+        help_text="Where this podcast lives within Learn"
+    )
+
+    def get_learn_url(self, instance) -> str:
+        """
+        Return the parent podcast's own page on Learn.
+
+        A podcast has no URL-forming parent of its own, hence the empty parent
+        list. `parent` is select_related by the `_podcasts` prefetch, so this
+        costs no extra query.
+        """
+        return learn_url_for_resource(instance.parent, [])
 
 
 class PodcastEpisodeSerializer(serializers.ModelSerializer):
diff --git a/learning_resources/serializers_test.py b/learning_resources/serializers_test.py
index cc9691ffea..36f71aff95 100644
--- a/learning_resources/serializers_test.py
+++ b/learning_resources/serializers_test.py
@@ -40,7 +40,7 @@
     LearningResource,
     LearningResourceRelationship,
 )
-from learning_resources.utils import path_slug
+from learning_resources.utils import learn_url_for_resource, path_slug
 from main.test_utils import assert_json_equal, drf_datetime
 from main.utils import frontend_absolute_url
 
@@ -261,6 +261,7 @@ def test_serialize_podcast_episode_playlists_to_json():
             "id": podcast.learning_resource.id,
             "title": podcast.learning_resource.title,
             "readable_id": podcast.learning_resource.readable_id,
+            "learn_url": learn_url_for_resource(podcast.learning_resource, []),
         }
     ]
 
diff --git a/learning_resources/utils.py b/learning_resources/utils.py
index b68c077649..1795f9783b 100644
--- a/learning_resources/utils.py
+++ b/learning_resources/utils.py
@@ -1007,7 +1007,7 @@ def build_program_children_content_bulk(program_resources):
 SLUG_MAX_LENGTH = 60
 
 # Path segments are mandatory, so a title that slugifies to nothing still needs
-# a segment. Matches the frontend's `pathSlug`.
+# a segment.
 BLANK_SLUG_PATH_SEGMENT = "resource"
 
 # Characters that are legal, unescaped, in a path segment: ! $ & ' ( ) * + , ; = : @ ~
@@ -1027,6 +1027,11 @@ def slugify_title(title: str) -> str:
     path segments substitute BLANK_SLUG_PATH_SEGMENT, the drawer omits its
     `resource_title` param.
 
+    The output charset is [a-z0-9-], and the frontend's `[slug]` pages depend on
+    that: they compare a path built from this slug against Next's
+    already-decoded route params, so a slug carrying a percent-encodable
+    character would redirect to a different spelling of itself and loop.
+
     NOT interchangeable with django.utils.text.slugify, which deletes
     punctuation instead of converting it to "-", applies no length limit, and
     has no "no ascii letters" rule. Those diverge on ~30% of current titles.
diff --git a/openapi/specs/v0.yaml b/openapi/specs/v0.yaml
index f180879934..dd35fdab4f 100644
--- a/openapi/specs/v0.yaml
+++ b/openapi/specs/v0.yaml
@@ -4544,8 +4544,13 @@ components:
           type: string
         readable_id:
           type: string
+        learn_url:
+          type: string
+          description: Where this podcast lives within Learn
+          readOnly: true
       required:
       - id
+      - learn_url
       - readable_id
       - title
     PodcastEpisodeResource:
diff --git a/openapi/specs/v1.yaml b/openapi/specs/v1.yaml
index 3e69979ff0..38049eb87a 100644
--- a/openapi/specs/v1.yaml
+++ b/openapi/specs/v1.yaml
@@ -15116,8 +15116,13 @@ components:
           type: string
         readable_id:
           type: string
+        learn_url:
+          type: string
+          description: Where this podcast lives within Learn
+          readOnly: true
       required:
       - id
+      - learn_url
       - readable_id
       - title
     PodcastEpisodeRequest:

From 3416120a79eb53bca0a2a98fdc3323a72352ede5 Mon Sep 17 00:00:00 2001
From: Ahtisham Shahid <ahtisham300@gmail.com>
Date: Fri, 11 Sep 2026 17:25:43 +0500
Subject: [PATCH 5/9] Sanitize and render rich-text descriptions from OVS
 (#3879)

* feat(ovs): sanitize and render rich-text descriptions from OVS

OVS is gaining a rich-text editor for video and collection descriptions
(mitodl/hq#13064, mitodl/odl-video-service#1585). Two things follow for Learn.

First, and independent of that work: the OVS ETL copied `description`
straight through, and six components render it with dangerouslySetInnerHTML.
Descriptions are plain text today so nothing is exploitable, but the moment
OVS allows formatting this is live HTML from a source we do not control.
`clean_description` runs both the video and the collection description through
the same allowlist the podcast ETL uses for show notes - links kept, because
links are the point of the feature.

Second, the display side assumed plain text in places:

- the series header interpolated `playlist.description`, so an author's
  formatting would have reached the learner as visible tags.
- VideoCard, SeriesVideoList and MoreFromPlaylist inject the description
  inside a Link, where an author's <a> is a nested anchor - invalid HTML that
  browsers resolve by splitting the row's own link. They now use the existing
  stripAnchorTags helper, keeping the words.
- descriptions had no styling for lists, links or emphasis. A shared
  richTextDescription rule set covers the full-width surfaces; the clamped
  previews flatten lists inline so a list cannot blow the box out.
- the schema.org VideoObject description carried raw markup. It is stripped
  locally rather than with common/htmlToPlainText, which is documented
  server-only (it pulls in isomorphic-dompurify) and this module is imported
  by a "use client" component.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* chore: prettier formatting

* fix(ovs): strip tags to a fixed point in the JSON-LD description

CodeQL, correctly: a single-pass replace(/<[^>]*>/g, "") is not idempotent -
removing one match can join its neighbours into a new tag, so <scr<div>ipt>
survives as <script>. This value lands inside a
<script type="application/ld+json"> block.

Not exploitable as it stood, because the injection point escapes </ - but a
helper that claims to return plain text should not lean on its caller for that,
and residual markup in schema.org data is wrong regardless.

Now loops to a fixed point, decodes entities before dropping any surviving
angle bracket so an entity cannot smuggle one back in.

* fix(ovs): render rich descriptions in valid containers

Review feedback from Copilot on #3879, all of it correct.

Every description surface was a Typography, and this theme's variantMapping
sends body1/body2 to <p> (smoot-design typography.ts) - so injecting <p>/<ul>
put block elements inside a <p>. That is invalid markup, browsers reparent it,
and it showed up as a real SSR hydration tree mismatch in the browser: React
reported <p> containing <p> and <ul>. The CSS flattening only changed
presentation, not validity.

All five now take component="div", typed with Pick<TypographyProps, "component">
following the pattern PodcastPage/EpisodeContentTabs.tsx already established for
its own sanitized descriptions: DescriptionText, MoreFromItemMeta,
PageDescription, EpisodeDescription, CardMetaValue. Verified in a browser - the
tree mismatch is gone; the only hydration warning left is Grammarly writing
data-gr-ext-installed onto <body>.

Two more findings from the same review:

- FeaturedVideo was a fourth description surface I missed entirely. It rendered
  into a literal styled.p with a two-line clamp. Now a div with the same inline
  flattening as the other previews. Anchors are kept here, unlike the card and
  episode rows: this description is a sibling of the title link rather than
  inside it, so a link is valid and clickable.

- the JSON-LD stripper only treated p/li/ul/ol/blockquote as boundaries, but the
  backend allowlist also keeps div, pre, caption, center, q and hr. So
  <div>First</div><div>Second</div> came out as "FirstSecond". All of them are
  boundaries now, with a regression case per tag.

Adds videoStructuredData.test.ts (16 cases): the per-tag boundaries above plus
the tag-reconstitution inputs behind the earlier CodeQL fix.

* fix(ovs): complete the container fix CI caught

Three typecheck errors on the previous commit, all mine.

Two files used Pick<TypographyProps, "component"> without importing the type.
Folded into the existing ol-components import rather than a second one, which
import/no-duplicates rejects.

The third was more than a missing import: VideoSeriesDetailPage renders
Styled.DescriptionText from its own VideoSeriesDetailPage.styled, not from
VideoDetailPage.styled. So the series page had a second, untyped DescriptionText
that also never received the rich-text rules - lists and links on that page were
unstyled, which the earlier commit missed entirely. It now takes the component
generic and the shared rules.

richTextDescription accordingly moves to shared.styled, which both page styled
modules and VideoPageHeader already import, instead of one page's styled module
importing another's.

Local typecheck had hidden all of this: it aborts in the api workspace on a
stale generated mitxonline client, so it never reached frontends/main. Checked
with `yarn workspace main exec tsc --noEmit` this time - no errors in these
files. lint-check and fmt-check clean.

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
---
 .../FeaturedVideo.tsx                         | 21 ++++-
 .../MoreFromPlaylist.tsx                      |  7 +-
 .../SeriesVideoList.tsx                       | 25 +++++-
 .../VideoPlaylistCollectionPage/VideoCard.tsx | 49 +++++++++---
 .../VideoDetailPage.styled.ts                 | 25 +++++-
 .../VideoDetailPage.tsx                       |  6 +-
 .../VideoPageHeader.tsx                       | 45 ++++++++---
 .../VideoPlaylistCollectionPage.test.tsx      | 21 +++++
 .../VideoSeriesDetailPage.styled.ts           | 15 +++-
 .../VideoSeriesDetailPage.tsx                 |  6 +-
 .../shared.styled.ts                          | 34 ++++++++
 .../videoStructuredData.test.ts               | 80 +++++++++++++++++++
 .../videoStructuredData.ts                    | 65 ++++++++++++++-
 learning_resources/etl/ovs.py                 | 34 +++++++-
 learning_resources/etl/ovs_test.py            | 67 ++++++++++++++++
 15 files changed, 463 insertions(+), 37 deletions(-)
 create mode 100644 frontends/main/src/app-pages/VideoPlaylistCollectionPage/videoStructuredData.test.ts

diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/FeaturedVideo.tsx b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/FeaturedVideo.tsx
index 5cea5f2bbd..a76694278f 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/FeaturedVideo.tsx
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/FeaturedVideo.tsx
@@ -130,8 +130,27 @@ const FeaturedTitle = styled.h2(({ theme }) => ({
   },
 }))
 
-const FeaturedDescription = styled.p(({ theme }) => ({
+/*
+ * A div, not a p: OVS descriptions are rich text, and <p>/<ul> inside a <p> is
+ * invalid markup that browsers reparent - which breaks both the two-line clamp
+ * and SSR hydration. The block tags are flattened inline for the same reason a
+ * real list would blow the clamp out. Anchors are kept: unlike the card and
+ * episode-row previews, this description is a sibling of the title link rather
+ * than inside it, so a link here is valid and clickable.
+ */
+const FeaturedDescription = styled.div(({ theme }) => ({
   ...theme.typography.body1,
+  "p, ul, ol, li": {
+    display: "inline",
+    margin: 0,
+    padding: 0,
+    listStyle: "none",
+  },
+  "p + p::before, li + li::before": { content: '" "' },
+  a: {
+    color: theme.custom.colors.red,
+    textDecoration: "underline",
+  },
   color: theme.custom.colors.darkGray1,
   margin: 0,
   overflow: "hidden",
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/MoreFromPlaylist.tsx b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/MoreFromPlaylist.tsx
index 6c90c54e5f..dd2c3f8a83 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/MoreFromPlaylist.tsx
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/MoreFromPlaylist.tsx
@@ -4,6 +4,7 @@ import { Skeleton } from "ol-components"
 import { formatDurationClockTime } from "ol-utilities"
 import type { VideoResource } from "api/v1"
 import { videoDetailPath } from "@/common/urls"
+import { stripAnchorTags } from "@/common/utils"
 import * as Styled from "./VideoDetailPage.styled"
 
 type MoreFromPlaylistProps = {
@@ -61,7 +62,11 @@ const MoreFromPlaylistItem: React.FC<{
         </Styled.MoreFromItemTitle>
         {video.description && (
           <Styled.MoreFromItemMeta
-            dangerouslySetInnerHTML={{ __html: video.description }}
+            component="div"
+            /* Row is a link; anchors from the description would nest. */
+            dangerouslySetInnerHTML={{
+              __html: stripAnchorTags(video.description),
+            }}
           />
         )}
       </Styled.MoreFromTextSide>
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/SeriesVideoList.tsx b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/SeriesVideoList.tsx
index 2b4cbbc9e5..1e882c8ee0 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/SeriesVideoList.tsx
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/SeriesVideoList.tsx
@@ -2,10 +2,11 @@
 
 import React from "react"
 import Link from "next/link"
-import { Typography, styled } from "ol-components"
+import { Typography, styled, type TypographyProps } from "ol-components"
 import { RiPlayFill, RiArrowRightSLine } from "@remixicon/react"
 import type { LearningResource } from "api/v1"
 import { formatDate, formatDurationClockTime } from "ol-utilities"
+import { stripAnchorTags } from "@/common/utils"
 
 const EpisodeNumber = styled.span<{ $isFirst?: boolean }>(
   ({ theme, $isFirst }) => ({
@@ -28,7 +29,22 @@ const EpisodeNumber = styled.span<{ $isFirst?: boolean }>(
   }),
 )
 
-const EpisodeDescription = styled(Typography)(({ theme }) => ({
+/*
+ * The Pick<TypographyProps, "component"> generic is what allows
+ * component="div" at the call site. A sanitized OVS description contains block elements (<p>, <ul>), which are invalid inside Typography's default element for these variants (<p>).
+ */
+const EpisodeDescription = styled(Typography)<
+  Pick<TypographyProps, "component">
+>(({ theme }) => ({
+  /* Clamped preview: description markup is flattened so a list cannot blow the
+     box out. Anchors are stripped in the component (the row is itself a link). */
+  "p, ul, ol, li": {
+    display: "inline",
+    margin: 0,
+    padding: 0,
+    listStyle: "none",
+  },
+  "p + p::before, li + li::before": { content: '" "' },
   color: theme.custom.colors.darkGray1,
   marginTop: "4px",
   maxWidth: "460px",
@@ -227,10 +243,13 @@ export const EpisodeItem: React.FC<EpisodeItemProps> = ({
               {episode.title}
             </EpisodeTitleLink>
 
+            {/* The whole row is a link, so anchors from the description
+                have to go - a nested <a> splits the row's own link. */}
             <EpisodeDescription
+              component="div"
               variant="body2"
               dangerouslySetInnerHTML={{
-                __html: episode.description ?? "",
+                __html: stripAnchorTags(episode.description ?? ""),
               }}
             />
           </EpisodeInfo>
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoCard.tsx b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoCard.tsx
index 96510acf63..c401c38e4c 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoCard.tsx
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoCard.tsx
@@ -1,8 +1,15 @@
 import React, { useState } from "react"
 import Image from "next/image"
 import Link from "next/link"
-import { Typography, styled, theme, Skeleton } from "ol-components"
+import {
+  Typography,
+  styled,
+  theme,
+  Skeleton,
+  type TypographyProps,
+} from "ol-components"
 import { formatDurationClockTime } from "ol-utilities"
+import { stripAnchorTags } from "@/common/utils"
 import type { VideoResource } from "api/v1"
 import {
   DurationBadge,
@@ -88,15 +95,30 @@ const CardMetaGroup = styled.div({
   gap: "3px",
 })
 
-const CardMetaValue = styled(Typography)(({ theme }) => ({
-  ...theme.typography.body2,
-  color: theme.custom.colors.silverGrayDark,
-  lineHeight: "22px",
-  overflow: "hidden",
-  display: "-webkit-box",
-  WebkitLineClamp: 2,
-  WebkitBoxOrient: "vertical",
-}))
+/*
+ * The Pick<TypographyProps, "component"> generic is what allows
+ * component="div" at the call site. A sanitized OVS description contains block elements (<p>, <ul>), which are invalid inside Typography's default element for these variants (<p>).
+ */
+const CardMetaValue = styled(Typography)<Pick<TypographyProps, "component">>(
+  ({ theme }) => ({
+    /* Clamped preview: description markup is flattened so a list cannot blow the
+     box out. Anchors are stripped in the component (the row is itself a link). */
+    "p, ul, ol, li": {
+      display: "inline",
+      margin: 0,
+      padding: 0,
+      listStyle: "none",
+    },
+    "p + p::before, li + li::before": { content: '" "' },
+    ...theme.typography.body2,
+    color: theme.custom.colors.silverGrayDark,
+    lineHeight: "22px",
+    overflow: "hidden",
+    display: "-webkit-box",
+    WebkitLineClamp: 2,
+    WebkitBoxOrient: "vertical",
+  }),
+)
 
 type VideoCardProps = {
   resource: VideoResource
@@ -135,7 +157,12 @@ const VideoCard: React.FC<VideoCardProps> = ({ resource, href }) => {
         </CardTitleRow>
         <CardMetaRow>
           <CardMetaGroup>
-            <CardMetaValue dangerouslySetInnerHTML={{ __html: description }} />
+            {/* The whole card is a link, so anchors from the description
+                have to go - a nested <a> splits the card's own link. */}
+            <CardMetaValue
+              component="div"
+              dangerouslySetInnerHTML={{ __html: stripAnchorTags(description) }}
+            />
           </CardMetaGroup>
         </CardMetaRow>
       </CardContent>
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoDetailPage.styled.ts b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoDetailPage.styled.ts
index 0668ddca07..dd57a7ce59 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoDetailPage.styled.ts
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoDetailPage.styled.ts
@@ -1,5 +1,6 @@
 import Link from "next/link"
-import { Typography, styled, theme } from "ol-components"
+import { Typography, styled, theme, type TypographyProps } from "ol-components"
+import { richTextDescription } from "./shared.styled"
 import VideoResourcePlayer from "@/page-components/VideoPlayer/VideoResourcePlayer"
 
 // Primitives shared with the other video pages, re-exported so consumers of this
@@ -104,8 +105,11 @@ export const BorderLine = styled.div(({ theme }) => ({
   },
 }))
 
-export const DescriptionText = styled(Typography)(({ theme }) => ({
+export const DescriptionText = styled(Typography)<
+  Pick<TypographyProps, "component">
+>(({ theme }) => ({
   ...theme.typography.body1,
+  ...richTextDescription,
   color: theme.custom.colors.darkGray2,
   marginBottom: "22px",
   fontSize: "18px",
@@ -187,7 +191,22 @@ export const MoreFromItemTitle = styled(Typography)({
   lineHeight: "26px" /* 130% */,
 })
 
-export const MoreFromItemMeta = styled(Typography)({
+/*
+ * The Pick<TypographyProps, "component"> generic is what allows
+ * component="div" at the call site. A sanitized OVS description contains block elements (<p>, <ul>), which are invalid inside Typography's default element for these variants (<p>).
+ */
+export const MoreFromItemMeta = styled(Typography)<
+  Pick<TypographyProps, "component">
+>({
+  /* Clamped to a couple of lines, so a real list would blow the box out.
+     Anchors are already stripped by the component; flatten the rest. */
+  "p, ul, ol, li": {
+    display: "inline",
+    margin: 0,
+    padding: 0,
+    listStyle: "none",
+  },
+  "p + p::before, li + li::before": { content: '" "' },
   ...theme.typography.body2,
   color: theme.custom.colors.silverGrayDark,
   overflow: "hidden",
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoDetailPage.tsx b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoDetailPage.tsx
index 2547e2edf0..ff1d2fc7e8 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoDetailPage.tsx
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoDetailPage.tsx
@@ -16,6 +16,7 @@ import { formatDurationClockTime } from "ol-utilities"
 import { absoluteUrl, videoDetailPath, videoPlaylistPath } from "@/common/urls"
 import { buildVideoStructuredData } from "./videoStructuredData"
 import type { VideoPlayerHandle } from "@/page-components/VideoPlayer/VideoResourcePlayer"
+import { addExternalLinkTargets } from "@/common/utils"
 import * as Styled from "./VideoDetailPage.styled"
 
 /** How many sibling videos the "More from" list shows at most. */
@@ -216,8 +217,11 @@ const VideoDetailPage: React.FC<VideoDetailPageProps> = ({
 
           {!isLoading && video?.description && (
             <Styled.DescriptionText
+              component="div"
               id="video-description"
-              dangerouslySetInnerHTML={{ __html: video.description }}
+              dangerouslySetInnerHTML={{
+                __html: addExternalLinkTargets(video.description),
+              }}
             />
           )}
 
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoPageHeader.tsx b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoPageHeader.tsx
index ad3c0175db..c977647fc4 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoPageHeader.tsx
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoPageHeader.tsx
@@ -1,7 +1,15 @@
 import React from "react"
-import { Breadcrumbs, Skeleton, Typography, styled } from "ol-components"
+import {
+  Breadcrumbs,
+  Skeleton,
+  Typography,
+  styled,
+  type TypographyProps,
+} from "ol-components"
 import type { VideoPlaylistResource } from "api/v1"
 import VideoContainer from "./VideoContainer"
+import { richTextDescription } from "./shared.styled"
+import { addExternalLinkTargets } from "@/common/utils"
 
 const BreadcrumbBar = styled.div(({ theme }) => ({
   padding: "18px 0 2px 0",
@@ -67,15 +75,22 @@ const PageTitle = styled.h1<{ isSeries?: boolean }>(({ theme, isSeries }) => ({
   },
 }))
 
-const PageDescription = styled(Typography)(({ theme }) => ({
-  color: theme.custom.colors.darkGray1,
-  ...theme.typography.body1,
-  lineHeight: "26px",
-  [theme.breakpoints.down("sm")]: {
-    ...theme.typography.body2,
-    lineHeight: "22px",
-  },
-}))
+/*
+ * The Pick<TypographyProps, "component"> generic is what allows
+ * component="div" at the call site. A sanitized OVS description contains block elements (<p>, <ul>), which are invalid inside Typography's default element for these variants (<p>).
+ */
+const PageDescription = styled(Typography)<Pick<TypographyProps, "component">>(
+  ({ theme }) => ({
+    ...richTextDescription,
+    color: theme.custom.colors.darkGray1,
+    ...theme.typography.body1,
+    lineHeight: "26px",
+    [theme.breakpoints.down("sm")]: {
+      ...theme.typography.body2,
+      lineHeight: "22px",
+    },
+  }),
+)
 
 const CollectionTitle = styled(Typography)(({ theme }) => ({
   ...theme.typography.body1,
@@ -132,7 +147,15 @@ const VideoPageHeader: React.FC<VideoPageHeaderProps> = ({
           {playlist === undefined ? (
             <Skeleton width={520} height={28} />
           ) : (
-            <PageDescription>{playlist.description}</PageDescription>
+            <PageDescription
+              component="div"
+              /* Rich text, sanitized during ETL. Rendered as markup rather
+                 than interpolated, or an author's formatting would appear to
+                 the learner as visible tags. */
+              dangerouslySetInnerHTML={{
+                __html: addExternalLinkTargets(playlist.description ?? ""),
+              }}
+            />
           )}
         </VideoContainer>
       </HeaderSection>
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoPlaylistCollectionPage.test.tsx b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoPlaylistCollectionPage.test.tsx
index 168bdb3bd0..c086f6ce0f 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoPlaylistCollectionPage.test.tsx
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoPlaylistCollectionPage.test.tsx
@@ -92,6 +92,27 @@ describe("VideoPage", () => {
 
       await screen.findByText(playlist.description!)
     })
+
+    test("renders a rich-text playlist description as markup, not tags", async () => {
+      // OVS descriptions are rich text now. The header used to interpolate the
+      // value, so an author's formatting reached the learner as visible tags.
+      const playlist = makePlaylist()
+      playlist.description =
+        "<p>A <strong>seminar</strong> series</p><ul><li>Start with " +
+        '<a href="https://learn.mit.edu/x">session 3</a></li></ul>'
+      setupApis({ playlistId: playlist.id, videos: [], playlist })
+
+      renderWithProviders(<VideoPage playlistId={playlist.id} />)
+
+      const emphasis = await screen.findByText("seminar")
+      expect(emphasis.tagName).toBe("STRONG")
+      expect(screen.getByRole("listitem")).toBeInTheDocument()
+      expect(screen.getByRole("link", { name: "session 3" })).toHaveAttribute(
+        "href",
+        "https://learn.mit.edu/x",
+      )
+      expect(screen.queryByText(/<strong>/)).not.toBeInTheDocument()
+    })
   })
 
   describe("featured video", () => {
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoSeriesDetailPage.styled.ts b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoSeriesDetailPage.styled.ts
index 5d12e79b6e..6f209def68 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoSeriesDetailPage.styled.ts
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoSeriesDetailPage.styled.ts
@@ -1,5 +1,6 @@
 import Link from "next/link"
-import { Typography, styled, theme } from "ol-components"
+import { Typography, styled, theme, type TypographyProps } from "ol-components"
+import { richTextDescription } from "./shared.styled"
 import { ButtonLink } from "@mitodl/smoot-design"
 import VideoContainer from "./VideoContainer"
 export { SkipLinksNav, StyledBreadcrumbs, VideoTitle } from "./shared.styled"
@@ -263,8 +264,18 @@ export const StyledDuration = styled.div(({ theme }) => ({
   color: theme.custom.colors.silverGrayDark,
 }))
 
-export const DescriptionText = styled(Typography)(({ theme }) => ({
+/*
+ * This page has its own DescriptionText - it is not the one in
+ * VideoDetailPage.styled - so it needs the same two things: the component
+ * generic, because a sanitized OVS description contains block elements that are
+ * invalid inside Typography's element for this variant (<p>), and the shared
+ * rich-text rules so lists and links are styled.
+ */
+export const DescriptionText = styled(Typography)<
+  Pick<TypographyProps, "component">
+>(({ theme }) => ({
   ...theme.typography.body2,
+  ...richTextDescription,
   color: theme.custom.colors.darkGray2,
   marginBottom: "16px",
   lineHeight: "22px",
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoSeriesDetailPage.tsx b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoSeriesDetailPage.tsx
index 8df08dff2b..6d79f5df94 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoSeriesDetailPage.tsx
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/VideoSeriesDetailPage.tsx
@@ -14,6 +14,7 @@ import * as Styled from "./VideoSeriesDetailPage.styled"
 import { buildVideoStructuredData } from "./videoStructuredData"
 import VideoResourcePlayer from "@/page-components/VideoPlayer/VideoResourcePlayer"
 import type { VideoPlayerHandle } from "@/page-components/VideoPlayer/VideoResourcePlayer"
+import { addExternalLinkTargets } from "@/common/utils"
 
 import VideoShareButton from "./VideoShareButton"
 
@@ -206,9 +207,12 @@ const VideoSeriesDetailPage: React.FC<VideoSeriesDetailPageProps> = ({
           {/* Description */}
           {!isLoading && video?.description && (
             <Styled.DescriptionText
+              component="div"
               id="video-description"
               style={nextVideo ? {} : { paddingTop: "40px" }}
-              dangerouslySetInnerHTML={{ __html: video.description }}
+              dangerouslySetInnerHTML={{
+                __html: addExternalLinkTargets(video.description),
+              }}
             />
           )}
 
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/shared.styled.ts b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/shared.styled.ts
index 675cc71bce..29218eadbc 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/shared.styled.ts
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/shared.styled.ts
@@ -3,6 +3,7 @@ import {
   Breadcrumbs,
   HEADER_HEIGHT,
   HEADER_HEIGHT_MD,
+  theme,
 } from "ol-components"
 import { RiPlayCircleFill } from "@remixicon/react"
 
@@ -110,3 +111,36 @@ export const VideoTitle = styled.h1<{ $compact?: boolean }>(
     },
   }),
 )
+
+/*
+ * Typography for rendered description markup. OVS descriptions are rich text
+ * now, so these surfaces receive <p>, <ul>/<ol>/<li>, <strong>/<em> and <a> -
+ * none of which the plain-text styles below cover on their own. The first/last
+ * child resets stop the block adding stray leading and trailing space.
+ */
+export const richTextDescription = {
+  p: { margin: "0 0 16px" },
+  "ul, ol": { margin: "0 0 16px", paddingLeft: "24px" },
+  li: { marginBottom: "6px" },
+  blockquote: {
+    margin: "0 0 16px",
+    paddingLeft: "16px",
+    borderLeft: `3px solid ${theme.custom.colors.lightGray2}`,
+    color: theme.custom.colors.darkGray1,
+  },
+  a: {
+    color: theme.custom.colors.red,
+    textDecoration: "underline",
+    textUnderlineOffset: "2px",
+    "&:hover": { color: theme.custom.colors.mitRed },
+  },
+  strong: { fontWeight: theme.typography.fontWeightBold },
+  em: { fontStyle: "italic" },
+  "> :first-of-type": { marginTop: 0 },
+  "> :last-child": { marginBottom: 0 },
+} as const
+
+/*
+ * The Pick<TypographyProps, "component"> generic is what allows
+ * component="div" at the call site. A sanitized OVS description contains block elements (<p>, <ul>), which are invalid inside Typography's default element for these variants (<p>).
+ */
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/videoStructuredData.test.ts b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/videoStructuredData.test.ts
new file mode 100644
index 0000000000..c0238378f1
--- /dev/null
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/videoStructuredData.test.ts
@@ -0,0 +1,80 @@
+import { buildVideoStructuredData } from "./videoStructuredData"
+import type { VideoResource } from "api/v1"
+
+/*
+ * schema.org values are plain text, but OVS descriptions are now rich text, so
+ * the builder has to strip markup. Two things have gone wrong here before and
+ * are pinned by the cases below:
+ *
+ *  - a single-pass tag strip is not idempotent, so removing one match can join
+ *    its neighbours into a new tag (CodeQL: incomplete multi-character
+ *    sanitization). This value lands inside a <script> block.
+ *  - only some block tags were treated as boundaries, so <div>a</div><div>b</div>
+ *    came out as "ab".
+ */
+const videoWith = (description: string): VideoResource =>
+  ({
+    id: 1,
+    title: "Session 3",
+    description,
+    last_modified: "2026-01-01T00:00:00Z",
+  }) as unknown as VideoResource
+
+const descriptionOf = (html: string): string => {
+  const data = buildVideoStructuredData(videoWith(html))
+  return (data?.description as string) ?? ""
+}
+
+describe("buildVideoStructuredData description", () => {
+  test("strips the markup an OVS description carries", () => {
+    expect(descriptionOf("<p>How <strong>markets</strong> price it.</p>")).toBe(
+      "How markets price it.",
+    )
+  })
+
+  test.each([
+    ["p", "<p>First</p><p>Second</p>"],
+    ["div", "<div>First</div><div>Second</div>"],
+    [
+      "blockquote",
+      "<blockquote>First</blockquote><blockquote>Second</blockquote>",
+    ],
+    ["pre", "<pre>First</pre><pre>Second</pre>"],
+    ["li", "<ul><li>First</li><li>Second</li></ul>"],
+    ["caption", "<caption>First</caption><caption>Second</caption>"],
+    ["center", "<center>First</center><center>Second</center>"],
+    ["q", "<q>First</q><q>Second</q>"],
+  ])(
+    "treats </%s> as a boundary rather than running words together",
+    (_tag, html) => {
+      // Every block tag main/constants.py ALLOWED_HTML_TAGS keeps has to separate.
+      expect(descriptionOf(html)).toBe("First Second")
+    },
+  )
+
+  test.each([
+    ["br", "First<br>Second"],
+    ["hr", "First<hr>Second"],
+  ])("treats <%s> as a boundary", (_tag, html) => {
+    expect(descriptionOf(html)).toBe("First Second")
+  })
+
+  test.each([
+    ["nested-tag reconstitution", "<scr<div>ipt>alert(1)</scr<div>ipt>"],
+    ["doubled brackets", "<<script>script>x<</script>/script>"],
+    ["entity-encoded tags", "&lt;script&gt;alert(1)&lt;/script&gt;"],
+  ])("leaves no angle bracket for %s", (_name, html) => {
+    const result = descriptionOf(html)
+    expect(result).not.toContain("<")
+    expect(result).not.toContain(">")
+  })
+
+  test("decodes the entities the sanitizer emits", () => {
+    expect(descriptionOf("<p>Sessions 1 &amp; 2</p>")).toBe("Sessions 1 & 2")
+  })
+
+  test("omits the description entirely when there is none", () => {
+    const data = buildVideoStructuredData(videoWith(""))
+    expect(data).not.toHaveProperty("description")
+  })
+})
diff --git a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/videoStructuredData.ts b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/videoStructuredData.ts
index a500f5ba53..65c31ddd82 100644
--- a/frontends/main/src/app-pages/VideoPlaylistCollectionPage/videoStructuredData.ts
+++ b/frontends/main/src/app-pages/VideoPlaylistCollectionPage/videoStructuredData.ts
@@ -12,6 +12,67 @@ const ISO_8601_DURATION_RE =
  *
  * See: https://developers.google.com/search/docs/appearance/structured-data/video
  */
+/*
+ * schema.org values are plain text, so the description has to be stripped of
+ * the markup OVS now sends. Deliberately not common/htmlToPlainText: that is
+ * documented server-only because it pulls in isomorphic-dompurify (jsdom), and
+ * this module is imported by a "use client" component. The input is already
+ * sanitized to a small tag set during ETL, so a strip plus the handful of
+ * entities nh3 emits is sufficient here.
+ */
+const HTML_ENTITIES: Record<string, string> = {
+  "&amp;": "&",
+  "&lt;": "<",
+  "&gt;": ">",
+  "&quot;": '"',
+  "&#39;": "'",
+  "&nbsp;": " ",
+}
+
+/*
+ * Strip tags to a fixed point rather than in one pass.
+ *
+ * A single `replace(/<[^>]*>/g, "")` is not idempotent: removing one match can
+ * join its neighbours into a new tag, so `<scr<div>ipt>` survives as `<script>`.
+ * CodeQL calls this incomplete multi-character sanitization and it is right -
+ * this value ends up inside a <script type="application/ld+json"> block. The
+ * injection point also escapes `</`, but a helper that claims to return plain
+ * text should not depend on its caller for that.
+ *
+ * Looping to a fixed point and then dropping any surviving angle bracket means
+ * the result cannot contribute to a tag in any context.
+ */
+const stripTags = (html: string): string => {
+  let previous = ""
+  let current = html
+  while (current !== previous) {
+    previous = current
+    current = current.replace(/<[^>]*>/g, "")
+  }
+  return current
+}
+
+const descriptionToPlainText = (html: string): string =>
+  stripTags(
+    html
+      /*
+       * Every block-level tag the backend allowlist keeps
+       * (main/constants.py ALLOWED_HTML_TAGS) is a boundary, or its neighbours
+       * run together: <div>First</div><div>Second</div> became "FirstSecond"
+       * when this list only covered p/li/ul/ol/blockquote.
+       */
+      .replace(/<\/(?:p|li|ul|ol|blockquote|div|pre|caption|center|q)>/gi, " ")
+      .replace(/<(?:br|hr)\s*\/?>/gi, " "),
+  )
+    // decode before dropping brackets, so an entity cannot smuggle one back in
+    .replace(
+      /&[a-z#0-9]+;/gi,
+      (entity) => HTML_ENTITIES[entity.toLowerCase()] ?? entity,
+    )
+    .replace(/[<>]/g, "")
+    .replace(/\s+/g, " ")
+    .trim()
+
 export function buildVideoStructuredData(
   video: VideoResource | undefined,
 ): Record<string, unknown> | null {
@@ -28,7 +89,9 @@ export function buildVideoStructuredData(
     "@context": "https://schema.org",
     "@type": "VideoObject",
     name: video.title,
-    ...(video.description ? { description: video.description } : {}),
+    ...(video.description
+      ? { description: descriptionToPlainText(video.description) }
+      : {}),
     thumbnailUrl: video.video?.cover_image_url || video.image?.url || undefined,
     uploadDate: video.last_modified,
     contentUrl: video.url ?? undefined,
diff --git a/learning_resources/etl/ovs.py b/learning_resources/etl/ovs.py
index 315db12a8b..8077c1b150 100644
--- a/learning_resources/etl/ovs.py
+++ b/learning_resources/etl/ovs.py
@@ -19,6 +19,11 @@
 from learning_resources.etl.loaders import update_index
 from learning_resources.etl.utils import extract_text_from_url
 from learning_resources.models import LearningResource
+from main.constants import (
+    ALLOWED_HTML_ATTRIBUTES_WITH_LINKS,
+    ALLOWED_HTML_TAGS_WITH_LINKS,
+)
+from main.utils import clean_data
 
 log = logging.getLogger(__name__)
 
@@ -216,6 +221,31 @@ def _get_source_url(video_data: dict) -> str | None:
     return None
 
 
+def clean_description(description: object) -> str:
+    """
+    Sanitize an OVS description before it is stored.
+
+    OVS descriptions are rich text authored in OVS, and every surface that shows
+    them here renders them as markup, so an unsanitized value would be live HTML
+    from a source we do not control. Links are kept - they are the point of the
+    feature - which is the same allowlist the podcast ETL uses for show notes.
+
+    Args:
+        description: the description from the OVS payload, which is untrusted
+            and not necessarily a string
+
+    Returns:
+        the sanitized description, or "" when there was nothing usable
+    """
+    if not isinstance(description, str):
+        return ""
+    return clean_data(
+        description,
+        tags=ALLOWED_HTML_TAGS_WITH_LINKS,
+        attributes=ALLOWED_HTML_ATTRIBUTES_WITH_LINKS,
+    )
+
+
 def _duration_to_iso8601(duration_seconds: float) -> str:
     """
     Convert a duration in seconds to ISO 8601 duration string.
@@ -331,7 +361,7 @@ def transform_video(video_data: dict) -> dict | None:
         "etl_source": ETLSource.ovs.name,
         "resource_type": LearningResourceType.video.name,
         "title": video_data.get("title", ""),
-        "description": video_data.get("description", ""),
+        "description": clean_description(video_data.get("description", "")),
         "url": _get_resource_url(video_data),
         "image": image_data,
         "last_modified": video_data.get("created_at"),
@@ -365,7 +395,7 @@ def transform_collection(collection_data: dict) -> dict:
         "playlist_id": collection_data["key"],
         "platform": PlatformType.ovs.name,
         "title": collection_data.get("title", ""),
-        "description": collection_data.get("description", ""),
+        "description": clean_description(collection_data.get("description", "")),
         "url": f"{base_url}/collections/{quote(str(collection_data['key']))}",
         "published": True,
     }
diff --git a/learning_resources/etl/ovs_test.py b/learning_resources/etl/ovs_test.py
index 1b86455e5d..9aac43ddda 100644
--- a/learning_resources/etl/ovs_test.py
+++ b/learning_resources/etl/ovs_test.py
@@ -21,6 +21,7 @@
     _get_cover_image_url,
     _get_resource_url,
     _get_source_url,
+    clean_description,
     extract,
     get_ovs_transcripts,
     get_ovs_videos_for_transcripts_job,
@@ -1023,3 +1024,69 @@ def test_skips_when_fetch_returns_empty(mocker, ovs_platform):
     mock_update_index.assert_not_called()
     video.refresh_from_db()
     assert video.transcript == ""
+
+
+class TestCleanDescription:
+    """
+    OVS descriptions are rich text now, and every surface here renders them as
+    markup, so they have to be sanitized on the way in.
+    """
+
+    @pytest.mark.parametrize(
+        ("raw", "expected"),
+        [
+            ("<p>plain</p>", "<p>plain</p>"),
+            ("<p><strong>bold</strong></p>", "<p><strong>bold</strong></p>"),
+            ("<ul><li>one</li></ul>", "<ul><li>one</li></ul>"),
+        ],
+    )
+    def test_allowed_markup_survives(self, raw, expected):
+        """Formatting an author applied in OVS must reach the learner"""
+        assert clean_description(raw) == expected
+
+    def test_links_survive_with_rel(self):
+        """Links are the point of the feature; nh3 hardens them"""
+        result = clean_description('<p><a href="https://learn.mit.edu">go</a></p>')
+        assert 'href="https://learn.mit.edu"' in result
+        assert 'rel="noopener noreferrer"' in result
+
+    @pytest.mark.parametrize(
+        ("raw", "forbidden"),
+        [
+            ("<p>hi</p><script>alert(1)</script>", "script"),
+            ('<img src="x" onerror="alert(1)">', "onerror"),
+            ('<p onmouseover="alert(1)">hover</p>', "onmouseover"),
+            ('<p style="color:red">styled</p>', "style="),
+            ('<a href="javascript:alert(1)">x</a>', "javascript"),
+        ],
+    )
+    def test_dangerous_markup_is_stripped(self, raw, forbidden):
+        """A forged or compromised payload must not become live markup"""
+        assert forbidden not in clean_description(raw)
+
+    @pytest.mark.parametrize("value", [None, "", 42, {"nope": True}])
+    def test_non_string_payloads(self, value):
+        """The payload is untrusted and not necessarily a string"""
+        assert clean_description(value) == ""
+
+    def test_transform_video_sanitizes(self, ovs_video_with_subtitles, settings):
+        """The sanitizing is wired into the transform, not just available"""
+        settings.OVS_API_BASE_URL = "https://ovs.example.com"
+        video = dict(ovs_video_with_subtitles)
+        video["description"] = "<p>ok</p><script>alert(1)</script>"
+        result = transform_video(video)
+        assert "script" not in result["description"]
+        assert "<p>ok</p>" in result["description"]
+
+    def test_transform_collection_sanitizes(self, settings):
+        """Series descriptions get the same treatment as video descriptions"""
+        settings.OVS_API_BASE_URL = "https://ovs.example.com"
+        result = transform_collection(
+            {
+                "key": "abc123",
+                "title": "A series",
+                "description": "<p>ok</p><script>alert(1)</script>",
+            }
+        )
+        assert "script" not in result["description"]
+        assert "<p>ok</p>" in result["description"]

From f9da62b1709e02a288dfa1ab8c702d9acdef63b6 Mon Sep 17 00:00:00 2001
From: Tobias Macey <tmacey@mit.edu>
Date: Fri, 11 Sep 2026 10:23:56 -0400
Subject: [PATCH 6/9] fix(sentry): set max_request_body_size to small and scrub
 Postgres DETAIL rows (#3915)

* fix(sentry): cap request bodies at 1KB and scrub Postgres DETAIL rows

Two ways learner data reaches Sentry, neither gated by send_default_pii.

Request bodies. The SDK sets request.data unconditionally at
sentry_sdk/integrations/_wsgi_common.py:123; max_request_body_size,
checked at :61, is the only control, and left unset it defaults to
"medium" -- 10,000-byte bodies. Nobody chose that. Measured over the
last 30 days, the write endpoints that actually raise are the sensitive
ones: SCIM user PATCH, /api/v1/enrollments/, /api/checkout/result/,
/api/checkout/redeem_discount/, /api/profile/details/, and CMS page
edits. Set to "small" explicitly, so the choice is findable at the call
site instead of in a dependency's defaults.

Postgres DETAIL lines. A constraint violation carries a DETAIL line that
echoes the whole offending row, and psycopg puts it in str(exc) -- so it
ships inside the exception value, which no SDK privacy option covers.
Measured on mitxonline MITXONLINE-6PK: a SCIM PATCH IntegrityError
reproducing a learner email address three times per event, 46,764
occurrences since 2026-05-27. before_send now truncates at the DETAIL
marker across exception values, logentry, and the legacy top-level
message, keeping the primary error that names the failure.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RVJKTGk9KHUTN2xfU59ujX

* fix(sentry): scrub DETAIL rows from the whole event, not three named fields

Copilot review, verified against sentry-sdk 2.55.0 source. The first pass
enumerated three paths -- exception values, logentry.message/.formatted,
and the legacy top-level message -- and missed every other field that can
carry the same string:

  breadcrumbs[].message   LoggingIntegration records each log record as a
                          breadcrumb (integrations/logging.py:311). This is
                          exactly MITXONLINE-6PK's shape: mechanism=logging,
                          logger=django_scim.views.
  logentry.params         record.args verbatim (:274), so
                          logger.error("...: %s", exc) carries it.
  frames[].vars           include_local_variables defaults to True
                          (consts.py:1028, utils.py:616), so a catch block
                          holding the exception in a local carries it.

Confirmed the old implementation leaked on all three shapes before
changing it; the new tests fail against it and pass against the walk.

Replaced with a recursive walk of the event instead of a longer path
list -- it covers these without enumerating them and does not go stale
when the SDK grows another such field. The walk only rewrites str leaves
and preserves everything else, with a test pinning that.

Copilot also suggested normalizing exception-valued params. Not needed:
client._prepare_event serializes the event before calling before_send
(client.py:650 vs :658), so every leaf is already a JSON primitive by
then and there are no live exception objects left to coerce.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RVJKTGk9KHUTN2xfU59ujX

* fix(sentry): scrub repr'd DETAIL lines and narrow the body-size comment

The SDK repr()s frame locals and logging params before before_send, so the
DETAIL line there carries a literal backslash-n and the old find() missed it.
Match both forms, and test through the real SDK. The body-size comment was
copied from mitxonline; it now describes what this app receives.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MYc2F3cFvSCfVzqeRMshGy

---------

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
---
 main/sentry.py      |  76 ++++++++++++++++-
 main/sentry_test.py | 198 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 273 insertions(+), 1 deletion(-)
 create mode 100644 main/sentry_test.py

diff --git a/main/sentry.py b/main/sentry.py
index 9a2d5fd754..4304b3b98e 100644
--- a/main/sentry.py
+++ b/main/sentry.py
@@ -1,6 +1,7 @@
 """Sentry setup and configuration"""
 
 import logging
+import re
 
 import sentry_sdk
 from celery.exceptions import WorkerLostError
@@ -18,6 +19,62 @@
 log = logging.getLogger()
 
 
+# Postgres appends a DETAIL line to constraint violations that echoes the whole
+# offending row -- on a users table that is the learner's name, email and
+# external UUID.  psycopg puts it in str(exc), so it ships inside the exception
+# value, where no SDK privacy setting reaches it: send_default_pii governs
+# user/cookie/header capture and max_request_body_size governs request bodies,
+# and neither touches exception text.
+#
+# The newline is matched both raw and as a literal backslash-n: the SDK repr()s
+# frame locals and non-string logging params during serialization, so there the
+# DETAIL line arrives as "...constraint\\nDETAIL: ..." inside a repr string.
+PG_DETAIL_RE = re.compile(r"(\n|\\n)DETAIL:.*", re.DOTALL)
+
+
+def scrub_pg_detail(text):
+    """Truncate a Postgres error string at its DETAIL line.
+
+    Keeps the primary message, which is what identifies the failure, and drops
+    the row echo plus any HINT/CONTEXT Postgres appends after it.
+    """
+    return PG_DETAIL_RE.sub(
+        lambda match: match.group(1) + "DETAIL:  [scrubbed]", text, count=1
+    )
+
+
+def scrub_pg_details(event):
+    """Truncate Postgres DETAIL lines everywhere in a Sentry event.
+
+    The row echo reaches Sentry through more fields than the exception value:
+    LoggingIntegration puts the log message in a breadcrumb
+    (BreadcrumbHandler._breadcrumb_from_record), logger.error("...: %s", exc)
+    puts it in logentry.params (EventHandler._emit), and captured stack-frame
+    locals carry it in frame vars because include_local_variables defaults to
+    True (serialize_frame).  Walking the whole event covers those without
+    enumerating them, and does not go stale when the SDK adds another.
+
+    Safe to walk naively because Client._prepare_event serializes the event
+    before calling before_send, so every leaf here is already a JSON
+    primitive -- no live exception objects to coerce.
+    """
+    return _scrub_node(event)
+
+
+def _scrub_node(node):
+    """Recurse through the serialized event, rewriting strings in place."""
+    if isinstance(node, str):
+        return scrub_pg_detail(node)
+    if isinstance(node, dict):
+        for key, value in node.items():
+            node[key] = _scrub_node(value)
+        return node
+    if isinstance(node, list):
+        node[:] = [_scrub_node(item) for item in node]
+        return node
+    return node
+
+
 def before_send(event, hint):
     """
     Filter or transform events before they're sent to Sentry
@@ -34,7 +91,7 @@ def before_send(event, hint):
         if isinstance(exc_value, SHUTDOWN_ERRORS):
             # so we don't want to report expected shutdown errors to sentry
             return None
-    return event
+    return scrub_pg_details(event)
 
 
 def init_sentry(  # noqa: PLR0913
@@ -74,6 +131,23 @@ def init_sentry(  # noqa: PLR0913
         environment=environment,
         release=version,
         before_send=before_send,
+        # Request bodies are NOT gated on send_default_pii: the SDK sets
+        # request.data unconditionally (RequestExtractor.extract_into_event)
+        # and this is the only control (request_body_within_bounds).  Left
+        # unset it defaults to "medium", i.e. 10,000-byte bodies.  Set
+        # explicitly so the choice is findable here rather than in a
+        # dependency's defaults.
+        #
+        # This applies to every Django view, the webhooks included.  The
+        # content_files webhook posts a few short fields (content_path, source,
+        # course ids), so its bodies still fit under the bound.
+        #
+        # It is not a hard 1KB cap: the bound is checked against the declared
+        # Content-Length, and a missing one counts as 0.  Under ASGI (granian
+        # serving main.asgi), Django takes CONTENT_LENGTH from the request
+        # header, so a chunked request without one has its parsed body
+        # captured in full.
+        max_request_body_size="small",
         traces_sample_rate=traces_sample_rate,
         profiles_sample_rate=profiles_sample_rate,
         # Sentry's auto-enabling integrations (langchain, openai, etc.) import
diff --git a/main/sentry_test.py b/main/sentry_test.py
new file mode 100644
index 0000000000..96cbe47e5c
--- /dev/null
+++ b/main/sentry_test.py
@@ -0,0 +1,198 @@
+"""Tests for Sentry event scrubbing."""
+
+import json
+import logging
+
+import pytest
+import sentry_sdk
+from sentry_sdk.integrations.logging import LoggingIntegration
+from sentry_sdk.transport import Transport
+
+from main.sentry import (
+    before_send,
+    scrub_pg_detail,
+    scrub_pg_details,
+)
+
+# A real MITXONLINE-6PK exception value, with the learner identifiers replaced.
+PG_INTEGRITY_ERROR = (
+    'null value in column "name" of relation "users_user" violates not-null '
+    "constraint\n"
+    "DETAIL:  Failing row contains (1863408, , 2026-08-07 18:38:14.503726+00, f, "
+    "learner@example.invalid, learner@example.invalid, null, f, t, "
+    "12d7dfc5-6f84-46db-9383-2d7079434173, 1863408, learner@example.invalid, f)."
+)
+PG_PRIMARY_MESSAGE = (
+    'null value in column "name" of relation "users_user" violates not-null constraint'
+)
+
+
+class FakeTransport(Transport):
+    """Collect outgoing events instead of sending them."""
+
+    def __init__(self):
+        super().__init__()
+        self.events = []
+
+    def capture_envelope(self, envelope):
+        self.events.extend(
+            item.payload.json for item in envelope.items if item.type == "event"
+        )
+
+
+@pytest.fixture
+def sentry_transport():
+    """Initialize the real SDK with before_send, and detach it afterwards."""
+    transport = FakeTransport()
+    sentry_sdk.init(
+        dsn="https://k@o0.ingest.sentry.io/0",
+        transport=transport,
+        before_send=before_send,
+        default_integrations=False,
+        integrations=[
+            LoggingIntegration(level=logging.INFO, event_level=logging.ERROR)
+        ],
+    )
+    yield transport
+    sentry_sdk.get_global_scope().set_client(None)
+
+
+def test_detail_line_is_truncated():
+    """The row echo goes; the primary error that names the failure stays."""
+    scrubbed = scrub_pg_detail(PG_INTEGRITY_ERROR)
+    assert scrubbed.startswith(PG_PRIMARY_MESSAGE)
+    assert "learner@example.invalid" not in scrubbed
+    assert "12d7dfc5-6f84-46db-9383-2d7079434173" not in scrubbed
+
+
+def test_escaped_detail_line_is_truncated():
+    """repr() turns the newline into a literal backslash-n; that form goes too."""
+    scrubbed = scrub_pg_detail(repr(Exception(PG_INTEGRITY_ERROR)))
+    assert PG_PRIMARY_MESSAGE in scrubbed
+    assert "learner@example.invalid" not in scrubbed
+
+
+def test_message_without_detail_is_unchanged():
+    """A message with no DETAIL line passes through untouched."""
+    message = "connection to server failed"
+    assert scrub_pg_detail(message) == message
+
+
+def test_hint_and_context_after_detail_are_dropped():
+    """HINT and CONTEXT follow DETAIL and can quote row data too."""
+    text = "boom\nDETAIL:  row data\nHINT:  try again\nCONTEXT:  SQL statement"
+    scrubbed = scrub_pg_detail(text)
+    assert "row data" not in scrubbed
+    assert "try again" not in scrubbed
+    assert "SQL statement" not in scrubbed
+
+
+def test_scrubs_exception_values_logentry_and_message():
+    """Every place the SDK can put an error string is covered."""
+    event = {
+        "exception": {"values": [{"value": PG_INTEGRITY_ERROR}]},
+        "logentry": {
+            "message": PG_INTEGRITY_ERROR,
+            "formatted": PG_INTEGRITY_ERROR,
+        },
+        "message": PG_INTEGRITY_ERROR,
+    }
+    scrub_pg_details(event)
+    assert "learner@example.invalid" not in repr(event)
+
+
+def test_before_send_scrubs_the_event():
+    """The scrub is wired into the before_send hook, not just callable."""
+    event = {"exception": {"values": [{"value": PG_INTEGRITY_ERROR}]}}
+    assert "learner@example.invalid" not in repr(before_send(event, {}))
+
+
+def test_scrubs_breadcrumb_messages():
+    """LoggingIntegration records the log message as a breadcrumb."""
+    event = {
+        "breadcrumbs": {
+            "values": [
+                {
+                    "type": "log",
+                    "category": "django_scim.views",
+                    "message": PG_INTEGRITY_ERROR,
+                }
+            ]
+        }
+    }
+    scrub_pg_details(event)
+    assert "learner@example.invalid" not in repr(event)
+
+
+def test_scrubs_logentry_params():
+    """logger.error("...: %s", exc) puts the repr'd exception in logentry.params."""
+    event = {
+        "logentry": {
+            "message": "Unable to complete SCIM call: %s",
+            "formatted": "Unable to complete SCIM call: " + PG_INTEGRITY_ERROR,
+            "params": [repr(Exception(PG_INTEGRITY_ERROR))],
+        }
+    }
+    scrub_pg_details(event)
+    assert "learner@example.invalid" not in repr(event)
+
+
+def test_scrubs_captured_frame_locals():
+    """include_local_variables defaults to True, so repr'd frame vars carry it."""
+    event = {
+        "exception": {
+            "values": [
+                {
+                    "value": "boom",
+                    "stacktrace": {
+                        "frames": [
+                            {
+                                "function": "save",
+                                "vars": {
+                                    "exc": repr(Exception(PG_INTEGRITY_ERROR)),
+                                    "retries": 3,
+                                },
+                            }
+                        ]
+                    },
+                }
+            ]
+        }
+    }
+    scrub_pg_details(event)
+    assert "learner@example.invalid" not in repr(event)
+    frame = event["exception"]["values"][0]["stacktrace"]["frames"][0]
+    assert frame["vars"]["retries"] == 3
+
+
+def test_walk_preserves_non_string_leaves():
+    """The walk must not coerce timestamps, ints or None into strings."""
+    event = {
+        "timestamp": 1757345533.179,
+        "level": "error",
+        "extra": {"count": 42, "missing": None, "flag": True},
+        "message": PG_INTEGRITY_ERROR,
+    }
+    scrub_pg_details(event)
+    assert event["timestamp"] == 1757345533.179
+    assert event["extra"] == {"count": 42, "missing": None, "flag": True}
+    assert "learner@example.invalid" not in event["message"]
+
+
+def test_real_sdk_scrubs_params_and_local_variables(sentry_transport):
+    """Go through the real SDK, which repr()s params and locals before before_send."""
+
+    def save():
+        exc = Exception(PG_INTEGRITY_ERROR)
+        raise exc
+
+    try:
+        save()
+    except Exception as e:  # noqa: BLE001
+        logging.getLogger("x").error("Unable to save: %s", e)  # noqa: TRY400
+        sentry_sdk.capture_exception(e)
+    sentry_sdk.flush()
+
+    assert len(sentry_transport.events) == 2
+    for event in sentry_transport.events:
+        assert "learner@example.invalid" not in json.dumps(event)

From b09a428b31429c57bd139fe9c73ad9500cf0c6a1 Mon Sep 17 00:00:00 2001
From: Ahtisham Shahid <ahtisham300@gmail.com>
Date: Sat, 12 Sep 2026 01:06:24 +0500
Subject: [PATCH 7/9] chore: refresh drf-lint baseline for ORM003-ORM006
 (#3928)

mitol-drf-lint 2026.8.28 added cross-file analysis and rules
ORM003-ORM009; the hook pins no version, so pre-commit.ci picked the new
release up when its cached env rebuilt. The checked-in baseline only
covered ORM002, leaving 41 pre-existing N+1 risks unsuppressed and every
build in the repo red.

Regenerate the baseline over all tracked serializers.py so existing debt
is grandfathered and recorded, while new violations still fail the hook.
Existing ORM002 entries are preserved; nothing is dropped.

Also ignore .drf_lint_cache.json, the cross-file index cache the new
version writes at the repo root.
---
 .gitignore             |  3 +++
 drf_lint_baseline.json | 43 +++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/.gitignore b/.gitignore
index e78ecff6ad..1e8fc16c8b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -152,3 +152,6 @@ load_testing/data/
 
 # Hacksnack game assets (copied by postinstall)
 frontends/main/public/games/hacksnack
+
+# drf-lint cross-file index cache
+.drf_lint_cache.json
diff --git a/drf_lint_baseline.json b/drf_lint_baseline.json
index 2222d8bddd..2a50349ca7 100644
--- a/drf_lint_baseline.json
+++ b/drf_lint_baseline.json
@@ -2,5 +2,46 @@
   "channels/serializers.py:132:24:ORM002",
   "channels/serializers.py:134:24:ORM002",
   "channels/serializers.py:136:24:ORM002",
-  "profiles/serializers.py:205:16:ORM002"
+  "channels/serializers.py:97:32:ORM003",
+  "learning_resources/serializers.py:103:4:ORM005",
+  "learning_resources/serializers.py:1281:44:ORM005",
+  "learning_resources/serializers.py:1315:61:ORM003",
+  "learning_resources/serializers.py:1320:59:ORM003",
+  "learning_resources/serializers.py:1328:12:ORM004",
+  "learning_resources/serializers.py:1344:21:ORM004",
+  "learning_resources/serializers.py:1357:11:ORM006",
+  "learning_resources/serializers.py:1358:60:ORM006",
+  "learning_resources/serializers.py:1362:24:ORM004",
+  "learning_resources/serializers.py:1525:11:ORM006",
+  "learning_resources/serializers.py:1526:19:ORM006",
+  "learning_resources/serializers.py:1527:11:ORM006",
+  "learning_resources/serializers.py:1528:19:ORM006",
+  "learning_resources/serializers.py:1529:15:ORM006",
+  "learning_resources/serializers.py:153:4:ORM005",
+  "learning_resources/serializers.py:163:4:ORM005",
+  "learning_resources/serializers.py:1822:4:ORM005",
+  "learning_resources/serializers.py:1830:20:ORM004",
+  "learning_resources/serializers.py:213:4:ORM005",
+  "learning_resources/serializers.py:428:4:ORM005",
+  "learning_resources/serializers.py:429:4:ORM005",
+  "learning_resources/serializers.py:487:49:ORM006",
+  "learning_resources/serializers.py:502:12:ORM006",
+  "learning_resources/serializers.py:541:4:ORM005",
+  "learning_resources/serializers.py:590:4:ORM005",
+  "learning_resources/serializers.py:605:17:ORM006",
+  "learning_resources/serializers.py:610:17:ORM006",
+  "learning_resources/serializers.py:620:17:ORM006",
+  "learning_resources/serializers.py:877:18:ORM004",
+  "learning_resources/serializers.py:926:16:ORM004",
+  "learning_resources/serializers.py:943:20:ORM004",
+  "learning_resources/serializers.py:965:20:ORM004",
+  "learning_resources_search/serializers.py:661:4:ORM005",
+  "learning_resources_search/serializers.py:663:4:ORM005",
+  "profiles/serializers.py:108:39:ORM006",
+  "profiles/serializers.py:108:60:ORM006",
+  "profiles/serializers.py:113:19:ORM006",
+  "profiles/serializers.py:205:16:ORM002",
+  "profiles/serializers.py:353:45:ORM004",
+  "profiles/serializers.py:359:45:ORM004",
+  "profiles/serializers.py:502:8:ORM006"
 ]

From fd9a67b1fada36d96e3e99e571e3a5c8dab5eab9 Mon Sep 17 00:00:00 2001
From: Carey P Gumaer <gumaerc@mit.edu>
Date: Fri, 11 Sep 2026 16:40:58 -0400
Subject: [PATCH 8/9] Only offer a run's courseware once it has started (#3925)

* pass start date into enrollment handlers and make sure a course has actually started before automatically redirecting to it

* titles should also not be clickable by non-admins if the course hasn't started yet

* allow Toaster to also display success messages and show one when you successfully enroll in a course but are not redirected

* revert the enroll success toast

Adding a success Snackbar belongs in smoot-design with a design that every
surface can reuse, not bolted onto an unrelated bug fix. Reverted here and
tracked separately.

The start-date gate is unchanged: enrolling in a run that has not started
still enrolls without redirecting, and the card re-renders as enrolled
showing when the run starts.

Toaster, toastStore and the test harness are back to their state on main.
The comment rework and the SiblingRunsAccordion wording that rode along in
the same commit are kept, which is why this is a manual revert rather than
a git revert.
---
 .../EnrolledCourseCard.test.tsx               |  49 +++
 .../CoursewareDisplay/EnrolledCourseCard.tsx  |  15 +-
 .../SiblingRunsAccordion.test.tsx             |  54 +++
 .../SiblingRunsAccordion.tsx                  |  14 +-
 .../UnenrolledCourseCard.test.tsx             | 320 +++++++++++++++++-
 .../UnenrolledCourseCard.tsx                  |   2 +
 .../CoursewareDisplay/courseDateUtils.ts      |  11 +
 .../hooks/useEnrollmentHandler.ts             |  26 +-
 8 files changed, 470 insertions(+), 21 deletions(-)

diff --git a/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/EnrolledCourseCard.test.tsx b/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/EnrolledCourseCard.test.tsx
index 1fde5e8ae5..e654b974fc 100644
--- a/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/EnrolledCourseCard.test.tsx
+++ b/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/EnrolledCourseCard.test.tsx
@@ -98,6 +98,55 @@ describe.each([
     },
   )
 
+  test.each([
+    { runDates: currentRunDates, expectLink: true, case: "started" },
+    { runDates: futureRunDates, expectLink: false, case: "not started" },
+  ])(
+    "Title links to courseware only once the run has started ($case)",
+    async ({ runDates, expectLink }) => {
+      setupUserApis()
+      const coursewareUrl = faker.internet.url()
+      const enrollment = mitxonline.factories.enrollment.courseEnrollment({
+        grades: [],
+        certificate: null,
+        run: { ...runDates, courseware_url: coursewareUrl },
+      })
+      renderWithProviders(<EnrolledCourseCard enrollment={enrollment} />)
+      const card = getCard()
+      const title = enrollment.run.course.title
+
+      if (expectLink) {
+        expect(within(card).getByRole("link", { name: title })).toHaveAttribute(
+          "href",
+          coursewareUrl,
+        )
+      } else {
+        // The heading still names the course, it just isn't a way in.
+        await waitFor(() => {
+          expect(
+            within(card).queryByRole("link", { name: title }),
+          ).not.toBeInTheDocument()
+        })
+        expect(within(card).getByText(title)).toBeInTheDocument()
+      }
+    },
+  )
+
+  test("Title links to courseware for staff before the run starts", async () => {
+    setupUserApis({ is_staff: true })
+    const coursewareUrl = faker.internet.url()
+    const enrollment = mitxonline.factories.enrollment.courseEnrollment({
+      grades: [],
+      certificate: null,
+      run: { ...futureRunDates, courseware_url: coursewareUrl },
+    })
+    renderWithProviders(<EnrolledCourseCard enrollment={enrollment} />)
+    const link = await within(getCard()).findByRole("link", {
+      name: enrollment.run.course.title,
+    })
+    expect(link).toHaveAttribute("href", coursewareUrl)
+  })
+
   test("Courseware button is a navigable link for staff even when course has not started", async () => {
     setupUserApis({ is_staff: true })
     const coursewareUrl = faker.internet.url()
diff --git a/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/EnrolledCourseCard.tsx b/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/EnrolledCourseCard.tsx
index 0654379ef3..e6c4746bf8 100644
--- a/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/EnrolledCourseCard.tsx
+++ b/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/EnrolledCourseCard.tsx
@@ -24,7 +24,7 @@ import {
   getDashboardEnrollmentStatus,
   pickCertificateEnrollment,
 } from "./model/dashboardViewModel"
-import { getCourseDateText } from "./courseDateUtils"
+import { canOpenCourseware, getCourseDateText } from "./courseDateUtils"
 import { isVerifiedEnrollmentMode } from "@/common/mitxonline"
 import { RiArrowUpCircleLine, RiAwardLine, RiMore2Line } from "@remixicon/react"
 import { useReplaceBasketItem } from "@/common/mitxonline/useReplaceBasketItem"
@@ -287,7 +287,7 @@ export const EnrolledCourseCard = ({
   const enrollmentMode = enrollment?.enrollment_mode
   const offerUpgrade = !enrollment?.b2b_contract_id
   const startDate = run?.start_date
-  const hasStarted = startDate ? isInPast(startDate) : true
+  const coursewareOpen = canOpenCourseware(startDate, { isStaff })
   const endDate = run?.end_date
   const hasEnded = endDate ? isInPast(endDate) : false
   const hasCourseDateText = getCourseDateText(startDate, endDate) !== null
@@ -335,7 +335,7 @@ export const EnrolledCourseCard = ({
       productId={run?.upgrade_product_id}
       isVerifiedProgramEnrollment={isVerifiedProgramEnrollment}
       readableId={run?.courseware_id}
-      coursewareUrl={coursewareUrl ?? undefined}
+      coursewareUrl={coursewareOpen ? (coursewareUrl ?? undefined) : undefined}
       programReadableIds={ancestorContext?.parentProgramReadableIds}
       programCoursewareId={
         ancestorContext?.programEnrollment?.program.readable_id
@@ -364,7 +364,7 @@ export const EnrolledCourseCard = ({
     ) : null
   const titleSection = (
     <Stack gap="6px">
-      {coursewareUrl ? (
+      {coursewareUrl && coursewareOpen ? (
         <TitleHeading as={headingLevel}>
           <EnrolledTitleLink
             size="medium"
@@ -381,13 +381,8 @@ export const EnrolledCourseCard = ({
       {endDateAndUpgradeSection}
     </Stack>
   )
-  // Determine if button should be disabled
-  // Staff can access courseware even before the course has started
   const courseHasEnded = run?.end_date ? isInPast(run.end_date) : false
-  const isDisabled = Boolean(
-    !coursewareUrl || // Enrolled but no action available
-      (!!startDate && !hasStarted && !isStaff), // Enrolled but course hasn't started yet
-  )
+  const isDisabled = Boolean(!coursewareUrl || !coursewareOpen)
   const isCompleted =
     enrollmentStatus === EnrollmentStatus.Completed || courseHasEnded
   const buttonText = isCompleted ? "View" : "Continue"
diff --git a/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/SiblingRunsAccordion.test.tsx b/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/SiblingRunsAccordion.test.tsx
index 55f9a3e099..c891670844 100644
--- a/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/SiblingRunsAccordion.test.tsx
+++ b/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/SiblingRunsAccordion.test.tsx
@@ -4,6 +4,7 @@ import {
   screen,
   setMockResponse,
   user,
+  waitFor,
   within,
 } from "@/test-utils"
 import * as mitxonline from "api/mitxonline-test-utils"
@@ -29,6 +30,12 @@ beforeEach(() => {
   // Each row resolves its own Receipt item from the order history; default to
   // none, tests override.
   setupOrderHistory()
+  // Rows read is_staff to decide whether pre-start courseware is reachable.
+  // The factory randomises it, so pin it off; the staff test overrides.
+  setMockResponse.get(
+    mitxonline.urls.userMe.get(),
+    mitxonline.factories.user.user({ is_staff: false }),
+  )
   setPerRunMenus(true)
 })
 
@@ -358,6 +365,53 @@ describe("SiblingRunsToggle + SiblingRunsPanel", () => {
     ).not.toBeInTheDocument()
   })
 
+  // A run that hasn't started cannot be completed, so drop the factory's
+  // default certificate; completion outranks the dates for the row label.
+  const makeUpcomingEnrollment = () =>
+    mitxonline.factories.enrollment.courseEnrollment({
+      certificate: null,
+      grades: [],
+      run: {
+        start_date: moment().add(30, "days").toISOString(),
+        end_date: moment().add(90, "days").toISOString(),
+        courseware_url: faker.internet.url(),
+      },
+    })
+
+  test.each([
+    { isStaff: false, expectLink: false },
+    { isStaff: true, expectLink: true },
+  ])(
+    "upcoming sibling run offers 'View content' only to staff (isStaff=$isStaff)",
+    async ({ isStaff, expectLink }) => {
+      setMockResponse.get(
+        mitxonline.urls.userMe.get(),
+        mitxonline.factories.user.user({ is_staff: isStaff }),
+      )
+      renderWithProviders(
+        <SiblingRunsAccordionHarness
+          enrollment={makeEnrollment()}
+          siblingEnrollments={[makeUpcomingEnrollment()]}
+        />,
+      )
+      await expandAccordion()
+      expect(await screen.findByText(/^Upcoming:/)).toBeInTheDocument()
+
+      const link = screen.queryByRole("link", {
+        name: /View content for Upcoming/,
+      })
+      if (expectLink) {
+        await waitFor(() => {
+          expect(
+            screen.getByRole("link", { name: /View content for Upcoming/ }),
+          ).toBeInTheDocument()
+        })
+      } else {
+        expect(link).not.toBeInTheDocument()
+      }
+    },
+  )
+
   test("upcoming sibling run label starts with 'Upcoming:'", async () => {
     // A run that hasn't started cannot be completed, so drop the factory's
     // default certificate; completion outranks the dates.
diff --git a/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/SiblingRunsAccordion.tsx b/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/SiblingRunsAccordion.tsx
index 626736652d..ad0baae01e 100644
--- a/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/SiblingRunsAccordion.tsx
+++ b/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/SiblingRunsAccordion.tsx
@@ -12,7 +12,11 @@ import {
   RiSubtractLine,
   RiTimeLine,
 } from "@remixicon/react"
-import { formatRunIdentifier, getRunTimeState } from "./courseDateUtils"
+import {
+  canOpenCourseware,
+  formatRunIdentifier,
+  getRunTimeState,
+} from "./courseDateUtils"
 import type { RunTimeState } from "./courseDateUtils"
 import { ActionButton, VisuallyHidden } from "@mitodl/smoot-design"
 import { EnrollmentStatusIcon } from "./EnrollmentStatus"
@@ -22,6 +26,8 @@ import { useOrderIdForRun } from "@/common/mitxonline/useOrderIdForResource"
 import { getRunMenuItems } from "./runMenuItems"
 import { useFeatureFlagEnabled } from "posthog-js/react"
 import { FeatureFlags } from "@/common/feature_flags"
+import { useQuery } from "@tanstack/react-query"
+import { mitxUserQueries } from "api/mitxonline-hooks/user"
 
 const UpcomingRunIcon = styled(RiTimeLine)(({ theme }) => ({
   width: "16px",
@@ -194,7 +200,11 @@ const RunListRow: React.FC<RunListRowProps> = ({
   enrollment,
   isFirst,
 }) => {
+  const mitxOnlineUser = useQuery(mitxUserQueries.me())
   const coursewareUrl = enrollment.run?.courseware_url
+  const coursewareOpen = canOpenCourseware(enrollment.run?.start_date, {
+    isStaff: mitxOnlineUser.data?.is_staff,
+  })
   /**
    * Resolved per row so each run's Receipt item reflects that run's own order.
    * Every row shares the one `orders/history` query, so N rows still cost a
@@ -241,7 +251,7 @@ const RunListRow: React.FC<RunListRowProps> = ({
         </Stack>
       </Stack>
       <Stack direction="row" gap="4px" alignItems="center" flexShrink={0}>
-        {coursewareUrl && (
+        {coursewareUrl && coursewareOpen && (
           <>
             <ViewContentLink
               href={coursewareUrl}
diff --git a/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/UnenrolledCourseCard.test.tsx b/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/UnenrolledCourseCard.test.tsx
index 209815ae59..1cd3db06d9 100644
--- a/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/UnenrolledCourseCard.test.tsx
+++ b/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/UnenrolledCourseCard.test.tsx
@@ -24,7 +24,10 @@ jest.mock("@/common/analytics/gtm", () => ({
 
 const mitxOnlineCourse = mitxonline.factories.courses.course
 
-const mitxUser = mitxonline.factories.user.user
+// The factory randomises is_staff, and staff bypass the start-date gate, which
+// would make these tests flaky. Staff tests pass it explicitly.
+const mitxUser: typeof mitxonline.factories.user.user = (overrides = {}) =>
+  mitxonline.factories.user.user({ is_staff: false, ...overrides })
 
 const setupUserApis = (overrides?: Parameters<typeof mitxUser>[0]) => {
   const userData = mitxonline.factories.user.user({
@@ -301,6 +304,8 @@ describe.each([
     user: ReturnType<typeof mitxUser>
     course: ReturnType<typeof mitxOnlineCourse>
     run?: ReturnType<typeof mitxonline.factories.courses.courseRun>
+    /** Defer the POST to control when the mutation settles. */
+    enrollResponse?: unknown
   }) => {
     setMockResponse.get(mitxonline.urls.userMe.get(), opts.user)
     setMockResponse.get(mitxonline.urls.enrollment.enrollmentsListV3(), [])
@@ -308,10 +313,13 @@ describe.each([
     const runId =
       opts.run?.courseware_id ?? opts.course.readable_id ?? undefined
     const enrollmentUrl = mitxonline.urls.b2b.courseEnrollment(runId)
-    setMockResponse.post(enrollmentUrl, {
-      result: "b2b-enroll-success",
-      order: 1,
-    })
+    setMockResponse.post(
+      enrollmentUrl,
+      opts.enrollResponse ?? {
+        result: "b2b-enroll-success",
+        order: 1,
+      },
+    )
 
     const countries = [
       { code: "US", name: "United States" },
@@ -332,6 +340,62 @@ describe.each([
     { trigger: "title-link" as const },
   ]
 
+  /**
+   * A response the test resolves by hand, giving `enrollAndSettle` a settle
+   * point to wait on. The B2B and verified redirects fire in `onSuccess` and
+   * leave no other trace, so asserting once the POST is merely issued can run
+   * before the redirect would have, and pass either way.
+   */
+  const deferredResponse = <T,>() => {
+    let resolve!: (value: T) => void
+    const promise = new Promise<T>((res) => {
+      resolve = res
+    })
+    return { promise, resolve }
+  }
+
+  /**
+   * Checks both kinds of leaving: the hard `window.location` redirect this
+   * guards, and a router navigation, so neither can creep back in.
+   */
+  const expectStayedPut = (
+    location: ReturnType<typeof renderWithProviders>["location"],
+    pathnameBefore: string,
+    hrefBefore: string,
+  ) => {
+    expect(window.location.href).toBe(hrefBefore)
+    expect(location.current.pathname).toBe(pathnameBefore)
+    expect(location.current.search).toBe("")
+  }
+
+  const enrollAndSettle = async (
+    card: HTMLElement,
+    release: () => void,
+  ): Promise<void> => {
+    const button = within(card).getByTestId("courseware-button")
+    await user.click(button)
+    await waitFor(() => {
+      expect(button).toHaveAttribute("aria-busy", "true")
+    })
+    release()
+    await waitFor(() => {
+      expect(button).toHaveAttribute("aria-busy", "false")
+    })
+  }
+
+  const START_DATE_CASES = [
+    {
+      case: "redirects to courseware when the run has started",
+      startDate: moment().subtract(7, "days").toISOString(),
+      expectRedirect: true,
+    },
+    {
+      case: "does not redirect when the run has not started",
+      startDate: moment().add(30, "days").toISOString(),
+      expectRedirect: false,
+    },
+  ]
+
   test.each(ENROLLMENT_TRIGGERS)(
     "B2B enrollment for complete profile bypasses just-in-time dialog ($trigger)",
     async ({ trigger }) => {
@@ -414,6 +478,93 @@ describe.each([
     },
   )
 
+  test("B2B enrollment redirects staff to courseware even before the run starts", async () => {
+    const userData = mitxUser({
+      is_staff: true,
+      legal_address: { country: "US" },
+      user_profile: { year_of_birth: 1988 },
+    })
+    const b2bContractId = faker.number.int()
+    const coursewareUrl = faker.internet.url()
+    const run = mitxonline.factories.courses.courseRun({
+      b2b_contract: b2bContractId,
+      is_enrollable: true,
+      start_date: moment().add(30, "days").toISOString(),
+      courseware_url: coursewareUrl,
+    })
+    const course = mitxOnlineCourse({ courseruns: [run], next_run_id: run.id })
+    const { enrollmentUrl } = setupEnrollmentApis({
+      user: userData,
+      course,
+      run,
+    })
+
+    renderWithProviders(
+      <UnenrolledCourseCard course={course} contractId={b2bContractId} />,
+    )
+
+    await user.click(within(getCard()).getByTestId("courseware-button"))
+
+    await waitFor(() => {
+      expect(makeRequest).toHaveBeenCalledWith(
+        expect.objectContaining({ method: "post", url: enrollmentUrl }),
+      )
+    })
+    // Staff keep pre-start courseware access, so the redirect still fires.
+    await waitFor(() => {
+      expect(window.location.href).toBe(coursewareUrl)
+    })
+  })
+
+  test.each(START_DATE_CASES)(
+    "B2B enrollment $case",
+    async ({ startDate, expectRedirect }) => {
+      const userData = mitxUser({
+        legal_address: { country: "US" },
+        user_profile: { year_of_birth: 1988 },
+      })
+      const b2bContractId = faker.number.int()
+      const coursewareUrl = faker.internet.url()
+      const run = mitxonline.factories.courses.courseRun({
+        b2b_contract: b2bContractId,
+        is_enrollable: true,
+        start_date: startDate,
+        end_date: moment(startDate).add(60, "days").toISOString(),
+        courseware_url: coursewareUrl,
+      })
+      const course = mitxOnlineCourse({
+        courseruns: [run],
+        next_run_id: run.id,
+      })
+      const enroll = deferredResponse<unknown>()
+      const { enrollmentUrl } = setupEnrollmentApis({
+        user: userData,
+        course,
+        run,
+        enrollResponse: enroll.promise,
+      })
+
+      const { location } = renderWithProviders(
+        <UnenrolledCourseCard course={course} contractId={b2bContractId} />,
+      )
+      const pathnameBefore = location.current.pathname
+      const hrefBefore = window.location.href
+
+      await enrollAndSettle(getCard(), () =>
+        enroll.resolve({ result: "b2b-enroll-success", order: 1 }),
+      )
+
+      expect(makeRequest).toHaveBeenCalledWith(
+        expect.objectContaining({ method: "post", url: enrollmentUrl }),
+      )
+      if (expectRedirect) {
+        expect(window.location.href).toBe(coursewareUrl)
+      } else {
+        expectStayedPut(location, pathnameBefore, hrefBefore)
+      }
+    },
+  )
+
   test("B2B enrollment targets the displayed (variant) run, not getBestRun's default pick", async () => {
     const userData = mitxUser({
       legal_address: { country: "US" },
@@ -482,6 +633,65 @@ describe.each([
   // ---------------------------------------------------------------------------
 
   describe("B2C (non-B2B) Enrollment", () => {
+    // The dialog is its own redirect path: the start date comes from the run
+    // picked there, not the one the card displayed.
+    test.each(START_DATE_CASES)(
+      "CourseEnrollmentDialog submission $case",
+      async ({ startDate, expectRedirect }) => {
+        setMockResponse.get(mitxonline.urls.userMe.get(), mitxUser())
+
+        const coursewareUrl = faker.internet.url()
+        // Both modes opens the dialog; a single run makes it preselect.
+        const run = mitxonline.factories.courses.courseRun({
+          b2b_contract: null,
+          is_enrollable: true,
+          start_date: startDate,
+          end_date: moment(startDate).add(60, "days").toISOString(),
+          courseware_url: coursewareUrl,
+          enrollment_modes: [
+            mitxonline.factories.courses.enrollmentMode({
+              requires_payment: false,
+            }),
+            mitxonline.factories.courses.enrollmentMode({
+              requires_payment: true,
+            }),
+          ],
+        })
+        const course = mitxOnlineCourse({
+          courseruns: [run],
+          next_run_id: run.id,
+        })
+        setMockResponse.post(mitxonline.urls.enrollment.enrollmentsListV1(), {})
+        setMockResponse.get(mitxonline.urls.enrollment.enrollmentsListV3(), [])
+
+        const { location } = renderWithProviders(
+          <UnenrolledCourseCard course={course} />,
+        )
+        const pathnameBefore = location.current.pathname
+        const hrefBefore = window.location.href
+
+        await user.click(within(getCard()).getByTestId("courseware-button"))
+        const dialog = await screen.findByRole("dialog", {
+          name: course.title,
+        })
+        await user.click(
+          within(dialog).getByRole("button", {
+            name: /Enroll for Free without a certificate/,
+          }),
+        )
+
+        // Fires inside the same onSuccess that decides where to go.
+        await waitFor(() => {
+          expect(trackCourseEnrolled).toHaveBeenCalledWith(course.title)
+        })
+        if (expectRedirect) {
+          expect(window.location.href).toBe(coursewareUrl)
+        } else {
+          expectStayedPut(location, pathnameBefore, hrefBefore)
+        }
+      },
+    )
+
     test.each(ENROLLMENT_TRIGGERS)(
       "Clicking $trigger opens CourseEnrollmentDialog for both-mode enrollment",
       async ({ trigger }) => {
@@ -570,6 +780,54 @@ describe.each([
       },
     )
 
+    test.each(START_DATE_CASES)(
+      "Free single-run enrollment $case",
+      async ({ startDate, expectRedirect }) => {
+        setMockResponse.get(mitxonline.urls.userMe.get(), mitxUser())
+
+        const coursewareUrl = faker.internet.url()
+        const run = mitxonline.factories.courses.courseRun({
+          b2b_contract: null,
+          is_enrollable: true,
+          start_date: startDate,
+          end_date: moment(startDate).add(60, "days").toISOString(),
+          courseware_url: coursewareUrl,
+          enrollment_modes: [
+            mitxonline.factories.courses.enrollmentMode({
+              requires_payment: false,
+            }),
+          ],
+        })
+        const course = mitxOnlineCourse({
+          courseruns: [run],
+          next_run_id: run.id,
+        })
+
+        setMockResponse.post(mitxonline.urls.enrollment.enrollmentsListV1(), {})
+        setMockResponse.get(mitxonline.urls.enrollment.enrollmentsListV3(), [])
+
+        const { location } = renderWithProviders(
+          <UnenrolledCourseCard course={course} />,
+        )
+        const pathnameBefore = location.current.pathname
+        const hrefBefore = window.location.href
+
+        await user.click(within(getCard()).getByTestId("courseware-button"))
+
+        await waitFor(() => {
+          expect(trackCourseEnrolled).toHaveBeenCalledWith(course.title)
+        })
+
+        if (expectRedirect) {
+          await waitFor(() => {
+            expect(window.location.href).toBe(coursewareUrl)
+          })
+        } else {
+          expectStayedPut(location, pathnameBefore, hrefBefore)
+        }
+      },
+    )
+
     test.each(ENROLLMENT_TRIGGERS)(
       "Clicking $trigger bypasses dialog for paid-only single-run enrollment",
       async ({ trigger }) => {
@@ -634,6 +892,7 @@ describe.each([
         const run = mitxonline.factories.courses.courseRun({
           b2b_contract: null,
           is_enrollable: true,
+          start_date: moment().subtract(7, "days").toISOString(),
           courseware_url: faker.internet.url(),
         })
         const course = mitxOnlineCourse({
@@ -687,6 +946,57 @@ describe.each([
       },
     )
 
+    test.each(START_DATE_CASES)(
+      "Verified program enrollment $case",
+      async ({ startDate, expectRedirect }) => {
+        setMockResponse.get(mitxonline.urls.userMe.get(), mitxUser())
+
+        const coursewareUrl = faker.internet.url()
+        const run = mitxonline.factories.courses.courseRun({
+          b2b_contract: null,
+          is_enrollable: true,
+          start_date: startDate,
+          end_date: moment(startDate).add(60, "days").toISOString(),
+          courseware_url: coursewareUrl,
+        })
+        const course = mitxOnlineCourse({
+          courseruns: [run],
+          next_run_id: run.id,
+        })
+        const programEnrollment =
+          mitxonline.factories.enrollment.programEnrollmentV3({
+            enrollment_mode: "verified",
+          })
+        const programEnrollmentEndpoint =
+          mitxonline.urls.verifiedProgramEnrollments.create(run.courseware_id)
+        const enroll = deferredResponse<unknown>()
+        setMockResponse.post(programEnrollmentEndpoint, enroll.promise)
+
+        const { location } = renderWithProviders(
+          <UnenrolledCourseCard
+            course={course}
+            ancestorContext={{ programEnrollment }}
+          />,
+        )
+        const pathnameBefore = location.current.pathname
+        const hrefBefore = window.location.href
+
+        await enrollAndSettle(getCard(), () => enroll.resolve({}))
+
+        expect(makeRequest).toHaveBeenCalledWith(
+          expect.objectContaining({
+            method: "post",
+            url: programEnrollmentEndpoint,
+          }),
+        )
+        if (expectRedirect) {
+          expect(window.location.href).toBe(coursewareUrl)
+        } else {
+          expectStayedPut(location, pathnameBefore, hrefBefore)
+        }
+      },
+    )
+
     test("Audit program enrollment opens CourseEnrollmentDialog when both enrollment modes are available", async () => {
       const userData = mitxUser()
       setMockResponse.get(mitxonline.urls.userMe.get(), userData)
diff --git a/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/UnenrolledCourseCard.tsx b/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/UnenrolledCourseCard.tsx
index b92c88cdd6..bc672642b3 100644
--- a/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/UnenrolledCourseCard.tsx
+++ b/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/UnenrolledCourseCard.tsx
@@ -85,12 +85,14 @@ export const UnenrolledCourseCard = ({
       b2bProgramId:
         ancestorContext?.parentProgramReadableIds?.[0] ??
         ancestorContext?.programEnrollment?.program.readable_id,
+      startDate: courseRun?.start_date,
     })
   }, [
     course,
     ancestorContext,
     readableId,
     coursewareUrl,
+    courseRun?.start_date,
     isContractPageResource,
     enrollment,
   ])
diff --git a/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/courseDateUtils.ts b/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/courseDateUtils.ts
index ffae5f224a..9637f0b823 100644
--- a/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/courseDateUtils.ts
+++ b/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/courseDateUtils.ts
@@ -22,6 +22,17 @@ export const getRunTimeState = (
   return "underway"
 }
 
+/**
+ * Whether this run's courseware can be opened yet; staff may preview early.
+ *
+ * Shared by every route in (card button, card title, sibling-run rows, upgrade
+ * and post-enrollment redirects) so they cannot disagree.
+ */
+export const canOpenCourseware = (
+  startDate?: string | null,
+  { isStaff = false }: { isStaff?: boolean } = {},
+): boolean => isStaff || getRunTimeState(startDate) !== "upcoming"
+
 /**
  * A run's date range. Returns "" when the run has neither date; prefer
  * `formatRunIdentifier` for anything a learner reads, since that case is not
diff --git a/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/hooks/useEnrollmentHandler.ts b/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/hooks/useEnrollmentHandler.ts
index 4728e13f36..57779b752b 100644
--- a/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/hooks/useEnrollmentHandler.ts
+++ b/frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/hooks/useEnrollmentHandler.ts
@@ -14,6 +14,9 @@ import { getCourseEnrollmentAction } from "@/common/mitxonline"
 import { useComplianceGate } from "@/common/mitxonline/useComplianceGate"
 import CourseEnrollmentDialog from "@/page-components/EnrollmentDialogs/CourseEnrollmentDialog"
 import { trackCourseEnrolled } from "@/common/analytics/gtm"
+import { canOpenCourseware } from "../courseDateUtils"
+import { mitxUserQueries } from "api/mitxonline-hooks/user"
+import { useQuery } from "@tanstack/react-query"
 
 const ENROLL_COURSE_ERROR =
   "Something went wrong enrolling you in this course. Please try again."
@@ -32,6 +35,8 @@ export const useEnrollmentHandler = () => {
   })
   const replaceBasketItem = useReplaceBasketItem()
   const { ensureCompliance } = useComplianceGate()
+  const mitxOnlineUser = useQuery(mitxUserQueries.me())
+  const isStaff = mitxOnlineUser.data?.is_staff
 
   const enroll = React.useCallback(
     async ({
@@ -44,6 +49,7 @@ export const useEnrollmentHandler = () => {
       programCoursewareId,
       programReadableIds,
       b2bProgramId,
+      startDate,
     }: {
       course: CourseWithCourseRunsSerializerV2
       readableId?: string
@@ -54,7 +60,18 @@ export const useEnrollmentHandler = () => {
       programCoursewareId?: string
       programReadableIds?: string[]
       b2bProgramId?: string
+      startDate?: string | null
     }) => {
+      /**
+       * Enrolling early is allowed, so only redirect once the courseware is
+       * open. Otherwise the learner stays put and the card they clicked
+       * re-renders as enrolled, showing when the run starts.
+       */
+      const finishEnrollment = (url: string, runStartDate?: string | null) => {
+        if (!canOpenCourseware(runStartDate, { isStaff })) return
+        window.location.href = url
+      }
+
       if (isB2B) {
         if (!readableId) {
           console.warn("Cannot enroll in B2B course: missing required data", {
@@ -90,7 +107,7 @@ export const useEnrollmentHandler = () => {
           },
           {
             onSuccess: () => {
-              window.location.href = destinationUrl
+              finishEnrollment(destinationUrl, startDate)
             },
           },
         )
@@ -125,7 +142,7 @@ export const useEnrollmentHandler = () => {
           { courserun_id: readableId, request_body: requestBody },
           {
             onSuccess: () => {
-              window.location.href = verifiedDestination ?? href
+              finishEnrollment(verifiedDestination ?? href, startDate)
             },
           },
         )
@@ -144,7 +161,7 @@ export const useEnrollmentHandler = () => {
                   enrollmentAction.run.courseware_url ??
                   href
                 if (destination) {
-                  window.location.href = destination
+                  finishEnrollment(destination, enrollmentAction.run.start_date)
                 }
               },
             },
@@ -158,7 +175,7 @@ export const useEnrollmentHandler = () => {
         }
 
         const onCourseEnroll = (run: CourseRunV2) => {
-          window.location.href = run.courseware_url!
+          finishEnrollment(run.courseware_url!, run.start_date)
         }
         NiceModal.show(CourseEnrollmentDialog, { course, onCourseEnroll })
       }
@@ -169,6 +186,7 @@ export const useEnrollmentHandler = () => {
       createEnrollment,
       createVerifiedProgramEnrollment,
       replaceBasketItem,
+      isStaff,
     ],
   )
 

From 78d678e8793a59b4c087194ebc8e4ff03fc89215 Mon Sep 17 00:00:00 2001
From: Doof <mitx-devops@mit.edu>
Date: Mon, 14 Sep 2026 07:05:13 +0000
Subject: [PATCH 9/9] Release 0.80.2

---
 RELEASE.rst      | 12 ++++++++++++
 main/settings.py |  2 +-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/RELEASE.rst b/RELEASE.rst
index 9bfa45f5bc..453d9a25d4 100644
--- a/RELEASE.rst
+++ b/RELEASE.rst
@@ -1,6 +1,18 @@
 Release Notes
 =============
 
+Version 0.80.2
+--------------
+
+- Only offer a run's courseware once it has started (#3925)
+- chore: refresh drf-lint baseline for ORM003-ORM006 (#3928)
+- fix(sentry): set max_request_body_size to small and scrub Postgres DETAIL rows (#3915)
+- Sanitize and render rich-text descriptions from OVS (#3879)
+- Build internal resource links from learn_url (#3885)
+- Update dependency sharp to v0.35.4 [SECURITY] (#3917)
+- Skip staff-only OLX content when ingesting edX course archives (#3909)
+- Update certificate description in Product Page CertificateTrackCard (#3924)
+
 Version 0.80.1
 --------------
 
diff --git a/main/settings.py b/main/settings.py
index 4938527cf8..a0f3353dd4 100644
--- a/main/settings.py
+++ b/main/settings.py
@@ -36,7 +36,7 @@
 from main.settings_pluggy import *  # noqa: F403
 from openapi.settings_spectacular import open_spectacular_settings
 
-VERSION = "0.80.1"
+VERSION = "0.80.2"
 
 log = logging.getLogger()