Under the delegated act to DSA Article 40, each Very Large Online Platform and Search Engine
must make a data catalogue available on its online interface. It describes the non-public data
assets that vetted researchers can request in their access applications under Article 40(4) for
research on systemic risks, including their structure and metadata.
Why do we monitor platforms' data catalogue pages?
Only the catalogues show what non-public data a platform holds, and researchers' DSA data access
applications must specify the data they concern. Platforms can edit these pages anytime, with no
changelog, so incomplete listings and later changes would pass unnoticed. For accountability and
transparency, the monitor snapshots every catalogue on a fixed schedule and publishes each change.
How to use our monitor
The monitor has two main functions, each shown below with real data from Google DE Youtube Data Catalogue DE's catalogue.
Review the monitoring timeline
Timeline of monitored changes
Each dot is a monitoring run. Colours show how significant the detected changes are, and numbers indicate how many platforms had changes.
28 Jul
20:25
30 Jul
20:27
6
1 Aug
20:31
2
3 Aug
20:35
1
5 Aug
20:39
4
7 Aug
20:44
3
9 Aug
20:49
2
11 Aug
20:54
5
13 Aug
20:59
3
14 Aug
13:00
1
15 Aug
21:02
4
17 Aug
21:08
2
19 Aug
21:13
8
21 Aug
21:18
8
23 Aug
21:22
2
25 Aug
21:27
6
27 Aug
21:31
5
29 Aug
21:37
3
31 Aug
21:40
6
2 Sep
21:45
8
4 Sep
21:52
11
6 Sep
22:01
2
8 Sep
22:06
5
10 Sep
22:12
6
AI summary of changes
An AI model reviews the changes across all platforms and writes a summary for each monitoring run. Each summary also includes an AI assessment per platform.
🤖substantive2026-08-23
A substantive change was found on the Google Shopping data catalogue, while a minor cosmetic change was identified on YouTube.
Google Youtube Data CatalogueminorGoogle DE Google Shopping Data Catalogue DEsubstantive
Review past monitoring runs
Click the dot of a past run on the timeline and the whole dashboard switches to its results. Read the AI summaries and the individual platform overview cards of that run.
Nothing is overwritten — every past run stays queryable exactly as it looked on the day.
Change assessments with colours
An AI model assigns detected changes one of four assessment types. Each type corresponds to a colour, which is shown on the timeline and the platform overview cards.
substantive
Substantive content changes: new or removed datasets, changed API endpoints, or meaningfully rewritten text.
minor
Minor content changes: small wording or formatting tweaks, corrected typos, updated dates, or edited footers.
noise
Rendering artefacts: dynamic tokens, session IDs, or invisible metadata. No real content changed.
mixed
Mixed findings across runs: at least one substantive change and at least one minor or noise change.
Filtering of monitoring results
The platform overview cards can be filtered by the language of the data catalogue or the latest change assessment, and sorted in multiple ways.
AllENDESignificantMinorA–ZMost significant
Language
Show all catalogues or only the English or German versions.
Filter
Narrow the cards by the latest assessment: all platforms, substantive changes, minor changes or noise, or fetch errors.
Sort
Order the cards alphabetically, by status, by date of the most recent change, or by significance of the latest assessment.
Explore monitoring runs per platform
Detailed results for each platform
Each platform overview card leads to the current version of the platform's data catalogue page, all monitoring snapshots, and an explorable change history.
Aliexpress
UnchangedT2
Shein
UnchangedT2
Google DE Youtube Data Catalogue DE
Changed
40 changes
Every version is archived
Each platform page starts with the source URL of the monitored catalogue, the time of the last monitoring run, and its content fingerprint, so any changes in the runs can be compared.
Last run: 10 Sep 2026, 22:15 (Berlin)Fingerprint: e9a5a7c4d2c8e0ab700ff257…
Explore the latest catalogue content
The Current Content panel shows the text of the platform's data catalogue page as captured in the latest snapshot, together with the number of outgoing links.
“Zum Hauptinhalt springen Auf developers.google.com werden Google eigene Cookies verwendet, um Google-Dienste bereitzustellen, deren Qualität zu verbessern und Datenverkehr zu analysieren. Weitere Informationen Ausblenden…”
128 outgoing links
captured in Google DE Youtube Data Catalogue DE's latest snapshot.
History of monitored changes
The change history lists every monitoring run of the platform with monitoring timestamp and summary of whether and how the page changed. An AI model assesses the most recent detected change and writes a short explanation.
🤖AI Assessmentminorcosmetic2026-09-10
The change is cosmetic because only minor wording and formatting changes were made, with no substantive link changes. The content remains functionally identical.
Timestamp
Change type
Links ±
2026-09-02
cosmetic
+15 −12
One row of 40 on its full history table.
Filtering by change type
Five change types are available for filtering the monitoring history.
noise
The hash changed but there is no visible difference, such as a token refresh or a session ID.
cosmetic
One or two lines were added or removed and no links changed; these are usually label or footer edits.
link change
Outgoing links were added or removed. This is the primary signal for catalogue updates.
content update
A substantive text change (3–20 lines) with no links added or removed.
structural
A large, imbalanced change (>20 lines), often a page rewrite. These cases warrant manual review.
Compare any monitoring runs
Clicking on any monitoring run in the change history opens a comparison of that snapshot's data catalogue page to the previous one. It shows an AI summary of the changes, the changed links, and a line-by-line comparison of both snapshots' data catalogue texts.
AI assessment of the changes
An AI model assesses the changes between the monitoring runs and writes a short explanation. The assessment explains the change type and its significance.
🤖AI Assessmentminorcosmetic2026-09-10
The change is cosmetic because only minor wording and formatting changes were made, with no substantive link changes. The content remains functionally identical.
Line-by-line comparison
The comparison shows the data catalogue texts of both monitoring runs. Select the side by side view, with removed lines marked in the previous snapshot and added lines in the current one, or the unified view that merges both texts into a single column with the changes marked inline.
