OpenTwo archives, queried live.
Every record below comes from The Met or Smithsonian Open Access and was filtered on that archive’s own rights field before it reached this page. 15 shown for “Hendrik Richters” — 43 records examined, 13 dropped by the rights gate.
Archives queried 2026-09-03 00:26 UTC · fetched live for this request
isPublicDomain field is true for this object.metadata_usage.access reads CC0 — a waiver, not an expired term.
Oboe in C
Hendrik Richters · before 1727
Merismopedia affixum P. Richter in Hauck & P. Richter
Artist not stated in the record
Shoes
Vincent van Gogh · 1888
Chroococcus obliteratus P. Richter in Hauck & P. Richter
Artist not stated in the record · Sep 1885
Cubiculum (bedroom) from the Villa of P. Fannius Synistor at Boscoreale
Artist not stated in the record · ca. 50–40 BCE
Aphanothece conferta P. Richter in Hauck & P. Richter
Artist not stated in the record · Feb 1892
Hydrocoleum hieronymii P. Richter in Hauck & P. Richter
Artist not stated in the record · Oct 1891
Gloeocapsa reicheltii P. Richter in Hauck & P. Richter
Artist not stated in the record · Sep 1890
Gongrosira schmidlei P. Richter in Hauck & P. Richter
Artist not stated in the record · 25 May 1893
Aphanothece nidulans P. Richter in Wittr. & Nordstedt
Artist not stated in the record · 9 Mar 1882
Protococcus grumosus P. Richter
Artist not stated in the record · 9 Mar 1882
Oscillatoria scandens P. Richter
Artist not stated in the record · 4 Mar 1881
Nostoc wollnyanum P. Richter in Wittr. & Nordstedt
Artist not stated in the record · 17 Mar 1883
Scytonema hansgirgianum P. Richter
Artist not stated in the record · 7 Aug 1883
Protococcus grumosus P. Richter
Artist not stated in the record · 9 Mar 1882
Where these records came from.
Two archives are wired, and only two. Each one is filtered on its own rights field — never on a title match, and never on the presence of an image file.
- The Met Collection API (Open Access)Rights field:
isPublicDomain. 3 matched · 3 examined · 0 dropped by the rights gate. Kept only where isPublicDomain === true and a file URL was published.3 shown - Smithsonian Open Access API (api.si.edu)Rights field:
content.descriptiveNonRepeating.metadata_usage.access. 3704 matched · 40 examined · 13 dropped by the rights gate. Kept only where metadata_usage.access === "CC0" and an image resource was published.12 shown
These figures describe the pass run at 2026-09-03 00:26 UTC, during this request. A completed pass is kept for 24 hours and replayed for an identical search, which is what keeps repeated queries inside Smithsonian’s 30-requests-per-hour allowance. A pass in which either archive failed to answer is never kept — an outage must not be replayed as though it were a finding about the catalogue.
Wikimedia Commons and the Library of Congress are deliberately not wired. Wikimedia was confirmed, on a live query, to return CC-BY material inside the same result set as genuine public domain works, and filtering it safely has not been designed yet. loc.gov was blocked by bot detection during the source evaluation, so its rights vocabulary has never been observed — and nothing here is built on a field nobody has read.
An image file is a rights claim. It never travels without its field.