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. 13 shown for “5c Documentary Express revenue stamp single on Adams Express Company’s receipt” — 41 records examined, 1 dropped by the rights gate.
Archives queried 2026-08-31 21:30 UTC · fetched live for this request
isPublicDomain field is true for this object.metadata_usage.access reads CC0 — a waiver, not an expired term.
Circus Sideshow (Parade de cirque)
Georges Seurat · 1887–88
5c Documentary Express revenue stamp single on Adams Express Company’s receipt
Artist not stated in the record · February 6, 1863
2c Black on Buff Paper Adams' City Express Post Single
Artist not stated in the record · 1850-1851
1c Documentary Express revenue stamp single and pair on photograph
Artist not stated in the record · 1864-1866
25c Black on Pink Paper Adams & Co.'s Express Single
Artist not stated in the record · 1854
5c prepaid United States Express Company single
Artist not stated in the record · c. 1854
5c Documentary Inland Exchange revenue stamp single on marriage certificate
Artist not stated in the record · September 14, 1871
5c Documentary Inland Exchange revenue stamp single on marriage license
Artist not stated in the record · January 26, 1864
Express from Richmond to Louisville posted to New York cover
Artist not stated in the record · August 8, 1861
5c New York Match Company revenue stamp single
Artist not stated in the record · 1872
5c Greenleaf and Company revenue stamp single
Artist not stated in the record · 1864
5c Petersburg, VA Confederate postmaster provisional single on cover
Artist not stated in the record · March 5, 1862
5c New York Consolidated Card Company revenue stamp single
Artist not stated in the record · 1876
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. 1 matched · 1 examined · 0 dropped by the rights gate. Kept only where isPublicDomain === true and a file URL was published.1 shown - Smithsonian Open Access API (api.si.edu)Rights field:
content.descriptiveNonRepeating.metadata_usage.access. 1011125 matched · 40 examined · 1 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 2026-08-31 21:30 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.