Check if a nanopublication is loaded
type: Nanopublication
has assertion: assertion
has provenance: provenance
has publication info: pubinfo
created: 2026-08-25T12:12:53Z
creator: Tobias Kuhn
license: https://creativecommons.org/licenses/by/4.0/
embeds: Check if a nanopublication is loaded

Check if a nanopublication is loaded
type: grlc-query
description: This query checks whether a given nanopublication has been loaded by the answering Nanopub Query instance. It returns the nanopublication's creation date if the nanopublication is present, and an empty result otherwise. It is designed to be as cheap as possible (a single indexed lookup), so it can be used to poll for the arrival of a just-published nanopublication, for example to delay a cache refresh until the new nanopublication has made its round trip through the network.
license: LICENSE-2.0
endpoint: meta
sparql: prefix npa: <http://purl.org/nanopub/admin/> prefix dct: <http://purl.org/dc/terms/> select ?date where { graph npa:graph { ?_np_iri dct:created ?date . } } limit 1

sig
has algorithm: RSA
signed by: Tobias Kuhn