Wikidata has an item called smartphone model.
I want to get all instances of it.
QUESTION: How to get the identifiers of the instances programma
Your question specifies the "Mediawiki API" but this is not possible.
Wikidata has a SPARQL query service at https://query.wikidata.org
The query that you want is:
PREFIX wd:
PREFIX wdt:
SELECT DISTINCT ?item
WHERE {
?item wdt:P31/wdt:P279* wd:Q19723451
}
This will list the Items that are an 'instance of'(P31) 'smartphone model'(Q19723451) or an 'instance of' a 'subclass of'(P279) 'smartphone model'(Q19723451).