When using go-ap/jsonld, to extend the context by a term use:
jsonld.WithContext(
jsonld.Context{
{IRI: jsonld.IRI(vocab.ActivityBaseURI)},
{Term: jsonld.Term("Hashtag"), IRI: jsonld.IRI("https://www.w3.org/ns/activitystreams#Hashtag")},
},
)
Instead of:
var ApEncoder = jsonld.WithContext(
jsonld.IRI(vocab.ActivityBaseURI),
jsonld.Context{
{Term: jsonld.Term("Hashtag"), IRI: jsonld.IRI("https://www.w3.org/ns/activitystreams#Hashtag")},
},
)
The latter ignores the terms.