Dealing with local subjects / identifiers / local-id / @id / blank nodes

[joepio]

Atomic Data subjects are HTTP(S) URLs that resolve. However, there are situations where we don't want to or can't generate a fully resolvable URL:

• Error messages that are not linked to a specific URL
• data created on a client that does not know where (or even if) the data will be hosted

Allow resources without an @id, as long as they have a local-id

In the summer of 2022, we added the /import endpoint which allows users to add JSON-AD without @id fields, but with local-id.

This works pretty well, but the situation still begs questions:

• How should stores internally store these resources without a subject? All my current implementations store resources using their @id, so if there is none, we can't store them.

Use the @id field with a custom local: scheme

Instead of relying on an extra property, we could re-use the @id field, but just use local: instead of http: