(IMHO the second URL is wrong because it returns only 355 and it's a CrossRef value not an OpenAlex value)
I think you should emit type and crossrefType as simple strings, and if you like to expose the above openalex filter URLs, you can form such URLs at the UI
Consider https://api.openalex.org/works/W4327890772 vs https://semopenalex.org/work/W4327890772
type
andcrossrefType
as simple strings, and if you like to expose the above openalex filter URLs, you can form such URLs at the UI