One of the use cases brought up was this. What if a user wants to get the sequence collection checksum(s) from either the name of the collections (e.g. grch38).

We determined that Sequence collections should be congruent with the approach taken by refget in terms of allowing human-readable alias-based queries.

In this issue: samtools/hts-specs/issues/329 it seems clear that refget was not intended to do this.

@andrewyatz says:

I viewed the aliases section as a bit where an API can say "I believe this is a known alias for this ID". Nothing more. Those known aliases could be other checksums e.g. if UniParc implemented this they could provide their crc64 checksums as an alias. Part of me feels that this is a buyer beware situation.

Secondly refget is not built to support sequence retrieval using an alias. Imagine the following URL /sequence/alias/chr1 and how impossible this is to resolve without additional metadata. Refget is trying to resolve this situation by using checksums so supporting alias lookup feels like it's going against refget's ethos.

That hopefully puts clear water between aliases e.g. chr1 and alternative methods of generating the checksum identifiers. We never intended to query the server by alias.

In light of this, I'd propose the seqcol spec specifically not provide endpoints that operate on human-readable aliases.

On the other hand, 'chr1' is a much more universal identifier than something like 'hg38', so perhaps there is some value in returning a list of identifiers that include "hg38" under "aliases".