What is a sidecar record?

[erlend.sh]

Continuing the discussion from [Proposal] Shared private Data for social posting:

@bmann.ca

BTW, I don’t call this a sidecar @nonbinary.computer and I think we should reserve that for “sidecar records”

This is one of those terms that comes up a lot, but we are using it with slightly different definitions in mind.

@bmann.ca what’s your definition of a ‘sidecar’ in an atproto context? Curious to see if that lines up with how @nonbinary.computer & @evelyn.northsky.team and others conceptualize it.

[bmann.ca]

A Sidecar Record is when you share a record ID with more information.

@snarfed.org and others have written about this extensively.

[snarfed.org]

Yes! Key early precedent and writeup: Lexicons, Pinned Posts, and Interoperability | Bluesky