How should versions.json relate to the STAC version extension?

[nlebovits]

Matthias pointed out that our versioning section defines semantics that are nearly identical to the existing STAC version extension — same concepts, different spelling. If we ever adopted the extension later, the two would collide.

Where we're leaning: adopt the version extension's fields (version, deprecated) and its link relations (predecessor-version, successor-version, latest-version) for everything that overlaps, and keep versions.json only for what the extension can't express — sync state, checksums, the update history. The remaining work is a careful pass deciding exactly which piece of information lives where.

Side question, non-blocking: is there any ecosystem precedent for a sync-state manifest like ours that we should align with?

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Part of the July 2026 spec sprint. Hub: discussion #570 · work tracker: epic #564 · everything here carries the spec-sprint label.