The Spine
Source: index.html (Industry Configurator); personality-vatican-8level.json (real 8-level Holy See/Vatican personality artifact); personality-general_reasoning-finra-1783102313180.json; ent-spine.lisp, ent-spine-validation.lisp, ent-tree.lisp (source zip); vatican.chandrahub.net (live-fetched, confirms the tree UI).
The Spine is Chandra's model of an organization's own regulatory or operational hierarchy — the scaffolding that determines what a "Level" means for a given deployment, before any actual data (Hub/Spoke, Chapter 2) is attached to it.
A Spine is an ordered sequence of Levels — Level 1 through Level N — each with:
attestation_boundary: true)Critically, a Level is not a Hub. The real personality artifacts are explicit and repeated on this point: Hub/table authoring, Spoke/row authoring, and physical instance assignment for a given Level are all "deferred_to_spine_editor" — a Level is a slot in the organizational hierarchy; what tables and records actually live inside it is decided later, by a different tool (Chapter 13), not by whoever designed the Spine's shape.
This is a real, easy-to-get-wrong detail, confirmed directly from the Vatican artifact's own logical_spine metadata:
"numbering_starts_at": 1,
"display_order": "top_to_bottom",
"stored_numbering": "bottom_up",
"invariant": "Level numbers are logical industry hierarchy coordinates only. They are not physical Instance numbers."
Concretely: in the Vatican 8-level spine, Level 8 is "Holy See / Apostolic See" — the top of the organizational hierarchy — while numbering starts at 1 at the bottom. When the Spine is displayed, it renders top-to-bottom (Holy See at the top of the screen), but the stored level number counts up from the bottom. Do not assume Level 1 is the top of a spine, and do not assume a Level's number has any relationship to which physical worker instance eventually hosts it — the artifact's own invariant states plainly that these are logical hierarchy coordinates, not physical instance numbers. Physical instance assignment is Chapter 13's job, computed later, independently of how the levels happen to be numbered.
It's worth stating the distinction plainly, since both are hierarchical and it's easy to conflate them:
| Spine / Level | Hub / Spoke | |
|---|---|---|
| What it represents | Organizational or regulatory structure | Actual business data |
| Who defines it | Industry Configurator (Chapter 6) produces the logical shape; Spine Editor (Chapter 13) authors it directly and packs it physically | Form Design (Chapter 14) per Hub |
| Governance unit | A Level can be an attestation boundary | Every Spoke has its own CU chain (Chapter 1) |
| Physical mapping | One or more Levels get packed into a physical worker instance (Chapter 13, using the CRC/ISS formula from Chapter 5) | A Hub lives inside whichever instance hosts its owning Level |
A useful mental model: the Spine answers "what kind of organization is this, and how is its authority structured" (a Vatican deployment's Spine looks nothing like a broker-dealer's); Hub/Spoke answers "what data do we actually keep, and in what shape" within whatever Level that data belongs to.
ent-spine-validation.lisp enforces structural rules on a Spine before it can be accepted (Chapter 2's Acceptance/Production distinction is exactly where this validation gets exercised): level numbers must be contiguous, exactly one Level has no parent (the top of the hierarchy, regardless of what its number happens to be under the bottom-up storage rule above), and parent/child references must resolve to Levels that actually exist in the same Spine. The Industry Configurator (Chapter 6) runs a version of this same validation live as you edit — it's the mechanism that keeps a hand-edited Level spine internally consistent before it's ever exported as a personality artifact.