Composing ontologies
A single sound ontology is useful; ontologies that compose are where the network value lives. Use this page when a question, claim, or workflow depends on two or more independently meaningful ontologies, owners, identity layers, or visibility domains.
Knowledge composes upward, like code libraries
Section titled “Knowledge composes upward, like code libraries”- Canonical wrefs are import statements — rooted in durable identity and rename-safe. Current committed fields remain exact-version-bound; a relationship that must follow future target versions requires the proposed explicit identity-binding contract rather than documentation fiction.
- Namespaces make imports partial: a consumer can take your identity layer (
*/identity/**) and a different provider’s domain layer — one library for most things, a different one for date handling. - Release Sets are version tags; the ontology Shapes are the package manifest: contracts are the API docs; golden cases and competency evaluations are the test suite and the CI badge a prospective consumer inspects before depending on you.
- Naming contracts and predicate declarations are what make an ontology composable-onto by strangers — the public interface, in both senses (the writer-convergence rule they enforce is in platform consequences).
What a composable ontology exports: charter and non-goals · owning authority · namespaces and identity rules · load-bearing external-identifier semantics · semantic contracts · predicate declarations with direction · provenance guarantees · release identity · the evaluation record · its permitted composition boundary. All of it queryable in */ontology/**.
The composition mechanisms
Section titled “The composition mechanisms”| Mechanism | Meaning | Primary contract concern |
|---|---|---|
| Shared canonical anchor | Members assert about the same canonical identity | Authority, identity stability, reference direction |
| Shared grounding dependency | Members independently depend on the same source layer | Provenance, rights, cadence, correlated failure |
| Bridge | Rival or differently scoped anchors related by attributed mapping assertions | Evidence, contestability, direction, temporal validity |
| Subscription/derivation dependency | One ontology consumes another’s release or write stream | Upstream identity and rebuildability |
| Cross-ontology derived assertion | A claim whose evidence spans ontologies | Method, temporal alignment, anti-inferences, the observational line |
Bridges deserve their own contracts. The two recurring situations: a private record → a public canonical anchor (RefersToOrganization about Arc(CRM account, public Organization) — for a firm, the single highest-leverage join it will ever build), and one provider’s anchor → a rival’s (SameFacility about Bond{theirs, ours} — the adapter pattern between competing identity layers, and itself curatable knowledge). For any bridge, settle: owning repo and writer · directed or symmetric · evidence class and resolution method · review policy · temporal validity · behavior when either endpoint changes or is deprecated.
Contestability is a feature. One owning repo per canonical Thing within a provider’s ontology — but multiple providers may publish competing canonical layers, consumers choose or combine, and cross-provider Same*/Distinct* assertions preserve disagreement rather than declaring a universal winner. Disagreement between transparent, evidence-carrying layers is knowledge.
Cross-ontology assertions carry the same safeguards as everything else: the precise identities and periods joined, the releases and evidence used, method and version, observation window, anti-inferences — and the observational line holds: a public composition may state a supported co-occurrence; conclusions belong to an owner.
The return path: composition exposes member defects — ambiguous identity, missing contracts, unreachable evidence. The member ontology is fixed through its own process (Stages 0–10) and re-released; the composition re-evaluates. Never patch around a broken member contract with hidden local conventions.
Decisions at the interface
Section titled “Decisions at the interface”The mirror model (world-model and self-model) is composition’s most valuable instance: an organization joins the public world-model to its private self-model through bridges, and its decision beliefs cite evidence in both. That pedigree-spanning property is queryable — “show me active decisions whose evidence never reaches the self-model” is a hygiene report — and the latency of the join (how fast an upstream change becomes a re-priced, re-staffed decision) is an engineering property an organization can own. Public layers commoditize by design; the interface does not.
The curator economy
Section titled “The curator economy”The normative core comes first and is not commercial: shared layers are auditable; interpretations are attributed; propositions are contestable; the observational line holds; private beliefs stay private. Given that, composition has natural economics:
- Namespace design is packaging. If rights were to scope by path, the naming contract would also be the price sheet — free base layers, premium enrichment layers, never-sold private beliefs. The namespace discipline that makes this possible is worth adopting for its query, token, and subscription value regardless.
- Layer-4 beliefs are the sellable class of knowledge. A curator who composes a free base into predictions and assessments holds something others would pay for — and maintained trust is what they would actually be buying: releases, passing evaluations, correction speed, a measurable track record.
- Provenance is the receipt. “Why do we believe this?” doubles as “what am I paying for?” The self-documenting ontology is, commercially, the storefront.