Define the canonical corpus wire schema

[ian-pascoe]

Question

What strict, versioned JSON Schema should represent the accepted canonical model without ad hoc fields? Produce the smallest schema and validation fixtures needed to decide the common record envelope, identifiers, record references, Snapshot selections, typed literals, Assertion bodies, Scope constraints, Activity roles, extension points, and optional JSON-LD mapping.

[ian-pascoe]

Prototype ready for review:

• Interactive wire-schema decision prototype
• JSON Schema 2020-12
• Ajv-checked validation fixtures
• Optional JSON-LD context

Branch: prototype/canonical-corpus-wire-schema
Commit: 55a3229

The prototype separates per-record JSON Schema validation from cross-record Corpus conformance. It remains open pending HITL review.

[ian-pascoe]

Resolution

Accepted the prototype wire contract without changes.

• JSON Schema 2020-12 is the normative Canonical record contract. Its $id is versioned, and a Corpus release manifest declares the version once. Records do not repeat it.
• Every record uses the closed id / type / optional extensions envelope. type selects one of the eight Canonical record kinds. Unknown fields fail validation.
• Canonical record references are bare absolute identifier strings. Source strings use typed literals.
• Snapshot IDs are urn:sha256:<64 lowercase hex> over exact bytes. The digest is not duplicated in a record field. Content and upstream source locators remain separate.
• Snapshot selections require a Snapshot ID and selector. Core selectors are text quote, text position, and byte range. Other selector types require an absolute profile IRI and profile-validated value.
• Typed literals require scalar value plus datatype; language is string-only and unit numeric-only.
• Assertion bodies are claim or relation. Every Assertion requires nonempty attributedTo and one generatedBy. scope and citations are optional but nonempty when present; absence means not recorded, never universal or verified.
• Activities use timestamped namespaced role bindings for inputs, outputs, Agents, methods, tools, and parameters rather than scenario-specific fields.
• Wire extensions live only under extensions keys that are absolute profile IRIs. Semantic extension uses Terms and Assertions.
• JSON-LD is a deterministic projection, not another Canonical record shape. Canonical records reject inline @context.
• Record schema validation and Corpus conformance are separate tiers. Corpus conformance checks cross-record identity, references and kinds, byte integrity, selector bounds, datatype meaning, time ordering, and provenance-role semantics.

Accepted prototype assets:

• Interactive decision prototype
• Prototype JSON Schema
• Validation fixtures
• Optional JSON-LD context

The prototype schema compiled in strict Ajv mode, every fixture produced its declared result, browser interactions worked, and the prototype had no WCAG A/AA violations. The accepted decision is recorded on main in commit e872c7e.