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Artifact-Type Packs

An artifact-type pack binds an artifactTypeId to a JSON Schema, an advisory rendering hint and export formats, so two hosts mean the same thing by one type. The manifest is schemas/v2/artifact-type-pack-manifest.schema.json, whose descriptions carry…

Status: Stable.

Normative home: artifactTypes.

Why this exists

An artifact-type pack binds an artifactTypeId to a JSON Schema, an advisory rendering hint and export formats, so two hosts mean the same thing by one type. The manifest is schemas/v2/artifact-type-pack-manifest.schema.json, whose descriptions carry the per-field rules; installation and signing follow packs.md.

A registry MUST refuse a manifest that mixes kind: "artifact-type" with nodes[], chains[] or prompts[], with pack_kind_invalid.

Schema distribution

The schema at schemaRef, inside the signed tarball, is the source of truth. Its canonical URL and $id is {HostBase}/schemas/artifacts/{artifactTypeId}.schema.json, served as application/schema+json.

  • A host advertising artifactTypes SHOULD serve each installed type's schema there, and MUST for a host-registered type whose schemaVersion it advertises.
  • A tarball copy and a served copy of one (artifactTypeId, schemaVersion) MUST be byte-identical.

At registry publish and at install, a host MUST reject, with pack_validation_failed, an artifact schema exceeding its bounds on serialized size, $ref depth or keyword/subschema count, and MUST compile under a wall-clock timeout. It SHOULD reject a pattern it cannot evaluate in linear time (invariant artifact-schema-compile-bounded).

Registration

A host advertising artifactTypes places each WorkflowNode.artifactType, nodes[].artifact.typeId and artifact.created.artifactType value in one tier: pack-registered (an installed pack declares it; registrationSource: "pack"), host-registered (a host-native type with a host-known schema; "host"), or unregistered.

  • Before emitting artifact.created for a registered type, the host MUST validate the payload against its schema as written, per its validation. On failure it MUST NOT emit and MUST surface the error; on success it sets registered: true and the matching registrationSource.
  • A host MAY emit registered: true for a host-registered type only if it serves that type's schema.
  • A host MUST NOT reject or schema-validate an unregistered value. It SHOULD emit registered: false and SHOULD log an unresolved-type warning.
  • A host not advertising artifactTypes treats every value as an opaque string.

The capability

artifactTypes advertises store, render and export independently; types overrides them per artifactTypeId, falling back to the global values (schemas/v2/capabilities.schema.json).

  • store — every path by which a host persists an artifact of a registered type MUST emit artifact.created; a host with a silent path MUST NOT advertise store: true for that type.
  • render, export — advisory. A host MUST NOT refuse to store an artifact, or fail a run, because it cannot render it.

Sources: RFCs 0071, 0075, 0141, 0145, 0205.