Interoperability

Agent Artifact is storage-neutral and UI-neutral. It should preserve native ids from adjacent systems rather than replacing them.

System	Alignment
MCP	Resources, content blocks, resource links, media content, and annotations inform refs and embedded content boundaries.
A2A	Peer-agent tasks and artifacts can carry artifact ids, parts, files, and handoff refs.
OCI descriptors	Media type, digest, size, and annotation patterns inform byte refs and export manifests.
W3C PROV	Entities, activities, and agents inform provenance refs.
Web Annotation	Selectors and targets inform part-level annotations and source links.
in-toto / SLSA	Attestation and provenance patterns inform integrity and generated-by records.
BagIt / RO-Crate	Package manifests and metadata inform export and handoff packages.
C2PA	Content provenance and ingredients inform generated media provenance.
CloudEvents	Event envelope reference.
OpenTelemetry	Trace and span correlation reference.

Boundary rule

If the question is "where are the bytes stored?", use storage. If the question is "how is this rendered?", use UI. If the question is "what did the agent produce and how can it be versioned, previewed, exported, cited, and handed off?", use Agent Artifact.