Package Artifact Manifest v1

Status: implemented, bounded, local evidence contract for issue #195. Audience: package, registry, and artifact-tooling contributors.

Purpose

Package Artifact Manifest v1 binds one package coordinate and its exact capsule/content/API-ABI facts to one closed target profile and one exact ordered artifact inventory. It is the artifact-level evidence carried by Registry Snapshot v2. It does not replace or alter the v1 registry document or snapshot.

The schema is semaprax.package-artifact-manifest.v1. The compact canonical object contains, in order: schema, package, version, capsule_digest, content_digest, api_abi_digest, target_profile, features, effects, capabilities, artifacts, and nonclaims. Its identity is SHA-256 over the domain semaprax.package-artifact-manifest.v1\0 followed by the exact canonical manifest bytes. The domain-separated digest is carried by the registry entry, not inside the manifest itself.

create_from_linked_build first invokes the existing exact Build-v2 verifier over the submitted module, manifest, evidence, capsule, sources, resolution, and options. It derives capsule_digest from that verified receipt, content_digest from the exact independently replayed Subject-v3 whose embedded Report-v2 equals the root package report consumed by the verified build, and api_abi_digest by domain-separated hashing of the verified Build-v2 export projection. Artifact paths, roles, byte lengths, and SHA-256 digests are derived from the exact raw three-artifact build. The returned manifest exposes derived_api_abi_digest; the registry admission API uses that value to populate the consumed publication rather than requiring a caller to reproduce the private digest algorithm.

Closed initial profile

The only admitted target profile is linked-effect-free-core-wasm-scalar.v2, the existing Offline Linked Scalar Core-Wasm Package Build v2. Its feature inventory is exactly, in this order:

1. linked-packages
2. scalar-exports

Effects and capabilities are both exactly empty. The artifact inventory is exactly:

Role	Path	Profile
core-wasm-module	module.wasm	linked-effect-free-core-wasm-scalar.v2
build-evidence	semaprax.package-build.evidence.json	same
build-manifest	semaprax.package-build.json	same

Every row also binds a nonzero bounded byte count and a lowercase SHA-256 digest. Roles, paths, rows, features, effects, and capabilities are ordered inventories, not sets to be sorted or repaired by a consumer. Missing, extra, duplicated, reordered, traversing, control-bearing, cross-profile, or spliced inventory values fail closed.

Bounds and replay

The manifest is at most 256 KiB. Inventories are capped at 32 items and the artifact inventory is fixed at three. Submitted JSON is checked before DOM use for byte count, compact canonical spelling, duplicate keys, trailing data, maximum depth, and structural work. Decoding validates the closed profile, regenerates the canonical bytes, and requires exact byte equality. Registry v2 then independently verifies the domain-separated digest. The three Build-v2 artifacts also have a checked cumulative limit of 16 MiB in the shared create/decode/verify validator; the exact boundary is admitted, while boundary plus one and a canonical three-times-16-MiB claimed inventory are refused.

Diagnostics are stable:

• SPX-PKR614: malformed or noncanonical manifest wire;
• SPX-PKR615: manifest digest association failure;
• SPX-PKR616: profile or inventory refusal;
• SPX-PKR617: manifest or inventory bound exceeded.

Authority boundary and nonclaims

Creation, decoding, and replay are pure in-memory operations. Only the verified producer API creates an admissible manifest; decoding a self-consistent wire is inspection, not producer authentication. A manifest is evidence, not permission. It grants no filesystem, registry, network, cache, process, signing, execution, or publication authority. V1 makes no claim for native artifacts, Component Model, WASI, dynamic linking, target execution, cross-platform conformance, signatures, publisher identity, transparency, or profiles with effects or capabilities.