Versioning and stability

The current package version in build.zig.zon is 0.1.1. Nether is pre-1.0: pin compatible source revisions and keep snapshot-producing binaries available. Changes are recorded in the changelog.

Independent version surfaces

Surface	Current source value	Meaning
Package	0.1.1	Binary/library release version
HVF snapshot	NSNP v5	128-byte header and HVF snapshot layout
KVM snapshot	NSKV v2	Separate KVM header and CPU/device layout
Nether control	proto_version=2	Reply framing and command handshake
Supervisor northbound control	proto_version=1	Supervisor's __info__ and ensure protocol

The supervisor accepts Nether protocol versions 1 and 2 on its southbound connections. The console has separate Nether and supervisor clients. Do not infer a wire version from a package version or a snapshot header.

Snapshots

Restore checks format versions and selected geometry/layout fields. That does not establish compatibility for arbitrary builds with the same version number, nor does it make snapshots portable across backends or hosts.

The HVF validate_snapshot mode and bake storage transforms operate on HVF snapshots. KVM snapshots have their own reader/writer. See snapshot storage and the KVM runbook.

The bake manifest hashes the Nether binary, image, and recipe. Baking uses those hashes for cache invalidation. Forking a base with a different recorded binary hash currently warns; it does not refuse solely because that hash differs. Runtime format validation still applies.

Control clients

Handshake with __info__ and handle the reported protocol version. Protocol v2 describes uniform framed replies. Command enumeration is available through __help__, but a shared command name does not imply identical backend behavior. See the backend notes in the command reference.

A future breaking wire or snapshot change should bump the corresponding format version. Before 1.0, downstream integrations should test their pinned combination; a successful handshake is not a complete compatibility test.