A microVM has no init unless something is it, and three of the jobs belong to nothing else in the guest: reaping whatever the workload orphans, turning a signal into an ordered shutdown, and being the guest end of the one channel out. None of it knows what it is running. The guest dials out on a fixed vsock port, says its protocol version first, is handed one boot descriptor — a command line, shares, output geometry, and what an exit means — and carries that out. There is no code path that branches on which workload started, which is the property the component exists to keep. It reports and does not supervise. When the workload ends, the exit goes up the channel and the session is over; `on_exit` says what the exit means, and starting something again is a decision for the end that can see whether restarting is repair or a loop. A signalled workload is reported as signalled with no exit code, because reporting 0 for a killed process makes a kill look like a clean run. Two seams keep this testable without a VM, which is the reason for both of them. Reaping runs against real forked children, with the subreaper bit making a test process inherit orphans the way PID 1 does. The channel is generic over the byte stream, so the exchange is driven over an in-memory pipe — the transport contributes nothing to the protocol beyond ordering and framing. The lifecycle types live in nesprotocol behind a feature, off by default: both ends of the channel read one definition and cannot drift from it silently, while the media components keep building without serde. Mounting shares is not implemented in this build. The descriptor's mounts are refused rather than ignored — a workload started without the shares it was promised fails later, somewhere else, for a reason nobody can see from here.
crates/
Shared Rust: a library another crate in this repo depends on. A binary someone
runs goes in apps/; shared JS/TS goes in
packages/. The split is by what a thing is, not by what
language it is written in — same rule on both sides of the repo.
Empty today. Components move here one at a time as they are opened.
Two rules
Every version is pinned in the root Cargo.toml. A member writes
tokio.workspace = true and never a version, so two crates in this tree cannot
disagree about a dependency.
Nothing here may depend on anything closed, or name it. This repo is public. A crate that needs a private component is in the wrong repo, and a comment explaining who calls this wants a category noun — "the caller", "a supervising agent" — rather than a name. The requirement is the interesting part; who currently satisfies it is not.