Module protocol 

Wire types for the daemon’s Unix-domain control socket.

The control plane speaks newline-delimited JSON (NDJSON): one DaemonEnvelope request per line, one DaemonReply response per line. New optional fields use #[serde(default, skip_serializing_if = ...)] so older peers stay byte-compatible on the wire.

Subscriptions (streaming replies)

Most ops are strictly request→one-reply. A subscription op is the one exception (#1267): when a service recognises the op as streaming (via DaemonService::subscribe) the server switches that connection to push mode and emits many DaemonReply lines on the same connection — an initial snapshot, then a fresh snapshot each time the service’s state changes (coalesced, and diffed so two identical frames are never sent in a row). Each pushed line is an ordinary DaemonReply::ok(payload); there is no new wire type, so a reader distinguishes a subscription only by continuing to read lines instead of stopping after one. The stream ends when the client sends any further line (an explicit cancel), disconnects, or the daemon shuts down.

The only subscription today is worktrees / subscribe, whose payload is the { "repos": [...] } tree snapshot. Back-compat is total: an older client never sends a subscription op, so it only ever sees the classic one-reply exchange.

Structs

DaemonEnvelope

A request sent to the daemon over the control socket.

DaemonReply

A response returned by the daemon over the control socket.

StatusReport

The payload of a built-in status reply: per-service status snapshots.

Constants

DAEMON_SERVICE

The reserved service name for the daemon’s own built-in operations (ping, status, shutdown). A None service targets the same.

MAX_LINE_BYTES

Maximum length, in bytes, of a single NDJSON line on the control socket.