logaritmiskandClaude Opus 5
b500882257
Stdio-first MCP servers exit the moment they see EOF on fd 0. Under the launchd agent the daemon's stdin is /dev/null, so a server that also speaks HTTP still shuts down seconds after binding its port, and there was no way to ask xy for anything else. Adds a per-server `stdin` mode: `inherit` (the default, unchanged), `null`, or `keep-open`. Under `keep-open` the child gets a pipe whose write end RealChild holds and never writes to, so a read blocks. The handle has to live on RealChild rather than on the TokioChild: `Child::wait()` opens with `drop(self.stdin.take())`, so leaving it where tokio put it reproduces the original bug the instant supervision starts. Refs #2 Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01TWLFEoRaRafJm1SpdhWQ6F
xy — HTTP MCP server supervisor
Daemon + CLI that launches and supervises HTTP-based MCP servers.
Build
cargo build --release
Run
target/release/xy daemon # foreground
Drop a server definition into $XDG_CONFIG_HOME/xy/servers/<name>.kdl
(see examples/insikt.kdl) and xy reload.
Commands:
xy list
xy status <name>
xy start <name|--all>
xy stop <name|--all>
xy restart <name|--all>
xy reload
xy logs <name> [--tail N] [--follow]
Exit codes: 0 success, 1 operational error, 2 daemon unreachable, 3 config invalid.
Waiting on a dependency
A server can declare a precondition that must hold before it is started:
wait-for {
path "~/.orbstack/run/docker.sock"
timeout "180s"
interval "1s"
}
Exactly one condition per block — path "<p>" (the path exists),
tcp "<host:port>" (a connection succeeds), or command "<c>" with optional
args (the process exits 0). timeout defaults to 120s and interval to 1s.
While waiting the server reports state waiting, and xy status <name> shows
which condition it is blocked on and for how long. If the timeout expires the
server is marked failed and is never spawned.
Waiting does not consume the restart budget: a slow dependency costs patience, not retries. This is what stops a Docker-backed server from being marked failed at login while the Docker daemon is still starting.
Start on login (macOS)
xy service install # write the LaunchAgent, load it, start the daemon
xy service uninstall # unload and remove the agent
xy service start # load an installed agent
xy service stop # unload until the next login
xy service status # show agent state
xy service install snapshots the current PATH into the agent, because a
launchd agent otherwise inherits only /usr/bin:/bin:/usr/sbin:/sbin and
supervised servers would not find their toolchains. Re-run with --force
after installing a new toolchain to refresh the snapshot.
xy service stop lasts until the next login. To disable start-on-login
permanently, use xy service uninstall.
The daemon writes to $XDG_STATE_HOME/xy/logs/daemon.log. Failures that happen
before the daemon starts logging — a missing binary, a malformed plist — are
visible only to launchd:
launchctl print gui/$UID/se.aceofba.xy