go-uds-jsonrpc

go-uds-jsonrpc is a tiny library for building local daemons in Go that talk to client processes over a Unix domain socket using newline-delimited JSON-RPC.

It sits between net/rpc (too rigid, gob-only, no push) and gRPC (too heavy, IDL, codegen, HTTP/2) for the very common case of:

one daemon, several local clients, one machine.

Features

• Three message shapes on one stream. Request (client → server), Response (server → client), Event (server-pushed, no ack). All serialized as one JSON object per \n-terminated line — debuggable with socat, scriptable from any language.
• Server scaffolding. Handler registry, panic recovery, OnConnect / OnDisconnect hooks, Broadcast/BroadcastFunc for events, context-driven shutdown.
• PID file + IsRunning. Single-instance guard that works on Unix (signal 0) and Windows (OpenProcess + GetExitCodeProcess).
• XDG-aware socket paths. $XDG_RUNTIME_DIR/<app>/<app>.sock on Linux, ~/Library/Caches/<app>/ on macOS, sensible fallback elsewhere.
• Signal handler. SIGTERM/SIGINT → shutdown, SIGHUP → reload, wired in one call.
• Zero dependencies. stdlib only.

What this is not

• Not RPC for the open internet. No TLS, no auth, no rate limiting. Unix-socket permissions (0700) are the auth model. Same-user-only.
• Not a service mesh. One listener, one process per daemon.
• Not JSON-RPC 2.0 compliant. We borrow the error codes for familiarity but use a leaner wire shape — no "jsonrpc": "2.0" preamble, no batch arrays, no notifications-vs-requests distinction beyond Event-vs-Request.

Sister projects