Hesper: Go daemons for persistent agent terminals across Macs

derzierau · October 11, 2026, 5:41am

I’m the maintainer of Hesper, an MIT-licensed native Mac workspace for Claude Code, Codex and shell agents. The UI is Swift/AppKit/SwiftUI with libghostty, but session ownership and multi-Mac connectivity live in Go.

The problem: several agents can be working on different Macs while their human needs one place to see terminals, notice approval/question states and return to the right session. The app talks only to its local hesperd over a Unix socket; that daemon owns PTYs and connects to the other machines.

Some implementation choices I’d like feedback on:

One multiplexed link per controller/host pair carries agent events and attaches, with direct connectivity when available and a self-hosted relay as rendezvous/fallback.
Terminal messages carry at most 32 KiB. A slow local attach past its 4 MiB queue is reattached with a fresh redraw rather than holding up the whole link.
Input during reconnect is dropped, not replayed. Mutation delivery can have an unknown outcome; we don’t promise exactly-once keystrokes.

I ran the existing transport harness on main (aa76851), on an M1 Max with Go 1.25.5. With injected 20 ms RTT per relay leg (40 ms echo network floor), 300 keystrokes measured 48.4 ms p50 / 59.9 ms p95. Direct loopback measured 0.8 / 3.5 ms. This is a fake-shell transport test with software keys, not app rendering or physical WAN/LAN latency, and not a competitor benchmark.

Engineering note and raw output:

github.com/derzierau/hesper

technical-forum-launch/docs/terminal-streaming-engineering.md

docs

# Keeping remote agent terminals responsive

Hesper is an MIT-licensed macOS workspace for Claude Code, Codex and shell
agents. Its interesting systems problem is not generating code: it is keeping
several interactive terminals usable when their processes live on different
Macs and one viewer or network connection stops keeping up.

This note describes the architecture and a reproducible transport measurement
on main at `aa76851f35dc326900f73e2630e29b4dc18a888e`. It is not a benchmark of
the v0.1.4 Homebrew binary or a comparison with other terminal applications.

## The window does not own the process

The native Swift/AppKit/SwiftUI app embeds libghostty for terminal rendering.
It talks only to the local Go daemon, `hesperd`, over a Unix socket. The daemon
owns the PTYs and agent state and acts as the gateway to other Macs. Closing
the UI and terminating the daemon are therefore different operations. This
does not mean an operating-system process survives a reboot.

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Project and Brew setup: GitHub - derzierau/hesper: Run Claude Code and Codex agents on every Mac you own, and steer them from one fast native window. · GitHub

v0.1.4 is released for macOS 14+, Intel and Apple silicon. Install Claude Code/Codex separately. One Mac needs no relay; multi-Mac currently requires your own relay and device setup. The measurements describe main, not the shipped Brew binary. Native review/diffs, checkpoint-based moves and live-agent forks on main are not yet in v0.1.4.

For people who’ve built PTY or remote-streaming systems: how would you test noisy-terminal interference and communicate dropped input during reconnect? I’d welcome criticism of the recovery boundary and benchmark methodology.