I built speedmux to make parallel agent workflows manageable from one terminal interface.
At a high level, the architecture is:
1. one terminal multiplexer process managing multiple concurrent sessions
2. per-session isolation so each agent/task can run independently
3. a persistent sidebar that tracks session state/activity without switching context
4. rendering/performance path powered by libghostty, which keeps interaction latency low even with multiple active sessions
It’s written in Go, and a lot of it was vibe-coded with Codex.
