Rui: an agent runtime that holds 100 agents in 2.5 MB of RAM
A local coding-agent runtime written in Zig that shares one host process across agent sessions instead of one process per agent, with reusable conversations, Bash approvals and crash recovery backed by SQLite.
Why it matters
Author-measured: 100 waiting agents cost 2.5 MB in Rui versus 112 MB in the lightest comparable harness; a compiled Zig binary with no runtime to load.
What you could build with it
A developer running a swarm of background coding agents on a small home server could switch the harness to Rui and keep dozens of idle sessions resident in a few megabytes, instead of watching each idle agent hold onto hundreds of megabytes.
Does it hold up?
Too early to judge: 5 GitHub stars and a quiet Show HN debut; the memory figures are the author's own measurements on one machine, with no independent replication yet.
Built with Rui
- Show HN: Rui, orchestrating 100 agents in 2.5 MB of RAMarticle · Tracks the 7 Nov Show HN debut, which recorded 1 point and 0 comments on its first day.
- Rui: a hundred agents in 2.5 MBarticle · Author blog with the measurement methodology: one Zig host process, sessions as state in SQLite, 2.6 KB per waiting agent.
- Show HN: Rui, orchestrating 100 agents in 2.5 MB of RAMarticle · Show HN thread where the author introduces Rui and its shared-host design.
Learn more
First spotted on github: source.
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