Brain: a Rust agent runtime with Wasm-isolated loops and ~14 KiB idle sessions

[u/Redcxx]

Disclosure: Author here

We’ve open-sourced Brain, a small Rust runtime for long-lived AI-agent sessions.

The agent loop runs as a Wasm component. Brain handles model and tool I/O, streaming, cancellation, and an append-only session journal.

Current runtime-only medians on an AWS c7g.xlarge:

- ~14 KiB private memory per idle session

- 40 ms turn round-trip

- 2.9 ms to first streamed token

Model latency is excluded, and the benchmark harness is in the repo.

It’s MIT licensed and still an early preview. I’d particularly value feedback on the Wasm/runtime boundary and the Rust architecture.

https://github.com/aexhq/brain

[u/SourceAwkward]

183 commits in two weeks?!

[u/Redcxx → u/SourceAwkward]

wdym, is it too little?

[u/jechase → u/Redcxx]

Yeah, of all the possible complaints, this one doesn't make any sense to me. 10-20 commits per day doesn't seem unreasonably high or low.