Rpi – a Rust rewrite of the Pi agent, 10× faster startup

MarleTangible · 2026-10-01T19:33:14

The table corrected:

  Metric          rpi (Rust)   Pi (TypeScript)   Difference
  --version       17.5 ms      169.5 ms          9.7x faster
  Cold start      17.7 ms      189.5 ms          10.7x faster
  RSS when ready  12.0 MiB     91.5 MiB          7.6x smaller
  Install size    21.8 MiB     ~385 MiB          ~18x smaller

vincent-uden · 2026-10-01T11:52:43

This kind of invalidate the pitch of Pi, the self-modifying harness. You can't use the Pi extensions I'm assuming...

Without a plan of your own for extensions this is comparing apples to oranges. My Pi startup time is dominated by loading extensions and skills, and I don't even have many to begin with!

(It seems like there is a pluging API judging by the Github repo. That wasn't linked in the comments by the time of my writing)

dv_dt · 2026-10-01T15:26:47

I wonder about adding a plugin shim for webassembly, or a Rust crate with integrated V8 engine (Bun?). But honestly, I use pi and I have yet to ask it to self-modify.

vincent-uden · 2026-10-01T15:44:49

I mean, kinda same. I've asked it to write skills but that is about it. And skills dont require this. But I do use other peoples extensions.

dv_dt · 2026-10-02T10:50:35

I suppose one potential drawback is that the visibility of the logic of a plugin is inherent in the pi ts extensions, and unless it's shipped with the rpi (pi-rust) extension, it may not be the same to use it. There are instances where I've seen pi go digging around in it's own docs & code to figure out how to do something.

bigfishhk · 2026-10-03T14:55:13

There is a tool named Docs that guides users on how to use RPi and how to write extensions. RPi has a plugin ABI to support extensions.

syrusakbary · 2026-10-01T15:57:57

Nice!

This is great. A few days ago we were able to enable running Pi fully in the browser (and in the iPhone). Demo here: https://wasmer.sh/?example=pi

I'd be curious if we could compile Rpi to WASIX (https://wasix.org) and get it there as well!

voidUpdate · 2026-10-01T12:04:18

That name won't be confusing at all

jokerx001 · 2026-10-09T07:31:26

en...even rust seems like more fast.But, for a coding agent in cli,this is not necessery.The important things is the community and extension.Pi agent in ts not slow.

bigfishhk · 2026-10-01T12:08:47

github repo: https://github.com/bigfish1913/pi-rust

Zeeshan_02 · 2026-10-04T18:37:24

How would you handle a co-founder whose commitment appears to have changed?

sejje · 2026-10-05T17:04:16

I'd make him use Claude Code