Charlie Cheever

@ccheever.com on 🦋/ working on @expo & @castlexyz

[Charlie Cheever @ccheever]

I want to share a preview of something I've been working on called Exact. It's a new Agent Native app framework written in Rust. It's extremely fast and tries to let you build exactly the experience you want with no compromises.

[Charlie Cheever @ccheever]

@g48in Works for all iOS apps

[Charlie Cheever @ccheever]

Introducing Expo Simulators

[Expo @expo]

Coding agents write mobile code faster than any team can review it.

🙌 Introducing Expo Simulators: cloud simulators built for agents.

Your agent runs its change on a cloud simulator or emulator and brings back the recording before it asks for your attention.

[Garrett Lord @GarrettLord]

So proud of our team! HandshakeAI didn't exist 2 years ago.

Today we’re on the inaugural AI 100 from @NewcomerMedia and @BessemerVP.

[Charlie Cheever @ccheever]

@dalmaer Web apps or mobile apps? Just curious.

[Tudor Achim @tachim]

A new frontier for hardware verification, open for all

[Mudassar Raza · building apps @mudassar6969]

This is huge! There's a workflow I've been wanting to build for a while, and Expo Simulators might finally make it possible. 🔥

[Peter Piekarczyk (🥧🚗🐥) @peterpme]

@ccheever @eiioth appdrop is so cool
i couldn't believe it

[Mike Pitre @mikepitre_]

@clerk 🤝 @expo exact

[James Ide @JI]

PSA: The CDC warns against high temperatures on a male’s lap. Literature in the NIH NLM suggests 35°C/95°F as a cutoff.

M5 MacBook Pro can exceed 43°C/110°F under high load like builds & simulators.

Let Expo infrastructure and your cloud agents take the heat. For the children.

[Charlie Cheever @ccheever]

Give these a try ASAP if you are trying out Exact. Extremely fast builds in cloud (often < 30 seconds). And even more exciting, the ability to send what you make to someone else on iPhone right away.

@eiioth is behind both of these, and they are early yet already excellent.

[Eliot Hertenstein @eiioth]

Exact is super performant. But it also enables an ultrafast developer experience.

Today we're announcing two services, both in alpha:
- Exact Build is a high speed (linux-based) iOS build service
- AppDrop is a simple way to sign and distribute IPAs to anyone

[JP ✨ @JPoliachik]

Claude go build this thing
then test and run on an Expo Simulator
and send me the recording so I can watch

this was the missing link for mobile devs, honestly

[James Ide @JI]

@dmarcosm98 @dalmaer Yes though Android support is much more nascent. We’ve put a lot more attention into iOS so far, and also may use the host platform on Android less than on iOS because UIKit performs and behaves well but Android Views may be worth rethinking.

[szymon @szdziedzic]

.@expo team is cooking!

[Expo @expo]

Some of what Expo Simulators unlock:

→ Agentic CI: every PR tested on a simulator, PASS or FAIL with the recording
→ Bug triage: a TestFlight screenshot becomes a reproduction and a fix
→ Review from a link: PMs and designers tap through the new build in their browser before merge

[James Ide @JI]

“Still in Kokiri forest and it’s not even the Lost Woods” level of busy

[Dion Almaer @dalmaer]

I ported 3 apps to Exact yesterday. Have to admit it was a pleasure. So different when you can explore something bleeding edge in an entirely new way. The “risk” and ROI equation is totally different.

[szymon @szdziedzic]

cloud simulators for your agents, no matter where they run, no matter what framework your app uses

use Expo Simulators to build software factories and agentic workflows that really scale

https://t.co/0aS7kCNlM9

[Joe Ryan @joe_d_ryan]

This week has been insane @expo

1. @expo Exact
2. @expo Simulators
3. @expo Explore
3. The new Expo app

[Bobby Goodlatte @rsg]

We’ve been using Expo Cloud Simulators to test builds of @trysunflower’s upcoming Beta

It’s an incredibly powerful tool. And useful even if you’re not using Expo’s cross-platform frameworks

Awesome product. Expo is on a roll lately 🚀

[Diego Arias @diegoarias941]

Very cool! But I dont see anyone asking the real important questions..

Can it run DOOM? Yes

My agents are currently testing and profiling DOOM built on Exact remotely via Simulators 🤯

[James Ide @JI]

Expo Simulators are here to help everyone achieve autonomous app development, whether you are a solo dev or at a top AI lab at a public company. Developers just like that were among the early adopters who previewed Expo Simulators and gave us lots of great feedback. Thank you!

We heard:
- Agents just know how to use the simulators
- The need for speed & security
- How Simulators power RL (for AI labs)
- “Thank you guys for building such a great product.”