Launching today

npm i -g hotcell

Launching today

Local sandboxes for AI agents on your Mac, Linux, bare metal

82 followers

Local sandboxes for AI agents on your Mac, Linux, bare metal

82 followers

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Command line tools

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AI Infrastructure Tools

Self-hostable sandbox SDK inspired by Cloudflare Sandbox SDK. works on any device (Mac, Linux, bare metal). super easy to use (both by human engineers and agents). you get full control over capacity/token spent per sandbox, you can default-deny egress but still allow access to LLM providers, and API keys never directly enter each sandbox (it creates per-sandbox tokens instead that die when the sandbox stops). npm i -g hotcell

Free

Launch tags:Open Source•Developer Tools•Artificial Intelligence

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Framer AI AgentsDesign and publish professional sites with AI

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npm i -g hotcell

Maker

📌

hello humans of PH :) i wanna share this open source project (apache 2.0) that i've been working on for the past 2 ish months or so. it's called hotcell and it lets you create/pause/manage sandboxes on any device (your laptop, linux vm, bare metal). i've tested it against various benchmarks that i found on computesdk (https://www.computesdk.com/bench...) as well as the one shared by dax (cofounder of open code) on twitter recently (link to his original thread and my reply https://x.com/sinasanm/status/20...) and generally the full benchmark results are here: https://github.com/sinameraji/ho...... i spent a lot of time on making sure both the devrloper experience and agent experience are smooth on it and im actively working to make it perform better against benchmarks. also api keys are never directly injected into the sandbox. instead it creates a per-sandbox token that becomes useless when the sandbox dies. as for isolation method, it can work with docker, apple VZ (vm grade isolation on mac) or firecracker for linux . primary use cases i imagine: * if you build agentic desktop apps that have filesystem access locally, hotcell makes it super easy to start a sandbox and bring whatever file needed to it, do the work in a new branch, create a PR and close the sandbox * if u just use claude code etc. and wanna spin up 5-6 diff environments without using worktree or cloning your project dirs, u can write a 1 line command like this to instantly have 5 sandboxes! hotcell create -n 5 --name feat --branch auto --opencode --repo https://github.com/you/app my inspiration was cloudflare sandbox sdk (but i noticed my friends and i couldn't use cloudflare in on-prem environment so i thought i'd build a local / open source one that works w any hardwarw). thank you and hope you like it.

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3d ago

What's the isolation model - containers, lightweight VMs, or something custom? Curious how heavy it feels on a laptop running a coding agent alongside the sandbox.

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5h ago

npm i -g hotcell

Maker

@kritishpuri not custom. 3 drivers: containers (docker) by default, or microvms, firecracker on linux/kvm and apple VZ on macos. you can set a default once at setup and can override it per sandbox (--driver), so a single daemon can run both tiers at once.

re: weight, here are some numbers (all in docs/benchmarks.md):

idle footprint measured ~54 mb of host ram per firecracker vm (40 on a 4-vcpu box).

on a real workload (clone + install + typecheck) virtualisation cost was ~16%.

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4h ago

StepGrab

Sandboxing agents locally makes a lot of sense to me. How much does the isolation cost you in practice on a Mac? Curious whether it's noticeable or whether it disappears into the noise.

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8h ago

the per-sandbox scoped tokens that die with the sandbox is honestly such a clean move, keeps api keys out of the blast radius without making the workflow annoying

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8h ago