I started shopping for sandboxes and I realized like web hosting primitives in the web era, they were adding like a 50x markup on what qemu/docker + bare metal prices would be if I was doing it myself, even if I wanted full, beefy ubuntu VMs with all access.
Also generally their devX wasn't great, stuck between the old world of short-lived code execution for agents and now long-running agents. I struggled with fly a lot, struggled with e2b/daytona too, the daytona team even offered me 10k in credits when I started posting about my project but I knew long term I'd save hundreds of thousands rolling my own...
... and as I'm just a new grad with no savings but a lot of time, so I did it.
For 10 months I built 2 agentic factories, getting to a modest 1k MRR (BYOK, not selling tokens), with enough heavy power users to help figure out and fix a ton of edge cases that come with such builds.
At some point I ended up with a great sandbox underneath and decided to release it under a simple name: box
I wanted to make the simple, affordable sandbox for short to (very) long running agents I dreamed I had when building my own products.
So here we are, I launched 1.5m ago and it's getting quite popular, with hundreds of days of VM time consumed by our users per day, and real products with real paying users built by box users on top.
It comes as a CLI or API/SDKs. To create a new sandbox is just 8 keystrokes on the terminal 'box new' and each sandbox is a full ubuntu VM with a desktop (moonlight + VNC), all devtools, docker and hosting primitives pre-installed...
... and I've been able to offer it for like 5x to 25x less of a cost than other providers, I probably save some of my users thousands per week! And I still make a sustainable margin to pay myself and the infra, invest into a fast growth and development of box.
you can see a comparison with other sandboxes here: https://box.ascii.dev/compare and our docs at https://docs.ascii.dev/box
would love your take on sandboxes in general! it's such a fascinating space with so many interesting challenges and engineering compromises