Re:Deno Sandbox
by simonw on Tuesday February 03, 2026 @01:27PM
(#46875015)
Note that you don't need to use Deno or JavaScript at all to use this product. Here's their Python client SDK: https://pypi.org/project/deno-sandbox/
Looks like the API protocol itself uses websockets: https://tools.simonwillison.net/zip-wheel-explorer?package=d...
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Re:Deno Sandbox
by koakuma-chan on Tuesday February 03, 2026 @08:08PM
(#46879982)
Because the sandbox is on their cloud, not on your local machine, which wasn't obvious to me.
It's stated under the "Sandboxes?" heading.
> Deno Sandbox gives you lightweight Linux microVMs (running in the Deno Deploy cloud) ...
Took this idea and ran with it using Fly's Sprites, inspired by Simon's https://simonwillison.net/2026/Feb/3/introducing-deno-sandbo.... Use case: Claude Code running in a sandboxed Sprite, making authenticated API calls via a Tokenizer proxy without credentials ever entering the sandbox.
Hit a snag: Sprites appear network-isolated from Fly's 6PN private mesh (fdf:: prefix inside the Sprite, not fdaa::; no .internal DNS). So a Tokenizer on a Fly Machine isn't directly reachable without public internet.
Asked on the Fly forum: https://community.fly.io/t/can-sprites-reach-internal-fly-se...
@tptacek's point upthread about controlling not just hosts but request structure is well taken - for AI agent sandboxing you'd want tight scoping on what the proxy will forward.