Observed arrival · 2026-08-30

Blastpen, a Room for Coding Agents to Be Wrong

blastpen.app Observed source

Editorial interest 86/100 Selection signal · not a rating of the site

An OS-isolated sandbox for running CLI coding agents inside their own git worktrees.

Landing page captured for the 2026-08-30 issue.

Field notes

Blastpen places a CLI coding agent in a separate git worktree and uses operating-system isolation rather than Docker or a host daemon. The page describes three network modes: fully isolated, user-allowlisted, and open, with blocked-host events intended to distinguish policy failures from broken commands. It also reports warm execution at 5.6 milliseconds in a hardware-isolated VM versus 3.7 milliseconds in a plain process jail, under a stated 12-core Linux test setup.

Observed signals

Read the marks

Editorial observations of this landing page, not a rating.

○OpenPublic substance visible

✦PrettyNotable craft visible

●ProPolished or operationally mature

◎NicheUnusually specific use

ƒJavaScriptBrowser-side code central

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