Archil finds short AI tool calls don’t need persistent sandbox

The author argues that most AI agent tool calls do not require a persistent, running sandbox for the entire session. By measuring coding-agent sessions, the author shows that the median tool call finishes in half a second and that starting short-lived Firecracker microVMs against a persistent disk is fast, cheap, and eliminates idle overhead. However, long-running processes, in-memory state, and commands exceeding five minutes still require a persistent sandbox. Open article →