Idle timers, waking and session limits

Mid-refactor, 20 minutes of silence

Your agent is 40 minutes into a refactor on a 4 vCPU / 8 GB box. It has written six files, a test run is queued in memory, and the model call stalls. Nothing touches the machine for 20 minutes.

1. 00:00

   The last command returns. The agent waits on the model, so no request, command or CPU use reaches the sandbox.

2. 00:20

   Still silent. Whether the machine is running, frozen or already gone depends entirely on the provider's default, not on anything you set.

3. 01:00

   The model answers and the agent sends its next command.

At 00:20 the provider keeps the machine, freezes it, or has ended it. At 01:00 the bill and the work diverge: a frozen machine resumes in place, a stopped one has lost the queued process, and a killed one returns an error.

What each provider does

Agent 37

Still running and still billing: nothing pauses it unless you opt in to auto-sleep.

Blaxel

Asleep after 15 minutes of idle connection, or about five seconds if the pricing page is right; the next request resumes it.

Boat

Awake at 00:20, because the clock counts from creation, not activity; it stops at the one-hour mark whether or not the work is finished.

boxd

Awake: hibernation needs four hours without TCP or UDP traffic, and a stalled model call makes none.

Cloudflare Sandbox

Still running at 20 minutes if the Durable Object stays active; if it goes inactive the instance stops shortly after, unless a timeout of up to 6 hours was set.

Daytona

Stops at 15 minutes even mid-build, because only external calls reset the timer; the VM class would pause at 60 minutes instead.

E2B

Killed at the five-minute timeout, losing the queued test run; a pause would have kept memory, but pausing is opt-in.

InstaBox

Still running at 00:20, paused at 00:30, and woken by the command at 01:00 with the process intact.

Lizard

Already gone: there is no idle timer, and a sandbox made through the SDK expires five minutes after creation.

Modal

Terminated at the five-minute default lifetime before the model answers, unless the timeout was raised to at most 24 hours.

Morph

Scaled to zero after an unpublished period of inactivity, with memory preserved; the 01:00 request wakes it.

Runtime

Paused at five minutes, woken by the 01:00 command in about a second, process and memory intact.

Sandboxer

Paused at 15 minutes on the lowest plan and later on higher ones; the one-hour auto-stop then stops it with memory and disk kept.

Sprites

Paused after about 30 seconds; the 01:00 command resumes warm memory in 100–500 ms.

Vercel Sandbox

Stopped at the five-minute session timeout; the next command starts a new session from the saved filesystem, not from memory.

Tensorlake

Ten minutes without proxied traffic suspends a named sandbox and deletes an ephemeral one; the plan caps the window at 2 hours, 24 hours or not at all.