Keeping the machine awake

A long turn is easy to walk away from. If Windows suspends the machine while claude.exe is mid-turn, the process is frozen where it stands: the turn never completes, and the session is still hanging there when you come back and notice.

While a chat pane is working, the extension asks Windows to keep the system running.

What it holds off, and what it does not

The request covers the idle sleep and hibernate timers, the case this exists for: start a long refactor, walk away, come back to a finished turn instead of a hung one.

The display still blanks on its own timer. Only the machine is kept running, so nothing is lit up for no reason.

It does not hold off:

• Sleep you asked for: closing the lid, the power button, Start → Sleep. Windows drops every power request on a deliberate sleep, by design: an application does not get to veto you.
• Modern standby on battery. On a laptop using modern standby (S0 low power idle), Windows terminates system power requests 5 minutes after the sleep timer expires, whatever we ask for. A turn longer than that can still be suspended while on battery. On AC power, and on older laptops using traditional S3 sleep, the hold lasts for the whole turn.
• Forced sleep: group policy, a critical battery level, or shutdown-style commands.

When it holds

Only while a chat pane is actually working:

a turn is running	held
background agents still running after the turn’s reply	held: the work outlives the reply
waiting for you to approve a tool	not held: nothing is computing, and you may be away
pane open but idle	not held
a CLI pane	never held

CLI panes are excluded on purpose. A terminal has no notion of a turn, and telling a running command apart from an idle prompt would mean scraping its output, which would eventually hold the machine awake forever on a pane sitting at a blinking cursor.

The hold is also released when the pane is closed, when claude.exe exits or is killed, and when Visual Studio shuts down. If the CLI stops responding entirely (no output, no exit) a watchdog releases the hold after 5 minutes of silence, or 15 while a compaction is running, since a healthy one produces no output. With the log level at Warn or higher the Output window records it: [power] pane #2 silent for 5 min, releasing the sleep block.

Seeing it

Windows can tell you who is keeping the machine awake. From an elevated prompt:

powercfg /requests

While a turn runs, the SYSTEM: section names us:

SYSTEM:
[PROCESS] …\devenv.exe
cv4vs Agents: a chat turn is running

Nothing there means nothing is held: which is the expected answer between turns, and while a permission prompt is waiting on you.

Turning it off

Tools → Options → cv4vs Agents → General → Prevent the machine from sleeping while a session is running. On by default; unticking it releases any hold immediately rather than at the end of the current turn.

See Options → General.