Empty windows

Run it

In a terminal, run npx empty-windows. Add --fee 200 to show your monthly fee next to the share of empty windows.

The command runs on your computer and makes no network request. It has no uploads, no telemetry and no account. It prints the empty windows, the days with no agent work and the hours when windows most often go empty, and it writes a card with totals only.

Source and package: empty-windows on npm.

How it counts

1. A window opens at the first agent activity and stays open for 5 hours.
2. The first activity after that opens the next window.
3. Each complete 5 hours with no activity between two windows is one empty window. A rest shorter than 5 hours counts as nothing.
4. A window with one short prompt counts as used, the same as a full window.
5. The range is the last 30 complete days in your local time. Today does not count.

What it reads

Claude Code

~/.claude/projects: user and assistant lines

Codex

~/.codex/sessions and ~/.codex/archived_sessions: response_item and event_msg lines

From each line it keeps the time, rounded down to the minute, and nothing else. It does not keep prompts, paths or repository names, so they cannot reach the card.

What the number does not say

The number is a lower bound. Only empty windows count, so quota that was left in a partly used window is not in it.

It makes no claim about plan limits. The command does not read your plan, and a provider can change its limits at any time.

The 5-hour window is a simple model of how these subscriptions measure use. It is not a statement from a provider.

The fee on the card is the number that you typed. The command does not turn it into money that you lost.

Work on another computer is not in your local logs.

From a marked TODO to a Night shift run

Rondar is an agent workspace. Its Night shift gives empty windows some work: you mark work during the day, and it runs in your quiet hours on quota above a reserve that you choose. It needs a subscription whose usage limits Rondar can read.

Turn it on

In Settings, Agent settings, turn on the Night shift. Choose your quiet hours, the projects, and the reserve to keep in each window.

Mark the work

Press Add to night shift on a TODO. A plan step or a Sentinel suggestion can go in the shift too.

Rondar reads your windows

In the quiet hours, Rondar reads the usage windows of your subscription connection. It starts the next item only when every window has more quota left than your reserve.

The work ends on a branch

The session works through the normal session queue and ends on a session branch. Until you decide, it opens no pull request and it cannot merge.

Decide in the morning

One notification reports the night. The Sentinel page shows each result with its preview, its diff and the quota that it used, and what reset unused. Open, Continue or Discard each result.

Try the Night shift