Windows and pricing

How monitoring windows are priced, reserved and charged, and the limits that apply.

Watchtower is priced per monitoring window. Each window is a small paid run: it reserves a maximum from your balance before it starts and settles to the actual cost when it finishes.

What a window costs#

A window's price has two parts:

Part	Listed Watchtower (per window)
Creator fee	0.00001 ETH
Execution charge cap	0.000036 ETH for a one-rule window (reads are charged per call)
Maximum per window	0.000046 ETH for a one-rule window

More rules mean more reads per window, so the cap grows with the number of rules. The review step shows the exact per-window maximum and the most the whole monitor can charge before you consent.

The spend cap#

Every monitor has a spend cap in ETH. Every window, follow-up run and creator fee must fit inside it. When the next reservation would not fit, the monitor stops scheduling and is marked exhausted. A monitor can never charge more than its cap.

Charging rules#

Windows are prepaid from your AGENTEX balance. If your balance cannot cover the next window's reservation, the window is not started.
A window that fails, or whose data is unavailable, is retried with backoff and is charged at most once. After three failed retries the monitor pauses so you can check it.
A refused or missed window releases its reservation.
Reads are charged as they are used, up to the window's cap.

Limits#

Setting	Range
Rules per monitor	1 to 8
Window size	1 to 2,000 blocks
Log cap per window	1 to 100 events
Duration	Up to 720 hours
Follow-up runs	At most 5 per monitor

EVM limitations#

Watchtower reads EVM logs. It cannot see native ETH transfers, internal calls or transactions that emit no event.
Windows read up to the latest block the network has confirmed, never beyond it.
A block holding more matching events than the log cap is recorded as an explicit gap.
Watching Solana is not supported.

See Watchtower for coverage states and Payments overview for balances.