Every CFO knows this week.

You build the 13-week cash forecast on Monday.

And by Friday a customer has paid late, a vendor has been paid early, and the forecast is already out of date. So you open the spreadsheet and start again.

Why not give this job to Claude Opus 5.5?

I gave it one file with our week 1 cash position, the collections we expect, and the payments already scheduled. It built the 13-week cash flow forecast. Then it tested the forecast, found what was wrong, and fixed it.

But that’s not it.

Plenty of tools can build a forecast. Claude Opus 5.5 checked its own work and improved it, the way a great CFO analyst would.

Anthropic released Opus 5.5 on September 22.

It costs about 40% less to run than Opus 5.

In Anthropic’s test of company earnings reports, where a single made-up figure meant a fail, Opus 5.5 passed 16 of 18 times. Opus 5 and Fable 5.1 didn’t pass once.

Today I’ll show you how to use Opus 5.5 as a CFO.

And set it up with a weekly cash forecast (.skill) and one file (.xlsx).

You install the weekly cash forecast (.skill), upload your week 1 cash file, and get a forecast you can update every week and take straight into your board deck.

Let’s dive in.

How to build a weekly cash forecast with new Claude Opus 5.5 as a CFO

Download the weekly cash forecast (.skill) below

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