How can I build a quick tool with Claude to give a client visibility into upcoming cash flow while I'm on vacation?

One member built an HTML tool with Claude for a client experiencing cash flow problems. She identified recurring items (since AP and incoming cash can be variable, but certain payments recur), then had Claude compare this against the past year of transaction history to check for anything missing or unusual. Claude then built an HTML tool where the client can select a date range and payment type to see upcoming obligations (e.g., payroll, rent) for the next few days or week while she's away. Some amounts are prepopulated with historical averages but made editable, since certain costs (like a credit card balance) can vary. The whole build took about 15 minutes.