plainbudget is a minimalist budgeting app that lets you sum your cashflow in plaintext: think Markdown, but it's a spreadsheet.
There are two kinds of value groups: cashflow and expense. A cashflow value group always starts with one or more + operations, followed by one or more – operations. Calculating a cashflow group will add an extra line with the result:
A more powerful command-line budgeting app is Ledger.