I just created a new GitHub repository for the Python scripts I use for my accounting workflow. It has a new approach to envelope budgeting that doesn't require virtual accounts and automatically updates an envelope every time a purchase is made. The budget process is outlined at Envelope Budgeting - Dexter, and there is a more detailed description at https://conery.github.io/dexter/envelopes_dex/. I used a NoSQL database in my system so it's not strictly a plain text accounting system, but the system imports and exports Journal files and the budget scheme would work in Ledger and hledger. I'm interested to hear what you all think!
Dexter is John Conery's PTA-friendly, open source accounting tool, written in python and requiring MongoDB. It has excellent documentation and an elegant approach to budgeting.