Build a self-hosted bookkeeping and finance app
According to the write-up, the poster first used ChatGPT for a high-level accounting plan, then had Claude turn it into an implementation plan, and used Codex to find gaps before sending revisions back through Claude’s UltraPlan for a few rounds. They then ran the plan to build a self-hosted Mac app where bank transactions come in through an MCP, Claude tags them to Schedule C categories, uncertain items go to a review queue, and the poster’s fixes become reusable rules. They say it handled a couple thousand transactions, was assembled end to end in two days covering a simple Android dashboard app, and cut their software spend from about $524 a year to a $60 yearly bank-feed cost.
- Agent or tool
- Claude
- Topic
- Finance
- Reported on
- Added
- 2026-10-15
Why it matters
Money tasks are tedious but high-stakes, which is exactly where a careful agent helps: it does the checking and paperwork while a person keeps the final say. It is one of 65 sightings filed under Finance on Agent Sightings (number 37 by interest), and one of 91 involving Claude.
How you could try it
Here is a reusable prompt, written by us in our own words, that captures the task. Paste it into Claude or any similar agent and adjust the details to your situation.
Finance task: build a self-hosted bookkeeping and finance app. Tabulate numbers, mark uncertainties, and do not file, pay, or submit until I confirm.
Tip: Keep the agent in 'propose, don't pay' mode: let it gather numbers and draft messages, and approve any payment or account change yourself.
Source
Read the original first-hand account on Reddit: https://www.reddit.com/r/ClaudeAI/comments/1uerum1/spent_a_weekend_getting_clau…. Our summary is a paraphrase; details are in the source.