About

I'm Bill Chappell. I'm a retired software developer. I spent my career integrating large systems for large companies, much of it in software for the radiopharmaceutical industry, including at Sofie Biosciences.

I built GAAPcore by directing coding agents. I spent my own time on the parts that decide whether software can be trusted: the specs, the data model, and the review.

How it was built

Spec first. Every transaction type has a written spec before any code: the business trigger, the journal entries, the FIFO effects, every validation with its error code, how it reverses, and the US GAAP notes. There are 129 of them now.

An independent review gate on every migration. Each of the 107 schema migrations went to a separate reviewer before it merged. The reviewer's job was to break it. Of the 31 migrations logged since early October, 20 came back on HOLD at least once, each with a concrete way to make the books wrong, and were fixed and reviewed again.

Thousands of automated checks. Every rule has a test that proves it refuses what it should. The database suites post realistic documents, try to break each rule, and roll back. The API has its own tests on top.

Gaps written down, not hidden. Every place the schema doesn't yet do what a spec needs is a numbered gap with a decision next to it. There are 402 so far.

From early October, under a written charter, I took myself out of the day-to-day loop. The agent chose the next item, put it through the review gate, and merged only on approval. I read the log and set direction.

Why I'm writing here

I'm looking for a few developers who build business software with coding agents and want an accounting core they don't have to write. If that's you, request access. If you'd rather have the console built for you, I can help with that too.