Overview
You already have the organs, and they already read one poops.json:
| Organ | Its job | You reach for it when |
|---|---|---|
| poops | bundler + static-site generator | you have pages to compile |
| septic | schema, REST API, generated forms, the build bridge | those pages need data |
| laxative | conductor — runs both on one origin | a form on the built page must POST to /api on the host that served it |
What was missing is that last row: running them as one thing, on the same host, so a generated <form> POSTs to /api on the origin that served the page. That's laxative — and it is the only piece of the three that isn't also useful alone.
Not an engine
laxative reimplements nothing. No templater (poops), no DB/CRUD (septic), no bundler, no form engine. It is init + dev + build + serve — a conductor over two mature tools. If it grows an engine, it's wrong.
Not (only) a template
Scaffolding a starter is one command (laxative init) and could be a template. laxative's real, net-new value is the one-origin runtime — dev/serve serving septic's API and poops's output together. That's the part a template can't be.