D001 - One target library for the collection

Status: decided Date: 2026-09-26

Prosperous is the one library that reaches a target, taken by the sibling projects as relative path dependencies. pros-cli and pros-gui are interaction surfaces over its crates and hold no rules of their own.

Why: two projects had begun building the same transport, and two copies drift. A command line and a window that apply the same rules from one place cannot disagree about a target.

Rejected:

• A transport copy inside each consumer: the copies drift and each fixes its defects alone.
• Publishing the crates and depending on versions: trades a checkout convention for a release process.
• Rules in the shims: a second front end then needs a second implementation.