Updated
What is re-derivation?
Definition
Re-derivation is when a coding agent works out an answer that another agent, or an earlier session, already figured out, because that knowledge was not saved anywhere it could read.
It is a pure-waste cost that scales with the size of a fleet: every agent and teammate pays to re-discover the same things.
The fix is a shared write path, so a thing learned once is readable by everyone next. That is what a record in an SSOT is for.
Give your agents one source of truth.
One current answer per query, with a freshness marker, in about a minute.
Open source. No cloud, no API keys. Your docs never leave your machine.