You're speccing features against business logic
you can't verify.

You write a spec. It describes what the feature should do. It's clear. It's detailed. You ship it to engineering.

Then someone Slacks the CS lead: "Wait — do we actually do this for enterprise accounts?" You don't know. So you ask the domain expert. They give you a partial answer. You reply-all with a half-clarification. Spec goes back to engineering. A week later, you're rebuilding what they already shipped.

This happens because your spec asked "what should the feature do" — not "what does the business actually require."

Most tools return a "no results" page when the answer doesn't exist yet. FieldRules is designed not to. By design, when your query hits a gap, the library captures the gap as structured context — what topic, what feature you're speccing, who the right expert is — and routes a live signal to that expert.

The expert doesn't get a documentation reminder. They get a card from a colleague: "The PM needs your expertise on enterprise billing before sending to engineering." They confirm the rule in 30–60 seconds, in their own words. Your next query gets answered — by the person who actually knows.

A domain expert knows why a rule exists. They know what breaks if you break it. They know the exception cases and the edge cases and the one thing that will never work even though it looks like it should.

But unless that expert is in the room when you write the spec, that reasoning stays in their head. Or scattered across a Slack thread that nobody else will ever read.