Throughliner's titular feature is the through line.
It's one of the most unusual things about it — and once you're used to it, you may wonder how you built without it.
The idea: every choice you make while building has a reason behind it. Normally that reason lives in your head, or in a chat that scrolls away, and a month later it's gone. The why-pipeline is a channel that carries the reason right alongside the work — the whole way — so it never gets lost.
Let's follow one decision through from one end of the build cycle to the other. Say, mid-conversation, you think: "Let's not make people sign up — just let them in. Signups can come later."
- It's caught the moment you say "please capture that.." — the decision and your reason (a signup wall scares people off before they've even tried the thing), appended to QUEUE as a "capture."
- It's kept when you plan — the capture is retrieved and further articulated in plain English as you settle it: the whole thought, not a shorthand label, into a work item at the top of QUEUE.
- It's carried into
/next— the reason travels with the work, so the app gets made the way you meant it. - It's recorded on
/donein your log — permanently, in words you'd actually recognize later.
Three months on you wonder: "Why don't I have accounts?" You ask Claude, and it searches the log using the INDEX and then reads your rationale straight back to you: "you skipped them on purpose, to lower the barrier to trying the app."
The why-pipeline never locks anything in. It just makes sure every decision is one you can actually see — so when you revisit it, you're deciding, not guessing.