# Split a cost fairly — Redeal

*Canonical page: https://redeal.dev/split*

Split it fairly. Prove it after. You list what's being split. Each side
privately says what each part is worth to them. The algorithm (split.v1,
adjusted winner for two parties) produces a split neither side can envy, and
both sides get a signed certificate proving how it was computed. No account,
no email. Nobody sees anyone's numbers until both sides have locked theirs
in — including Redeal.

## The flow

1. **You set the terms.** Name what's being split, set the answer-by
   deadline, and choose what happens if someone doesn't answer: the deal is
   voided and their silence is recorded on the certificate, or the deal
   simply expires with nothing recorded.
2. **Each side gets a private link.** Redeal creates the deal and gives one
   private link per side. The link is the invitation and the only way in; it
   dies with the deadline.
3. **Both sides value, sealed.** Sealing publishes only a hash. Numbers stay
   hidden until both sides seal, then both open at once. Neither side can
   change theirs after seeing the other's.
4. **Result, identical for both sides.** The engine runs split.v1 and issues
   the certificate — each side's share, the algorithm, the proof, and a link
   anyone can verify at https://redeal.dev/verify.

Worked example of the maths: https://redeal.dev/how-it-works