# Redeal — Fair splits, provably

Two or more parties (people or AI agents) submit sealed inputs. A published,
deterministic algorithm computes the split. Everyone receives an identical
signed certificate that anyone can verify.

- Split a cost now: https://redeal.dev/split
- Pick one at random: https://redeal.dev/random
- Read the API docs: https://redeal.dev/docs

## Check a certificate

Verification is free, forever, and needs no account. Paste a certificate ID at
https://redeal.dev/verify — the signature and the transparency-log inclusion
proof are recomputed on every request. The API gives the same answer:
`GET https://api.redeal.dev/v1/verify/{cert_id}`.

## The v1 catalogue — three algorithms, nothing else

- **split.v1** (n ≤ 16) — fair division. Split a cost or a set of items so
  nobody envies anyone's share. Adjusted winner for two parties, proportional
  for more.
- **shapley.v1** (n ≤ 8) — share by contribution. Shapley value over a declared
  coalition function.
- **random.v1** (n ≤ 10,000) — verifiable random pick. Entropy is the XOR of
  every party's sealed nonce and the drand beacon at a pre-declared round.

## The protocol, in four steps

1. **COMMIT** — each party submits a hash of their input. Nobody can see the
   inputs, not even Redeal, and no one can adapt their input to anyone else's.
2. **REVEAL** — once all commitments are in, inputs are revealed and checked
   against the hashes. A party that flakes gets named in a non-participation
   certificate.
3. **COMPUTE** — the algorithm is published and deterministic: no floats, no
   external data, no randomness Redeal controls.
4. **CERTIFY** — every party receives an identical signed certificate,
   appended to a public transparency log.

## Why you don't have to trust Redeal

- The engine is built to be audited, with published test vectors.
- Inputs are sealed until lock-in.
- Computation is deterministic: no AI, no floats, no external price feeds.
- Every certificate is appended to a public Merkle transparency log
  (signed tree head: `GET /v1/log/tree-head`).
- Every certificate is signed; the verifying public keys are published
  at `GET /v1/status`.
- Raw inputs are never sold or shared and never enter telemetry
  (data policy: https://redeal.dev/trust/data-policy).

Redeal certificates describe a computation, not a ruling. Redeal is not
arbitration, mediation, escrow, or legal advice, and never holds money.