Exchange
The Webycash exchange is an application module that runs inside your wallet. It trades across
bearer rails (Webcash, Voucher) and arbitrable rails (Bitcoin ARK, RGB) using the extro-402-scheme primitives. It is
not a centralized exchange: there is no server-side matching engine and no custody. Peers and
autonomous agents are both first-class participants — see Peers & Agents (PA2AP).
Settlement is not always atomic, and never custodial.
Bearer legs cannot be locked in a contract. When a bearer asset trades against an arbitrable asset, settlement is referee-mediated, bounded-risk, and non-atomic — there is a defined window where one party has acted and the other has not. RGB ↔ RGB can settle through an RGB-server-enforced state transition. The site never holds funds and the referee never holds bearer secrets or both halves of a 2-of-2.
Asset classes
Bearer secret, splittable by server replace. No conditional script.
Bearer secret with issuer/contract namespace, splittable. No conditional script.
VTXO / signature-controlled. Supports 2-of-2 referee-style release and refund.
Fungible RGB asset. Programmable state via RGB server / AluVM / HTLC predicate.
Non-fungible RGB asset. Programmable, non-splittable state via RGB server / AluVM.
At least one side of any cross-rail exchange involving a bearer asset must be referee-arbitrable or contract-arbitrable: Bitcoin ARK or RGB. Two bearer rails together cannot be made safe and are rejected.
How it settles
Publish
Makers sign limit orders and publish them into a peer-replicated orderbook torrent. Publishing costs 0.1% of order value, paid to active seeders.
Discover
Each wallet sorts the locally observed book by price. A market order walks that book; the taker chooses which orders to fill.
Settle
The taker submits exact order requests. The arbitrable leg releases only against fresh proof the other leg reached the required state.
Worked fee example: publishing an order worth 1.000 units costs 0.001 units (0.1%); with 10 active seeders that is 0.0001 units (0.01%) each. See orderbook economics.
Documentation
Supported pairs
The full pair matrix: which combinations are allowed, referee-mediated, conditional, or forbidden.
Security model
Race-bounded flows, bearer-leg risk, and the invariants that keep settlement non-custodial.
Referee
What the referee can and cannot see, why it is not custody, and the fail-to-deliver flow.