2 posts tagged with "preorder"

This is part two of a two-part series on building a presale on Cardano. Part one covered the on-chain contract - how a purchase receipt is enforced so a participation is only recorded if the buyer really paid. This post is about the app on top of it.

Standing up a presale used to mean wiring a sale contract, an indexer, a payment flow, and a UI before you could take a single order. With the EffectStream preorder launchpad, creating a campaign on Cardano comes down to two steps: clone and publish. This post walks through the app built on top of that contract - and the piece that makes the Cardano side genuinely fast: UTxORPC.

A presale (a launchpad / preorder) sells a catalog of items before they exist: a buyer commits funds now, and the project records who bought what so it can fulfil later. The thing you actually want to guarantee is simple to say and surprisingly subtle to enforce: a participation should only be recorded if the buyer really paid for it — the right amount, to the right address, while the sale is open, and (optionally) crediting whoever referred them.

This post is about doing that guarantee on-chain on Cardano, with a small Aiken minting-policy validator that issues a "purchase receipt" only when the payment rules are met — and about where the rest of the presale logic (catalog, prices, conversion rates) lives so the whole thing stays deterministic. The same app also runs the EVM flow, and the Cardano contract is built to be compatible with that EVM presale — same catalog, same referral model, same recorded state — which we'll come back to once the Cardano picture is clear.