How the Gallery works

(Testnet06 deployment — real mechanics, test value.)

One idea: the contract enforces what marketplaces usually just promise

On most NFT platforms, royalties and fees are policy — the platform’s code decides, and the platform can change it. In the Gallery, the rules live in an on-chain contract that anyone can read, and the important ones cannot be changed by anyone, ever:

• The artist’s royalty is fixed when the token is minted (0%–50%) and is paid on every sale, automatically, from inside the settlement. No marketplace opt-out, no “royalty optional” toggle.
• The platform fee is currently 2.5% and the contract hard-caps it at 5% as an immutable constant. No upgrade, vote, or administrator can ever raise it past that.
• Settlement is escrowed and conservation-checked. When you buy, your payment goes into a contract-controlled escrow, and the contract pays out artist + platform + seller in the same transaction — and asserts that the amounts add up to exactly what you paid, to 12 decimal places. If a single fraction went missing, the sale would abort.

The open standard underneath

The Gallery is the production implementation of the Kadena NFT standard v1 — three open interfaces (nft-asset-v1, nft-market-v1, nft-xchain-v1) that define what a token is, how a fixed-price sale must settle, and how a token moves between chains.

The standard is owned and published on-chain by the Pact Community Organization (PCO) in its own namespace, the way Kadena’s own fungible-v2 standard underlies every token contract. Any other marketplace can implement the same interfaces, and one wallet or indexer works across all of them. The Gallery is the first — not the owner — of the standard.

Interfaces on a Kadena chain can never be upgraded. What PCO published is permanent on this network. That’s the point: the compatibility surface can’t be pulled out from under anyone.

What a Gallery token is

A Gallery NFT is a 1-of-1: one token, one owner, indivisible. At mint, the creator fixes three things permanently:

“Sale-only” (transferable: false) is the strong royalty guarantee: such a token has no royalty-free exit — it cannot be gifted, and it cannot even move to another chain except to its own current owner.

What happens when you buy

1. You sign a payment of exactly the listed price — your signature authorizes that amount to the escrow and nothing else. If the seller re-prices after you signed, your purchase simply fails; you can never be made to overpay.
2. The contract pays, in one atomic transaction: the artist’s royalty (at the rate fixed at mint), the platform fee (at the rate snapshotted when the item was listed — a fee change never affects an existing listing), and the seller’s remainder.
3. The contract asserts the escrow balance returned exactly to where it started.
4. Ownership flips to you, and a SOLD event with the full split is emitted for any indexer to read.

The platform fee is Smart Pacts’ funding: it routes on-chain to the Smart Pacts funding account on the same chain where the sale happened.

Cross-chain moves

Kadena is 20 braided chains, and a Gallery token can relocate between them natively: a two-step process where the token is sealed on the source chain and, with a cryptographic proof (SPV), re-created on the target chain — royalty terms and all. Listings never travel (you must delist first), and a sale-only token may relocate only to its own owner, so the transport layer cannot be used to dodge a royalty. See Move between chains.

Verify it yourself

Nothing above requires trusting this page:

• Contract: n_d97ffd2ca290429b5dc85ce551a8d07d038e9641.smartpacts-gallery — one identical hash on all 20 chains, checkable with (at 'hash (describe-module "…smartpacts-gallery")) against any node, or on the community explorer.
• The standard: n_e82dd10f74b7e8c253553de95629fdfa35cf8379.nft-asset-v1 / nft-market-v1 / nft-xchain-v1 — published hashes in the PCO contract catalog.
• Live parameters: (…smartpacts-gallery.get-platform-fee) returns 250 (basis points); the 5% ceiling is the MAX-PLATFORM-FEE-BPS constant in the source.