Great to see more people getting involved in the development of Nostr marketplaces I read your article about NCC and have to say that it highlights some serious flaws in its conception. Firstly, NIP-15 is problematic and its design is limited. Additionally, the use of NSEC Bunker is discouraged, as it involves storing merchant keys in a database and using them to sign transactions on behalf of the merchant. This approach is risky and creates a single point of failure. If the NSEC Bunker is compromised, you become responsible for the security of the keys, which is a significant weakness.

You mention key delegation, but I don't think it's a viable solution due to its complexity and implications for merchant reputation and WOT. Implementing this solution and make it work for everyone would require a significant amount of design and enforcement.

The approach we was following to resolve the interactivity problem is to place interactive actions in the correct context. For example, instead of the merchant initiating the payment request when it receives a new order, the buyer should initiate it using the public or private information delegated by the merchant to the marketplace. The marketplace can be a server, but the risk is minimised since payment details can be public, like the ones in kind:0 or nip61, or encrypted using the marketplace's app keys. Even if payment details are compromised, the damage is limited compared to the potential consequences of exposing private keys.

I'd be happy to continue discussing the challenges of Nostr marketplaces. We're currently working on a new specification for Nostr marketplaces that relies heavily on NIP-99 and addresses the requirements for e-commerce that NIP-15 describes. Our goal is to create a specification that enables interoperability across the entire Nostr ecosystem, which is currently lacking. NIP-15 is flawed, and NIP-99 is too broad, leading to custom implementations that break ecosystem interoperability and harm users.

We're collaborating with the main developers of other Nostr marketplaces, such as Shopstr and Cypher, to create a more solid specification. I invite you to take a look and engage with our efforts. It would be amazing to achieve real interoperability within the e-commerce specification, which is essential for the success of the Nostr ecosystem. Without further ado, I'm happy to continue the conversation and glad to see more people interested in participating and collaborating. Please feel free to participate in the conception of the new specification. https://github.com/gzuuus/nips/pull/1