DAP Building Blocks

Decentralized Agnostic Paytags (DAPs) are a new approach to sending and receiving payments across different apps and currencies. To understand how DAPs work, it’s essential to grasp the key components that make up the DAP ecosystem. In this section, we’ll explore the building blocks of DAPs and how they interact to simplify cross-platform payments.

Decentralized Identifiers (DIDs)

At the heart of the DAP ecosystem are Decentralized Identifiers (DIDs). A DID is a unique, cryptographically-verifiable identifier that represents an individual, organization, or entity. DIDs are designed to be self-sovereign, meaning that the owner has full control over their identifier and can prove ownership without relying on a central authority.

In the context of DAPs, DIDs serve as the foundation for associating payment addresses with a human-readable handle. When a user registers a DAP, they’re essentially creating a mapping between their DID and a chosen handle.

DAP Handles

A DAP handle is a human-friendly, email-like identifier that can be shared with others to send and receive payments. It consists of two parts: a local handle and a domain. For example: @alice/example.com.

The local handle is unique within the context of the domain. It’s up to the domain owner to define the format and requirements for local handles, but typically they follow a set of common conventions to ensure readability and compatibility.

DAP Registries

DAP registries are the services responsible for managing the mapping between DAP handles and DIDs. Each domain that supports DAPs must provide its own registry, which exposes a standardized API for registering and resolving DAP handles.

When a user registers a DAP handle, the registry associates the handle with the user’s DID and stores this mapping. When someone wants to send a payment to a DAP, they query the registry to resolve the handle to its corresponding DID.

Money Addresses

Money addresses are the final piece of the DAP puzzle. They represent the actual destination for a payment, whether it’s a cryptocurrency wallet, a bank account, or any other type of financial account.

In the DAP ecosystem, money addresses are expressed as Uniform Resource Names (URNs) with a standardized format: urn:<currency_code>:<address>. For example, a Bitcoin address might be represented as urn:btc:1BvBMSEYstWetqTFn5Au4m4GFg7xJaNVN2.

When a user registers a DAP, they can associate one or more money addresses with their DID. This allows them to receive payments in multiple currencies or at multiple destinations.

Putting it All Together

Now that we’ve covered the key building blocks, let’s walk through a typical DAP payment flow to see how they all fit together:

1. Alice registers a DAP handle (@alice/example.com) with her DID (did:example:123) at the example.com DAP registry.
2. Alice associates a Bitcoin address (urn:btc:1BvBMSEYstWetqTFn5Au4m4GFg7xJaNVN2) with her DID.
3. Bob wants to send Alice a payment, so he queries the example.com registry to resolve @alice/example.com to Alice’s DID.
4. Bob retrieves Alice’s Bitcoin address from her DID document and sends the payment to urn:btc:1BvBMSEYstWetqTFn5Au4m4GFg7xJaNVN2.

By abstracting away the complexity of different payment networks and currencies, DAPs provide a simple, unified interface for sending and receiving payments. The decentralized nature of DIDs and the standardized APIs for DAP registries ensure that the ecosystem remains open, interoperable, and resilient.

Next Steps

Now that you have a high-level understanding of the DAP building blocks, you might want to:

• Dive deeper into the benefits and use cases for DAPs in our Why DAPs? section.
• Explore how DAPs compare to traditional payment solutions in our Comparing Alternatives section.
• Learn more about the technical specifications for DAPs in our Reference section.

If you have any questions or feedback, don’t hesitate to reach out to our team. We’re here to help you navigate the exciting world of Decentralized Agnostic Paytags!