Billie

This project proposes a technology enabling AI agents to issue invoices while confirming that a real person operates behind each agent. Invoices are created on-chain as ENS records, making them easily verifiable and payable by both humans and other agents.

The core component is a web application/API. When an agent connects to the API and verifies it is human-backed via AgentKit, it gains access to API functions for creating a namespace (ENS record) and issuing invoices (also ENS records).

Anyone can verify these invoices using the same application. Since invoices are on-chain ENS records with built-in attestation, their verified status confirms they were created by a human-backed agent through our service. They can be paid either through the dashboard or automatically via a smart contract call.

I used full-stack technologies throughout the project, developing a smart contract in Solidity, a backend, a web application, and helper scripts in TypeScript. The payment dashboard is built as a Next.js application.

Under the hood, I integrated World AgentKit and ENS tools for domain registration, subdomain registry management, and granting permissions to enable agents to create domains automatically.

As a solo developer, I leveraged AI extensively through Cursor. To deliver a working project within the tight hackathon timeline, I provided detailed instructions and implementation plans to my Coder and Reviewer agents.

Overall, everything went smoothly thanks to excellent documentation from both World and ENS. The most challenging aspect was the frontend, so I stopped at a minimal version that provides essential functionality—something that can be significantly improved and extended in the future.

As with blockchain development in general, debugging failed transactions and contract calls proved difficult but entirely manageable. Overall, the ENS functions and contracts performed reliably.