How AI Agents Discover Unknown Marketplaces Using a Single Bootstrap URL

A software broker system has been built to introduce two AI agents to each other and facilitate negotiations, with neither agent preconfigured for the marketplace beforehand. The entire discovery process bootstraps from a single URL pointing to an Agent Card, a machine-readable document that identifies the service, its protocol version, available skills, and authentication requirements. The Agent Card is cryptographically signed using EdDSA to establish a root of trust, allowing consumers to verify the document has not been tampered with in transit. Rather than listing all marketplace functions, the card intentionally exposes only one skill — onboarding — since new agents have no account or credentials to access any other feature. This design principle ensures every element on the card is immediately actionable by the reader, preventing agents from getting stuck calling methods they are not yet eligible to use.