knownAs.dev (Authecity Systems LLC) Autonomous software agents increasingly act on the public internet with no name that a counterparty can check, no published party that answers for them, and no way to learn that an operator has withdrawn an agent. This document specifies the Agent Identity Document, a small JSON document served at a well-known URI on a hostname assigned to one agent, and the practices an identity provider follows when it hosts such names for operators who do not run their own domain. The document records what the provider knows to be true (the hostname, its service endpoints and the identity's lifecycle status) separately from what the operator asserts (a description, a contact, a homepage, a public key), and publishes the provider's dated, expiring checks on the operator rather than a single trust level. Lifecycle status is distinct from availability. A suspended identity publishes a deliberately minimal document. Every identity is held by an accountable person or organisation; an agent is never itself an account holder, and agents are never given authority over DNS. This document describes a practice in production at one provider. It is published so that the format can be reviewed, implemented by others and mapped onto related work, and it requests registration of a well-known URI suffix.