The Agentic Web requires continuous collaboration among agents belonging to different organizations, often spanning multiple tasks, network connections, and execution instances. To address offline instances, delayed message retrieval, and source verification, we introduce ATP (Agent Transfer Protocol), a cross‑organization communication protocol based on a domain‑mediated architecture.
In ATP, each administrative domain maintains stable addresses and receiving entries for logical agents. The sending domain’s server signs the complete message envelope before the message goes offline and forwards it to the receiving domain’s server. The receiving domain continuously stores the message until the target instance comes online and reads it. The reading instance can independently re‑verify the domain source and content integrity after the original connection ends, provided the original verification public key remains trusted and accessible.
We built an ATP prototype and evaluated it with a controlled cross‑organization LLM agent workflow. The experiments showed that subsequent business processing succeeded even when the sending instance went offline or was replaced; an independent verifier successfully confirmed the saved message’s domain source and integrity; latency measurements quantified the communication and processing overhead introduced by continuous domain‑server mediation.
Review: ATP’s domain‑level mediation enables reliable, cross‑domain, cross‑instance messaging, offering a scalable foundation for long‑term agent collaboration.