ACP (Agent Communication Protocol) is an open specification for inter-agent messaging developed by the BeeAI team. It enables AI agents built across different frameworks and infrastructures to discover each other’s capabilities, exchange rich content (text, code, files, media), collaborate on long-running tasks, and share state when needed. The protocol supports synchronous, asynchronous, streaming, and background responses, and has been submitted to the Linux Foundation under the A2A standard.