MCP attempts to standardize how AI agents interact with the world via various programs, and it's already very popular. One web aggregator for MCP servers (essentially, the portals for different programs or tools that agents can access) lists over 15,000 servers already. Working out how to govern how AI agents interact with each other is arguably an even steeper challenge, and it's one the Agent2Agent protocol (A2A), introduced by Google in April, tries to take on. Whereas MCP translates requests between words and code, A2A tries to moderate exchanges between agents, which is an "essential next step for the industry to move beyond single-purpose agents," Rao Surapaneni, who works with A2A at Google Cloud, wrote in an email to MIT Technology Review. Google says 150 companies have already partnered with it to develop and adopt A2A, including Adobe and Salesforce.