Deciphering the alphabet soup of agentic AI protocols

MCP, A2A, ACP, or UTCP? It seems like every other day, orgs add yet another AI protocol to the agentic alphabet soup, making it all the more confusing. Below, we'll share what all these abbreviations actually mean and share why they are important for the future of AI.

On the surface, all the protocols serve a similar purpose. They are all trying to standardize how AI agents communicate, with the main distinction often being what exactly they're trying to talk to.

While by no means a comprehensive accounting of all the agentic protocols competing for industry adoption, most can be divided into four or five buckets: agent-to-tool, agent-to-agent, agent-to-user, domain-specific agent protocols, and all the frameworks that glue them together.

Agent-to-tool protocols: MCP, UTCP

The category that's gotten the most attention over the past year is tool-calling protocols.

Of these, the open source Model Context Protocol (MCP ...