Everyone's Building Agent Protocols. None of Them Talk Yet.
Personal Agent Protocol, MCP, WebMCP -- the plumbing is splitting before it converges.
This month brought a stack of agent protocols: Meta, Sierra, Walmart and Stripe's Personal Agent Protocol for sign-in and approval, Shopify's WebMCP for agent checkout, and the older Model Context Protocol for tool access.
The intent is right -- agents need a standard way to authenticate and act. The problem is they don't interoperate yet. Each vendor ships their own and hopes theirs wins.
We've seen this movie with instant messaging and smart-home hubs. The user gets a fragmentscape of incompatible agents until one protocol wins or a bridge appears.
If you build on agents, pick the protocol your key partners actually support, not the coolest one. Interop will arrive; betting early on a loser is the cost of impatience.