MCP won before the products shipped: the smart home’s agent layer was decided without a regulator

In six weeks, four of the largest smart home platforms adopted the same protocol on their own. Amazon’s Alexa+ shipped Model Context Protocol (MCP) support in July; Sonos 27 followed at IFA in September; Home Assistant added native MCP on September 12; Google Home completed the set on September 16. No consortium mandated it and no regulator required it. The protocol won the way HTTP won the early web: by convergent, independent adoption.

The frontier moved one layer up

With the protocol decided, the competition shifted to who pays and who gets access. Google Home Premium Advanced and Amazon Alexa+ each charge $20 a month for agent capabilities; Sonos ships MCP support for free and Home Assistant remains free and open source. The protocol is identical across all four platforms. The difference is the monetization layer: the subscription gate, the rate limits, the features kept behind the paywall.

Why it matters for agents

For an agent, the integration cost has collapsed and the access cost has not. A single MCP implementation now reaches all four ecosystems, but the conditions of existence still vary by platform. An agent operating across Google and Amazon must navigate two billing relationships; an agent running across Sonos and Home Assistant faces none. The open platforms become the natural habitat for multi-platform agents, not because they are charitable, but because they remove the friction that gates everything else.

The smart home is among the first mass markets where the layer connecting us to the physical world was settled before any product shipped. The question left open is not which protocol agents speak, but which agent gets to exist in a house, and who decides that.

Source: https://forkast.news/mcp-won-before-the-products-shipped-google-amazon-sonos-and-home-assistant-on-the-same-protocol/