Originally published on rohitraj.tech
Google\'s WebMCP hit a public Chrome 149 origin trial this month, and it quietly changes how AI agents use your site: instead of scraping the DOM, your page hands the agent a typed list of things it can do. Here is the builder read — what WebMCP actually is, the exact document.modelContext API with copy-paste code, how it differs from MCP, the prompt-injection failure mode the tutorials skip, and whether you should ship it today (honest answer: register the API, gate the writes, wait on the trial).
Read the full version with code samples, diagrams, and architecture details: WebMCP Guide 2026: Turn Your Website Into Tools for Browser AI Agents
More engineering notes: rohitraj.tech/en/notes
