Announced at Google I/O 2026 (May 19-20), WebMCP is a proposed open web standard that allows AI agents running inside or alongside a browser to interact with web pages through a structured tool interface. The design mirrors the Model Context Protocol (MCP) pattern popularised by desktop AI tooling but targets the browser runtime directly, letting agents perform tasks like form submission, navigation, and data extraction in a governed, structured way rather than through fragile DOM scraping. Chrome 149 will open an experimental origin trial for developers to prototype against the API. For web developers, WebMCP introduces a new surface area that sites may need to explicitly support or restrict. The origin trial will be the first opportunity to evaluate how agent-accessible tool definitions are declared and permissioned. Because the proposal is framed as an open standard rather than a Chrome-only feature, it is likely to draw engagement from other browser vendors and frameworks that already integrate MCP-style tooling.