## The in-page surface
WebMCP is an experimental browser API. A site registers tools with `document.modelContext.registerTool`, and an agent running in the page can discover and call them.
## Same-origin, no credentials
Corsen Context’s bridge is same-origin only and omits credentials. It refuses to register inside a frame.
## One contract, three surfaces
The same four tools are exposed over WebMCP inside the page, MCP over HTTP, and llms.txt for discovery.