
MCP Apps: How AI Agents Render Real UIs Inside Your Chat Window
MCP Apps (SEP-1865) extend the Model Context Protocol so AI agents can return full HTML/CSS/JavaScript interfaces instead of plain text. Backed by Anthropic and OpenAI jointly, they turn chat windows into application platforms with sandboxed iframes, bidirectional JSON-RPC, and 10 launch partners including Figma, Slack, and Salesforce.








