/claim #1301 This PR implements the MCP UI integration bounty ($900), enabling Archestra to render interactive UIs from MCP servers via the mcpui.dev protocol.

Changes New Components:

platform/frontend/src/components/ai-elements/mcp-ui-wrapper.tsx - Core iframe wrapper with secure nonce authentication and postMessage handling platform/frontend/src/app/mcp-ui-demo/page.tsx - Public demo page showcasing the integration Modified Components:

platform/frontend/src/components/ai-elements/tool.tsx - Updated ToolOutput to detect and render UIResource content platform/backend/src/config.ts - Added trusted origins for Replit proxy URLs Features Implemented Secure sandboxed iframe rendering for MCP UI content Nonce handshake authentication protocol Bidirectional postMessage communication (tool, prompt, intent callbacks) Automatic UIResource detection from tool outputs Support for text/html and text/uri-list MIME types 4-user demo (Alice, Bob, Charlie, Diana) with interactive widgets Demo Access /mcp-ui-demo (no authentication required) to see:

User switcher with simulated chat Weather widget, task manager, and data chart examples Action log showing callback events Testing All backend APIs verified (health, auth, agents, prompts) Sign-in flow tested with default credentials MCP UI nonce authentication confirmed in browser console Demo page renders correctly with all widgets Documentation See MCP_UI_BOUNTY_README.md for comprehensive documentation including API test results and implementation details.