Crate mcp_preview 

MCP Preview Server

A browser-based development environment for testing MCP Apps widgets. Defaults to standard MCP Apps mode with full AppBridge support. Use --mode chatgpt to activate ChatGPT strict protocol emulation.

Usage

cargo pmcp preview --url http://localhost:3000 --open

Features

• Widget rendering in isolated iframe
• Full window.mcpBridge / window.openai simulation
• Environment controls (theme, locale, display mode)
• DevTools panel (state, console, network, events)
• Live proxy to MCP server via HTTP

Modules

wasm_builder

WASM build orchestration and artifact caching

Structs

OAuthPreviewConfig

OAuth configuration for browser-based PKCE flow.

PreviewConfig

Configuration for the preview server

PreviewServer

MCP Preview Server

Enums

PreviewMode

Preview mode controlling protocol validation strictness