CtxPort is a browser extension and companion documentation website that lets users copy AI conversations (from ChatGPT, Claude, Gemini, DeepSeek, Grok, Doubao, GitHub) as structured Markdown Context Bundles. It solves 'context rot' by enabling portable, lossless migration of conversations between AI tools without uploading data to third parties. The architecture is a modern monorepo using pnpm workspaces and Turborepo, with separate packages for schema validation (Zod), markdown serialization, plugin-based extraction, and shared UI components. The browser extension (Manifest V3, WXT, React 19, Tailwind CSS 4) injects copy buttons and sidebar list icons into supported platforms, while the documentation website (Next.js + Nextra) provides multilingual (en/zh) user guides and feature descriptions. All processing is client-side; no data is uploaded. The codebase demonstrates strong engineering practices including a plugin system for extensibility, a strategy pattern for content flatteners, clean separation of concerns, and comprehensive CI/CD pipelines. Some fragility exists in DOM selectors and platform APIs, but the architecture is well-structured for adaptation.