- Implement createUIMessageStream pattern for modern streaming
- Add ChatSDKError class for structured error handling
- Migrate from deprecated streamText.ts to createUIMessageStream
- Fix tool schema validation by using inputSchema instead of parameters
- Add resumable-stream support with Redis fallback
- Update chat component to use DefaultChatTransport
- Enhance provider options for GPT-5 models with reasoning effort
- Improve Datadog initialization to prevent duplicate loading
- Add comprehensive error handling throughout chat API
- Successfully tested streaming functionality with Playwright

All streaming and MCP tool integration now working correctly.

- Remove GitHubButton and DocsButton imports from chat-header.tsx
- Remove GitHubButton and DocsButton imports from signed-out-header.tsx
- Clean up header layouts by removing button containers
- Maintain clean, minimal header design without external links

- Add framer-motion animations to attachment previews and suggested actions
- Create comprehensive UsageTracker component with token/cost tracking
- Support pricing for all major models (Claude, GPT, Gemini)
- Enable file attachment functionality in multimodal input
- Improve input box design with modern border styling and focus states
- Add Badge component for UI consistency
- Enhance button styling with consistent hover states
- Integrate usage tracking into both signed-in and signed-out layouts
- Add smooth entrance/exit animations throughout the interface

All features now match the polished Vercel AI chatbot design.

- Implement full sidebar system with collapsible functionality, mobile responsive design, keyboard shortcuts (Cmd/Ctrl+B), and state persistence
- Add message editing functionality allowing users to edit their messages with auto-resizing textarea and proper state management
- Add enhanced message actions with copy, edit (user messages), upvote/downvote (AI messages) functionality
- Copy CodeBlock component with syntax highlighting and copy functionality from Vercel repo
- Copy PromptInput elements for modular input design
- Add getTextFromMessage utility function for message text extraction
- Update gitignore to exclude Vercel reference repository
- All components copied directly from Vercel AI chatbot reference for consistency

- Change config path from .env.local to .env
- Support both POSTGRES_URL and DATABASE_URL environment variables
- Improve error messaging for missing database configuration

- Fix z-index conflicts between sidebar and model selector dropdown
- Always show "New Chat" button regardless of sidebar state
- Wire up usage tracker to display token count and cost information
- Add proper z-index layering: header (z-20) > dropdown (z-100) > sidebar (z-10)