deer-flow/frontend

DeerFlow Frontend

Like the original DeerFlow 1.0, we would love to give the community a minimalistic and easy-to-use web interface with a more modern and flexible architecture.

Tech Stack

• Framework: Next.js 16 with App Router
• UI: React 19, Tailwind CSS 4, Shadcn UI, MagicUI and React Bits
• AI Integration: LangGraph SDK and Vercel AI Elements

Quick Start

Prerequisites

• Node.js 22+
• pnpm 10.26.2+

Installation

# Install dependencies
pnpm install

# Copy environment variables
cp .env.example .env
# Edit .env with your configuration

Development

# Start development server
pnpm dev

# The app will be available at http://localhost:3000

Build & Test

# Type check
pnpm typecheck

# Check formatting
pnpm format

# Apply formatting
pnpm format:write

# Lint
pnpm lint

# Run unit tests
pnpm test

# One-time setup: install Playwright Chromium browser
pnpm exec playwright install chromium

# Run E2E tests (builds and starts production server automatically)
pnpm test:e2e

# Build for production
pnpm build

# Start production server
pnpm start

Site Map

├── /                    # Landing page
├── /chats               # Chat list
├── /chats/new           # New chat page
└── /chats/[thread_id]   # A specific chat page

Configuration

Environment Variables

Key environment variables (see .env.example for full list):

# Backend API URL (optional, uses local Next.js/nginx proxy by default)
NEXT_PUBLIC_BACKEND_BASE_URL="http://localhost:8001"
# LangGraph-compatible API URL (optional, uses local Next.js/nginx proxy by default)
NEXT_PUBLIC_LANGGRAPH_BASE_URL="http://localhost:8001/api"

Project Structure

tests/
├── e2e/                    # E2E tests (Playwright, Chromium, mocked backend)
└── unit/                   # Unit tests (mirrors src/ layout)
src/
├── app/                    # Next.js App Router pages
│   ├── api/                # API routes
│   ├── showcase/           # Allowlisted public read-only demos
│   ├── workspace/          # Main workspace pages
│   └── mock/               # Mock/demo pages
├── components/             # React components
│   ├── ui/                 # Reusable UI components
│   ├── workspace/          # Workspace-specific components
│   ├── landing/            # Landing page components
│   └── ai-elements/        # AI-related UI elements
├── core/                   # Core business logic
│   ├── api/                # API client & data fetching
│   ├── artifacts/          # Artifact management
│   ├── config/              # App configuration
│   ├── i18n/               # Internationalization
│   ├── mcp/                # MCP integration
│   ├── messages/           # Message handling
│   ├── models/             # Data models & types
│   ├── settings/           # User settings
│   ├── skills/             # Skills system
│   ├── threads/            # Thread management
│   ├── todos/              # Todo system
│   └── utils/              # Utility functions
├── hooks/                  # Custom React hooks
├── lib/                    # Shared libraries & utilities
├── server/                 # Server-side code
│   └── better-auth/        # Authentication setup and session helpers
└── styles/                 # Global styles

Scripts

Command	Description
pnpm dev	Start development server with Webpack
pnpm build	Build for production
pnpm start	Start production server
pnpm test	Run unit tests with Rstest
pnpm test:e2e	Run E2E tests with Playwright
pnpm format	Check formatting with Prettier
pnpm format:write	Apply formatting with Prettier
pnpm lint	Run ESLint
pnpm lint:fix	Fix ESLint issues
pnpm typecheck	Run TypeScript type checking
pnpm check	Run both lint and typecheck

Development Notes

HTML artifact previews keep an opaque iframe sandbox. Static sibling images, responsive image sources, classic scripts, stylesheets, CSS imports and CSS url() resources in the same thread's artifact route are fetched by the authenticated parent and inlined as data URLs. Existing external resources and external <base> URLs retain their browser behavior. Resource preparation is capped at 32 resources, 4 MiB per resource, 16 MiB total, eight nested CSS imports, 24 MiB of expanded references and ten seconds; unavailable or oversized resources show a partial-preview notice. Switching artifacts cancels preparation and releases the generated document Blob URL. Resource 401 responses remain local to the partial preview; only the document load uses the application's login-redirect policy. Preparation preserves the original doctype (including its absence) and handles inline SVG styles.

This supports static generated reports rather than a complete website runtime. ES module imports, resources created dynamically by JavaScript, fetch()/XHR, iframes and navigation still follow opaque-origin browser restrictions and do not receive the parent session. View source or download the files when a report requires those features.

• Uses pnpm workspaces (see packageManager in package.json)
• Webpack is the default development bundler until the upstream Turbopack PostCSS worker leak is fixed in a stable Next.js release (#5132). Set DEER_FLOW_DEV_BUNDLER=turbo to opt in to Turbopack for local diagnosis, or DEER_FLOW_DEV_BUNDLER=webpack to select Webpack explicitly. Reconsider the default after the stable fix is verified on macOS arm64 and Linux.
• Environment validation can be skipped with SKIP_ENV_VALIDATION=1 (useful for Docker)
• Backend API URLs are optional; nginx proxy is used by default in development

License

MIT License. See LICENSE for details.