Nan Gao e8c7df9042
feat(channels): arbitrate IM transports with a per-provider leader lease (#6843)
* feat(channels): arbitrate IM transports with a per-provider leader lease

Every Gateway instance connected every enabled IM platform with the same
bot credentials, so channels could not run on more than one instance
(Telegram 409 storms, Discord answering twice, scattered per-process
state). channels.leader_lease was reserved by #6746; this implements it.

- channel_leases table (migration 0041): one row per provider. Acquire is
  one dialect-native upsert decided against the database clock and bumps
  a fencing epoch; renew extends only a live lease at the holder's epoch;
  release sets the expiry to 0 so a peer takes over on its next tick.
- app/channels/leadership.py: the holder's local monotonic deadline
  (send time of the last confirmed renewal + lease_seconds); holds() turns
  false one renewal interval early, so the transport stops at least
  grace_seconds before a peer may connect. DB calls are bounded.
- ChannelService: start fence in _start_channel (no DB call) behind every
  start path; fixed-rate supervisor renews/acquires and runs transport
  starts/stops as per-provider tasks; takeover reloads the provider's
  saved config; failed starts back off; shutdown releases only leases
  whose transport stopped. get_status reports leader/leader_here and the
  holder's transport state on every instance.
- Notification worker leaves rows of providers another instance holds.
- Gate: the enabled=false refusal now recommends auto/true; an explicit
  true with database.backend memory is refused when a channel is enabled.
- Docs, Helm, deployment guides, AGENTS.md and CHANGELOG updated.

* docs(changelog): link the channel leader lease entry to #6843

* fix(channels): see peer-held leases for providers absent from local config

Review on #6843: a provider connected from the web UI on a peer never
enters this instance's channel config, so the notification worker here
still claimed its rows (and parked them for 900s) and GET /api/channels/
reported no leader for it. Every supervision round, and startup, now also
reads the whole lease table once (bounded), and notification exclusions
and status use those observations: a provider whose live lease a peer
holds is left to it even without local config.

Running that read concurrently with renewals exposed that, through
SQLAlchemy's aiosqlite adapter, an UPDATE ... RETURNING racing a read on
another connection can hand back one of its own bind values instead of
the column (stored rows stay correct; plain sqlite3 and raw aiosqlite do
not show it). A lease must never take such a row for a confirmed
renewal, so acquire/renew/release now decide by affected-row count and
acquire reads its epoch back in the same transaction.

---------

Co-authored-by: Willem Jiang <willem.jiang@gmail.com>
2026-10-14 13:51:42 +08:00
..
2026-01-14 09:58:53 +08:00
2026-02-10 22:07:25 +08:00

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

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

  • 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.