OpenLabel

A web-based image annotation platform for creating polygon masks, PNG masks, and skeleton/keypoint annotations. Supports multi-user collaboration with role-based access control.

Features

• Polygon/Vector Masks — draw vector-based annotations directly on images
• PNG Masks — upload and edit raster masks with undo support
• Skeleton Annotations — keypoint-based pose annotation with customizable templates
• Custom Model Predictions — integrate external prediction APIs for assisted labeling
• Multi-User Support — groups, roles, and per-project access control
• Admin Panel — manage users, groups, and projects
• Project Import/Export — share projects as ZIP archives

Tech Stack

Layer	Technology
Frontend	Vanilla JS (ES modules) + Vite
CSS	Bootstrap 5
Backend	FastAPI + Uvicorn
Database	SQLite
Images	Pillow

Prerequisites

• Python 3.10+
• Node.js 18+ and npm

Installation

1. Clone the repository

git clone https://github.com/VladimirTalyzin/open-label.git
cd open-label

2. Install frontend dependencies

npm install

3. Set up the backend

cd server
python -m venv .venv

# Windows
.venv\Scripts\activate

# Linux / macOS
source .venv/bin/activate

pip install -r requirements.txt

Running (Development)

You need two terminals — one for the frontend dev server and one for the API.

Terminal 1 — Frontend (port 3000)

npm run dev

Terminal 2 — Backend (port 8001)

cd server

# Windows
.venv\Scripts\activate

# Linux / macOS
source .venv/bin/activate

uvicorn main:app --host 0.0.0.0 --port 8001 --reload

Open http://localhost:3000 in your browser. The Vite dev server proxies API requests to the FastAPI backend automatically.

Windows shortcut

Two batch files are provided for convenience:

• start_ui.cmd — starts the Vite dev server
• start_api.cmd — starts the FastAPI backend

Building for Production

npm run build

The compiled frontend is output to dist/. In production the FastAPI server serves these static files directly — no separate frontend server is needed.

Start the production server:

cd server
uvicorn main:app --host 0.0.0.0 --port 8001

Production Deployment (Linux)

Example systemd and Nginx configs are provided in the deploy/ directory:

• deploy/open-label.service — systemd unit file
• deploy/open-label.poisk.com.conf — Nginx reverse proxy config

Configuration

Setting	Default	Description
API_PORT	8001	Backend port (env variable)
PREVIEW_WIDTH	200	Thumbnail preview width in pixels

Admin password is stored in server/admin_password.txt (created automatically with default value admin on first run).

Project Structure

open-label/
├── src/                  # Frontend source (JS, CSS, HTML)
├── server/
│   ├── main.py           # FastAPI application
│   ├── database.py       # SQLite database layer
│   ├── settings.py       # Configuration
│   ├── requirements.txt  # Python dependencies
│   └── projects/         # Project data storage (gitignored)
├── deploy/               # Systemd & Nginx configs
├── package.json          # Frontend dependencies & scripts
└── vite.config.js        # Vite build & proxy config

License

MIT