Dify Backend API

Setup and Run

[!IMPORTANT]

In the v1.3.0 release, poetry has been replaced with uv as the package manager for Dify API backend service.

uv and pnpm are required to run the setup and development commands below.

Using scripts (recommended)

The scripts resolve paths relative to their location, so you can run them from anywhere.

Run setup (copies env files and installs dependencies).
```
./dev/setup
```
Review api/.env, web/.env.local, and docker/middleware.env values (see the SECRET_KEY note below).
Start middleware (PostgreSQL/Redis/Weaviate).
```
./dev/start-docker-compose
```
Start backend (runs migrations first).
```
./dev/start-api
```
Start Dify web service.
```
./dev/start-web
```
Set up your application by visiting http://localhost:3000.
Optional: start the worker service (async tasks, runs from api).
```
./dev/start-worker
```
Optional: start Celery Beat (scheduled tasks).
```
./dev/start-beat
```

Manual commands

Show manual setup and run steps

These commands assume you start from the repository root.

Start the docker-compose stack.

The backend requires middleware, including PostgreSQL, Redis, and Weaviate, which can be started together using docker-compose.

cp docker/middleware.env.example docker/middleware.env
# Use mysql or another vector database profile if you are not using postgres/weaviate.
docker compose -f docker/docker-compose.middleware.yaml --profile postgresql --profile weaviate -p dify up -d

Copy env files.

cp api/.env.example api/.env
cp web/.env.example web/.env.local

Install UV if needed.

pip install uv
# Or on macOS
brew install uv

Install API dependencies.
```
cd api
uv sync --group dev
```
Install web dependencies.
```
cd web
pnpm install
cd ..
```

Start backend (runs migrations first, in a new terminal).

cd api
uv run flask db upgrade
uv run flask run --host 0.0.0.0 --port=5001 --debug

Start Dify web service (in a new terminal).
```
cd web
pnpm dev:inspect
```
Set up your application by visiting http://localhost:3000.

Optional: start the worker service (async tasks, in a new terminal).

cd api
uv run celery -A app.celery worker -P threads -c 2 --loglevel INFO -Q dataset,priority_dataset,priority_pipeline,pipeline,mail,ops_trace,app_deletion,plugin,workflow_storage,conversation,workflow,schedule_poller,schedule_executor,triggered_workflow_dispatcher,trigger_refresh_executor,retention

Optional: start Celery Beat (scheduled tasks, in a new terminal).
```
cd api
uv run celery -A app.celery beat
```

Environment notes

[!IMPORTANT]

When the frontend and backend run on different subdomains, set COOKIE_DOMAIN to the site’s top-level domain (e.g., example.com). The frontend and backend must be under the same top-level domain in order to share authentication cookies.

Generate a SECRET_KEY in the .env file.

bash for Linux

sed -i "/^SECRET_KEY=/c\SECRET_KEY=$(openssl rand -base64 42)" .env

bash for Mac

secret_key=$(openssl rand -base64 42)
sed -i '' "/^SECRET_KEY=/c\
SECRET_KEY=${secret_key}" .env

Testing

Install dependencies for both the backend and the test environment
```
cd api
uv sync --group dev
```

Run the tests locally with mocked system environment variables in tool.pytest_env section in pyproject.toml, more can check Claude.md

cd api
uv run pytest                           # Run all tests
uv run pytest tests/unit_tests/         # Unit tests only
uv run pytest tests/integration_tests/  # Integration tests

# Code quality
./dev/reformat               # Run all formatters and linters
uv run ruff check --fix ./   # Fix linting issues
uv run ruff format ./        # Format code
uv run basedpyright .        # Type checking