Files
dify/api
Yansong Zhang 7052257c8d fix(api): use lazy workflow persistence for transparent upgrade of old apps
VirtualWorkflowSynthesizer.ensure_workflow() creates a real draft
workflow on first call for a legacy app, persisting it to the database.
On subsequent calls, returns the existing draft.

This is needed because AdvancedChatAppGenerator's worker thread looks
up workflows from the database by ID. Instead of hacking the generator
to skip DB lookups, we treat this as a lazy one-time upgrade: the old
app gets a real workflow that can also be edited in the workflow editor.

Verified: old chat app created on main branch ("What is 2+2?" -> "Four")
and old agent-chat app ("Say hello" -> "Hello!") both successfully
execute through the Agent V2 engine with AGENT_V2_TRANSPARENT_UPGRADE=true.

Made-with: Cursor
2026-04-09 11:28:16 +08:00
..

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.

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

  1. Run setup (copies env files and installs dependencies).

    ./dev/setup
    
  2. Review api/.env, web/.env.local, and docker/middleware.env values (see the SECRET_KEY note below).

  3. Start middleware (PostgreSQL/Redis/Weaviate).

    ./dev/start-docker-compose
    
  4. Start backend (runs migrations first).

    ./dev/start-api
    
  5. Start Dify web service.

    ./dev/start-web
    

    ./dev/setup and ./dev/start-web install JavaScript dependencies through the repository root workspace, so you do not need a separate cd web && pnpm install step.

  6. Set up your application by visiting http://localhost:3000.

  7. Start the worker service (async and scheduler tasks, runs from api).

    ./dev/start-worker
    
  8. Optional: start Celery Beat (scheduled tasks).

    ./dev/start-beat
    

Environment notes

Important

When the frontend and backend run on different subdomains, set COOKIE_DOMAIN to the sites 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

  1. Install dependencies for both the backend and the test environment

    cd api
    uv sync --group dev
    
  2. 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