Update README.md (#5228)

api/README.md

    sed -i "/^SECRET_KEY=/c\SECRET_KEY=$(openssl rand -base64 42)" .env
    ```
 4. Create environment.
-   - Anaconda  
-   If you use Anaconda, create a new environment and activate it
-   ```bash
-   conda create --name dify python=3.10
-   conda activate dify
-   ```
-   - Poetry  
-   If you use Poetry, you don't need to manually create the environment. You can execute `poetry shell` to activate the environment.
-5. Install dependencies
-   - Anaconda  
-   ```bash
-   pip install -r requirements.txt
-   ```
-   - Poetry  
+
+   Dify API service uses [Poetry](https://python-poetry.org/docs/) to manage dependencies. You can execute `poetry shell` to activate the environment.
+
+   > Using pip can be found [below](#usage-with-pip). 
+   
+6. Install dependencies
+   
    ```bash
    poetry install
    ```
+   
    In case of contributors missing to update dependencies for `pyproject.toml`, you can perform the following shell instead.
-   ```base
+
+   ```bash
    poetry shell                                               # activate current environment
    poetry add $(cat requirements.txt)           # install dependencies of production and update pyproject.toml
    poetry add $(cat requirements-dev.txt) --group dev    # install dependencies of development and update pyproject.toml
    ```
-6. Run migrate
+
+7. Run migrate
 
    Before the first launch, migrate the database to the latest version.
+   
+   ```bash
+   poetry run python -m flask db upgrade
+   ```
 
+8. Start backend
+    
    ```bash
-   flask db upgrade
+   poetry run python -m flask run --host 0.0.0.0 --port=5001 --debug
    ```
 
-   ⚠️ If you encounter problems with jieba, for example
+9. Start Dify [web](../web) service.
+10. Setup your application by visiting `http://localhost:3000`...
+11. If you need to debug local async processing, please start the worker service.
 
+   ```bash
+   poetry run python -m celery -A app.celery worker -P gevent -c 1 --loglevel INFO -Q dataset,generation,mail
    ```
-   > flask db upgrade
-   Error: While importing 'app', an ImportError was raised:
+
+   The started celery app handles the async tasks, e.g. dataset importing and documents indexing.
+
+
+## Testing
+
+1. Install dependencies for both the backend and the test environment
+   
+   ```bash
+   poetry install --with dev
+   ``` 
+   
+2. Run the tests locally with mocked system environment variables in `tool.pytest_env` section in `pyproject.toml`
+   
+   ```bash
+   cd ../
+   poetry run -C api bash dev/pytest/pytest_all_tests.sh
    ```
 
-   Please run the following command instead.
 
+## Usage with pip
+
+> [!NOTE]  
+> In the next version, we will deprecate pip as the primary package management tool for dify api service, currently Poetry and pip coexist.
+
+1. Start the docker-compose stack
+
+   The backend require some middleware, including PostgreSQL, Redis, and Weaviate, which can be started together using `docker-compose`.
+
+   ```bash
+   cd ../docker
+   docker-compose -f docker-compose.middleware.yaml -p dify up -d
+   cd ../api
    ```
-   pip install -r requirements.txt --upgrade --force-reinstall
+   
+2. Copy `.env.example` to `.env`
+3. Generate a `SECRET_KEY` in the `.env` file.
+
+   ```bash
+   sed -i "/^SECRET_KEY=/c\SECRET_KEY=$(openssl rand -base64 42)" .env
    ```
 
-7. Start backend:
+4. Create environment.
+   
+   If you use Anaconda, create a new environment and activate it
+  
+   ```bash
+   conda create --name dify python=3.10
+   conda activate dify
+   ```
+      
+6. Install dependencies
+   
+   ```bash
+   pip install -r requirements.txt
+   ```
+
+7. Run migrate
+
+   Before the first launch, migrate the database to the latest version.
+
+   ```bash
+   flask db upgrade
+   ```
+
+8. Start backend:
    ```bash
    flask run --host 0.0.0.0 --port=5001 --debug
    ```
-8. Setup your application by visiting http://localhost:5001/console/api/setup or other apis...
-9. If you need to debug local async processing, please start the worker service.
+9. Setup your application by visiting http://localhost:5001/console/api/setup or other apis...
+10. If you need to debug local async processing, please start the worker service.
    ```bash
    celery -A app.celery worker -P gevent -c 1 --loglevel INFO -Q dataset,generation,mail
    ```
    ```bash
    dev/pytest/pytest_all_tests.sh
    ```
+