# Dependencies - `Depends()` and `Security()`

## `Depends()`

Dependencies are handled mainly with the special function `Depends()` that takes a callable.

Here is the reference for it and its parameters.

You can import it directly from `fastapi`:

```python
from fastapi import Depends
```

::: fastapi.Depends

## `Security()`

**Describe alternatives you've considered**
A clear and concise description of any alternative solutions or features you've considered.

**Additional context**

# How To - Recipes

Here you will see different recipes or "how to" guides for **several topics**.

Most of these ideas would be more or less **independent**, and in most cases you should only need to study them if they apply directly to **your project**.

If something seems interesting and useful to your project, go ahead and check it, but otherwise, you might probably just skip them.

/// tip

  @Benchmark
  void postStrings(int reps) {
    for (int i = 0; i < reps; i++) {
      eventBus.post("hello there");
    }
  }

  @Subscribe
  public void handleStrings(String string) {
    // Nothing to do here.
  }

            URL url = new URL(originalRepository.getUrl());
            return !(isLocal(url.getHost()) || url.getProtocol().equals("file"));
        } catch (MalformedURLException e) {
            // bad url just skip it here. It should have been validated already, but the wagon lookup will deal with it
            return false;
        }
    }

    private static boolean isLocal(String host) {

	httpServer.MaxHeaderBytes = DefaultMaxHeaderBytes
	return httpServer
}

// SetMinIOVersion -- MinIO version from the main package is set here
func SetMinIOVersion(version string) {
	GlobalMinIOVersion = version
}

// SetDeploymentID -- Deployment Id from the main package is set here
func SetDeploymentID(deploymentID string) {
	GlobalDeploymentID = deploymentID

**Environment (please complete the following information):**
 - OS: [e.g. Windows 10]
 - Browser [e.g. chrome, safari]
 - Version [e.g. 13.5.0]

**Additional context**

  // which overrides ImmutableSet & which ImmutableSortedSet extends.
  // It is necessary here because otherwise the builder() method
  // would be inherited from the emulated ImmutableSet.
  // TODO(cpovirk): should we be including other methods from the shim here and
  // in ImmutableSortedMap?
  @Deprecated
  public static <E> ImmutableSortedSet.Builder<E> builder() {

There are many posts, articles, tools, and projects, related to **FastAPI**.

Here's an incomplete list of some of them.

/// tip

If you have an article, project, tool, or anything related to **FastAPI** that is not yet listed here, create a <a href="https://github.com/fastapi/fastapi/edit/master/docs/en/data/external_links.yml" class="external-link" target="_blank">Pull Request adding it</a>.

///

def test_get_no_item(client: TestClient):
    response = client.get("/items/foo")
    assert response.status_code == 404, response.text
    assert response.json() == {"detail": "Item not found, there's only a plumbus here"}


def test_get(client: TestClient):
    response = client.get("/items/plumbus")
    assert response.status_code == 200, response.text
    assert response.json() == "plumbus"