# Sub-dependencies { #sub-dependencies }

You can create dependencies that have **sub-dependencies**.

They can be as **deep** as you need them to be.

**FastAPI** will take care of solving them.

## First dependency "dependable" { #first-dependency-dependable }

You could create a first dependency ("dependable") like:

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

```sh
export MINIO_DOMAIN=mydomain.com
minio server /data
```

For advanced use cases `MINIO_DOMAIN` environment variable supports multiple-domains with comma separated values.

```sh
export MINIO_DOMAIN=sub1.mydomain.com,sub2.mydomain.com
minio server /data
```

## Explore Further

* [MinIO Quickstart Guide](https://docs.min.io/community/minio-object-store/operations/deployments/baremetal-deploy-minio-on-redhat-linux.html)

### Top-level application { #top-level-application }

First, create the main, top-level, **FastAPI** application, and its *path operations*:

{* ../../docs_src/sub_applications/tutorial001.py hl[3, 6:8] *}

### Sub-application { #sub-application }

Then, create your sub-application, and its *path operations*.

    private static rpc.sid_t buildSidT(byte revision, byte[] identAuth, int... subs) {
        rpc.sid_t s = new rpc.sid_t();
        s.revision = revision;
        s.sub_authority_count = (byte) subs.length;
        s.identifier_authority = Arrays.copyOf(identAuth, 6);
        s.sub_authority = Arrays.copyOf(subs, subs.length);
        return s;
    }

    @Nested

    class BaseWithTypeVar<T> {}
    class Outer<O> {
      class Sub<X> extends BaseWithTypeVar<List<X>> {}

      class Sub2<Y extends Sub2<Y>> extends BaseWithTypeVar<List<Y>> {}
    }
    ParameterizedType subtype =
        (ParameterizedType)
            new TypeToken<BaseWithTypeVar<List<?>>>() {}.getSubtype(Outer.Sub.class).getType();
    assertEquals(Outer.Sub.class, subtype.getRawType());

    }

    @Test
    @DisplayName("clone: copies all relevant fields")
    void clone_copiesFields() {
        Subject subj = new Subject();
        Kerb5Authenticator auth = new Kerb5Authenticator(subj, "DOM", "user", "pass");
        auth.setUser("alice");
        auth.setRealm("EXAMPLE.COM");
        auth.setService("cifs");
        auth.setUserLifeTime(123);

    class BaseWithTypeVar<T> {}
    class Outer<O> {
      class Sub<X> extends BaseWithTypeVar<List<X>> {}

      class Sub2<Y extends Sub2<Y>> extends BaseWithTypeVar<List<Y>> {}
    }
    ParameterizedType subtype =
        (ParameterizedType)
            new TypeToken<BaseWithTypeVar<List<?>>>() {}.getSubtype(Outer.Sub.class).getType();
    assertEquals(Outer.Sub.class, subtype.getRawType());

## Details { #details }

The first `"/static"` refers to the sub-path this "sub-application" will be "mounted" on. So, any path that starts with `"/static"` will be handled by it.

The `directory="static"` refers to the name of the directory that contains your static files.

The `name="static"` gives it a name that can be used internally by **FastAPI**.

		}
	}
	return nil
}

// Help - return sub-system level help
type Help struct {
	SubSys          string         `json:"subSys"`
	Description     string         `json:"description"`
	MultipleTargets bool           `json:"multipleTargets"`
	KeysHelp        config.HelpKVS `json:"keysHelp"`
}

// GetHelp - returns help for sub-sys, a key for a sub-system or all the help.

# Including WSGI - Flask, Django, others { #including-wsgi-flask-django-others }

You can mount WSGI applications as you saw with [Sub Applications - Mounts](sub-applications.md){.internal-link target=_blank}, [Behind a Proxy](behind-a-proxy.md){.internal-link target=_blank}.

For that, you can use the `WSGIMiddleware` and use it to wrap your WSGI application, for example, Flask, Django, etc.

## Using `WSGIMiddleware` { #using-wsgimiddleware }