Así que vamos a usar ese mismo conocimiento para documentar cómo debería verse la *API externa*... creando la(s) *path operation(s)* que la API externa debería implementar (las que tu API va a llamar).

/// tip | Consejo

Cuando escribas el código para documentar un callback, podría ser útil imaginar que eres ese *desarrollador externo*. Y que actualmente estás implementando la *API externa*, no *tu API*.

Y si lo haces, tendrás un pequeño formulario de autorización para escribir un `username` y `password` (y otros campos opcionales):

<img src="/img/tutorial/security/image02.png">

/// note | Nota

No importa lo que escribas en el formulario, aún no funcionará. Pero llegaremos allí.

///

Esto por supuesto no es el frontend para los usuarios finales, pero es una gran herramienta automática para documentar interactivamente toda tu API.

        override fun describeTo(description: Description) {
          description.appendText(platform)
        }

        override fun matches(item: Any?): Boolean = getPlatformSystemProperty() == platform
      }

    fun fromMajor(version: Int): Matcher<PlatformVersion> =
      object : TypeSafeMatcher<PlatformVersion>() {
        override fun describeTo(description: Description) {

//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package disk

// SameDisk reports whether di1 and di2 describe the same disk.
func SameDisk(disk1, disk2 string) (bool, error) {
	return false, nil

---
name: Bug report
about: A reproducible problem
title: ''
labels: bug
assignees: ''

---

Good bug reports include a failing test! Writing a test helps you to isolate and describe the problem, and it helps us to fix it fast. Bug reports without a failing test or reproduction steps are likely to be closed.

Here’s an example test to get you started.

        stale-issue-label: "status:stale"
        days-before-stale: 0
        days-before-close: 30

        stale-issue-label: "status:stale"
        days-before-stale: 0
        days-before-close: 30

        - Refactoring
        - Other
    validations:
      required: true
  - type: textarea
    id: description
    attributes:
      label: Problem description
      description: |
        Please describe the problem as concisely as possible.
    validations:
      required: true
  - type: textarea
    id: context
    attributes:
      label: Context (optional)
      description: |

      // can happen because multiple locks may share the same LockGraphNode. In
      // this situation, throw an IllegalStateException as defined by contract
      // described in the documentation of WithExplicitOrdering.
      Preconditions.checkState(
          this != acquiredLock,
          "Attempted to acquire multiple locks with the same rank %s",
          acquiredLock.getLockName());

And your **FastAPI** application might also be composed of several files/modules, etc.

### **FastAPI** app file { #fastapi-app-file }

Let's say you have a file structure as described in [Bigger Applications](bigger-applications.md){.internal-link target=_blank}:

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

In the file `main.py` you have your **FastAPI** app: