O usuário da sua API (um desenvolvedor externo) criará uma fatura na sua API com um request POST.

Então sua API irá (vamos imaginar):

* Enviar a fatura para algum cliente do desenvolvedor externo.
* Coletar o dinheiro.
* Enviar a notificação de volta para o usuário da API (o desenvolvedor externo).
    * Isso será feito enviando um request POST (de *sua API*) para alguma *API externa* fornecida por esse desenvolvedor externo (este é o "callback").

class Item(BaseModel):
    name: str
    description: Union[str, None] = Field(
        default=None, title="The description of the item", max_length=300
    )
    price: float = Field(gt=0, description="The price must be greater than zero")
    tax: Union[float, None] = None


@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Annotated[Item, Body(embed=True)]):
    results = {"item_id": item_id, "item": item}

    hashed_password = fake_password_hasher(user_in.password)
    user_in_db = UserInDB(**user_in.model_dump(), hashed_password=hashed_password)
    print("User saved! ..not really")
    return user_in_db


@app.post("/user/", response_model=UserOut)
async def create_user(user_in: UserIn):
    user_saved = fake_save_user(user_in)

     * part of the public API. In particular, this method can be changed or deleted without prior notice and must not be
     * used by plugins.
     *
     * @param phase The phase to check for, must not be {@code null}.
     * @return {@code true} if the phase has been seen.
     */
    public boolean hasLifecyclePhase(String phase) {

@Experimental
public interface SuperPomProvider extends Service {

    /**
     * Gets the super POM for the specified model version.
     *
     * @param version The model version to retrieve the super POM for (e.g. "4.0.0"), must not be {@code null}.
     * @return The super POM, never {@code null}.
     * @throws SuperPomProviderException if the super POM could not be retrieved
     */
    @Nonnull
    Model getSuperPom(@Nonnull String version);

async def get_current_active_user(current_user: User = Depends(get_current_user)):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login(form_data: OAuth2PasswordRequestForm = Depends()):
    user_dict = fake_users_db.get(form_data.username)
    if not user_dict:

@Deprecated(since = "4.0.0")
public interface ProjectDependenciesResolver {

    /**
     * Resolves the transitive dependencies of a project.
     *
     * @param request The resolution request holding the parameters, must not be {@code null}.
     * @return The resolution result, never {@code null}.
     * @throws DependencyResolutionException If any project dependency could not be resolved.
     */

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package init

import (
	"os"

	"github.com/klauspost/cpuid/v2"
)

func init() {
	// All MinIO operations must be under UTC.
	os.Setenv("TZ", "UTC")

	// Temporary workaround for
	// https://github.com/golang/go/issues/49233
	// Keep until upstream has been fixed.

METHODS_WITH_BODY = {"GET", "HEAD", "POST", "PUT", "DELETE", "PATCH"}
REF_PREFIX = "#/components/schemas/"

import (
	"fmt"
	"testing"
)

func Benchmark_bucketMetacache_findCache(b *testing.B) {
	bm := newBucketMetacache("", false)
	const elements = 50000
	const paths = 100
	if elements%paths != 0 {
		b.Fatal("elements must be divisible by the number of paths")
	}
	var pathNames [paths]string
	for i := range pathNames[:] {
		pathNames[i] = fmt.Sprintf("prefix/%d", i)
	}
	for i := range elements {
		bm.findCache(listPathOptions{