This includes, for example:

* Email notifications sent after performing an action:
    * As connecting to an email server and sending an email tends to be "slow" (several seconds), you can return the response right away and send the email notification in the background.
* Processing data:
    * For example, let's say you receive a file that must go through a slow process, you can return a response of "Accepted" (HTTP 202) and process the file in the background.

This is normally called a **webhook**.

## Webhooks steps { #webhooks-steps }

The process normally is that **you define** in your code what is the message that you will send, the **body of the request**.

You also define in some way at which **moments** your app will send those requests or events.

    opt Tasks
        operation -->> tasks: Send background tasks
    end
    opt Raise other exception
        tasks -->> tasks: Handle exceptions in the background task code
    end
```

/// info

只會向用戶端送出「一個回應」。可能是其中一個錯誤回應，或是來自該路徑操作的回應。

一旦送出了其中一個回應，就不能再送出其他回應。

///

/// tip

    opt Tasks
        operation -->> tasks: Send background tasks
    end
    opt Raise other exception
        tasks -->> tasks: Handle exceptions in the background task code
    end
```

/// info

Only **one response** will be sent to the client. It might be one of the error responses or it will be the response from the *path operation*.

//
//	{label:} WORD[.cond] [ arg {, arg} ] (';' | '\n')
//
// It adds any labels to p.pendingLabels and returns the word, cond,
// operand list, and true. If there is an error or EOF, it returns
// ok=false.
//
// line may reuse the memory from scratch.
func (p *Parser) line(scratch [][]lex.Token) (word, cond string, operands [][]lex.Token, ok bool) {
next:
	// Skip newlines.

    opt Tasks
        operation -->> tasks: Send background tasks
    end
    opt Raise other exception
        tasks -->> tasks: Handle exceptions in the background task code
    end
```

/// info

Une **seule réponse** sera envoyée au client. Il peut s'agir d'une des réponses d'erreur ou de la réponse provenant du *chemin d'accès*.

    end
    dep ->> operation: Ejecutar dependencia, por ejemplo, sesión de BD
    opt raise
        operation -->> dep: Lanzar Exception (por ejemplo, HTTPException)
        opt handle
            dep -->> dep: Puede capturar excepción, lanzar una nueva HTTPException, lanzar otra excepción
        end
        handler -->> client: Response HTTP de error
    end

        if (githubToken.isPresent) {
            requestBuilder.header("Authorization", "token ${githubToken.get()}")
        }
        val response = HttpClient.newHttpClient().send(requestBuilder.build(), HttpResponse.BodyHandlers.ofString())
        if (response.statusCode() > 399) {
            throw RuntimeException("Failed to get issues: $uri ${response.statusCode()} ${response.body()}")
        }

    opt Tasks
        operation -->> tasks: Send background tasks
    end
    opt Raise other exception
        tasks -->> tasks: Handle exceptions in the background task code
    end
```

/// info

클라이언트에는 **하나의 응답**만 전송됩니다. 이는 오류 응답 중 하나일 수도 있고, *경로 처리*에서 생성된 응답일 수도 있습니다.

이러한 응답 중 하나가 전송된 후에는 다른 응답을 보낼 수 없습니다.

///

/// tip

				p.errorf("unrecognized suffix .%q", cond)
				return
			}

		case sys.AMD64, sys.I386:
			if err := x86.ParseSuffix(prog, cond); err != nil {
				p.errorf("%v", err)
				return
			}
		case sys.RISCV64:
			if err := riscv.ParseSuffix(prog, cond); err != nil {
				p.errorf("unrecognized suffix .%q", cond)
				return
			}
		default:
			p.errorf("unrecognized suffix .%q", cond)
			return
		}
	}