添加回调前，首先看下常规 API 应用是什么样子。

常规 API 应用包含接收 `Invoice` 请求体的*路径操作*，还有包含回调 URL 的查询参数 `callback_url`。

这部分代码很常规，您对绝大多数代码应该都比较熟悉了：

```Python hl_lines="10-14  37-54"
{!../../docs_src/openapi_callbacks/tutorial001.py!}
```

/// tip | "提示"

`callback_url` 查询参数使用 Pydantic 的 <a href="https://pydantic-docs.helpmanual.io/usage/types/#urls" class="external-link" target="_blank">URL</a> 类型。

///

constraints.SafeHtml.message                = {item} may have unsafe html content.
constraints.ScriptAssert.message            = script expression "{script}" didn't evaluate to true.
constraints.URL.message                     = {item} must be a valid URL.
constraints.Required.message                = {item} is required.
constraints.TypeInteger.message             = {item} should be numeric.

constraints.SafeHtml.message                = {item} may have unsafe html content.
constraints.ScriptAssert.message            = script expression "{script}" didn't evaluate to true.
constraints.URL.message                     = {item} must be a valid URL.
constraints.Required.message                = {item} is required.
constraints.TypeInteger.message             = {item} should be numeric.

  <<<modelVersion>>>, <<<artifactId>>>, <<<profiles>>> (injected in phase 1) and <<<prerequisites>>>.

  Notice that the 5 URLs from the model (<<<project.url>>>, <<<project.scm.connection>>>, <<<project.scm.developerConnection>>>,
  <<<project.scm.url>>> and <<<project.distributionManagement.site.url>>>) have a special inheritance handling:

message NonResourceRule {
  // Verb is a list of kubernetes non-resource API verbs, like: get, post, put, delete, patch, head, options.  "*" means all.
  repeated string verbs = 1;

  // NonResourceURLs is a set of partial urls that a user should have access to.  *s are allowed, but only as the full,
  // final step in the path.  "*" means all.
  // +optional
  repeated string nonResourceURLs = 2;
}

option go_package = "k8s.io/api/networking/v1";

// HTTPIngressPath associates a path with a backend. Incoming urls matching the
// path are forwarded to the backend.
message HTTPIngressPath {
  // path is matched against the path of an incoming request. Currently it can
  // contain characters disallowed from the conventional "path" part of a URL
  // as defined by RFC 3986. Paths must begin with a '/' and must be present

  // `nonResourceURLs` is a set of url prefixes that a user should have access to and may not be empty.
  // For example:
  //   - "/healthz" is legal
  //   - "/hea*" is illegal
  //   - "/hea" is legal but matches nothing
  //   - "/hea/*" also matches nothing
  //   - "/healthz/*" matches all per-component health checks.
  // "*" matches all non-resource urls. if it is present, it must be the only entry.

message NonResourceRule {
  // Verb is a list of kubernetes non-resource API verbs, like: get, post, put, delete, patch, head, options.  "*" means all.
  repeated string verbs = 1;

  // NonResourceURLs is a set of partial urls that a user should have access to.  *s are allowed, but only as the full,
  // final step in the path.  "*" means all.
  // +optional
  repeated string nonResourceURLs = 2;
}

labels.web_crawling_configuration	=	Exploration Web
labels.web_crawling_title_details	=	Configuration de l'exploration Web
labels.included_urls	=	URL incluses pour l'exploration
labels.excluded_urls	=	URL exclues pour l'exploration
labels.included_doc_urls	=	URL incluses pour l'indexation
labels.excluded_doc_urls	=	URL exclues pour l'indexation
labels.user_agent	=	Agent utilisateur
labels.web_crawling_button_create	=	Créer

labels.depth = 깊이
labels.excludedPaths = 크롤링에서 제외 할 경로
labels.excludedUrls = 크롤링에서 제외 할 URL
labels.excludedDocPaths = 검색에서 제외 할 경로
labels.excludedDocUrls = 검색에서 제외 할 URL
labels.hostname = 호스트 이름
labels.id = ID
labels.includedPaths = 크롤링 경로
labels.includedUrls = 크롤링하는 URL
labels.includedDocPaths = 검색 대상으로하는 경로
labels.includedDocUrls = 검색 대상이되는 URL
labels.maxAccessCount = 최대 접속 수
labels.name = 이름
labels.numOfThread = 스레드 수