## The normal **FastAPI** app

Let's first see how the normal API app would look like before adding the callback.

It will have a *path operation* that will receive an `Invoice` body, and a query parameter `callback_url` that will contain the URL for the callback.

This part is pretty normal, most of the code is probably already familiar to you:

```Python hl_lines="9-13  36-53"
{!../../../docs_src/openapi_callbacks/tutorial001.py!}
```

!!! tip

// PolicyRule holds information that describes a policy rule, but does not contain information
// about who the rule applies to or which namespace the rule applies to.
message PolicyRule {
  // Verbs is a list of Verbs that apply to ALL the ResourceKinds contained in this rule. '*' represents all verbs.
  repeated string verbs = 1;

| `contact` | `dict` | The contact information for the exposed API. It can contain several fields. <details><summary><code>contact</code> fields</summary><table><thead><tr><th>Parameter</th><th>Type</th><th>Description</th></tr></thead><tbody><tr><td><code>name</code></td><td><code>str</code></td><td>The identifying name of the contact person/organization.</td></tr><tr><td><code>url</code></td><td><code>str</code></td><td>The...

// PolicyRule holds information that describes a policy rule, but does not contain information
// about who the rule applies to or which namespace the rule applies to.
message PolicyRule {
  // Verbs is a list of Verbs that apply to ALL the ResourceKinds contained in this rule. '*' represents all verbs.
  repeated string verbs = 1;

// PolicyRule holds information that describes a policy rule, but does not contain information
// about who the rule applies to or which namespace the rule applies to.
message PolicyRule {
  // Verbs is a list of Verbs that apply to ALL the ResourceKinds contained in this rule. '*' represents all verbs.
  repeated string verbs = 1;

The new [ParseCookie] function parses a Cookie header value and
returns all the cookies which were set in it. Since the same cookie
name can appear multiple times the returned Values can contain
more than one value for a given key.

The new [ParseSetCookie] function parses a Set-Cookie header value and

Let's say you have a *path operation* with a path `/files/{file_path}`.

But you need `file_path` itself to contain a *path*, like `home/johndoe/myfile.txt`.

So, the URL for that file would be something like: `/files/home/johndoe/myfile.txt`.

### OpenAPI support

OpenAPI doesn't support a way to declare a *path parameter* to contain a *path* inside, as that could lead to scenarios that are difficult to test and define.

            display = ParameterDisplay.PROMPT,
            allowEmpty = false,
            description = "The name of the test to run, as should be passed to --tests. Can't contain spaces since there are problems with Teamcity's escaping, you can use * instead."
        )
        text(
            testJvmVersionParameter,
            JvmVersion.java11.major.toString(),

  // capabilities. This must contain at least one address but no more than
  // 100. These are all assumed to be fungible and clients may choose to only
  // use the first element. Refer to: https://issue.k8s.io/106267
  // +listType=set
  repeated string addresses = 1;

  // conditions contains information about the current status of the endpoint.
  optional EndpointConditions conditions = 2;

then an `api/next` file with the line

    pkg net/http, function F #12345

should have a corresponding file named `doc/next/6-stdlib/99-minor/net/http/12345.md`.
At a minimum, that file should contain either a full sentence or a TODO,
ideally referring to a person with the responsibility to complete the note.

Use the following forms in your markdown: