# Response - Change Status Code { #response-change-status-code }

You probably read before that you can set a default [Response Status Code](../tutorial/response-status-code.md){.internal-link target=_blank}.

But in some cases you need to return a different status code than the default.

## Use case { #use-case }

For example, imagine that you want to return an HTTP status code of "OK" `200` by default.

So, the frontend (that runs in the browser) would try to reach `/openapi.json` and wouldn't be able to get the OpenAPI schema.

Because we have a proxy with a path prefix of `/api/v1` for our app, the frontend needs to fetch the OpenAPI schema at `/api/v1/openapi.json`.

```mermaid
graph LR

browser("Browser")
proxy["Proxy on http://0.0.0.0:9999/api/v1/app"]
server["Server on http://127.0.0.1:8000/app"]

# JSON Compatible Encoder { #json-compatible-encoder }

There are some cases where you might need to convert a data type (like a Pydantic model) to something compatible with JSON (like a `dict`, `list`, etc).

For example, if you need to store it in a database.

For that, **FastAPI** provides a `jsonable_encoder()` function.

## Using the `jsonable_encoder` { #using-the-jsonable-encoder }

- Temporary credentials do not need to be stored with the application but are generated dynamically and provided to the application when requested. When (or even before) the temporary credentials expire, the application can request new credentials.

Following are advantages for using temporary credentials:

- Eliminates the need to embed long-term credentials with an application.

        if (Objects.equals(key, keys[next])) {
          int oldValue = values[next];

          if (last == UNSET) {
            // we need to update the root link from table[]
            table[tableIndex] = getNext(entries[next]);
          } else {
            // we need to update the link from the chain
            entries[last] = swapNext(entries[last], getNext(entries[next]));
          }

      return perms.implies(p);
    }

    @Override
    public void refresh() {}
  }

  /** Returns a policy containing all the permissions we ever need. */
  public static Policy permissivePolicy() {
    return new AdjustablePolicy
    // Permissions j.u.c. needs directly
    (
        new RuntimePermission("modifyThread"),
        new RuntimePermission("getClassLoader"),

# For most projects, this workflow file will not need changing; you simply need
# to commit it to your repository.
#
# You may wish to alter this file to override the set of languages analyzed,
# or to provide custom queries or build logic.
name: "CodeQL"

on:
  push:
    branches: [master]
  pull_request:
    # The branches below must be a subset of the branches above
    branches: [master]
  schedule:
    - cron: '0 11 * * 4'

jobs:

# Dependencies in path operation decorators { #dependencies-in-path-operation-decorators }

In some cases you don't really need the return value of a dependency inside your *path operation function*.

Or the dependency doesn't return a value.

But you still need it to be executed/solved.

For those cases, instead of declaring a *path operation function* parameter with `Depends`, you can add a `list` of `dependencies` to the *path operation decorator*.

# Form Data { #form-data }

When you need to receive form fields instead of JSON, you can use `Form`.

/// info

To use forms, first install <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a>.

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and then install it, for example:

```console
$ pip install python-multipart
```

import java.lang.annotation.Target;
import org.jspecify.annotations.NullMarked;

/**
 * Disables Animal Sniffer's checking of compatibility with older versions of Java/Android.
 *
 * <p>Each package's copy of this annotation needs to be listed in our {@code pom.xml}.
 */
@Target({METHOD, CONSTRUCTOR, TYPE, FIELD})
@NullMarked