# `FastAPI` class

Here's the reference information for the `FastAPI` class, with all its parameters, attributes and methods.

You can import the `FastAPI` class directly from `fastapi`:

```python
from fastapi import FastAPI
```

::: fastapi.FastAPI
    options:
        members:
            - openapi_version
            - webhooks
            - state
            - dependency_overrides
            - openapi

  private static final String E12 = "1-2";
  private static final String E12_A = "1-2a";
  private static final String E21 = "2-1";
  private static final String E23 = "2-3";

  @Parameters
  public static Collection<Object[]> parameters() {
    return Arrays.asList(
        new Object[][] {
          {UNDIRECTED}, {DIRECTED},
        });
  }

  private final EdgeType edgeType;

    display-name: "elastic / elasticsearch # %BRANCH% - branch protection"
    description: Elasticsearch %BRANCH% branch protection.
    node: master
    triggers:
      - timed: "H 7 * * *"
    scm: []
    parameters: []
    builders:
      - shell: |
          #!/bin/bash
          set +x
          STATUS=$(curl -s https://api.github.com/repos/elastic/elasticsearch/branches/%BRANCH% | jq '.protected')

# 路徑參數與數值驗證 { #path-parameters-and-numeric-validations }

就像使用 `Query` 為查詢參數宣告更多驗證與中繼資料一樣，你也可以用 `Path` 為路徑參數宣告相同類型的驗證與中繼資料。

## 匯入 `Path` { #import-path }

首先，從 `fastapi` 匯入 `Path`，並匯入 `Annotated`：

{* ../../docs_src/path_params_numeric_validations/tutorial001_an_py310.py hl[1,3] *}

/// info

FastAPI 在 0.95.0 版加入並開始推薦使用 `Annotated`。

如果你使用更舊的版本，嘗試使用 `Annotated` 會出錯。

     *
     * @param <T>
     *            The return type of the method
     * @param method
     *            The method. Cannot be {@literal null}
     * @param args
     *            The arguments used for the method call
     * @return The result of dispatching the {@code static} method using the parameters {@code args}
     * @throws IllegalAccessRuntimeException

 * high-level RAG workflow methods that allow each provider to optimize
 * prompt construction, parameter tuning, and response parsing.
 */
public interface LlmClient {

    /**
     * Performs a chat completion request.
     *
     * @param request the chat request containing messages and parameters
     * @return the chat response from the LLM
     * @throws LlmException if an error occurs during the request
     */

{* ../../docs_src/configure_swagger_ui/tutorial002_py310.py hl[3] *}

この設定により、シンタックスハイライトの配色テーマが変わります:

<img src="/img/tutorial/extending-openapi/image04.png">

## 既定の Swagger UI パラメータの変更 { #change-default-swagger-ui-parameters }

FastAPI には、多くのユースケースに適した既定の設定パラメータが含まれています。

既定では次の設定が含まれます:

{* ../../fastapi/openapi/docs.py ln[9:24] hl[18:24] *}

引数 `swagger_ui_parameters` に別の値を指定することで、これらを上書きできます。

* The alternative documentation will also reflect the new query parameter and body:

![ReDoc](https://fastapi.tiangolo.com/img/index/index-06-redoc-02.png)

### Recap { #recap }

In summary, you declare **once** the types of parameters, body, etc. as function parameters.

You do that with standard modern Python types.

        } catch (IllegalArgumentException e) {
            assertTrue(e.getMessage().contains("Both name and dataStore parameters are required"));
            assertTrue(e.getMessage().contains("dataStore: null"));
        }
    }

    // Test add method with both null parameters
    @Test
    public void test_add_bothNull() {
        try {
            dataStoreFactory.add(null, null);

# Dependencies - `Depends()` and `Security()`

## `Depends()`

Dependencies are handled mainly with the special function `Depends()` that takes a callable.

Here is the reference for it and its parameters.

You can import it directly from `fastapi`:

```python
from fastapi import Depends
```

::: fastapi.Depends

## `Security()`