```console
$ pip install "fastapi[standard]"

---> 100%
```

</div>

**Note**: Make sure you put `"fastapi[standard]"` in quotes to ensure it works in all terminals.

## Example { #example }

### Create it { #create-it }

Create a file `main.py` with:

```Python
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")

```json
{
    "reason": <string>
}
```

The reason message is returned to the client.

## Example Plugin Implementation

///

## Overriding the defaults { #overriding-the-defaults }

Using the information above, you can use the same utility function to generate the OpenAPI schema and override each part that you need.

For example, let's add <a href="https://github.com/Rebilly/ReDoc/blob/master/docs/redoc-vendor-extensions.md#x-logo" class="external-link" target="_blank">ReDoc's OpenAPI extension to include a custom logo</a>.

import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Immutable;
import org.apache.maven.api.annotations.Nonnull;

/**
 * Indicates when the dependency will be used.
 * For example, it may be at compile time only, at runtime, or at test time.
 * For a given dependency, the scope is directly derived from the
 * {@link org.apache.maven.api.model.Dependency#getScope()} and will be used when using {@link PathScope}

    return NavigableSetTestSuiteBuilder.using(
            new TestSetGenerator<E>() {

              @Override
              public SampleElements<E> samples() {
                return delegate.samples();
              }

              @Override
              public E[] createArray(int length) {
                return delegate.createArray(length);
              }

You can add code to be run with the `request`,  before any *path operation* receives it.

And also after the `response` is generated, before returning it.

For example, you could add a custom header `X-Process-Time` containing the time in seconds that it took to process the request and generate a response:

{* ../../docs_src/middleware/tutorial001.py hl[10,12:13] *}

/// tip

# 
# The relation mappings between sequence and table.
# If you don't specify the mappings, you cannot insert a record of the table by sequence. 
# The table names are treated as case insensitive.
# 
# Example:
# map:{
#     ; PURCHASE     = SEQ_PURCHASE
#     ; MEMBER       = SEQ_MEMBER
#     ; MEMBER_LOGIN = SEQ_MEMBER_LOGIN
#     ; PRODUCT      = SEQ_PRODUCT
# }
#
# *The line that starts with '#' means comment-out.

  /**
   * Returns a signed value indicating how many nested invocations of {@link #next} (if positive) or
   * {@link #previous} (if negative) are needed to reach {@code end} starting from {@code start}.
   * For example, if {@code end = next(next(next(start)))}, then {@code distance(start, end) == 3}
   * and {@code distance(end, start) == -3}. As well, {@code distance(a, a)} is always zero.
   *

    "tax": 3.2,
    "tags": [
        "rock",
        "metal",
        "bar"
    ],
    "images": [
        {
            "url": "http://example.com/baz.jpg",
            "name": "The Foo live"
        },
        {
            "url": "http://example.com/dave.jpg",
            "name": "The Baz"
        }
    ]
}
```

/// info | informação

A GODEBUG setting is a `key=value` pair
that controls the execution of certain parts of a Go program.
The environment variable `GODEBUG`
can hold a comma-separated list of these settings.
For example, if a Go program is running in an environment that contains

	GODEBUG=http2client=0,http2server=0

then that Go program will disable the use of HTTP/2 by default in both
the HTTP client and the HTTP server.