# Settings and Environment Variables { #settings-and-environment-variables }

In many cases your application could need some external settings or configurations, for example secret keys, database credentials, credentials for email services, etc.

Most of these settings are variable (can change), like database URLs. And many could be sensitive, like secrets.

For this reason it's common to provide them in environment variables that are read by the application.

/// tip

// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License

class="external-link" target="_blank">existing pull requests</a> for your language. You can filter the pull requests by the ones with the label for your language. For example, for Spanish, the label is <a href="https://github.com/fastapi/fastapi/pulls?q=is%3Aopen+sort%3Aupdated-desc+label%3Alang-es+label%3Aawaiting-review" class="external-link" target="_blank">`lang-es`</a>.

* Review those pull requests, requesting changes or approving them. For the languages I don't speak, I'll wait for several others...

// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License

# OpenAPI Webhooks { #openapi-webhooks }

There are cases where you want to tell your API **users** that your app could call *their* app (sending a request) with some data, normally to **notify** of some type of **event**.

This means that instead of the normal process of your users sending requests to your API, it's **your API** (or your app) that could **send requests to their system** (to their API, their app).

This is normally called a **webhook**.

// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License

- Go to Users
  - Edit the user
    - Add your MinIO policy (ex: `readwrite`) in `Tag`
    - Save

- Open your favorite browser and visit: **http://`CASDOOR_ENDPOINT`/.well-known/openid-configuration**, you will see the OIDC configure of Casdoor.

### Configure MinIO

```
export MINIO_ROOT_USER=minio
export MINIO_ROOT_PASSWORD=minio123
minio server /mnt/export
```

Here are all the available options to configure OpenID connect

Hiding your documentation user interfaces in production *shouldn't* be the way to protect your API.

That doesn't add any extra security to your API, the *path operations* will still be available where they are.

If there's a security flaw in your code, it will still exist.

// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License

					}

					// Expire 50%
					expired := time.Now().Add(-time.Hour * 2)
					for _, v := range l.lockMap {
						for i := range v {
							if rng.Intn(2) == 0 {
								v[i].TimeLastRefresh = expired.UnixNano()
							}
						}
					}
					start = time.Now()
					l.expireOldLocks(time.Hour)