}
```

then *your API* will process the invoice, and at some point later, send a callback request to the `callback_url` (the *external API*):

```
https://www.external.org/events/invoices/2expen51ve
```

with a JSON body containing something like:

```JSON
{
    "description": "Payment celebration",
    "paid": true
}
```

software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.
-->

## Враження

"_[...] I'm using **FastAPI** a ton these days. [...] I'm actually planning to use it for all of my team's **ML services at Microsoft**. Some of them are getting integrated into the core **Windows** product and some **Office** products._"

<div style="text-align: right; margin-right: 10%;">Kabir Khan - <strong>Microsoft</strong> <a href="https://github.com/tiangolo/fastapi/pull/26" target="_blank"><small>(ref)</small></a></div>

---

/*
 * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
 * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
 */

package org.jetbrains.kotlin.analysis.api.descriptors.symbols.psiBased

import org.jetbrains.kotlin.analysis.api.descriptors.Fe10AnalysisContext
import org.jetbrains.kotlin.analysis.api.descriptors.Fe10AnalysisFacade.AnalysisMode

    The Apache projects are characterized by a collaborative, consensus based development process, an open and
    pragmatic software license, and a desire to create high quality software that leads the way in its field.
    We consider ourselves not simply a group of projects sharing a server, but rather a community of developers
    and users.
  </description>
  <licenses>
    <license>
      <name>The Apache Software License, Version 2.0</name>

/*
 * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
 * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
 */

package org.jetbrains.kotlin.analysis.api.descriptors.symbols.descriptorBased

import org.jetbrains.kotlin.analysis.api.KtInitializerValue
import org.jetbrains.kotlin.analysis.api.base.KtContextReceiver

 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package util

import common.Arch
import common.BuildToolBuildJvm
import common.JvmVendor
import common.JvmVersion

  <packaging>pom</packaging>
  <name>Maven</name>
  <version>2.0</version>

```

</div>

That command line program called `fastapi` is **FastAPI CLI**.

FastAPI CLI takes the path to your Python program and automatically detects the variable with the FastAPI (commonly named `app`) and how to import it, and then serves it.

For production you would use `fastapi run` instead. 🚀

/*
 * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
 * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
 */

package org.jetbrains.kotlin.analysis.api.descriptors.symbols.psiBased

import com.intellij.psi.PsiElement
import org.jetbrains.kotlin.analysis.api.KtAnalysisApiInternals
import org.jetbrains.kotlin.analysis.api.annotations.KtAnnotationsList