import org.jetbrains.kotlin.analysis.low.level.api.fir.util.originalDeclaration
import org.jetbrains.kotlin.analysis.project.structure.DanglingFileResolutionMode
import org.jetbrains.kotlin.analysis.project.structure.KtDanglingFileModule
import org.jetbrains.kotlin.analysis.project.structure.KtModule
import org.jetbrains.kotlin.analysis.utils.printer.parentOfType
import org.jetbrains.kotlin.fileClasses.javaFileFacadeFqName

**FastAPI** provides a convenience tool to structure your application while keeping all the flexibility.

!!! info
    If you come from Flask, this would be the equivalent of Flask's Blueprints.

## An example file structure

Let's say you have a file structure like this:

```
.
├── app
│   ├── __init__.py
│   ├── main.py
│   ├── dependencies.py

import org.jetbrains.kotlin.light.classes.symbol.annotations.annotateByKtType
import org.jetbrains.kotlin.load.java.structure.impl.JavaClassImpl
import org.jetbrains.kotlin.load.java.structure.impl.JavaTypeImpl
import org.jetbrains.kotlin.load.java.structure.impl.JavaTypeParameterImpl
import org.jetbrains.kotlin.load.java.structure.impl.source.JavaElementSourceFactory
import org.jetbrains.kotlin.load.kotlin.TypeMappingMode

import org.jetbrains.kotlin.analysis.low.level.api.fir.project.structure.llFirModuleData
import org.jetbrains.kotlin.analysis.low.level.api.fir.sessions.LLFirSession
import org.jetbrains.kotlin.analysis.low.level.api.fir.sessions.llFirSession
import org.jetbrains.kotlin.analysis.low.level.api.fir.util.codeFragment
import org.jetbrains.kotlin.analysis.project.structure.KtDanglingFileModule

So, we are going to focus only on the differences.

## File structure

Let's say you have a directory named `my_super_project` that contains a sub-directory called `sql_app` with a structure like this:

```
.
└── sql_app
    ├── __init__.py
    ├── crud.py
    ├── database.py
    ├── main.py
    └── schemas.py
```

This is almost the same structure as we had for the SQLAlchemy tutorial.

 *
 * There is no benefit to invoking multiple `close()` methods for the same response body.
 *
 * For synchronous calls, the easiest way to make sure a response body is closed is with a `try`
 * block. With this structure the compiler inserts an implicit `finally` clause that calls
 * [close()][Response.close] for you.
 *
 * ```java
 * Call call = client.newCall(request);
 * try (Response response = call.execute()) {

  //  1. certificate must contain one or more PEM blocks.
  //  2. All PEM blocks must have the "CERTIFICATE" label, contain no headers, and the encoded data
  //   must be a BER-encoded ASN.1 Certificate structure as described in section 4 of RFC5280.
  //  3. Non-PEM content may appear before or after the "CERTIFICATE" PEM blocks and is unvalidated,
  //   to allow for explanatory text as described in section 5.2 of RFC7468.
  //

import org.jetbrains.kotlin.analysis.low.level.api.fir.api.getOrBuildFirFile
import org.jetbrains.kotlin.analysis.low.level.api.fir.api.getOrBuildFirOfType
import org.jetbrains.kotlin.analysis.project.structure.KtSourceModule
import org.jetbrains.kotlin.backend.jvm.JvmBackendExtension
import org.jetbrains.kotlin.codegen.ClassBuilderMode
import org.jetbrains.kotlin.codegen.generateLanguageVersionSettingsBasedMetadataFlags

    ```Python hl_lines="8-11"
    {!> ../../../docs_src/dependencies/tutorial001.py!}
    ```

That's it.

**2 lines**.

And it has the same shape and structure that all your *path operation functions* have.

You can think of it as a *path operation function* without the "decorator" (without the `@app.get("/some-path")`).

And it can return anything you want.

 * each event pair are used to link the event in case of concurrent or repeated events e.g.
 * `dnsStart(call, domainName)` → `dnsEnd(call, domainName, inetAddressList)`.
 *
 * Events are typically nested with this structure:
 *
 *  * call ([callStart], [callEnd], [callFailed])
 *    * proxy selection ([proxySelectStart], [proxySelectEnd])
 *    * dns ([dnsStart], [dnsEnd])
 *    * connect ([connectStart], [connectEnd], [connectFailed])