It was one of the first examples of **automatic API documentation**, and this was specifically one of the first ideas that inspired "the search for" **FastAPI**.

/// note

Django REST Framework was created by Tom Christie. The same creator of Starlette and Uvicorn, on which **FastAPI** is based.

///

/// check | "Inspired **FastAPI** to"

Have an automatic API documentation web user interface.

///

///

/// info

To declare headers, you need to use `Header`, because otherwise the parameters would be interpreted as query parameters.

///

## Automatic conversion

`Header` has a little extra functionality on top of what `Path`, `Query` and `Cookie` provide.

Most of the standard headers are separated by a "hyphen" character, also known as the "minus symbol" (`-`).

## OpenAPI

OpenAPI (previously known as Swagger) is the open specification for building APIs (now part of the Linux Foundation).

**FastAPI** is based on **OpenAPI**.

That's what makes it possible to have multiple automatic interactive documentation interfaces, code generation, etc.

OpenAPI has a way to define multiple security "schemes".

plugins {
  kotlin("jvm")
  id("org.jetbrains.dokka")
  id("com.vanniktech.maven.publish.base")
  id("binary-compatibility-validator")
}

project.applyOsgi(
  "Export-Package: okhttp3.java.net.cookiejar",
  "Automatic-Module-Name: okhttp3.java.net.cookiejar",
  "Bundle-SymbolicName: com.squareup.okhttp3.java.net.cookiejar"
)

dependencies {
  api(projects.okhttp)
  compileOnly(libs.findbugs.jsr305)

plugins {
  kotlin("jvm")
  id("org.jetbrains.dokka")
  id("com.vanniktech.maven.publish.base")
  id("binary-compatibility-validator")
}

project.applyOsgi(
  "Export-Package: okhttp3.logging",
  "Automatic-Module-Name: okhttp3.logging",
  "Bundle-SymbolicName: com.squareup.okhttp3.logging"
)

dependencies {
  api(projects.okhttp)
  compileOnly(libs.findbugs.jsr305)

  testCompileOnly(libs.findbugs.jsr305)

package okhttp3.internal.graal

import org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement
import org.graalvm.nativeimage.hosted.Feature
import org.graalvm.nativeimage.hosted.RuntimeResourceAccess

/**
 * Automatic configuration of OkHttp for native images.
 *
 * Currently, includes all necessary resources.
 */
class OkHttpFeature : Feature {
  @IgnoreJRERequirement

/// note

It doesn't matter what you type in the form, it won't work yet. But we'll get there.

///

This is of course not the frontend for the final users, but it's a great automatic tool to document interactively all your API.

It can be used by the frontend team (that can also be yourself).

It can be used by third party applications and systems.

  testApi(libs.assertk)
  testImplementation(kotlin("test"))
}

animalsniffer {
  isIgnoreFailures = true
}

tasks.jar {
  manifest {
    attributes("Automatic-Module-Name" to "okhttp3.curl")
    attributes("Main-Class" to "okhttp3.curl.MainCommandLineKt")
  }
}

tasks.shadowJar {
  mergeServiceFiles()
}

graal {
  mainClass("okhttp3.curl.MainCommandLineKt")

  id("org.jetbrains.dokka")
  id("com.vanniktech.maven.publish.base")
  id("binary-compatibility-validator")
  id("ru.vyarus.animalsniffer")
}

project.applyOsgi(
  "Export-Package: okhttp3.tls",
  "Automatic-Module-Name: okhttp3.tls",
  "Bundle-SymbolicName: com.squareup.okhttp3.tls"
)

dependencies {
  api(libs.squareup.okio)
  implementation(projects.okhttp)
  compileOnly(libs.findbugs.jsr305)

    }
}
```

Again, doing just that declaration, with **FastAPI** you get:

* Editor support (completion, etc.), even for nested models
* Data conversion
* Data validation
* Automatic documentation

## Special types and validation

Apart from normal singular types like `str`, `int`, `float`, etc. you can use more complex singular types that inherit from `str`.