*    purpose of the certificate like "Entrust Root Certification Authority - G2" or
 *    "www.squareup.com".
 *
 *  * **A set of hostnames.** These are in the certificate's subject alternative name (SAN)
 *    extension. A subject alternative name is either a literal hostname (`squareup.com`), a literal
 *    IP address (`74.122.190.80`), or a hostname pattern (`*.api.squareup.com`).
 *

    val MIXED = "multipart/mixed".toMediaType()

    /**
     * The "multipart/alternative" type is syntactically identical to "multipart/mixed", but the
     * semantics are different. In particular, each of the body parts is an "alternative" version of
     * the same information.
     */
    @JvmField
    val ALTERNATIVE = "multipart/alternative".toMediaType()

    /**

import okhttp3.tls.internal.der.ObjectIdentifiers.RSA_ENCRYPTION
import okhttp3.tls.internal.der.ObjectIdentifiers.SHA256_WITH_RSA_ENCRYPTION
import okhttp3.tls.internal.der.ObjectIdentifiers.SUBJECT_ALTERNATIVE_NAME
import okio.Buffer
import okio.ByteString
import okio.ByteString.Companion.decodeBase64
import okio.ByteString.Companion.decodeHex
import okio.ByteString.Companion.encodeUtf8

        .build()
    server.useHttps(serverHandshakeCertificates.sslSocketFactory())
    url = server.url("/robots.txt")
  }

  /**
   * Test connecting to the main host then an alternative, although only subject alternative names
   * are used if present no special consideration of common name.
   */
  @Test
  fun commonThenAlternative() {
    server.enqueue(MockResponse())
    server.enqueue(MockResponse())

    // these checks test alternative subjects. The test data contains an
    // alternative subject starting with a japanese kanji character. This is
    // not supported by Android because the underlying implementation from
    // harmony follows the definition from rfc 1034 page 10 for alternative
    // subject names. This causes the code to drop all alternative subjects.

# Alternatives, Inspiration and Comparisons

What inspired **FastAPI**, how it compares to alternatives and what it learned from them.

## Intro

**FastAPI** wouldn't exist if not for the previous work of others.

There have been many tools created before that have helped inspire its creation.

  const val SHA256_WITH_ECDSA = "1.2.840.10045.4.3.2"
  const val RSA_ENCRYPTION = "1.2.840.113549.1.1.1"
  const val SHA256_WITH_RSA_ENCRYPTION = "1.2.840.113549.1.1.11"
  const val SUBJECT_ALTERNATIVE_NAME = "2.5.29.17"
  const val BASIC_CONSTRAINTS = "2.5.29.19"
  const val COMMON_NAME = "2.5.4.3"
  const val ORGANIZATIONAL_UNIT_NAME = "2.5.4.11"

## Standards-based benefits, alternative documentation

And because the generated schema is from the <a href="https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.1.0.md" class="external-link" target="_blank">OpenAPI</a> standard, there are many compatible tools.

![Swagger UI](https://fastapi.tiangolo.com/img/index/index-01-swagger-ui-simple.png)

### Alternative API docs

And now, go to <a href="http://127.0.0.1:8000/redoc" class="external-link" target="_blank">http://127.0.0.1:8000/redoc</a>.

You will see the alternative automatic documentation (provided by <a href="https://github.com/Rebilly/ReDoc" class="external-link" target="_blank">ReDoc</a>):

The `lifespan` parameter of the `FastAPI` app takes an **async context manager**, so we can pass our new `lifespan` async context manager to it.

```Python hl_lines="22"
{!../../../docs_src/events/tutorial003.py!}
```

## Alternative Events (deprecated)

!!! warning