import org.elasticsearch.common.io.stream.StreamInput;
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Fork;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Param;
import org.openjdk.jmh.annotations.Scope;

You can read it as a header parameter and use it to resume the stream from where the client left off:

{* ../../docs_src/server_sent_events/tutorial004_py310.py hl[25,27,31] *}

## SSE with POST { #sse-with-post }

SSE works with **any HTTP method**, not just `GET`.

This is useful for protocols like [MCP](https://modelcontextprotocol.io) that stream SSE over `POST`:

{* ../../docs_src/server_sent_events/tutorial005_py310.py hl[14] *}

[project.optional-dependencies]
standard = [
    "fastapi-cli[standard] >=0.0.8",
    # For the test client
    "httpx >=0.23.0,<1.0.0",
    # For templates
    "jinja2 >=3.1.5",
    # For forms and file uploads
    "python-multipart >=0.0.18",
    # To validate email fields
    "email-validator >=2.0.0",
    # Uvicorn with uvloop
    "uvicorn[standard] >=0.12.0",
    # # Settings management

import org.elasticsearch.search.aggregations.bucket.terms.StringTerms;
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Fork;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Param;
import org.openjdk.jmh.annotations.Scope;

		},
		{
			// This works since LazyQuotes is true:
			file:            "invalid-badextraq.csv",
			recordDelimiter: "\n",
			fieldDelimiter:  ",",
			sendErr:         nil,
			header:          true,
			wantColumns:     []string{"header1", "header2", "header3"},
			wantFields:      "ok1,ok2,ok3\n" + `a word,"b"""` + "\n",
			wantErr:         io.EOF,
		},
		{
			// This works since LazyQuotes is true:

import org.elasticsearch.search.aggregations.bucket.histogram.DateHistogramAggregationBuilder;
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Fork;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Param;
import org.openjdk.jmh.annotations.Scope;

  @StartStop
  public final MockWebServer server = new MockWebServer();

  @Test
  void test() {
    ...
  }
}
```

Requirements
------------

MockWebServer's JUnit 5 integration works on Android 7.0+ (API level 24+) and Java 8+. Note that

      label: What would you like to be added?
      description: |
        Feature requests are unlikely to make progress as issues. Please consider engaging with SIGs on slack and mailing lists, instead.
        A proposal that works through the design along with the implications of the change can be opened as a KEP.
        See https://git.k8s.io/enhancements/keps#kubernetes-enhancement-proposals-keps
    validations:
      required: true

import okhttp3.HttpUrl;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.logging.HttpLoggingInterceptor;
import okhttp3.logging.LoggingEventListener;

/**
 * Just checking compilation works
 */
public class OkHttpCaller {
  public static Call callOkHttp(HttpUrl url) {
    OkHttpClient client = new OkHttpClient
      .Builder()

You could put your XML content in a string, put that in a `Response`, and return it:

{* ../../docs_src/response_directly/tutorial002_py310.py hl[1,18] *}

## How a Response Model Works { #how-a-response-model-works }

When you declare a [Response Model - Return Type](../tutorial/response-model.md) in a path operation, **FastAPI** will use it to serialize the data to JSON, using Pydantic.