Stream Server-Sent Events

GEThttps://api.testingapis.com/api/stream/sseSign in to see this endpoint's URL

The stream opens with retry: 3000; each event has an id, event: message and a JSON data line, and the stream ends with event: done. Send a Last-Event-ID: N header to resume after event N.

Swagger UI buffers the whole response and cannot show events as they arrive. Use curl instead:``curl -N "https://api.testingapis.com/api/stream/sse?count=5&interval=500"Swagger UI buffers the whole response and cannot show events as they arrive. Use curl instead:``curl -N "https://api.testingapis.com…"

Parameters 3

Name	Type	Description
`count`	query · integer (int32)	Number of events to send (1-100, default 10). Default: 10.
`interval`	query · integer (int32)	Delay between events in milliseconds (100-5000, default 1000). Default: 1000.
`Last-Event-ID`	header · string	Resume the stream after this event id.

Responses

200: A text/event-stream of events.

Example

Request

curl -X GET "https://api.testingapis.com/api/stream/sse?count=3&interval=200" \
  -H "X-TestingApis-Key: YOUR_API_KEY"

Response200 OK

Content-Type: text/event-stream
Cache-Control: no-cache

: connected, streaming events 1..3
retry: 3000

id: 1
event: message
data: {"id":1,"message":"Event 1 of 3","timestamp":"2026-09-30T18:26:40.039Z"}

id: 2
event: message
data: {"id":2,"message":"Event 2 of 3","timestamp":"2026-09-30T18:26:40.247Z"}

id: 3
event: message
data: {"id":3,"message":"Event 3 of 3","timestamp":"2026-09-30T18:26:40.459Z"}
… (1 more lines)

The parameters, request and response examples and the live Try it panel for this endpoint are for signed-in members. Accounts are free and take a few seconds to create.

Try itSign-in requiredUses your key

api.testingapis.com

curl 'https://api.testingapis.com/api/stream/sse?count=3&interval=200' \
  -H 'X-TestingApis-Key: YOUR_API_KEY'

const res = await fetch("https://api.testingapis.com/api/stream/sse?count=3&interval=200", {
  headers: {
    "X-TestingApis-Key": "YOUR_API_KEY",
  },
});
console.log(res.status, await res.text());

const res = await fetch("https://api.testingapis.com/api/stream/sse?count=3&interval=200", {
  headers: {
    "X-TestingApis-Key": "YOUR_API_KEY",
  },
});
const body: string = await res.text();
console.log(res.status, body);

import requests

res = requests.get(
    "https://api.testingapis.com/api/stream/sse?count=3&interval=200",
    headers={
        "X-TestingApis-Key": "YOUR_API_KEY",
    },
)
print(res.status_code, res.text)

using var client = new HttpClient();
using var request = new HttpRequestMessage(HttpMethod.Get, "https://api.testingapis.com/api/stream/sse?count=3&interval=200");
request.Headers.TryAddWithoutValidation("X-TestingApis-Key", "YOUR_API_KEY");
using var response = await client.SendAsync(request);
Console.WriteLine($"{(int)response.StatusCode} {await response.Content.ReadAsStringAsync()}");

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

public class Main {
    public static void main(String[] args) throws Exception {
        HttpClient client = HttpClient.newHttpClient();
        HttpRequest request = HttpRequest.newBuilder(URI.create("https://api.testingapis.com/api/stream/sse?count=3&interval=200"))
                .header("X-TestingApis-Key", "YOUR_API_KEY")
                .GET()
                .build();
        HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
        System.out.println(response.statusCode() + " " + response.body());
    }
}

package main

import (
	"fmt"
	"io"
	"net/http"
)

func main() {
	req, err := http.NewRequest("GET", "https://api.testingapis.com/api/stream/sse?count=3&interval=200", nil)
	if err != nil {
		panic(err)
	}
	req.Header.Set("X-TestingApis-Key", "YOUR_API_KEY")
	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()
	data, err := io.ReadAll(res.Body)
	if err != nil {
		panic(err)
	}
	fmt.Println(res.StatusCode, string(data))
}

GEThttps://api.testingapis.com/api/stream/sse?count=3&interval=200

Query

countinteger (int32)

intervalinteger (int32)

Headers

Last-Event-IDstring

The response is shown as it arrives.