HTTP Fornecedor

Simular Resposta 521 Web Server Is Down

Cloudflare-specific. The origin server refused the connection.

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1 Resposta HTTP

Resposta HTTP
HTTP/1.1 521 Web Server Is Down
Content-Type: application/json
Date: Tue, 25 Feb 2026 12:00:00 GMT
Content-Length: 58

{
  "error": "server_error",
  "message": "Web Server Is Down"
}

2 Testar com curl

terminal
curl -i https://httpbin.org/status/521

3 Retornar 521 Web Server Is Down no Seu Framework

django
from django.http import JsonResponse


def my_view(request):
    return JsonResponse(
        {"error": "server_error", "message": "Web Server Is Down"},
        status=521,
    )
flask
from flask import Flask, jsonify

app = Flask(__name__)


@app.route("/endpoint")
def my_endpoint():
    return jsonify({"error": "server_error", "message": "Web Server Is Down"}), 521
fastapi
from fastapi import FastAPI
from fastapi.responses import JSONResponse

app = FastAPI()


@app.get("/endpoint")
def my_endpoint():
    return JSONResponse(
        content={"error": "server_error", "message": "Web Server Is Down"},
        status_code=521,
    )
express.js
// Express.js
app.get('/endpoint', (req, res) => {
  res.status(521).json({"error": "server_error", "message": "Web Server Is Down"});
});
spring boot
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import java.util.Map;

@RestController
public class MyController {

    @GetMapping("/endpoint")
    public ResponseEntity<Map<String, Object>> myEndpoint() {
        return ResponseEntity
            .status(521)
            .body(Map.of("error", "web_server_is_down",
                         "message", "Web Server Is Down"));
    }
}
go net/http
package main

import (
    "encoding/json"
    "net/http"
)

func myHandler(w http.ResponseWriter, r *http.Request) {
    w.Header().Set("Content-Type", "application/json")
    w.WriteHeader(521)
    json.NewEncoder(w).Encode(map[string]string{
        "error":   "web_server_is_down",
        "message": "Web Server Is Down",
    })
}
ruby on rails
class MyController < ApplicationController
  def my_action
    render json: {"error": "server_error", "message": "Web Server Is Down"},
           status: :web_server_is_down
  end
end
asp.net core
// ASP.NET Core Minimal API
app.MapGet("/endpoint", () =>
    Results.Json(
        new { error = "web_server_is_down", message = "Web Server Is Down" },
        statusCode: 521
    )
);

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