Observe an HTTP QUERY request

Prediction

The browser should send OPTIONS before QUERY because QUERY is not a CORS-safelisted method. The intended request should then carry JSON content even though its semantics are safe and idempotent.

Controlled observation

Choose one of two reviewed query shapes. Both target the same fixed resource, declare application/json, and return a small fixed dataset. The response’s Accept-Query field advertises the accepted query media type. The result panel shows the final QUERY response; use browser developer tools to inspect the automatically generated OPTIONS exchange.

Explanation

QUERY places the query representation in request content while preserving safe and idempotent semantics. Its Content-Type defines the query format; Accept-Query advertises which formats the resource accepts. In a cross-origin browser, preflight separately asks whether the page may send the QUERY method and JSON content type.

HTTP/1.1 200 OK
Accept-Query: "application/json"
Cache-Control: private, max-age=30

{"query":{"limit":2,"status":"active"},"results":[{"id":101,"name":"Ada","status":"active"},{"id":103,"name":"Sam","status":"active"}],"scenario":"query-method"}

'curl' '--include' '--request' 'QUERY' '--header' 'Accept: application/json' '--header' 'Content-Type: application/json' '--data' '{"status":"active","limit":2}' 'https://lab.httpclarity.com/v1/query'

const response = await fetch("https://lab.httpclarity.com/v1/query", {
  "method": "QUERY",
  "headers": {
    "Accept": "application/json",
    "Content-Type": "application/json"
  },
  "body": "{\"status\":\"active\",\"limit\":2}"
});
console.log(response.status, await response.text());

<?php
$options = ['http' => [
    'method' => 'QUERY',
    'ignore_errors' => true,
    'header' => 'Accept: application/json\\r\\nContent-Type: application/json',
    'content' => '{"status":"active","limit":2}',
]];
$context = stream_context_create($options);
$body = file_get_contents('https://lab.httpclarity.com/v1/query', false, $context);
var_dump($http_response_header, $body);