<?php $client = new http\Client(); $request = new http\Client\Request(); $body = new http\Message\Body(); $body->append('{"number":1,"string":"f\\"oo","arr":[1,2,3],"nested":{"a":"b"},"arr_mix":[1,"a",{"arr_mix_nested":{}}]}'); $request->setRequestUrl('http://mockbin.com/har'); $request->setRequestMethod('POST'); $request->setBody($body); $request->setHeaders(array('content-type' => 'application/json')); $client->enqueue($request)->send(); $response = $client->getResponse(); echo $response->getBody();