Sample files to use Magento 2 REST and SOAP API. Using Token-based authentication and OAuth-based authentication method.

Magento2-API-OAuth-based_authentication.php

<?php
function sign($method, $url, $data, $consumerSecret, $tokenSecret)
{
	$url = urlEncodeAsZend($url);
 
	$data = urlEncodeAsZend(http_build_query($data, '', '&'));
	$data = implode('&', [$method, $url, $data]);
 
	$secret = implode('&', [$consumerSecret, $tokenSecret]);
 
	return base64_encode(hash_hmac('sha1', $data, $secret, true));
}
 
function urlEncodeAsZend($value)
{
	$encoded = rawurlencode($value);
	$encoded = str_replace('%7E', '~', $encoded);
	return $encoded;
}
 
// REPLACE WITH YOUR ACTUAL DATA OBTAINED WHILE CREATING NEW INTEGRATION
$consumerKey = '1fuj3asjsk4w3qb3cx44ik5ue188s30s';
$consumerSecret = 'lcey0h5uyt26slvtws5okaiqh8ojju5d';
$accessToken = 'b41sqrw1cfqh598yfoygd836c4ll3cr8';
$accessTokenSecret = 'lywj45gighqo3knl6bv6i61n2jf6iv0a';
 
$method = 'GET';
$url = 'http://magento.m2/index.php/rest/V1/customers/2';
 
//
$data = [
	'oauth_consumer_key' => $consumerKey,
	'oauth_nonce' => md5(uniqid(rand(), true)),
	'oauth_signature_method' => 'HMAC-SHA1',
	'oauth_timestamp' => time(),
	'oauth_token' => $accessToken,
	'oauth_version' => '1.0',
];
 
$data['oauth_signature'] = sign($method, $url, $data, $consumerSecret, $accessTokenSecret);
 
$curl = curl_init();
 
curl_setopt_array($curl, [
    CURLOPT_RETURNTRANSFER => 1,
    CURLOPT_URL => $url,
	CURLOPT_HTTPHEADER => [
		'Authorization: OAuth ' . http_build_query($data, '', ',')
	]
]);
 
$result = curl_exec($curl);
curl_close($curl);
var_dump($result);

Magento2-API-Token-based_authentication_SOAP_API.php

<?php
$request = new SoapClient("http://magento.m2/index.php/soap/?wsdl&services=integrationAdminTokenServiceV1", array("soap_version" => SOAP_1_2));
$token = $request->integrationAdminTokenServiceV1CreateAdminAccessToken(array("username"=>"admin", "password"=>"GN2vKgfsszz43u"));
 
$opts = array(
            'http'=>array(
                'header' => 'Authorization: Bearer '.json_decode($token->result)
            )
        );
 
$wsdlUrl = 'http://magento.m2/soap/default?wsdl&services=directoryCurrencyInformationAcquirerV1';
 
$context = stream_context_create($opts);
$soapClient = new SoapClient($wsdlUrl, ['version' => SOAP_1_2, 'context' => $context]);
 
$soapResponse = $soapClient->__getFunctions();

Magento2-API-Token-based_authenticationrest_API.php

<?php
$userData = array("username" => "admin", "password" => "mypassword");
$ch = curl_init("http://magento.m2/index.php/rest/V1/integration/admin/token");
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CUsRLOPT_POSTFIELDS, json_encode($userData));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array("Content-Type: application/json", "Content-Lenght: " . strlen(json_encode($userData))));
 
$token = curl_exec($ch);
 
$ch = curl_init("http://magento.m2/index.php/rest/V1/customers/1");
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "GET");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array("Content-Type: application/json", "Authorization: Bearer " . json_decode($token)));
 
$result = curl_exec($ch);
 
var_dump($result);

You've summarized it very simply. That's great!