Magento 2 out of the box API use

[lnobs]

I have a fresh LUMA sample data site set up.

I set up an integration user so that I could access the API with the proper security keys.

I saw in the Imagine 2016 video that there are some out of the box APIs to use and Swagger gives some technical details on constructs.

But I am a beginner at this. 

I need some "how to" steps, in PHP code, for doing basic connectivity, like "Request all Items from the Item Table". And if I need to on the back end enable certain functions by editing some files, I need those steps outlined as well.

I have been unable to find this anywhere. All snippets and documentation assume that I know more than I do. 

***************************************************************

Many many thanks to http://blog.i13websolution.com/
and their Content
MAGENTO 2 REST API EXAMPLE

I was able to make minor edits to their example code in order to conduct a basic conversation with my sample data site. Since this is working with only a back end user name and password, the integration user and generated security keys are not involved. Hope to learn more about that concept soon.

<?php

//Authentication rest API magento2.Please change url accordingly your url

$adminUrl='mywebsite.com/index.php/rest/V1/integration/admin/token';

$ch = curl_init();

$data = array("username" => "myusername", "password" => "mypassword");

$data_string = json_encode($data);

$ch = curl_init($adminUrl);

curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_POSTFIELDS, $data_string);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
'Content-Type: application/json',
'Content-Length: ' . strlen($data_string))
);

$token = curl_exec($ch);

$token= json_decode($token);

//Use above token into header

$headers = array("Authorization: Bearer $token");

//Please note 24-MB01 is sku

$requestUrl='mywebsite.com/index.php/rest/V1/products/24-MB01';

$ch = curl_init();

$ch = curl_init($requestUrl);

curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

$result = curl_exec($ch);

$result= json_decode($result);

print_r($result);

[springerin]

i've found very usefull for this https://www.getpostman.com/ that among other stuff ( like setting up the authorization need for magento) it shows you also the code generated for the call you are testing

and example 

<?php

$curl = curl_init();

curl_setopt_array($curl, array(
  CURLOPT_URL => "http://m2-playground.dev/rest/V1/products/MH07-M-Green",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PUT",
  CURLOPT_POSTFIELDS => "{\n  \"product\": {\n    \"sku\": \"MH07-M-Green\",\n    \"name\": \"Hero Hoodie-M-Green new\",\n    \"attributeSetId\": 9\n  },\n  \"saveOptions\": true\n}",
  CURLOPT_HTTPHEADER => array(
    "authorization: OAuth oauth_consumer_key=\"33mun8ejynbmsii298tcd1r1g521k6gp\",oauth_token=\"vmm8mmo0oc52ysgbg68wqp22qtmp4hbn\",oauth_signature_method=\"HMAC-SHA1\",oauth_timestamp=\"1466211088\",oauth_nonce=\"LUBaL2\",oauth_version=\"1.0\",oauth_signature=\"WQrhwzcV4wGr67S%2FWX7Z2usjvLM%3D\"",
    "cache-control: no-cache",
    "content-type: application/json",
    "postman-token: 6cf9c3e6-8041-e09f-5807-62c4a8fa98e9"
  ),
));

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}