Make a POST Request from PHP With Guzzle

I work extensively with APIs and a variety of serverside scripting languages, and best practice does change over time. Many of the most popular posts on my blog are10 years old because apparently, I was interesting in 2008. Two in particular from around that time relate to making POST requests from PHP, and I'd do it completely differently today. So, in an attempt to overcome some of the past crimes of the Internet in general and PHP in particular: here's how to make a POST request in PHP, today, in a PHP 7+ world (it probably works in PHP 5 too).

Dependencies: GuzzleHTTP

Guzzle is brilliant. If you make web requests with PHP, use Guzzle. Guzzle actually does a bunch of other things too, but today, we're making a POST request.

Install Guzzle like this:

composer require guzzlehttp/guzzle 

If you are not using Composer yet then I strongly recommend you give it a whirl. The project itself has excellent documentation and there are some excellent guides around such as this one from Scotch. Seriously, do it. This post can wait.

Once the package is installed then you will need this at the top of index.php:

require "vendor/autoload.php"; 

Now we can write some code!

Make a POST Request

Using Guzzle, we create a client, then instruct the client to make requests.

For testing, we can send requests to the excellent httpbin.org, this is an endpoint that will return you some JSON telling you what you sent to it. The code needs to:

• create a client with the URL
• send a POST request to /post
• capture the response and output it (it's pretty printed JSON, you could easily json_decode() this if you wanted)

require "vendor/autoload.php";

$client = new \GuzzleHttp\Client(["base_uri" => "http://httpbin.org"]);
$response = $client->post("/post");

echo $response->getBody();

There, we did it! I think this is simpler to write than the old-style Curl equivalents and crucially much easier to read than my second favorite approach, which is to use PHP's streams. Note that you can still pass a context option to Guzzle if you need to.

Send Form Data With Your Post Request

It's pretty unlikely that you'd want to send a POST request, so while I've outlined the process, there's some more detail to look at here.

Here's an example with some form fields being sent as data; run this code and you'll see that httpbin returns this in it's "form" element.

require "vendor/autoload.php";

$client = new \GuzzleHttp\Client(["base_uri" => "http://httpbin.org"]);
$options = [
    'form_params' => [
        "fruit" => "apple"
       ]
   ]; 
$response = $client->post("/post", $options);

echo $response->getBody();

This is for a simple form; there's also a multipart parameter if you need that.

Send JSON With Your Post Request

An increasingly common use case for sending HTTP requests is to call APIs, and for that, you probably want to pass JSON. Here's an example that does that:

require "vendor/autoload.php";

$client = new \GuzzleHttp\Client(["base_uri" => "http://httpbin.org"]);
$options = [
    'json' => [
        "fruit" => "apple"
       ]
   ]; 
$response = $client->post("/post", $options);

echo $response->getBody();

Look very closely! All that changes is form_params becomes json and Guzzle automagically sorts out headers and JSON encoding and everything for us. If you didn't want the magic, then you can set the body and headers to meet the requirements of the application.

HTTP Requests In the Wild

It's good to keep up with the current best practice in the industry, but this is absolutely NOT the only way to do this! Many APIs also provide an SDK, Frameworks have their own HTTP clients, and it's very likely that quite a few of them use Guzzle under the hood anyway. Hopefully, this showed you one option for a clean and modern way to handle HTTP requests from PHP. Now I'm off to update those old posts with a link to this one!