PHP APIs: REST, GraphQL, and gRPC — What to Choose in 2025?

Introduction: API is Not Magic, It's a Tool

When your PHP site stops being a static page and starts communicating with the outside world — Telegram bots, payment gateways, or your own mobile app — you inevitably encounter APIs (Application Programming Interfaces). It's simply a contract: "If you send me a request in this format, I will return data to you." Today, on the PHP arena, there are three main players: classic REST, flexible GraphQL, and bold gRPC. Which one to choose? Let's figure it out with real-life examples.

This article is written for those who already know how to write PHP and want to broaden their horizons. We won't just copy the documentation; we'll look at each protocol through the eyes of a developer solving a real problem.

REST API in PHP: The Tried-and-True Classic

REST (Representational State Transfer) is not a protocol, but an architectural style. It uses HTTP methods (GET, POST, PUT, DELETE) to work with resources. If you've ever written file_get_contents('https://api.example.com/users') — you've already worked with REST.

Why Does REST Remain King?

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• Simplicity: any HTTP client can work with it.
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• Caching: GET requests can be cached at the HTTP level.
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• Broad Support: from curl to specialized libraries.
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Example of a REST Client in PHP with Guzzle

The Guzzle library is the de facto standard for HTTP requests in PHP. Install it via Composer: composer require guzzlehttp/guzzle.

<?php\nrequire 'vendor/autoload.php';\n\nuse GuzzleHttp\\Client;\n\n$client = new Client([\n    'base_uri' => 'https://jsonplaceholder.typicode.com/',\n    'timeout'  => 5.0,\n]);\n\n// GET request\n$response = $client->get('posts/1');\n$post = json_decode($response->getBody(), true);\necho "Post title: " . $post['title'] . PHP_EOL;\n\n// POST request\n$response = $client->post('posts', [\n    'json' => [\n        'title' => 'New Post',\n        'body' => 'Post text',\n        'userId' => 1\n    ]\n]);\necho "Created post with ID: " . json_decode($response->getBody(), true)['id'];\n?>

What did we do? We simply sent HTTP requests. REST doesn't require a special library — you can even use file_get_contents() with a context, but Guzzle provides convenient error handling, middleware, and streaming.

When is REST Not the Best Choice?

If you need to fetch related data (e.g., a post + author + comments), REST will force you to make multiple requests. This is where GraphQL steps in.

GraphQL in PHP: Request Only What You Need

GraphQL is a query language developed by Facebook. The client describes the response structure itself. One request — one response, without over-fetching or under-fetching data.

How Does GraphQL Work in PHP?

Server-side: the webonyx/graphql-php library (installation: composer require webonyx/graphql-php). Client-side: a regular HTTP POST request with a JSON body.

Example of a GraphQL Query from PHP

<?php\nrequire 'vendor/autoload.php';\n\nuse GuzzleHttp\\Client;\n\n$client = new Client(['base_uri' => 'https://countries.trevorblades.com/']);\n\n$query = '\nquery GetCountry {\n    country(code: "RU") {\n        name\n        capital\n        currency\n        languages {\n            name\n        }\n    }\n}';\n\n$response = $client->post('', [\n    'json' => ['query' => $query]\n]);\n\n$data = json_decode($response->getBody(), true);\necho "Country: " . $data['data']['country']['name'] . PHP_EOL;\necho "Capital: " . $data['data']['country']['capital'] . PHP_EOL;\necho "Currency: " . $data['data']['country']['currency'] . PHP_EOL;\necho "Languages: ";\nforeach ($data['data']['country']['languages'] as $lang) {\n    echo $lang['name'] . " ";\n}\n?>