PHP File Upload

The aws-sdk-php package is a heavyweight Composer dependency for what is, at heart, a few HTTP requests — and on shared hosting or a lean WordPress install you may not want it at all. files.link works with the curl extension that ships with PHP, or with Guzzle if you already have it, and the upload is three calls. Request a presigned URL by POSTing metadata to /v1/files/{folderId} with your API key in the Authorization header (raw key, no Bearer prefix); PUT the bytes to the returned url; POST /v1/files/confirm-upload with the file id. With the bundled curl extension and no Composer dependency at all:

<?php
$api = 'https://api.files.link';
$key = getenv('FILESLINK_KEY');
$folder = 'your-folder-id';
$path = 'invoice.pdf';

// 1. request a presigned PUT URL
$ch = curl_init("$api/v1/files/$folder");
curl_setopt_array($ch, [
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_POST => true,
  CURLOPT_HTTPHEADER => ["Authorization: $key", 'Content-Type: application/json'],
  CURLOPT_POSTFIELDS => json_encode(['filesMetadata' => [['name' => 'invoice.pdf']]]),
]);
$meta = json_decode(curl_exec($ch), true);
$slot = $meta['urls'][0];

// 2. PUT the file bytes
$ch = curl_init($slot['url']);
curl_setopt_array($ch, [
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_PUT => true,
  CURLOPT_INFILE => fopen($path, 'rb'),
  CURLOPT_INFILESIZE => filesize($path),
]);
curl_exec($ch);

// 3. confirm
$ch = curl_init("$api/v1/files/confirm-upload");
curl_setopt_array($ch, [
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_POST => true,
  CURLOPT_HTTPHEADER => ["Authorization: $key", 'Content-Type: application/json'],
  CURLOPT_POSTFIELDS => json_encode(['ids' => [$slot['id']]]),
]);
curl_exec($ch);

Using CURLOPT_INFILE streams the file rather than loading it into a string, which keeps you under PHP's memory_limit for large uploads — the usual bottleneck in PHP file handling. In a framework you'd reach for the native client: Laravel's Http::withHeaders(['Authorization' => $key])->post(...) for the metadata and confirm steps and ->withBody(...)->put(...) for the bytes; Symfony's HttpClient or Guzzle work the same way.

On WordPress, wp_remote_post and wp_remote_request (which supports PUT) let a plugin fire the upload from a hook with the key stored in wp_options — handy for offloading media to a CDN-backed store without bundling an SDK. Confirmed public files come back as permanent CDN URLs; private files use signed URLs with a short expiry, chosen at upload with a flag. For files above ~100MB (up to 1TB) the multipart endpoint streams chunks so you never exceed memory_limit.

Billing is prepaid credits, so an over-eager batch job costs credits, not a runaway bill. Compared to aws-sdk-php you drop a large dependency and a credentials file for a contract that's a few curl_setopt lines. Related: the WordPress media storage page for that specific offload, and the cloud file storage API page for the full route reference.