Twilio API API in PHP

Twilio API API in PHP

This guide shows you how to integrate the Twilio API into your PHP application. SMS, Voice, WhatsApp, Video, and Verify APIs for omnichannel customer engagement.

Prerequisites

  • PHP installed on your system
  • An Twilio API API key (sign up at https://twilio.com)
  • Basic familiarity with HTTP APIs

Installation

composer require guzzlehttp/guzzle

Basic Usage

<?php
$apiKey = getenv('API_KEY') ?: 'YOUR_API_KEY';
$baseUrl = 'https://api.twilio.com';

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $baseUrl . '/v1/resources');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    'Authorization: Bearer ' . $apiKey,
    'Content-Type: application/json',
]);

$response = curl_exec($ch);
$httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

echo "Status: $httpCode\n";
echo $response . "\n";
?>

Error Handling

<?php
$apiKey = getenv('API_KEY') ?: 'YOUR_API_KEY';
$baseUrl = 'https://api.twilio.com';

function callApiWithRetry($url, $headers, $maxRetries = 3) {
    $ch = curl_init();
    for ($attempt = 0; $attempt <= $maxRetries; $attempt++) {
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
        $response = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        if ($httpCode === 429) {
            sleep(60);
            continue;
        }
        if ($httpCode < 500) {
            break;
        }
        sleep(pow(2, $attempt));
    }
    curl_close($ch);
    return [$httpCode, $response];
}

$url = $baseUrl . '/v1/resources';
$headers = ['Authorization: Bearer ' . $apiKey, 'Content-Type: application/json'];
list($code, $resp) = callApiWithRetry($url, $headers);
echo "Status: $code\n";
echo $resp . "\n";
?>

Advanced Usage

<?php
class TwilioClient {
    private $apiKey;
    private $baseUrl;

    public function __construct($apiKey, $baseUrl = 'https://api.twilio.com') {
        $this->apiKey = $apiKey;
        $this->baseUrl = rtrim($baseUrl, '/');
    }

    public function request($method, $path, $data = null) {
        $ch = curl_init();
        $url = $this->baseUrl . '/v1' . $path;
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_HTTPHEADER, [
            'Authorization: Bearer ' . $this->apiKey,
            'Content-Type: application/json',
        ]);
        curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $method);
        if ($data !== null) {
            curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($data));
        }
        $response = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);
        if ($httpCode >= 400) {
            throw new Exception("API Error: HTTP $httpCode");
        }
        return json_decode($response, true);
    }

    public function listResources($params = []) {
        $query = http_build_query($params);
        $path = '/resources' . ($query ? '?' . $query : '');
        return $this->request('GET', $path);
    }

    public function createResource($data) {
        return $this->request('POST', '/resources', $data);
    }
}

$client = new TwilioClient(getenv('API_KEY') ?: 'YOUR_API_KEY');
$resources = $client->listResources(['limit' => 50]);
echo "Found " . count($resources['data'] ?? []) . " resources\n";
?>

Best Practices

  • Store your API key in an environment variable, never in source code
  • Implement retry logic with exponential backoff for 429 and 5xx errors
  • Set reasonable timeouts (10-30 seconds) for all API calls
  • Log request IDs from response headers for debugging
  • Cache responses where appropriate to reduce API calls

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