Building a Simple API Client SDK

Wrap an HTTP client with typed, predictable methods and standardized error handling. The examples separate the essential operation from the conditions a production implementation must enforce.

What It Does

Wrap an HTTP client with typed, predictable methods and standardized error handling.

Prerequisites

Use a dedicated development environment with test accounts and records. Separate authorization, validation and error handling from response formatting; never copy demonstration-only secrets into production.

Example 1: Core Behavior

The first example isolates the core operation so its result is easy to understand.

<?php
$opts = ['timeout'=>5,'connect_timeout'=>2,'verify_tls'=>true];
if ($opts['timeout'] <= 0 || !$opts['verify_tls']) throw new RuntimeException('Unsafe client config');
echo json_encode($opts);

Example 2: Alternative or Failure Case

The second example demonstrates an alternative outcome, rule or failure condition.

<?php
$status=503; $body='{"message":"Unavailable"}';
if ($status>=500) { echo 'Retryable upstream error'; } else { echo json_decode($body,true,512,JSON_THROW_ON_ERROR)['message']; }

Practical Example: Applying the Rule

This practical workflow performs the relevant operation, with strict error checks. Configure the required transport or database driver before running it.

<?php
final class CatalogClient {
    public function __construct(private string $baseUrl) {
        if ($baseUrl !== 'https://api.example.test') throw new InvalidArgumentException('Unapproved API host');
    }
    public function find(int $id): array {
        $ch = curl_init($this->baseUrl . '/items/' . $id);
        curl_setopt_array($ch, [CURLOPT_RETURNTRANSFER => true, CURLOPT_CONNECTTIMEOUT => 3, CURLOPT_TIMEOUT => 8, CURLOPT_FOLLOWLOCATION => false]);
        $body = curl_exec($ch);
        if ($body === false) throw new RuntimeException('API transport failure: ' . curl_errno($ch));
        $status = curl_getinfo($ch, CURLINFO_RESPONSE_CODE);
        if ($status !== 200) throw new RuntimeException('Unexpected API status: ' . $status);
        $data = json_decode($body, true, 512, JSON_THROW_ON_ERROR);
        if (!is_array($data) || !isset($data['id'])) throw new UnexpectedValueException('Invalid API response');
        return $data;
    }
}
$client = new CatalogClient('https://api.example.test');
echo json_encode($client->find(12), JSON_THROW_ON_ERROR);

Important Behavior and Edge Cases

Set TLS verification, timeouts, auth and retry policy at the transport boundary.

Comparison with Related Functions or Patterns

Common Beginner Mistakes

Key Takeaways

• Wrap an HTTP client with typed, predictable methods and standardized error handling.
• Set TLS verification, timeouts, auth and retry policy at the transport boundary.
• A thin SDK hides transport details without recreating a full HTTP framework.

Select this API or pattern based on its documented behavior and the trust boundaries in your own application, and test all external integrations against their actual deployments.