API Authentication in CodeIgniter

API Authentication in CodeIgniter — a practical guide to CodeIgniter API authentication with clear examples you can reuse in real projects.

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Short description

Common options: API keys, session auth for first-party apps, or JWT for stateless APIs.

Simple API key filter idea

$key = $this->request->getHeaderLine('X-API-Key');
if ($key !== env('API_KEY')) {
    return $this->response->setStatusCode(401)->setJSON(['error' => 'Unauthorized']);
}