Logging in PHP (Structured Logs You Can Trust)

Good logging makes you faster when things break.

What to log

• errors + stack traces
• important actions (order created, payment success)
• request id, user id (if safe), endpoint, timestamp

Basic log helper

function log_event(string $message, array $context = []): void {
  $line = date("Y-m-d H:i:s") . " " . $message . " " . json_encode($context) . PHP_EOL;
  file_put_contents(__DIR__ . "/app.log", $line, FILE_APPEND);
}

Example usage

log_event("order_created", ["order_id" => 123, "user_id" => 10]);

Pro tip

In real apps, use a mature logger like Monolog (via Composer). Same idea, better tools.

Next: Environment variables and config management (no hardcoding secrets).