> For the complete documentation index, see [llms.txt](https://antonshevchuk.gitbook.io/php-for-beginners/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://antonshevchuk.gitbook.io/php-for-beginners/appendix/psr-3-logger-interface-monolog.md).

# PSR-3: Logger Interface; Monolog