---
title: "Developer corner"
manual: "LIA Imageserver"
version: "main"
permalink: "https://docs.typo3.org/permalink/lia/lia_imageserver:developer@main"
source: "Developer/Index.rst"
rendered: "2026-10-01T15:01:11+00:00"
---

# Developer corner {#developer}

This chapter is for developers who extend the processing chain: listen to the
PSR-14 event fired before every rendering, register custom instruction
classes, or implement a delivery backend that understands the overlay
contract.

-   [Events](https://docs.typo3.org/permalink/lia/lia_imageserver:events@main)
-   [The overlay contract](https://docs.typo3.org/permalink/lia/lia_imageserver:the-overlay-contract@main)