---
title: Developers
slug: developers
description: Build on Personizely: the JavaScript API, the REST API with API keys and OAuth, the MCP server for AI assistants, and the server-side SDK (Preview).
docTags: 
createdAt: 2026-10-16T19:48:15.169Z
---

Personizely gives developers several ways to build on it: the JavaScript API (`window.ply`) to track events and goals, run campaigns and control widgets in the browser; the REST API, authenticated with API keys or OAuth, to manage campaigns, widgets and results from your own systems; the MCP server, which connects AI assistants such as Claude and ChatGPT to your account; and the server-side SDK, in Preview, for full-stack experiments and feature flags in Node, edge and browser code.

- [REST API](docId\:HG88NTwtq60d17m6jFErF)
- [API keys and connected apps](docId\:T7lxFvTpjSqPdNkC67kun)
- [JavaScript API (window.ply)](docId\:d64TegyOiwNA2GFG1eXPm)
- [Server-side SDK (@personizely/sdk) – Preview](docId\:EngKfM5d8BirDq9140PvL)
- [MCP server](docId\:usaccUEvfdBFWxe_Z1uuN)