The **ptr‑core** library provides utilities for server‑side rendering (SSR) of React/Redux applications that need to wait for asynchronous data fetching before the HTML can be generated. It supplies a request‑counter, a Redux middleware to keep the counter in sync with async actions, and a `createRenderFn` helper that repeatedly re‑renders a component until all pending requests finish (or a retry limit is hit), returning the rendered data as a promise. This package is aimed at developers building universal (isomorphic) React apps who need deterministic SSR handling of data‑loading side effects.