  The detection of entanglement provides a definitive proof of quantumness. Its
ascertainment might be challenging for hot or macroscopic objects, where
entanglement is typically weak, but nevertheless present. Here we propose a
platform for measuring entanglement by connecting the objects of interest to an
uncontrolled quantum network, whose emission (readout) is trained to learn and
sense the entanglement of the former. First, we demonstrate the platform and
its features with generic quantum systems. As the network effectively learns to
recognise quantum states, it is possible to sense the amount of entanglement
after training with only non-entangled states. Furthermore, by taking into
account measurement errors, we demonstrate entanglement sensing with precision
that scales beyond the standard quantum limit and outperforms measurements
performed directly on the objects. Finally, we utilise our platform for sensing
gravity-induced entanglement between two masses and predict an improvement of
two orders of magnitude in the precision of entanglement estimation compared to
existing techniques.
