A new detection array called GASTLY (GAs-Silicon Two-Layer sYstem) has been designed to detect and identify low-energy light particles emitted in nuclear reactions of astrophysical interest. Devoted to the measurement of nanobarn cross-sections, the system is optimised for large solid angle coverage and for low-energy detection thresholds. The array consists of eight modules, each comprising an ionisation chamber and a large area silicon strip detector. Its modularity and versatility allow for use in a variety of experiments. Here we report on the performance of the array as obtained during its commissioning phase with standard α -particle sources and during in-beam tests with an intense 12C beam. Typical energy resolutions ΔE(FWHM)/E of about 3% and 2% were obtained for the ionisation chambers and the silicon detectors, respectively. The status of the development of individual strip readout, based on ASIC technology, is also presented.