We present the Living Swift-XRT Point Source (LSXPS) catalogue and real-time transient detector. This system allows us for the first time to carry out low- latency searches for new transient X-ray events fainter than those available to the current generation of wide-field imagers, and report their detection in near real time. Previously, such events could only be found in delayed searches, e.g. of archival data; our low-latency analysis now enables rapid and ongoing follow- up of these events, enabling the probing of time-scales previously inaccessible. The LSXPS is, uniquely among X-ray catalogues, updated in near real time, making this the first up-to-date record of the point sources detected by a sensitive X-ray telescope: the SwiftX-ray Telescope. The associated upper limit calculator likewise makes use of all available data allowing contemporary upper limits to be rapidly produced on demand. These facilities, which enable the low-latency transient system, are also fully available to the community, providing a powerful resource for time-domain and multimessenger astrophysics.

Cone search capability for table J/MNRAS/518/174/sources (Sources table is the main LSXPS table)

Cone search capability for table J/MNRAS/518/174/sclean (Clean subset of the source table those with a best Det Flag of 0 or 1 for Good or Reasonable)

Cone search capability for table J/MNRAS/518/174/suclean (Ultraclean subset of the sclean table those with Det=0 and FField=0)

Cone search capability for table J/MNRAS/518/174/datasets (Information about every individual datasets, observations and stacked images in LSXPS)

Cone search capability for table J/MNRAS/518/174/dclean (Subset of datasets.dat where FFlag=0 or 1)

Cone search capability for table J/MNRAS/518/174/duclean (Subset of dclean where FFlag=0)

Cone search capability for table J/MNRAS/518/174/detect (*Specific individual X-ray detections catalog in all band before combination to create sources)

Cone search capability for table J/MNRAS/518/174/xcorr (Details of the cross correlation between the LSXPS sources and other catalogues)

Cone search capability for table J/MNRAS/518/174/trans (Transient counterpart checked by the XRT team and classed into 'possible transient' categories)