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The van der Waals kagome materials Nb3X8 (X = halide) have gained attention for properties such as single band Mott Hubbard insulators, a kagome flat band near the Fermi level, unconventional frustrated magnetism, etc. In this work, we aim to study single crystals of the cluster magnet candidate Nb3Cl8. Nb3Cl8 exhibits a magnetic-nonmagnetic phase transition with a concomitant structural phase transition at ~90 K, which was hypothesized by a charge disproportionation with the interplay between the spin and lattice environments. To study the origin of its disordered magnetic texture, direct access to the electronic valence, which accounts for the unpaired correlated electron spins, is required. This was absent or insensitive in previous X-ray/neutron diffraction reports. In this vein, we perform X-ray absorption spectroscopy measurements to directly probe the transition-metal Nb L2,3-edge and its ligand Cl K-edge across the magnetic transition. These measurements will help characterize the valence of Nb/Cl site in each phase, and shed light to the underlying microscopic interactions of the proposed quantum cluster trimer magnetism.