Muscle specific kinase (MuSK) is a receptor tyrosine kinase that plays a crucial role in development and maintenance of the neuromuscular junction (NMJ). Lack of MuSK is lethal and defective MuSK signaling causes muscle weakness. MuSK activity is tightly regulated and requires the nerve-derived heparansulphate proteoglycan Agrin. However, signal transduction induced by MuSK activation is not well understood. Here, we used proximity labeling to decipher the MuSK interactome by identifying and characterizing interaction partners of MuSK upon Agrin stimulation. To uncover the early and late events in the MuSK signaling cascade, muscle cells were stimulated with Agrin for 2 h, 4 h and 8 h. Overall, our study reveals that CrkL functions as a signaling hub to recruit different molecules for distinct signaling outcomes and contributes to a better understanding of the complex mechanisms that regulate NMJ formation.