Accurate myelination of vertebrate neuronal circuits is crucial for their function, as the exact amount and distribution of myelin ensheathing an axon influences the timing and energy efficiency of neurotransmission. This is especially evident in multiple sclerosis (MS), where myelin regeneration after damage often produces thinner, shorter, or misdirected sheaths that fail to support normal nerve function. However, the molecular mechanisms that ensure accurate myelin growth and repair to maintain optimal conduction remain poorly understood. Recent studies suggest that adhesion proteins at the axon-myelin interface regulate myelin growth and targeting, as their genetic manipulation mistargets myelin to neuron somas and reduces sheath length, similar to MS defects. However, how individual adhesion proteins are dynamically regulated along axons to ensure accurate myelination is unknown. To address this, we developed a reporter knock-in zebrafish for Nfascb (Nfascb-EGFP), a critical myelin adhesion protein. This model allows us to visualize endogenous Nfascb in real time at single-cell resolution and revealed that Nfascb clusters specifically at the edges of mature myelin sheaths, suggesting a role in sheath growth and stabilization after formation. In parallel, we established a zebrafish line that enables proximity labeling of GFP-tagged proteins in oligodendrocytes. Combined with our Nfascb-GFP line, this approach allows us to identify molecular interactors of Nfascb that may serve as key regulators of adhesion formation, and thereby support accurate myelin growth and repair.