Directional scattering enabled by multimode interference in high-index nanostructures provides exceptional control over light manipulation, but achieving flexible spectral tuning remains challenging. To address this, we propose a hybrid nanoantenna that integrates transition metal dichalcogenides (TMDs) with the phase-change material ${\mathrm{Ge}}_2{\mathrm{Sb}}_2{\mathrm{Se}}_4{\mathrm{Te}}_1$ (GSST), enabling continuous spectral tuning of unidirectional forward scattering. This tunability arises from the GSST phase transition. With carefully optimized parameters, this transition induces virtually synchronous redshifts of the electric and magnetic dipole Mie resonances while preserving their near-zero phase difference, thereby maintaining the Kerker condition throughout the amorphous-crystalline transformation. This enables on-demand active spectral tuning of the unidirectional forward scattering. We further demonstrate flexible switching between single- and dual-wavelength unidirectional forward scattering enabled by the self-hybridized exciton-Mie interaction in the ${\mathrm{MoTe}}_2$-GSST nanoantenna. Additionally, we explore the influence of the GSST phase transition on the scattering directionality under self-hybridization, showing that the transition alters the overlap between the exciton and Mie resonances and thereby modulates the coupling strength, ultimately suppressing dual-wavelength scattering. Our work introduces a paradigm for actively tunable nanoantennas, combining dynamic phase-change materials with exciton resonances.

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• Light-matter interaction
• Metamaterials
• Nanophotonics
• Nanostructures