This work demonstrates the high-fidelity generation of 4-photon Greenberg-Horne-Zeilinger (GHZ) states on a chip using a bright quantum-dot-based single-photon source and a low-loss reconfigurable glass photonic circuit. The density matrix of the generated states was reconstructed using full quantum-state tomography, achieving an experimental fidelity of \(\mathcal{F}_{\text{GHZ}_4} = (86.0 \pm 0.4)\%\) and a purity of \(P_{\text{GHZ}_4} = (76.3 \pm 0.6)\%\). The entanglement of the generated states was certified through a semi-device-independent approach, violating a Bell-like inequality by more than 39 standard deviations. Additionally, a four-partite quantum secret sharing protocol was implemented on-chip, achieving a qubit-error rate of 10.87\%. These results highlight the potential of combining quantum-dot technology with glass photonic circuits for scalable entanglement generation and distribution.This work demonstrates the high-fidelity generation of 4-photon Greenberg-Horne-Zeilinger (GHZ) states on a chip using a bright quantum-dot-based single-photon source and a low-loss reconfigurable glass photonic circuit. The density matrix of the generated states was reconstructed using full quantum-state tomography, achieving an experimental fidelity of \(\mathcal{F}_{\text{GHZ}_4} = (86.0 \pm 0.4)\%\) and a purity of \(P_{\text{GHZ}_4} = (76.3 \pm 0.6)\%\). The entanglement of the generated states was certified through a semi-device-independent approach, violating a Bell-like inequality by more than 39 standard deviations. Additionally, a four-partite quantum secret sharing protocol was implemented on-chip, achieving a qubit-error rate of 10.87\%. These results highlight the potential of combining quantum-dot technology with glass photonic circuits for scalable entanglement generation and distribution.