GLM-5 is Z.ai's (formerly Zhipu AI) flagship open-source foundation model, built on a 744-billion-parameter Mixture-of-Experts architecture with 40 billion active parameters. It is engineered for complex systems design and long-horizon agent workflows, delivering production-grade performance on large-scale programming tasks that rivals leading closed-source models. With advanced agentic planning, deep backend reasoning, and iterative self-correction, GLM-5 moves beyond code generation to full-system construction and autonomous execution.