GLM 4.5 Air sits beside Z.ai's flagship GLM-4.5 as a lighter, agent-focused sibling in the same family. Both models share a Mixture-of-Experts design that Z.ai built in-house, but GLM 4.5 Air uses a more compact parameter configuration aimed at workloads where latency and cost efficiency matter more than maximum capacity. The model ships with open weights, and Z.ai's public release positions the GLM-4.5 series as a unified foundation that natively combines reasoning, coding, and agentic behavior in a single checkpoint rather than bolting those capabilities on through separate fine-tunes.

For practical use, GLM 4.5 Air offers hybrid inference through two operating modes: a thinking mode for multi-step reasoning and tool use, and a non-thinking mode for fast, real-time interaction, with a reasoning-enabled switch that lets developers toggle between them. This dual-mode setup makes the model a flexible backbone for agent pipelines that need to plan carefully on hard tasks yet respond quickly on routine turns. Because the weights are openly published, teams can also self-host and tune the model for domain-specific agents, complementing its built-in tool calling and reasoning strengths.