GLM-4.5-Air is a Mixture-of-Experts language model from Zhipu AI's GLM-4.5 series, reported with roughly 18.6 billion total parameters and about 12 billion active parameters per inference. The architecture is built around a hybrid reasoning design that supports both a thinking mode for complex reasoning and tool use and a non-thinking mode for immediate conversational replies, giving developers a single model that can switch between deliberate multi-step problem solving and lightweight dialogue. Independent coverage of the broader GLM-4.5 launch described the family as emphasizing strong reasoning, coding, and agentic capabilities, positioning Air as a workhorse variant within that lineup rather than the largest flagship model.
Intended use centers on conversational AI, tool-augmented reasoning, and bilingual applications across English and Chinese, making the model a practical fit for chat assistants, code-generation helpers, and agent pipelines that orchestrate external tools. Open weights and MIT-licensed distributions (as observed in community quantizations) lower the barrier for self-hosting and experimentation, and compatibility with mainstream inference stacks such as Transformers, vLLM, and SGLang makes deployment straightforward for teams that want to balance latency, throughput, and cost. Quantized 4-bit derivatives further reduce memory footprint, so Air can serve on more modest hardware while preserving the reasoning and tool-use behavior of the base model.
