What shipped? GLM 5.3, the latest model from Z.ai (Zhipu AI / Tsinghua), is now available on Vercel AI Gateway.
What changed? The model slug is zai/glm-5.3. GLM 5.3 improves over GLM 5.2 in complex software engineering and multi-step agent tasks — while producing fewer output tokens at the same effort setting. Z.ai also reports better vulnerability discovery on DeepsecBench, including reasoning across successive stages of an exploitation chain.
It keeps the same 1M token context window and 128K max output from GLM 5.2, and supports function calling, structured output, streaming, and context caching.
Why does a builder care? GLM is one of the most capable open-weight model families from China, and it's gaining ground on coding and security benchmarks. Through AI Gateway you get it alongside 300+ other models with unified billing, failover, and no platform markup — including on Bring Your Own Key requests.