GLM 5.3 now available on AI Gateway

Vercel's AI Gateway now offers GLM 5.3 from Z.ai, which improves on GLM 5.2 in complex software engineering and multi-step agent tasks while producing fewer output tokens. Z.ai reports stronger vulnerability discovery, as measured by DeepsecBench, and the model supports a 1M token context window and 128K token output.

GLM 5.3 from Z.ai https://vercel.com/ai-gateway/models/glm-5.3 is now available on AI Gateway. GLM 5.3 has improvements vs. GLM 5.2 at complex software engineering and at agent tasks that run across many steps, and it reaches those results while producing fewer output tokens than GLM 5.2 did at the same effort level. Z.ai also reports stronger vulnerability discovery, including reasoning across the successive stages of an exploitation chain. DeepsecBench https://vercel.com/ai-gateway/leaderboards/deepsecbench measures that work directly, scoring how reliably a model finds security vulnerabilities in application code and what a run costs, and it covers GLM-5.3 at both high and max effort. GLM 5.3 takes text input, with a 1M token context window and a maximum output of 128K tokens, both unchanged from GLM 5.2. It supports function calling, structured output, streaming, and context caching. To use the model, the slug is zai/glm-5.3 : To use it in a coding agent https://vercel.com/docs/ai-gateway/coding-agents , run vercel ai-gateway coding-agents setup to connect agents like Claude Code, Codex, OpenCode, Cursor, Pi, and more, then select zai/glm-5.3 inside the agent. AI Gateway provides a unified API for calling models, tracking usage and cost, and configuring retries, failover, and performance optimizations for higher-than-provider uptime. It includes built-in custom reporting https://vercel.com/changelog/custom-reporting-ai-gateway , Zero Data Retention support https://vercel.com/blog/zdr-on-ai-gateway , budgets for API keys https://vercel.com/docs/ai-gateway/authentication-and-byok/api-keys , routing rules https://vercel.com/docs/ai-gateway/models-and-providers/routing-rules , and more. AI Gateway reflects provider pricing with no markup and does not charge a platform fee on inference, including on Bring Your Own Key https://vercel.com/docs/ai-gateway/authentication-and-byok/byok BYOK requests.