GLM 5.3

What GLM 5.3 is for

Z.ai says GLM-5.3 delivers broad gains in demanding software engineering and agent tasks and works with favored coding agents right now. Z.ai lists api.z.ai endpoints for OpenAI Chat Completion, OpenAI Response, and Anthropic Message protocols, but says the API presently runs solely over the OpenAI Chat Completion-compatible option.

What Z.ai says it does well

• Improved cybersecurity capabilities, including reasoning across multiple stages of exploitation
• Supports three reasoning effort levels: low, high, and max

Where to use it

• Model API via OpenAI Chat Completion protocol at https://api.z.ai/api/coding/paas/v4
• Model API via OpenAI Response protocol at https://api.z.ai/api/v1
• Model API via Anthropic Message protocol at https://api.z.ai/api/anthropic
• Users with previously subscribed (including expired) GLM Coding Plan can access the model API only through the OpenAI Chat Completion-compatible protocol

Limits Z.ai mentions

• Supports text-only inputs
• Always operates with reasoning enabled; disabling reasoning is no longer supported
• Pipelines for environment generation still require meaningful human-in-the-loop work