Z.ai GLM 5.3 arrives on Amazon Bedrock with managed APIs, cross-Region inference and prompt caching

What changed

AWS announced on October 5 that Z.ai's GLM 5.3 is now available on Amazon Bedrock. AWS describes it as a 753B-parameter mixture-of-experts model optimized for coding and long-horizon agentic workloads. Developers can access it through fully managed Bedrock APIs with cross-Region inference, prompt caching and service tiers, and AWS provides examples using its OpenAI-compatible Responses API and an authorized Strix security test. This entry records GLM 5.3's new Amazon Bedrock distribution channel rather than claiming the model itself first launched on October 5.