Today, AWS announces the availability of xAI's Grok 4.3 model on Amazon Bedrock. With this launch, xAI joins Amazon Bedrock as a model provider, giving you even more choice as you build generative AI applications across reasoning, agentic, and enterprise workflows.

Grok 4.3 is a reasoning-first model that offers always-on and configurable reasoning effort (none, low, medium, high). Because reasoning is always active rather than optional, it behaves more consistently across multi-step agent loops than models that can skip thinking. It also offers strong tool use and instruction-following capabilities for building multi-step agents, and token efficiency to help keep high-volume inference cost-effective. Grok 4.3 is especially well suited to enterprise workloads such as contract review, case law research, credit agreement analysis, and financial document Q&A, while delivering consistent, high-quality results across conversational AI, search, chat, and multi-turn workflows. Grok 4.3 runs on Mantle, a new inference engine in Amazon Bedrock designed for price performance, with support for tool calling, structured output, and response streaming.

See region availability of Grok 4.3 for list of supported regions. To get started, visit the Grok 4.3 model detail page in our documentation.