Analysis
Amazon has made xAI's Grok 4.3 generally available on Bedrock, the first time an xAI model has been offered through the platform. The move makes xAI the third major independent lab available on Bedrock alongside Anthropic and OpenAI, turning Amazon's managed-model marketplace into a genuine multi-lab venue where enterprises can swap frontier models behind a single procurement and security layer.
The positioning is aggressive on price. At $1.25 per million input tokens and $2.50 per million output tokens, Grok 4.3 is the cheapest US-lab frontier reasoning model on Bedrock, paired with a 1-million-token context window and configurable reasoning effort. It runs on Mantle, Amazon's new inference engine built for price-performance, with support for tool calling, structured output and streaming.
“It runs on Mantle, Amazon's new inference engine built for price-performance, with support for tool calling, structured output and streaming.”
For xAI, distribution through AWS is the real prize: it instantly reaches enterprises that buy through Amazon and won't touch a standalone API. For Anthropic and OpenAI, a low-priced, capable rival on the same shelf sharpens the cost competition just as the Trump administration's restrictions complicate Anthropic's footing -- a reminder that on Bedrock, model choice increasingly comes down to price, latency and trust.
