Claude Sonnet 4.5 (2025-09-29) (AWS Bedrock)

Claude Sonnet 4.5 belongs to the Claude Sonnet family and is positioned as a mid-generation update within Anthropic's evolving assistant roster, sitting between earlier Sonnet releases and newer successors such as Claude Sonnet 4.6. The variant is distributed through the AWS Bedrock channel, making it accessible to teams already working within Amazon's managed AI infrastructure. As a closed-weights model, it is offered only via hosted inference rather than downloadable artifacts, which is consistent with Anthropic's broader distribution approach for its Claude lineup.

From a practical standpoint, the model supports text, image, and PDF inputs while returning text outputs, and it accommodates large workloads through its substantial context window and generous maximum output length. Its capability set — including reasoning, tool calling, structured output, attachment handling, and temperature control — makes it well suited for agentic pipelines, document analysis, and structured data extraction tasks. Teams evaluating this variant should weigh it against sibling Claude Sonnet entries and newer 4.6-era options depending on whether frontier recency or proven stability matters more for their deployment.