AWS gives Claude Code two paths to single-region inference

AWS published two ways to keep Claude Code inference inside one region instead of one geography, according to a post from its machine learning team. Cross-Region inference is Bedrock's default because it routes prompts to whichever region has capacity, and that default breaks residency rules for customers who need every request to stay put, not just stay in-country.

The first path sets the environment variable CLAUDE_CODE_USE_MANTLE=1 alongside AWS_REGION and pins the model by its plain ID. AWS supports it in seven regions: Ireland, Stockholm, Tokyo, Melbourne, N. Virginia, Ohio and Oregon.

The second path uses classic Bedrock with an application inference profile ARN. Only eu-west-2, London, has that profile wired up for Opus 4.6 and Sonnet 4.6, per AWS's post.

The seven-to-one gap

AWS calls that split decisive for most people setting this up. Outside London, anyone who wants Opus 4.6 or Sonnet 4.6 pinned to a single region has to take the Mantle path, not the ARN one, because the ARN path isn't wired up past eu-west-2. That's a bet worth tracking: if AWS adds inference profiles for the newest models in more regions, the seven-versus-one gap closes and the ARN path stops being a London-only workaround. Until then, it is.