Function getBedrockRegionPrefix

src/utils/model/bedrock.ts:222–235

(
  modelId: string,
)

 * - "claude-sonnet-4-5-20250929" → undefined (first-party format)
 */
export function getBedrockRegionPrefix(
  modelId: string,
): BedrockRegionPrefix | undefined {
  // Extract the inference profile ID from ARN format if present
  // ARN format: arn:aws:bedrock:<region>:<account>:inference-profile/<profile-id>
  const effectiveModelId = extractModelIdFromArn(modelId)

  for (const prefix of BEDROCK_REGION_PREFIXES) {
    if (effectiveModelId.startsWith(`${prefix}.anthropic.`)) {
      return prefix
    }
  }
  return undefined
}

/**
 * Apply a region prefix to a Bedrock model ID.