Select Language:
Are you trying to upgrade your Claude model from version 3.5 to 4 and set it up for cross-region inference? If so, here’s how you can approach solving the issues you’re facing.
First, ensure your AWS IAM policy correctly grants the necessary permissions. Based on what you’ve shared, your current policy allows retrieving knowledge bases, invoking models, and running cross-region inference profiles. However, the error indicates that your user or role doesn’t have permission to invoke the specific model resource, which may be due to an explicit deny somewhere in your AWS organization’s Service Control Policies (SCPs).
Since your client states no SCPs are in place, the problem could be related to permissions on the role being assumed or the specific resource permissions. Double-check the following:
Verify IAM Role Permissions: Ensure that the role used by your Lambda or client has permissions to call
bedrock:InvokeModelon the precise resource ARN. Sometimes, the resource ARN must be exact, including account ID, region, and model version.ADVERTISEMENTUpdate the Policy for Cross-Region Access: Make sure your policy includes permissions for all regions where the model might be invoked. Your current policy includes a wildcard region (
arn:aws:bedrock:*), which should generally work, but confirm that your actual resource ARNs match this pattern.Check for Conflicting Policies: Even if there are no SCPs, individual IAM policies attached to your role or user might have explicit deny statements that override allow permissions.
Resource ARNs in your Policy: Confirm that the ARNs in your policy exactly match those used in your invocation calls. Sometimes, even small differences can cause permission issues.
Testing Permission: Use AWS IAM Policy Simulator to test whether your current policy allows invoking the model. This can help identify permission gaps.
Role Trust Relationship: Make sure the Lambda role or user has the correct trust relationships set up to assume roles, if applicable.
If after reviewing these steps the issue persists, consider explicitly adding a more generalized permission, such as allowing bedrock:InvokeModel on all resources, to see if that resolves the problem temporarily for troubleshooting:
json
{
“Effect”: “Allow”,
“Action”: “bedrock:InvokeModel”,
“Resource”: “*”
}
Remember to tighten permissions back down once tested, to follow best practices for security.
By carefully reviewing your IAM policies, ensuring resource ARNs match, and confirming there are no conflicting deny policies, you should be able to successfully upgrade to Claude 4 and enable cross-region inference.






