Error: dynamodb could not connect to the endpoint url

“Could not connect to the endpoint URL” means the client failed to establish a usable connection to the configured endpoint. Check the endpoint and transport first. An IAM denial normally arrives as an HTTP service response, rather than a connection failure.

1. Read the endpoint URL in the exception. For AWS, verify the Region and remove accidental local endpoint overrides. For DynamoDB Local, use HTTP and the configured local port.
2. Test DNS and TCP connectivity from the application’s environment, including its container or VPC subnet. Verify proxy, firewall, route-table, and network ACL settings.
3. For a private subnet, configure a suitable DynamoDB VPC endpoint or a NAT route. Inside Docker, use the service hostname for a sibling container instead of localhost.
4. Confirm the local process is running before retrying. A listener on a different host port will not answer the configured URL.

Once connectivity works, repeat the signed SDK request and diagnose any authentication or authorization error separately. Avoid disabling certificate verification to work around a TLS failure; fix the trust chain or endpoint.

See local connection setup and AWS documentation.