Aws_credentialsAWS credential resolution. Every t states its source explicitly — there is no implicit default, the same way every Kafka config states its security posture explicitly via Kafka_security.t.
Aws_errorShared error type for every aws-eio-family package. Service-specific backends (s3-eio, dynamo-eio) extend this with their own variants rather than reinventing HTTP/signature/network/credential failure cases.
Aws_httpHTTP transport shared by every aws-eio backend: TLS (via Aws_tls), exponential backoff with full jitter on retryable failures, and SigV4 signing.