AWS Lambda now supports direct read configuration for Amazon S3 Files

AWS Lambda now supports direct read settings, allowing functions to choose between high-performance storage for S3 Files or S3 buckets for reading. This enables optimizing throughput and latency for application needs. S3 Files provides low-latency data from high-performance storage or high-throughput reads from S3 buckets, automatically routing each operation to the optimal storage. By default, Lambda only supports direct reads from S3 buckets for functions configured with 512 MB of memory, lacking control over the direct read setting for specific application requirements. This release allows explicit enabling or disabling of direct reads for S3 Files regardless of function memory size. Enabling direct reads fetches files larger than 1 MB directly from S3 buckets at maximum throughput, while smaller files are served from high-performance storage. Disabling direct reads serves all reads from high-performance storage with minimal latency. This feature is available in all AWS commercial regions, AWS GovCloud (US-East) and AWS GovCloud (US-West) regions, except Asia Pacific (New Zealand), Middle East (Bahrain), and Middle East (UAE). The direct read setting can be configured via the AWS Management Console, AWS CLI, AWS SDK, and AWS CloudFormation, with no additional charges beyond standard Lambda and S3 Files fees. For details on using S3 Files with Lambda functions, see the AWS Lambda developer guide.

Why it matters

This update is useful for developers who need to optimize the integration between Lambda functions and S3 Files, particularly those building scalable data processing pipelines or stateful agentic workloads.