AWS Lambda now supports direct read configuration for Amazon S3 Files

AWS Lambda now supports configuring functions to directly read from S3 Files high-performance storage or S3 buckets. This allows optimizing file read throughput and latency for application needs. S3 Files provides data from high-performance storage with low latency or offers high-throughput reads from S3 buckets, automatically routing each operation to the optimal storage. Previously, Lambda only supported direct reads from S3 buckets for functions configured with 512 MB of memory, with no control over the direct read setting, limiting performance optimization for specific application requirements. This feature enables explicit enabling or disabling of direct reads for Lambda functions, independent of function memory size. When enabled, files larger than 1 MB are read directly from S3 buckets at maximum throughput, while smaller files are served from high-performance storage. When disabled, all reads are served from high-performance storage with minimum 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. There are no additional charges beyond standard Lambda and S3 Files pricing. For details on using S3 Files with Lambda functions, see the AWS Lambda developer guide.

Why it matters

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