Amazon Bedrock AgentCore Runtime now supports bring-your-own file system from Amazon S3 Files and Amazon EFS

Posted on: May 6, 2026

Amazon Bedrock AgentCore Runtime now supports bring-your-own file system, enabling developers to attach their Amazon S3 Files and Amazon EFS access points directly to agent runtimes. AgentCore Runtime mounts the file system into every session at a path you specify, and your agent reads and writes files using standard file operations  - no custom mount code, no privileged containers, and no download orchestration before the agent can start working is needed.

This complements the existing managed session storage (in public preview), which AgentCore Runtime can automatically provision. Bring-your-own file system is for the data you already own and want to share: skills, tool libraries, reference datasets, knowledge bases, and project files that should be available across sessions, across microVM lifecycles, or across multiple agents. Developers can mount an Amazon S3 Files file system to access data through both standard file operations and S3 APIs, with changes automatically synchronized between the file system and the S3 bucket. Alternatively, they can mount an Amazon EFS access point for a purpose-built, shared NFS file system. Both options deliver sub-millisecond latency for active data and support NFS close-to-open consistency.

This unlocks patterns that were previously difficult to build. Agents can load shared skills, prompt templates, or curated datasets at session start without re-downloading at every new session initialization. Long-running workflows can persist intermediate results and resume work in future sessions. Multiple agents, or multiple sessions of the same agent, can collaborate on the same dataset, with one producing outputs that another consumes as inputs.

To get started, developers provide an access point ARN, and the agent runtime must be configured with a VPC. Bring-your-own file system is available across all 15 AWS Regions where AgentCore Runtime is supported. For the full list, see Supported AWS Regions. To learn more, see File system configurations in AgentCore Runtime.