AgentCore Runtime: Support for shared filesystem mounts (S3 Files / EFS) across sessions

Question

I'm running an AI agent on AgentCore Runtime with a companion memory daemon ([agent-memory-daemon](https://github.com/tverney/agent-memory-daemon)) that consolidates and curates memory files on the filesystem. The daemon needs a shared, persistent directory that's accessible across all sessions and survives container freeze/thaw cycles.

The recently launched managed session storage (preview) is per-session and isolated, which doesn't work for shared state like agent memory that needs to be readable by any session.

Currently I work around this by running a custom S3 sync layer (~200 lines of Python) that restores files from S3 on startup, syncs periodically in the background, and handles race conditions with OpenClaw's workspace initialization. This adds complexity, latency on cold starts, and potential data loss if the container is killed before a sync completes.

**Request:** Support mounting a shared filesystem — specifically S3 Files or EFS — in AgentCore Runtime via `filesystemConfigurations`. This would allow:

- A memory daemon and agent tasks to share a filesystem without custom sync code
- Data to persist across container freeze/thaw without explicit S3 backup/restore
- Multiple sessions to access the same shared state (memory files, workspace artifacts)
- Zero cold-start penalty for filesystem restoration

S3 Files is a natural fit since it provides NFS access to S3 data with no sync overhead, and AgentCore already integrates with S3 for other purposes.

**Use case:** Personal AI assistant with long-term memory curation. The daemon writes organized memory files (MEMORY.md index + topic files) that the agent reads at the start of every conversation. Today this requires ~200 lines of sync glue code that could be eliminated with a shared mount.

re:Post Agent · Accepted Answer

Amazon Bedrock AgentCore Runtime currently supports managed session storage in preview, which provides persistent filesystem state across stop/resume cycles. However, this storage is specifically designed to be isolated per session - each session receives its own dedicated persistent directory at a configured mount path, and the storage communication is confined to a single session's data and cannot access other sessions or AgentCore Runtime environments.

The current session storage capability is intentionally session-isolated for security and data separation purposes. When you configure session storage by adding a `sessionStorage` entry to `filesystemConfigurations`, the mount path (which must start with `/mnt` followed by a folder name) creates a persistent directory that survives when that specific session's compute terminates and resumes. However, this storage is not shared across different sessions.

For your use case of sharing memory files across multiple sessions, the current architecture does not support shared filesystem mounts like S3 Files or EFS through the `filesystemConfigurations` parameter. The session storage feature is designed for use cases like durable filesystem scratch space, code generation and iteration, and long-running analysis with checkpoints - all within the context of a single session.

For structured data that needs to be retained beyond individual session lifetimes and potentially shared across sessions, Amazon Bedrock AgentCore offers AgentCore Memory as a separate service. This provides purpose-built persistent storage designed specifically for agent workloads, with both short-term and long-term memory capabilities. However, this is a different service from filesystem-based storage.

Your current approach of using a custom S3 sync layer is a reasonable workaround given the current capabilities, though I understand it adds complexity. The feature you're requesting - shared filesystem mounts accessible across all sessions - would represent a significant architectural change from the current session-isolated design model.  
**Sources**  
[Persist session state across stop/resume with a filesystem configuration (Preview) - Amazon Bedrock AgentCore](https://docs.aws.amazon.com/bedrock-agentcore/latest/devguide/runtime-persistent-filesystems.html)  
[Amazon Bedrock AgentCore Runtime now supports managed session storage for persistent agent filesystem state (preview) - AWS](https://aws.amazon.com/about-aws/whats-new/2026/03/bedrock-agentcore-runtime-session-storage/)  
[Use isolated sessions for agents - Amazon Bedrock AgentCore](https://docs.aws.amazon.com/bedrock-agentcore/latest/devguide/runtime-sessions.html)  
[Persist session state with filesystem configuration and execute shell commands | Artificial Intelligence](https://aws.amazon.com/blogs/machine-learning/persist-session-state-with-filesystem-configuration-and-execute-shell-commands/)

AgentCore Runtime: Support for shared filesystem mounts (S3 Files / EFS) across sessions

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