Shared memory

Shared memory gives multiple agents access to the same files and working context. Each shared memory repository is a Git repository hosted in Letta Cloud and owned by your organization.

Older Letta API guides use shared memory blocks for one in-context memory block attached to multiple agents. The legacy memory block API still supports this pattern, but users should migrate to shared memory repositories instead.

Memory	Ownership	Use
MemFS	One agent	Store the agent’s identity, skills, and long-term memory
Shared memory repository	Your organization	Share knowledge and working files between agents

Use shared memory for team conventions, product knowledge, research, plans, and documents that multiple agents maintain.

How agents access shared memory

Attach a repository to each agent that needs it. The agent’s system prompt lists the repository path and its top-level files. Letta Code clones the repository beside the agent’s MemFS at:

$MEMORY_DIR/../<repository-name>/

The agent reads and edits the repository with normal file and Git tools. The agent must commit and push its changes. Other agents can then pull those commits into their own checkouts.

An attached repository can also provide skills to its agents. Put each skill in skills/<skill-name>/SKILL.md at the repository root. Letta Code stops loading these skills when you detach the repository.

Letta Code clones a repository when it first becomes available. Later synchronization fast-forwards the local checkout from its remote. Use letta shared-memory sync to pull attached repositories or create a missing checkout.

Manage shared memory

You can create new shared memories with:

letta shared-memory create --name team-memory

Attach a shared memory to each agent with the attach subcommand:

letta shared-memory attach team-memory --agent <agent-id>
letta shared-memory attach team-memory --agent <other-agent-id>

The web and desktop apps can also create and attach shared memories. Applications can manage persistent repository attachments with the Agent SDK.

Cloud agents can also use the bundled managing-shared-memory skill to create, attach, detach, synchronize, and inspect repository history.

Shared memory repositories require cloud-hosted agents. Local agents use their own MemFS and project files.