Migrating Memory This skill helps migrate memory blocks from an existing agent to a new agent, similar to macOS Migration Assistant for AI agents. Requires Memory Filesystem (memfs) This workflow is memfs-first. If memfs is enabled, do not use the legacy block commands — they can conflict with file-based edits. To check: Look for a memory_filesystem block in your system prompt. If it shows a tree structure starting with /memory/ including a system/ directory, memfs is enabled. To enable: Ask the user to run /memfs enable , then reload the CLI. When to Use This Skill User is setting up a new agent that should inherit memory from an existing one User wants to share memory blocks across multiple agents User is replacing an old agent with a new one User mentions they have an existing agent with useful memory Migration Method (memfs-first) Export → Copy → Sync This is the recommended flow: Export the source agent's memfs to a temp directory letta memfs export --agent < source-agent-id
--out /tmp/letta-memfs- < source-agent-id
Copy the files you want into your own memfs system/ = attached blocks (always loaded) root = detached blocks Example: cp -r /tmp/letta-memfs-agent-abc123/system/project ~/.letta/agents/ $LETTA_AGENT_ID /memory/system/ cp /tmp/letta-memfs-agent-abc123/notes.md ~/.letta/agents/ $LETTA_AGENT_ID /memory/ Sync to API letta memfs sync --agent $LETTA_AGENT_ID This gives you full control over what you bring across and keeps everything consistent with memfs. Legacy Fallback (only if memfs is disabled) If memfs is not enabled , you can use block-level commands: letta blocks list letta blocks copy letta blocks attach ⚠️ Do not use these if memfs is enabled — they can diverge from file-based edits. Handling Duplicate Label Errors You cannot have two blocks with the same label. If you try to copy/attach a block and you already have one with that label, you'll get a duplicate key value violates unique constraint error. Solutions: Use --label (copy only): Rename the block when copying: letta blocks copy --block-id < id
--label project-imported Use --override (copy or attach): Automatically detach your existing block first: letta blocks copy --block-id < id
--override letta blocks attach --block-id < id
--override If the operation fails, the original block is automatically reattached. Manual detach first: Use the memory tool to detach your existing block: memory(agent_state, "delete", path="/memories/