Using Cloud MCP

Letta Cloud stores MCP server connections per agent. The letta cloud-mcp CLI lists and runs those servers' tools through the Letta API, so it works from any surface where the agent runs: cloud sandboxes (chat.letta.com), Letta Desktop, and terminals.

Workflow

1. List MCP servers connected to this agent:

letta cloud-mcp list

2. Pick the relevant id from the JSON output, then list its tools:

letta cloud-mcp tools <mcp-server-id>

3. Pick a tool id, inspect its name and description, and run it with a JSON object:

letta cloud-mcp run <mcp-server-id> <tool-id> --args '{"key":"value"}'

Rules

• Do not ask for an agent ID unless the user wants another agent. The CLI reads LETTA_AGENT_ID/AGENT_ID from the environment.
• Treat command output as JSON. Summarize relevant results instead of pasting large raw payloads.
• If list is empty, ask the user to connect an MCP server to the agent on the MCP servers page.
• If tools is empty for a connected server, the server's tools were never synced. Ask the user to resync the server from the MCP servers page; the CLI has no refresh action.
• If a connected server has type stdio, its tools cannot run on hosted Letta Cloud. Tell the user instead of retrying.
• This requires a signed-in Letta Cloud agent. MCP servers configured locally in the terminal (/mcp) are unrelated to this CLI.