Constellation

Constellation is a stateful agent cloud: it manages your agent state (memories and context), allowing you to easily interact with your stateful agents from anywhere in the world.

Agents created through Constellation can be accessed from any machine: your laptop, GitHub Actions, a sandbox, remote VM, or a Mac Mini. You can also chat with agents through chat.letta.com or through the desktop app.

graph TD
    Constellation["🌌 Constellation"]
    Constellation --> A["💻 Your Laptop"]
    Constellation --> B["☁️ Cloud VM"]
    Constellation --> C["🖥️ Mac Mini"]
    Constellation --> D["📦 Sandbox"]

Cloud-managed vs local state

When you create agents with the local backend (the default mode), your agent is created on your device: the “source of truth” for your agent’s memories, context, and message history lives entirely in your local system.

With the local backend, you are responsible for managing your agent’s state: if you delete your local .letta directory, you are deleting your agents. To keep your agent’s state safe, we recommend creating regular backups of your local state, and mirroring your agents memory to GitHub via the /memory-repository command.

Constellation allows you to store your agent state in the cloud: instead of being stuck on your local machine, your agent lives in Constellation, and can be teleported to any device via the Letta Code agent harness.

This means that you can access your agent from anywhere in the world, as long as you can access the internet. You can download Letta Code on any machine, and instantly chat with any of your (Constellation-managed) agents, without having to clone or copy agent state.

Features

Agents that live on Constellation have access to cloud-specific features, including:

• chat.letta.com: Chat with any of your agents via our mobile-friendly interface
• Cloud sandboxes: When running via chat.letta.com, Constellation will automatically provision cloud sandboxes to enable full computer user (and MemFS) capabilities
• Full API access: Interact with your agents programatically via the Letta API
• Remote & Multi-Env: Agents work across multiple environments. Make any machine available as a remote environment by running letta server --env-name "..."
• Secrets: Make secrets available as environment variables (across machines) while obfuscating their values from context

Comparison breakdown:

Capability	Local mode	Constellation (Cloud)
Agent state	Stored on the current machine	Available across devices and environments
Works without a Letta login	Yes	No
Appears in chat.letta.com	No	Yes
Desktop app access from other machines	No	Yes
Messaging integrations	No	Yes
Remote environments with letta server	No for local agents	Yes
Model inference	Uses providers you connect locally	Uses Letta account providers and connected BYOK providers

Local agents do not appear in Constellation or any of the cloud platform services (e.g. in the API, or web app).