Multi Device Zones

Multi-Device Zones

Multi-Device Zones group several Easy Local MCP devices behind the same Relay and expose one shared MCP connector for the whole group.

Each device still owns its existing per-device McpRelay, Agent token, MCP token, local workspaces, LOCK state, and feature permissions. The Zone adds a control plane and a lightweight MCP router above those existing security boundaries.

Architecture

flowchart TD
    A[ChatGPT] -->|Zone MCP URL| Z[Zone MCP Router]
    Z --> M[ZoneManager Durable Object]
    Z --> R1[McpRelay: Windows]
    Z --> R2[McpRelay: Mac mini]
    R1 --> A1[Windows Agent]
    R2 --> A2[Mac Agent]

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The Zone router does not store or use the individual devices' plaintext MCP tokens. It routes internally to the selected per-device Relay, while the target Agent continues to enforce its local LOCK state and configured capabilities.

What a Zone stores

A dedicated Cloudflare Durable Object stores only Zone management state:

• Zone name
• Zone administrator credential hash
• Zone MCP connector credential hash
• joined device IDs and display names
• platform / architecture / version metadata
• one-time join-code hashes and expiration times

The administrator and Zone MCP tokens are returned only when created or rotated. The Relay stores their SHA-256 hashes.

Open the Zone manager

On a Relay that includes Zone support, open:

https://your-relay.example/admin

The page can:

• create a Zone
• show the shared Zone MCP connector URL when it is created
• rotate the Zone connector credential
• generate a one-time join code
• list devices and their online/offline state
• remotely unlock an online Zone member for 5, 15, 30, or 60 minutes
• rename a device
• revoke a device

The /admin dashboard requires a Relay Admin login backed by RELAY_ADMIN_TOKEN_HASH. Without that configuration, the management plane fails closed. REGISTRATION_TOKEN_HASH remains a separate compatibility mechanism for non-admin registration flows and is not the Relay administrator credential.

Existing Zones created before the Relay Admin registry remain valid. After upgrading, sign in to /admin and use Import Existing Zone with the Zone ID and existing Zone Admin Token. The token is used only to verify that Zone and is not stored. If the Zone predates the shared connector, choose Rotate Connector once to create a Zone MCP URL.

Join another device

The desktop Control Center is the preferred path:

1. Configure the device to use the same Relay as the Zone.
2. In Relay Admin, open the Zone and choose Create Join Code.
3. On a fresh device, paste the code into Zone Join Code (optional) before the first Save & Start Agent. The first registration joins the Zone directly.
4. On an already registered device, open Zone membership, paste the code, and choose Join Zone.

The Control Center automatically stops the Agent when needed, retires the previous Relay registration, consumes the Join Code, creates fresh per-device Zone credentials, restarts the Agent, and waits for the new registration before reporting success.

Before joining, the Control Center explicitly warns that the Relay Administrator will be able to route Zone MCP requests to this device, remotely unlock privileged capabilities for a limited time while the device is online, and revoke the device. Zone membership also disables Standalone Always Unlocked.

The Join Code is single-use and expires after 10 minutes by default. The display name defaults to the local hostname and can be renamed later by the Zone administrator.

CLI remains available for headless installations:

localmcp join <zone-code>

For the CLI flow, stop Easy Local MCP before staging the join, then start it normally to complete registration.

Leave a Zone

In Zone membership, choose Leave Zone. The device authenticates the request with its current Agent credential, removes itself from the Zone, invalidates its Zone-era credentials, receives fresh standalone credentials on the same Relay, and restarts automatically. The Relay Admin device list is updated as part of the leave operation, so a normal leave does not leave an offline ghost device behind.

Use one connector in ChatGPT

Configure ChatGPT with the Zone MCP URL shown when the Zone is created or when Rotate Connector is used:

https://your-relay.example/mcp/z/<zone-id>/<zone-mcp-token>

The Zone connector exposes:

• list_devices
• the normal LocalMCP tools discovered from the currently available Zone devices

Routed LocalMCP tools include an additional required device argument.

Example:

{
  "device": "MacMini-M4",
  "workspace": "PlayCover",
  "path": "README.md"
}

The device value can be a unique device display name or the exact device ID returned by list_devices.

If multiple devices have the same display name, use the device ID.

Permissions and LOCK state

The Zone connector is a routing layer, not a permission bypass.

For example, if a target device is locally LOCKED:

ChatGPT
  -> Zone MCP
  -> target McpRelay
  -> target Agent
  -> local authorization rejects privileged execution

Read-only capabilities that are permitted locally continue to work. Writes, shell commands, processes, or external MCP execution remain subject to the target device's normal LocalMCP policy.

A Relay Administrator can use Remote Unlock for an online Zone member. The allowed durations are 5, 15, 30, or 60 minutes. This control action travels through the authenticated Relay Admin control plane and the existing Agent WebSocket; it is not an MCP tool and cannot be invoked with only the Zone MCP URL. The Agent verifies that the requested Zone matches its own membership before applying the remote lease. Local Lock now immediately overrides a remote unlock.

Connector rotation

The Zone administrator can choose Rotate Connector in /admin.

Rotation:

1. creates a new Zone MCP token;
2. stores only the new token hash;
3. immediately invalidates the previous Zone MCP URL.

Device Agent and per-device MCP credentials are not changed.

Revocation

Revoking a device from the Zone:

1. removes it from the Zone device list;
2. invalidates that device's Relay Agent and MCP credentials;
3. disconnects its active Agent WebSocket.

The revoked device must register or join again before it can reconnect.

Credential separation

The credentials have different purposes:

• Relay Admin token: signs in to the Relay-wide /admin control plane; the Worker is configured with RELAY_ADMIN_TOKEN_HASH
• Relay Admin session: short-lived browser session stored as an HttpOnly, Secure, SameSite=Strict cookie; only its hash is stored by the Relay
• registration token: optionally protects legacy/non-admin registration operations on a self-hosted Relay
• Zone admin token: manages one Zone and supports delegated Zone administration/import verification
• Zone MCP token: authenticates the shared ChatGPT connector
• join code: short-lived, single-use credential for adding one device
• Agent token: authenticates one local Agent to its per-device Relay
• per-device MCP token: authenticates the legacy/direct connector for one device

Do not use the Zone admin token as a ChatGPT connector credential.

Compatibility

Per-device MCP URLs remain available. This means an existing single-device connector can continue working while the same device also belongs to a Zone.

The shared Zone connector is additive and does not require changing the target device's workspace configuration or LocalMCP security settings.

Current behavior

The Zone router discovers and merges tool schemas from online devices. list_devices remains available so ChatGPT can check device names and online state before choosing a target.

A tool that is not available on the selected device is rejected by that device rather than silently redirected elsewhere.