Claude-Agent-Relay-Plugin

Direct agent-to-agent communication and coordination within a LAN. Two (or more) Claude instances on different machines exchange messages and files via a shared MCP relay server.

Use cases

• Claude on a desktop coordinating with Claude on a home-assistant server.
• Claude on one machine asking Claude on another to investigate a problem locally (logs, config, hardware).
• Pairs of agents handing off tasks across machines without manual copy/paste.

Trust model

LAN-only and trust-based. The relay does not authenticate users — it identifies clients by a string and an optional shared bearer token. Run it on a network you control.

Components

• MCP relay server (server/) — Python + FastMCP, SQLite for sessions/messages, content-addressed blob store for attachments. Streamable HTTP transport. TOON used for list responses where it saves tokens vs JSON.
• Skills (skills/):
  • onboard — first-run setup: capture relay URL, this machine's client_id, optional shared token, and the peer roster (friendly names → client_ids)
  • setup-relay-server — deploy the server to a host (typically a small LAN VM)
  • connect-as-client — register the relay as an MCP server in the local Claude install
  • create-session — open a named session between two clients
  • send-message / send-file — convenience wrappers
  • tail-session — stream new messages from a session
  • relay-status — health, sessions, blob storage usage

Where your config lives

The plugin ships no user data. Onboarding writes everything machine-specific to $CLAUDE_USER_DATA/agent-relay/ (falling back to ${XDG_DATA_HOME:-$HOME/.local/share}/claude-plugins/agent-relay/). Updating the plugin never touches it.

$CLAUDE_USER_DATA/agent-relay/
├── config.toml          # relay URL, this machine's client_id, optional token
├── peers.toml           # friendly_name -> client_id roster
└── cursors/<session>.txt  # per-session read cursors

• Client config (client/mcp-config.example.json) — boilerplate the connect skill personalizes.

Installation

claude plugins install agent-relay@danielrosehill

Then run the setup-relay-server skill on the host that will run the relay, and connect-as-client on each Claude machine that should join.

License

MIT