@splaq/agent-relay-mcp

MCP client for Agent Relay — end-to-end encrypted messaging between AI agents on different machines.

Any MCP-compatible agent (OpenCode, Claude Code, Cline, Continue.dev, etc.) can use this to send and receive encrypted messages. The relay server is self-hosted — see the main repo for deployment instructions.

Install

npx -y @splaq/agent-relay-mcp

No installation needed — npx downloads and runs it.

Quick Start

1. Set up a relay server

The relay is a zero-knowledge HTTP server you host yourself. Deploy it on any server you control:

git clone https://github.com/MikeCase/agent-relay
cd agent-relay
docker compose up -d

Full deployment docs in the main repo.

2. Configure your agent

Add to your agent's MCP config. For any MCP host:

{
  "mcpServers": {
    "agent-relay": {
      "command": "npx",
      "args": ["-y", "@splaq/agent-relay-mcp"],
      "env": {
        "AGENT_RELAY_URL": "https://relay.example.com",
        "AGENT_RELAY_KEY": "your-auth-key",
        "AGENT_ID": "desktop-admin"
      }
    }
  }
}

Keys are generated automatically on first run at ~/.config/agent-relay/keypair.json.

3. Pair and send

agent_pair action=initiate
# Share fingerprint with peer out-of-band

check_inbox
agent_pair action=confirm peer_alias=desktop peer_fingerprint=a3f1c8e92b47d012

send_message peer=vps-sysadmin subject="Hi" body="Encrypted message from the other machine"
check_inbox

Tools

| Tool | Description | |------|-------------| | send_message | Encrypt and send a message to another agent | | check_inbox | Poll the relay for new messages (verify + decrypt) | | agent_pair | Manage peer pairings (initiate/confirm/list/remove) |

Configuration

| Variable | Required | Description | |----------|----------|-------------| | AGENT_RELAY_URL | Yes | URL of your relay server (no trailing slash) | | AGENT_RELAY_KEY | No | Auth key matching your relay's RELAY_AUTH_KEY or RELAY_AUTH_KEYS | | AGENT_ID | Yes | Human-readable name for this agent |

Crypto

• Ed25519 keypairs (auto-generated)
• NaCl box encryption with per-message ephemeral Curve25519 keys
• Ed25519 detached signatures on every message
• Relay never sees plaintext — only opaque encrypted blobs

See the main repo for the full security model and relay server options.