a2a-message-send

name	a2a-message-send
description	Send agent-to-agent (A2A) messages via Redis pub/sub with optional ACP WebSocket delivery. Use when agents need to communicate, broadcast to the triad, or check agent health. Compatible with the npm OpenClaw gateway.

A2A Message Send Skill

Send messages between collective agents via Redis queues (npm gateway compatible) with optional real-time delivery via ACP WebSocket.

Architecture

Agent --> a2a-redis.js --> Redis (openclaw:a2a:inbox:{agentId})
                         |
                         +--> ACP Adapter (optional) --> npm Gateway (port 18789)

npm Gateway reads from same Redis keys for agent delivery.

Redis prefix: openclaw:a2a: (shared with npm gateway — no migration needed)

Configuration

# Redis (required)
REDIS_URL=redis://localhost:6379

# ACP WebSocket (optional — for real-time delivery)
OPENCLAW_GATEWAY_TOKEN=9b54947854ee05186fb5363d0ea113685794d08d4ab45f80
OPENCLAW_GATEWAY_WS=ws://localhost:18789/a2a

Usage

Basic Messaging

const { sendMessage, getMessages, connectACP } = require('./a2a-redis.js');

// Send a message (always works — Redis queue)
const result = await sendMessage('steward', 'alpha', 'Triad meeting now');
// → { success: true, messageId: 'msg_1743...', from: 'steward', to: 'alpha' }

// Get inbox messages
const messages = await getMessages('alpha', 10);

// Mark as read
await markAsRead('alpha', 'msg_1743...');

Real-Time via ACP

// Connect to npm gateway for real-time delivery
const acp = await connectACP({ agentId: 'alpha' });

// Now messages go via WebSocket when agent is online
const result = await sendMessage('steward', 'alpha', 'Urgent!', { via: 'acp' });
// → { success: true, acpDelivered: true }

// Listen for incoming messages
acp.on('message', (msg) => {
  console.log(`${msg.from}: ${msg.content}`);
});

// Disconnect
await disconnectACP();

Broadcast to Triad

const { broadcastToTriad } = require('./a2a-redis.js');

await broadcastToTriad('steward', 'Phase 3 deliberation starting');
// → { success: true, sentTo: ['alpha', 'beta', 'charlie'], count: 3 }

Health Checks

const { pingAgent, pingTriad } = require('./a2a-redis.js');

// Ping single agent
const result = await pingAgent('steward', 'alpha');
// → { success: true, response: 'pong', latency: 2, target: 'alpha', registered: true }

// Ping all triad members
const triad = await pingTriad('steward');
// → { success: true, responses: { alpha: {...}, beta: {...}, charlie: {...} } }

Agent Registration

const { registerAgent, getRegisteredAgents, unregisterAgent } = require('./a2a-redis.js');

// Register as active
await registerAgent('alpha', { role: 'triad', skills: ['deliberate', 'vote'] });

// List all registered agents
const agents = await getRegisteredAgents();
// → ['steward', 'alpha', 'beta', 'charlie', ...]

// Unregister
await unregisterAgent('alpha');

Redis Key Reference

Key	Type	Purpose
openclaw:a2a:inbox:{agentId}	List	Message queue per agent
openclaw:a2a:agents	Set	Registered agent IDs
openclaw:a2a:agent:{agentId}	Hash	Agent metadata
openclaw:a2a:broadcast	Pub/Sub	Real-time broadcast channel
openclaw:a2a:read:{agentId}	Set	Read message IDs

Message Format

{
  messageId: 'msg_1743...',
  from: 'steward',
  to: 'alpha',
  content: 'Triad meeting now',
  timestamp: '2026-04-03T01:00:00.000Z',
  priority: 'normal',
  type: 'task'
}

Migration Notes

This skill was originally written for the archived gateway/openclaw-gateway.js (simple JSON WebSocket protocol). It has been migrated:

• ✅ Redis key space (openclaw:a2a:*) is identical to npm gateway — no data migration needed
• ✅ ACP adapter added for real-time WebSocket delivery when connected to npm gateway
• ✅ Fallback to Redis queue always works (npm gateway uses same keys)
• ⚠️ If using ACP real-time delivery, both agents must be ACP-connected

Dependencies

npm install ioredis ws