nirholas/skills/a2a-multi-agent

Skill: A2A Multi-Agent Orchestration

Turn XActions into an A2A-compatible agent that can discover, communicate with, and delegate tasks to other AI agents using Google's Agent-to-Agent protocol.

When to Use

• User wants to connect XActions with external AI agents
• User needs multi-agent orchestration (decompose → delegate → aggregate)
• User asks about A2A protocol, agent cards, or inter-agent communication
• User wants to run the A2A server or manage agent discovery
• User needs real-time task streaming between agents

Files

| File | Purpose | |------|---------| | src/a2a/types.js | Shared constants, factories, validators | | src/a2a/skillRegistry.js | MCP tool → A2A skill bridge | | src/a2a/agentCard.js | Agent Card generation (.well-known/agent.json) | | src/a2a/taskManager.js | Task lifecycle (create, transition, execute) | | src/a2a/bridge.js | A2A ↔ MCP translation layer + NLP | | src/a2a/streaming.js | SSE streaming for real-time updates | | src/a2a/push.js | Webhook push notifications | | src/a2a/auth.js | API key + JWT inter-agent auth | | src/a2a/discovery.js | Agent registry, skill matching, trust scoring | | src/a2a/orchestrator.js | Task decomposer + delegator + orchestrator | | src/a2a/server.js | Express HTTP server (port 3100) | | src/a2a/index.js | Barrel export + CLI commands + factory | | dashboard/a2a.html | Web dashboard for monitoring |

Quick Start

Start the A2A server

# Via CLI
xactions a2a start --port 3100

# Directly
node src/a2a/server.js

# With session cookie for browser automation
node src/a2a/server.js --cookie "YOUR_X_SESSION_COOKIE"

Check health

curl http://localhost:3100/a2a/health

View Agent Card

curl http://localhost:3100/.well-known/agent.json

Send a task

curl -X POST http://localhost:3100/a2a/tasks \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "tasks/send",
    "params": {
      "message": {
        "role": "user",
        "parts": [{"type": "text", "text": "get profile for @nichxbt"}]
      }
    },
    "id": "1"
  }'

Discover an agent

xactions a2a discover https://other-agent.example.com

List skills

xactions a2a skills
xactions a2a skills --query "scrape"

Architecture

┌─────────────────────────────────────────────────────┐
│                   A2A Protocol Layer                 │
│  ┌──────────┐  ┌──────────┐  ┌──────────────────┐  │
│  │  Agent    │  │   Task   │  │   Streaming /    │  │
│  │  Card     │  │  Manager │  │   Push Notify    │  │
│  └────┬─────┘  └────┬─────┘  └────────┬─────────┘  │
│       │              │                 │             │
│  ┌────┴──────────────┴─────────────────┴──────────┐ │
│  │              HTTP Server (Express)              │ │
│  └────────────────────┬────────────────────────────┘ │
│                       │                              │
│  ┌────────────────────┴────────────────────────────┐ │
│  │        Bridge (A2A ↔ MCP Translation)           │ │
│  └────────────────────┬────────────────────────────┘ │
│                       │                              │
│  ┌────────────────────┴────────────────────────────┐ │
│  │           Skill Registry (140+ tools)           │ │
│  └─────────────────────────────────────────────────┘ │
│                                                      │
│  ┌─────────────┐  ┌────────────┐  ┌──────────────┐  │
│  │  Discovery  │  │   Auth     │  │ Orchestrator │  │
│  │  + Trust    │  │  (JWT/Key) │  │ (Decompose)  │  │
│  └─────────────┘  └────────────┘  └──────────────┘  │
└──────────────────────────────────────────────────────┘

Key Concepts

Agent Card

Every A2A agent publishes a JSON document at /.well-known/agent.json describing its capabilities, skills, and supported protocols.

Skills

XActions converts its 140+ MCP tools into A2A skills, each with a unique ID (xactions.<tool_name>), description, input schema, and category tags.

Task Lifecycle

submitted → working → completed
                   → failed
         → canceled
         → input-required → working

Trust Scoring

Remote agents are scored 0-100 based on success ratio (40%), longevity (20%), recency (20%), and volume (20%).

Task Decomposition

Complex natural-language tasks are automatically broken into ordered sub-tasks with dependency tracking ($step1, $step2.field).

Endpoints

| Method | Path | Description | |--------|------|-------------| | GET | /.well-known/agent.json | Agent Card | | POST | /a2a/tasks | Create task (tasks/send or tasks/sendSubscribe) | | GET | /a2a/tasks/:id | Get task | | POST | /a2a/tasks/:id/cancel | Cancel task | | GET | /a2a/tasks/:id/stream | SSE stream | | POST | /a2a/tasks/:id/message | Push notification | | GET | /a2a/health | Health check | | GET | /a2a/skills | List skills | | POST | /a2a/orchestrate | Execute orchestrated task | | POST | /a2a/orchestrate/plan | Get execution plan | | GET | /a2a/agents | List discovered agents | | POST | /a2a/agents/discover | Discover remote agents |

CLI Commands

xactions a2a start [--port] [--cookie] [--no-auth]
xactions a2a status [--url]
xactions a2a skills [--query]
xactions a2a agents [--url]
xactions a2a discover <url>
xactions a2a task "<description>"