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
node src/a2a/server.js

# 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

curl -X POST http://localhost:3100/a2a/agents/discover \
  -H 'Content-Type: application/json' \
  -d '{"url": "https://other-agent.example.com"}'

List skills

curl http://localhost:3100/a2a/skills
curl 'http://localhost:3100/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 145 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

Running and driving the server

The CLI has no A2A subcommand. The A2A agent is an HTTP server, and every operation is one of the endpoints in the table above.

# Start it (defaults to port 3100)
node src/a2a/server.js

# Or on another port, with a session attached
A2A_PORT=3200 XACTIONS_SESSION_COOKIE=your_auth_token node src/a2a/server.js

# Is it up?
curl http://localhost:3100/a2a/health

# What can it do?
curl http://localhost:3100/.well-known/agent.json
curl 'http://localhost:3100/a2a/skills?query=scrape'

# Which other agents does it know about?
curl http://localhost:3100/a2a/agents

# Give it a task
curl -X POST http://localhost:3100/a2a/orchestrate \
  -H 'Content-Type: application/json' \
  -d '{"task": "Scrape the profile of @nasa and summarise it"}'