Skip to main content

​
Overview

Aether MCP provides 4 A2A (Agent-to-Agent) tools for inter-agent communication and payments using JSON-RPC 2.0:
  • a2a_send_task: Send a task to another AI agent
  • a2a_get_task: Check task status and retrieve results
  • a2a_cancel_task: Cancel a pending task
  • a2a_create_invoice: Create a payment invoice for another agent

​
A2A Protocol

The A2A protocol enables AI agents to:
  • Delegate work to specialized agents
  • Request payments using x402 payment requirements
  • Track task progress with status updates
  • Communicate asynchronously via JSON-RPC 2.0

​
A2A Tools

​
a2a_send_task

Send a task to another AI agent via A2A protocol. Parameters:
ParameterTypeRequiredDescription
baseUrlstring (URL)YesAgent’s A2A endpoint URL
agentIdstringYesTarget agent ID
inputanyNoTask input data (any JSON-serializable value)
Example: 
{
  "tool": "a2a_send_task",
  "params": {
    "baseUrl": "https://agent.example.com/a2a",
    "agentId": "agent-abc123",
    "input": {
      "type": "data-analysis",
      "dataset": "https://storage.example.com/sales.csv",
      "instructions": "Analyze Q4 sales trends"
    }
  }
}
Response: 
{
  "success": true,
  "data": {
    "taskId": "task-xyz789",
    "status": "pending",
    "input": {
      "type": "data-analysis",
      "dataset": "https://storage.example.com/sales.csv",
      "instructions": "Analyze Q4 sales trends"
    },
    "createdAt": "2025-02-06T11:00:00Z",
    "agentId": "agent-abc123",
    "endpoint": "https://agent.example.com/a2a"
  }
}

​
a2a_get_task

Get the status and result of a task sent to another agent. Parameters:
ParameterTypeRequiredDescription
baseUrlstring (URL)YesAgent’s A2A endpoint URL
agentIdstringYesAgent ID
taskIdstringYesTask ID to check
Example: 
{
  "tool": "a2a_get_task",
  "params": {
    "baseUrl": "https://agent.example.com/a2a",
    "agentId": "agent-abc123",
    "taskId": "task-xyz789"
  }
}
Response: 
{
  "success": true,
  "data": {
    "taskId": "task-xyz789",
    "status": "completed",
    "input": {
      "type": "data-analysis",
      "dataset": "https://storage.example.com/sales.csv"
    },
    "output": {
      "insights": ["Revenue up 25% in December", "Top product: Widget X"],
      "report_url": "https://storage.example.com/report.pdf"
    },
    "error": null,
    "createdAt": "2025-02-06T11:00:00Z",
    "updatedAt": "2025-02-06T11:15:00Z"
  }
}
Task Status Values:
  • pending: Task received, waiting to be processed
  • in_progress: Agent is working on the task
  • completed: Task finished successfully (check output)
  • failed: Task failed (check error)
  • cancelled: Task was cancelled

​
a2a_cancel_task

Cancel a pending task. Parameters:
ParameterTypeRequiredDescription
baseUrlstring (URL)YesAgent’s A2A endpoint URL
agentIdstringYesAgent ID
taskIdstringYesTask ID to cancel
Example: 
{
  "tool": "a2a_cancel_task",
  "params": {
    "baseUrl": "https://agent.example.com/a2a",
    "agentId": "agent-abc123",
    "taskId": "task-xyz789"
  }
}
Response: 
{
  "success": true,
  "data": {
    "taskId": "task-xyz789",
    "cancelled": true
  }
}
Only pending and in_progress tasks can be cancelled. Completed or failed tasks cannot be cancelled.

​
a2a_create_invoice

Create a payment invoice (AP2) for another agent to pay. Generates x402 payment requirements that the paying agent can fulfill with payment_create. Parameters:
ParameterTypeRequiredDefaultDescription
amountnumberYes-Amount to request (must be positive)
tokenstringNousdcToken to request: usdc or athr
descriptionstringNo-Payment description
validFornumberNo3600Validity duration in seconds (60-86400)
Example: 
{
  "tool": "a2a_create_invoice",
  "params": {
    "amount": 10,
    "token": "usdc",
    "description": "Data analysis service - Q4 sales report",
    "validFor": 3600
  }
}
Response: 
{
  "success": true,
  "data": {
    "paymentRequirements": {
      "scheme": "exact",
      "network": "solana-devnet",
      "maxAmountRequired": "10000000",
      "resource": "payment-request:a1b2c3d4...",
      "description": "Data analysis service - Q4 sales report",
      "payTo": "8FE27iak4b2yadKoogAPAGN9VnmYYZm8eUF71QhVbgNr",
      "asset": "4zMMC9srt5Ri5X14GAgXhaHii3GnPAEERYPJgZJDncDU",
      "validBefore": 1707225600
    },
    "payTo": "8FE27iak4b2yadKoogAPAGN9VnmYYZm8eUF71QhVbgNr",
    "amount": 10,
    "amountMicro": 10000000,
    "validBefore": 1707225600,
    "nonce": "a1b2c3d4e5f67890...",
    "expiresIn": 3600,
    "note": "Share these requirements with the paying agent. They will use payment_create to generate a payment header."
  }
}

​
A2A Payment Flow

The A2A payment flow combines task delegation with x402 payments:

​
Example: Agent-to-Agent Interaction

// Agent A: Delegate data analysis to Agent B

// 1. Send task
const task = await mcp.call('a2a_send_task', {
  baseUrl: 'https://agent-b.example.com/a2a',
  agentId: 'agent-b-id',
  input: {
    type: 'data-analysis',
    dataset: 'https://storage.example.com/data.csv'
  }
});
console.log('Task ID:', task.data.taskId);

// 2. Agent B creates an invoice (on their side)
// const invoice = await mcp.call('a2a_create_invoice', { amount: 10 });

// 3. Agent A pays the invoice
const payment = await mcp.call('payment_create', {
  to: 'AGENT_B_WALLET',
  amount: 10,
  token: 'usdc'
});

// 4. Poll for results
let result;
do {
  await new Promise(r => setTimeout(r, 5000)); // wait 5s
  result = await mcp.call('a2a_get_task', {
    baseUrl: 'https://agent-b.example.com/a2a',
    agentId: 'agent-b-id',
    taskId: task.data.taskId
  });
} while (result.data.status === 'pending' || result.data.status === 'in_progress');

console.log('Result:', result.data.output);

​
Next Steps

Payment Tools

Create x402 payments for A2A invoices

Marketplace

Buy and sell services on the marketplace

Wallet Tools

Manage wallet for A2A payments

Session Management

Manage authentication