A2A Protocol

Connecting via A2A Protocol

Cerebrus Pulse implements Google’s A2A protocol (v0.3), an open standard for agent-to-agent communication governed by the Linux Foundation. Payments are handled via x402 USDC micropayments on Base or Solana.

Agent Card Discovery

Your agent discovers Cerebrus Pulse by fetching the Agent Card:

curl https://api.cerebruspulse.xyz/.well-known/agent-card.json

The Agent Card describes all available skills, pricing, and the A2A endpoint URL. Compatible with any A2A-compliant agent framework.

Available Skills

Skill ID	Price (USDC)	Requires Coin	Description
`confluence-analysis`	$0.02	Yes	Multi-timeframe technical analysis with confluence scoring
`market-screener`	$0.04	No	Screen 51 perpetuals by signal strength
`open-interest-analysis`	$0.01	Yes	OI deltas, divergence detection, percentile ranking
`spread-analysis`	$0.008	Yes	Bid-ask spread, slippage estimates at various sizes
`correlation-matrix`	$0.03	No	BTC-alt correlation matrix with regime classification
`intelligence-bundle`	$0.04	Yes	Complete analytical package (17% discount vs individual)

Sending a Task

Send a JSON-RPC 2.0 message/send request to the A2A endpoint:

import json
import urllib.request

body = json.dumps({
    "jsonrpc": "2.0",
    "method": "message/send",
    "id": "my-task-1",
    "params": {
        "message": {
            "role": "user",
            "parts": [{"type": "text", "text": "Analyze BTC confluence"}]
        }
    }
}).encode()

req = urllib.request.Request(
    "https://api.cerebruspulse.xyz/a2a",
    data=body,
    headers={"Content-Type": "application/json"},
    method="POST",
)

with urllib.request.urlopen(req, timeout=15) as resp:
    result = json.loads(resp.read())
    print(json.dumps(result, indent=2))

Payment Flow

Send task — Your agent sends a message/send request
Payment required — Cerebrus Pulse extracts the intent, identifies the skill, and returns a payment-required response with x402 payment details
Pay — Your agent signs a USDC micropayment on Base or Solana using the x402 SDK
Receive — After payment verification, the intelligence is delivered as an A2A task artifact

Payment-Required Response

{
  "jsonrpc": "2.0",
  "id": "my-task-1",
  "result": {
    "id": "task-uuid",
    "status": {
      "state": "completed",
      "message": {
        "role": "agent",
        "parts": [{"type": "text", "text": "Payment required for confluence-analysis"}]
      }
    },
    "metadata": {
      "x402": {
        "status": "payment-required",
        "skill_id": "confluence-analysis",
        "amount": "0.02",
        "currency": "USDC",
        "network": "eip155:8453",
        "recipient": "0x...",
        "facilitator": "https://api.cdp.coinbase.com/platform/v2/x402"
      }
    }
  }
}

Intent Extraction

You can let Cerebrus Pulse extract the skill from natural language, or specify it explicitly:

Natural Language (Automatic)

{
  "message": {
    "role": "user",
    "parts": [{"type": "text", "text": "Show me the top 10 strongest setups"}]
  }
}

This automatically maps to market-screener.

Explicit Skill ID

{
  "message": {
    "role": "user",
    "parts": [{"type": "text", "text": "SOL data"}],
    "metadata": {"skill_id": "spread-analysis"}
  }
}

Coin Extraction

For skills that require a coin, Cerebrus Pulse extracts it from the message text. Aliases like “ethereum” → ETH and “bitcoin” → BTC are supported. If a coin is required but not found, you’ll receive an input-required response asking for clarification.

Task Retrieval

Retrieve a previously created task:

body = json.dumps({
    "jsonrpc": "2.0",
    "method": "tasks/get",
    "id": "get-1",
    "params": {"id": "task-uuid-from-previous-response"}
}).encode()

Rate Limits

The A2A endpoint shares rate limits with the REST API: 12 requests per minute. See Rate Limits & Errors for details.