Overview

Complete MCP-native integration layer for enabling OpenClaw AI agents to execute autonomous transactions on the x402 protocol.

How It Works

Claw402 provides a Model Context Protocol (MCP) tool suite that translates natural language payment instructions into protocol-level x402 transactions. Agents describe payment intent in declarative semantics, and Claw402 handles blockchain execution, signing, and settlement verification.

MCP Tool Suite

Six core tools provide complete lifecycle management for agent-initiated payments.

Use this for:

• Enabling AI agents to autonomously transact on x402

• Building economic agents with payment capabilities

• Integrating blockchain payments into agent workflows

• Autonomous invoice settlement and SaaS subscriptions

View MCP Tool Schemas →

Real-Time Transaction Streams (Optional)

Subscribe to real-time transaction status updates via WebSocket connections for agent monitoring and reactive workflows.

Use this for:

• Real-time transaction confirmation monitoring

• Building agent dashboards with live transaction feeds

• Reactive agent workflows triggered by settlement events

• Immediate settlement notifications for time-sensitive operations

View Transaction Streams →

Integration Methods

Claw402 supports three integration approaches:

1. OpenClaw Native Provider

from openclaw import Agent
from claw402 import X402Provider

agent = Agent(
    name="payment_assistant",
    providers=[X402Provider(
        network="mainnet-beta",
        wallet_path="~/.config/solana/agent.json"
    )]
)

2. Standalone MCP Server

claw402 serve \
  --network mainnet-beta \
  --wallet ~/.config/solana/agent.json \
  --port 3402

3. REST API Proxy

curl -X POST https://api.claw402.xyz/v1/mcp/tool/initialize_payment \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json"

MCP Tool Catalog

Tool Name	Purpose	Agent Use Case
x402.initialize_payment	Create new payment session	"Pay invoice #4291 for $250 USDC"
x402.authorize_transaction	Sign and submit transaction	Agent approves transaction after validation
x402.verify_settlement	Confirm blockchain finality	Verify payment completed before delivering service
x402.query_balance	Check wallet balances	"Do I have enough SOL to pay this invoice?"
x402.estimate_fees	Calculate transaction costs	Pre-flight fee estimation for budget constraints
x402.cancel_payment	Cancel pending session	Abort payment if conditions not met

Authentication

Agent Wallet Configuration

All MCP tool calls are authenticated via agent-managed signing keys:

# Generate agent wallet
solana-keygen new -o ~/.config/solana/agent.json

# Configure Claw402 provider
export CLAW402_WALLET_PATH=~/.config/solana/agent.json
export CLAW402_NETWORK=mainnet-beta

Approval Policies

Configure multi-tier approval workflows for agent transaction authorization:

# claw402.approval.yaml
policies:
  - name: auto_approve_small
    max_amount: 10_000000  # 0.01 SOL
    action: auto_approve

  - name: require_confirmation_medium
    max_amount: 100_000000  # 0.1 SOL
    action: require_agent_confirmation

  - name: block_large
    max_amount: 1_000_000000  # 1 SOL
    action: human_approval_required

See Authentication for security architecture details.

MCP Protocol Format

Tool Call Structure

{
  "tool": "x402.initialize_payment",
  "parameters": {
    "amount": "0.1 SOL",
    "recipient": "[email protected]",
    "purpose": "API access subscription",
    "settlement_constraint": "immediate"
  }
}

Tool Response Format

{
  "success": true,
  "result": {
    "session_id": "sess_x4k9j2n8p5",
    "payment_address": "9xQeWvG816bUx9EPjHmaT23yvVM2ZWbrrpZb9PusVFin",
    "expires_at": "2026-03-01T18:30:00Z",
    "status": "pending_authorization"
  },
  "timestamp": 1709315400000
}

Error Response Format

{
  "success": false,
  "error": {
    "code": "INSUFFICIENT_BALANCE",
    "message": "Agent wallet balance insufficient for transaction",
    "details": {
      "required": "0.1 SOL",
      "available": "0.05 SOL",
      "shortfall": "0.05 SOL"
    }
  },
  "timestamp": 1709315400000
}

Security Model

Non-Custodial Architecture

• Hardware Security Module (HSM) isolation for private keys

• Agent signing context never exposes keys to LLM context windows

• Approval policies enforce transaction constraints

• Audit logging captures complete transaction context

Idempotency

All MCP tools support idempotent operations via idempotency_key parameter:

{
  "tool": "x402.authorize_transaction",
  "parameters": {
    "session_id": "sess_x4k9j2n8p5",
    "idempotency_key": "unique_key_per_intent"
  }
}

Rate Limits

Agent transaction throughput limits apply based on subscription tier:

Plan	Transactions/Minute	Concurrent Sessions
Developer	10	5
Production	100	50
Enterprise	Custom	Custom

See Rate Limits →

No SDK Required

Claw402 operates as a standard MCP server compatible with any MCP-capable agent framework:

• OpenClaw (Python)

• Claude Code (TypeScript)

• LangChain (Python/TypeScript)

• AutoGPT (Python)

• Custom MCP clients

Want examples? Check out the examples →