openclaw-x402

The shortest path from agent demo to agent commerce.

An MCP server where tools cost RTC to use. Claude calls a paid tool and it just works -- payment happens automatically via the x402 protocol (HTTP 402 Payment Required).

Also includes drop-in Flask middleware for adding x402 payments to any REST API.

5-Second Demo

from openclaw_x402.mcp_server import mcp, _gate, _paid_result

@mcp.tool
def premium_export(format: str = "json", payment_token: str = "") -> str:
    """[0.1 RTC] Premium data export."""
    err = _gate(payment_token, 0.1, "premium_export", "Premium data export")
    if err:
        return err
    return _paid_result({"data": "your premium content", "format": format}, 0.1, payment_token)

That is a paid MCP tool. Agents that call it without paying get a 402 response with payment instructions. Agents that pay 0.1 RTC get the data.

Install

pip install openclaw-x402

How It Works

Agent calls tool
    |
    v
No payment token? -----> Return 402 + price + payment instructions
    |                          |
    |                     Agent signs RTC transfer to treasury
    |                          |
    |                     Agent retries with payment_token
    |
Has payment token
    |
    v
Verify on RustChain -----> Invalid? Return error + retry instructions
    |
    v
Execute tool, return result

Claude Desktop / Claude Code Setup

Add to your MCP config (~/.claude/claude_desktop_config.json or project .mcp.json):

{
  "mcpServers": {
    "openclaw-x402": {
      "command": "python",
      "args": ["-m", "openclaw_x402"],
      "env": {
        "RUSTCHAIN_NODE": "https://50.28.86.131",
        "TREASURY_WALLET": "your-wallet-id",
        "X402_TESTNET": "0"
      }
    }
  }
}

Claude now has access to paid tools. It can call list_prices (free) to see what is available, then pay for premium_search, miner_profile, or bcos_report.

Built-in Tools

Add Your Own Paid Tools

from openclaw_x402.mcp_server import mcp, _gate, _paid_result

@mcp.tool
def gpu_inference(prompt: str = "", model: str = "llama-7b", payment_token: str = "") -> str:
    """[0.5 RTC] Run GPU inference job.

    Args:
        prompt: The input prompt.
        model: Model name to use.
        payment_token: RTC payment JSON. Omit to get payment instructions.
    """
    err = _gate(payment_token, 0.5, "gpu_inference", "Run GPU inference job")
    if err:
        return err
    result = run_model(prompt, model)
    return _paid_result({"output": result}, 0.5, payment_token)

# Free tools use the normal FastMCP decorator
@mcp.tool
def check_queue() -> str:
    """[FREE] Check GPU job queue length."""
    return '{"queue_length": 3}'

Get Discovered + Trusted

After your paid MCP tool or Flask route exposes a reachable /.well-known/x402.json manifest, add it to agentic.market so buyer agents can discover the service.

To help buyers evaluate whether an endpoint is worth paying for, publish the public trust signals that apply to your service:

• MAKO Pulse tracks x402 service availability and schema/payment behavior across the public directory.
• GET /pulse.json can expose a seller's current Pulse score for uptime and endpoint health.
• GET /api/reputation/wallet can summarize a seller wallet's track record across endpoints as a 0-100 reputation score and tier.

These discovery and reputation resources are external to openclaw-x402. Use them as public pointers for buyers, while openclaw-x402 continues to handle your local paid-tool and payment-verification flow.

Payment Token Format

When an agent pays for a tool, it includes a payment_token argument:

{
  "tx_id": "abc123...",
  "from": "agent-wallet-id",
  "amount": 0.1
}

The server verifies this transaction exists on RustChain (a successful on-chain lookup with matching treasury destination, sufficient amount, and a confirmed sender) before executing the tool. Verification is always required — X402_TESTNET only hints which node to use and never bypasses verification or accepts a payment on trust.

Flask Middleware (REST APIs)

For traditional HTTP APIs (not MCP), use the Flask middleware:

from flask import Flask, jsonify
from openclaw_x402 import X402Middleware

app = Flask(__name__)
x402 = X402Middleware(app, treasury="0xYourBaseAddress")

@app.route("/api/premium/data")
@x402.premium(price="10000", description="Premium data export")  # $0.01 USDC
def premium_data():
    return jsonify({"data": "your premium content"})

The Flask middleware uses USDC on Base chain via Coinbase facilitator. The MCP server uses RTC on RustChain. Same pattern, two payment rails.

Environment Variables

Why x402 + MCP

HTTP 402 has been a reserved status code since 1999. x402 gives it a real protocol. MCP gives AI agents a tool interface. Together: agents discover tools, see prices, pay, and use them -- no human in the loop.

This is the infrastructure layer for agent commerce. Every GPU cluster, every API, every dataset can become a paid tool that any agent can use.

Links

• x402 Protocol -- HTTP 402 Payment Required standard
• MCP (Model Context Protocol) -- Agent tool interface
• RustChain -- Proof-of-Antiquity blockchain
• FastMCP -- Python MCP framework
• Coinbase x402 -- x402 on Base chain

License

MIT