x402 Payment Protocol for TRON Agents

Invoke x402-enabled AI agent endpoints with automatic USDT micropayments on TRON.

Quick Start

Option 1: Run Pre-built (Recommended for Agents)

The skill is pre-bundled into a single file. No installation required.

node dist/index.js --url <URL> [options]

Option 2: Development

npm install
npm start -- --url <URL>

Tool Reference

• Wallet: A TRON private key must be available. The skill automatically looks for it in:
  1. TRON_PRIVATE_KEY environment variable.
  2. ~/.mcporter/mcporter.json (AIBank standard configuration).
  3. x402-config.json in the current directory.
  4. ~/.x402-config.json in the home directory.
• USDT on TRON: Wallet needs USDT and some TRX for gas.

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Tool Reference

x402_tron_invoke

Invokes an HTTP endpoint. If payment is required (402), it automatically:

1. Negotiates payment requirements.
2. Checks USDT allowance. If insufficient, it performs an infinite approval (MAX_UINT256) to minimize future transactions.
3. Signs the payment permit (EIP-712).
4. Retries the request with the payment signature.

Example: Chat with Agent

url: https://api.example.com/chat
method: POST
body: {"prompt": "Tell me a joke"}

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Agent Discovery

You can discover available endpoints and their pricing by checking the agent's manifest.

Fetch Agent Manifest

url: https://api.example.com/.well-known/agent.json
method: GET

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Security Rules for Agents

• No Private Key Output: The Agent MUST NOT print, echo, or output the TRON_PRIVATE_KEY or any other signing secret to the dialogue context.
• Internal Loading Only: The Agent should rely on the skill or underlying scripts to load the key internally.
• No Export Commands: The Agent MUST NOT execute shell commands that contain the private key as a literal string (e.g., export TRON_PRIVATE_KEY=...).
• Sanitized Logs: Ensure that logs or error messages do not leak the key.

Troubleshooting

"Private key not found"

Ensure the TRON_PRIVATE_KEY environment variable is set or a valid x402-config.json exists in the expected locations. Agent Note: If this error occurs, simply inform the user that the environment is not configured. DO NOT attempt to search for or read private keys from files yourself.

"Insufficient Allowance"

The tool will attempt to broadcast an infinite approve transaction. This requires TRX for gas. Ensure your wallet has TRX.

"Transaction Failed"

Check if you have enough USDT and TRX.

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Binary and Image Handling

If the endpoint returns an image (Content-Type: image/*) or binary data (application/octet-stream):

1. The data is automatically saved to a temporary file (e.g., /tmp/x402_image_... or /tmp/x402_binary_...).
2. The tool returns a JSON object with:
   • file_path: Path to the temporary file.
   • content_type: The MIME type of the content.
   • bytes: File size in bytes.
3. Important: The Agent is responsible for deleting the temporary file after it has been used or processed.

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Network Reference