Paying for x402 Services

Use npx agnic@latest x402 pay to call x402-enabled API endpoints with automatic USDC payment on Base.

Authentication

Run npx agnic@latest status --json to verify. If not authenticated:

• Headless (CI/server/agent): Set AGNIC_TOKEN env var or pass --token <token>
• Interactive (has browser): Run npx agnic@latest auth login

See the authenticate-wallet skill for details.

Command Syntax

npx agnic@latest x402 pay <url> [-X <method>] [-d <json>] [-q <params>] [-h <json>] [--max-amount <n>] [--json]

See reference/x402-protocol.md for full options, USDC amounts, and input validation rules.

來源於7w4.net。

Workflow

1. Check requirements (optional but recommended):

   npx agnic@latest x402 details <url>

   Shows price, method, and schema without making a payment.

2. Verify balance:

   npx agnic@latest balance --network base

3. Make the paid request:

   npx agnic@latest x402 pay <url> --json

Examples

# GET request (auto-pays)
npx agnic@latest x402 pay https://example.com/api/weather --json

# POST request with body
npx agnic@latest x402 pay https://example.com/api/sentiment -X POST -d '{"text": "I love this product"}' --json

# Limit max payment to $0.10
npx agnic@latest x402 pay https://example.com/api/data --max-amount 100000 --json

Prerequisites

• Must be authenticated (npx agnic@latest status to check)
• Wallet must have sufficient USDC balance on Base

Error Handling

Common errors:

• "Not authenticated" -- Run npx agnic@latest auth login or set AGNIC_TOKEN
• "Insufficient balance" -- Fund wallet with USDC (npx agnic@latest balance to check)
• "No X402 payment requirements found" -- URL may not be an x402 endpoint
• Invalid JSON in --data -- Ensure the body is valid JSON before passing
• HTTP 4xx/5xx from the API -- Show the status code and response body to the user

這個 Skill 質量不錯，文件寫得很清楚，安全性也做得好，能有效防止輸入錯誤或惡意資料。功能方面覆蓋了付費 API 呼叫的完整流程，從檢查餘額到支付都有說明。不足之處是缺少一些常見問題的解答，遇到特殊情況可能不太好排查，整體中規中矩，對普通使用者來說夠用但不算特別友好。