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 \x3Ctoken>
• Interactive (has browser): Run npx agnic@latest auth login

See the authenticate-wallet skill for details.

Command Syntax

npx agnic@latest x402 pay \x3Curl> [-X \x3Cmethod>] [-d \x3Cjson>] [-q \x3Cparams>] [-h \x3Cjson>] [--max-amount \x3Cn>] [--json]

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

Workflow

1. Check requirements (optional but recommended):

   npx agnic@latest x402 details \x3Curl>
   

   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 \x3Curl> --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