Pay-per-request APIs from Python: skip the API key, pay with USDC instead

API keys are friction. Signup, billing portal, monthly minimums, credential rotation. For agents and scripts that call APIs occasionally, there's a better model: pay per call, no account needed. The x402 protocol does this at the HTTP level. Your script gets a 402 Payment Required response, pays automatically, and retries. Here's how it works from Python. Install pip install "x402[httpx,evm]" Call a pay-per-request API import asyncio import httpx from x402 import x402Client from x402.http.clients.httpx import x402AsyncTransport from x402.mechanisms.evm.exact import ExactEvmScheme from x402.mechanisms.evm import EthAccountSigner from eth_account import Account # Wire up your wallet once account = Account . from_key ( " 0xYOUR_PRIVATE_KEY " ) signer = EthAccountSigner ( account ) wallet = x402Client () wallet . register ( " eip155:* " , ExactEvmScheme ( signer = signer )) async def search ( query : str ): transport = x402AsyncTransport ( wallet ) async with httpx . AsyncClient ( transpor