APIs that charge per call.

#The catalog

Every route is pay-per-call in USDC on Base. Unpaid requests get a 402 with a signed price — your agent pays, retries once, gets the answer.

curl -s "https://x402-extract-wg5z.onrender.com/validate?url=https://example.com"

#Try it free

The real /extract-fields engine behind a free endpoint — full result, right here, no wallet.

#You pay only on 200

Settlement is atomic with success. If the handler doesn't return 200, no payment is submitted — the 402 simply expires.

• Deterministic. Same input, same output, every time. No temperature, no prompt drift, no surprises at 3am. The diff route is stateless by design — you pass previous, it diffs, nothing is stored.
• Honest nulls. A field is either found or it isn't. Misses come back null, listed in missing, confidence 0. Nothing is invented to fill a gap.
• Proven, not promised. On Nov 2 a self-test hit a thin page: the handler returned 422 and submitted no settlement. The atomicity above isn't a claim — it's the day's log.

#Calling it from an agent

Official x402 Python package. The 402 → sign → retry loop is handled for you.

import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

client = x402ClientSync()
register_exact_evm_client(client,
    EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as s:
    r = s.post("https://x402-extract-wg5z.onrender.com/extract-fields", json={
        "text": "Invoice #INV-42 from Acme Ltd. Total: $1,234.50.",
        "fields": ["invoice_no", "company", "amount"]})
    print(r.json()["extracted"])
    # {'invoice_no': 'INV-42', 'company': 'Acme Ltd', 'amount': '1234.50'}

#The honest count

#Machine-readable

Three documents, zero scraping — this is how agents discover and verify us.