x402: pay per call for VAT, EORI, company and sanctions checks

Short answer: After the free tier (20 calls/day per IP), paid routes on api.wsystem.dev answer HTTP 402 with an x402 v2 challenge in the PAYMENT-REQUIRED header (scheme exact, USDC on Base, network eip155:8453). An x402 client signs the payment and retries with PAYMENT-SIGNATURE (or X-PAYMENT); the facilitator (PayAI) settles it. Routes are declared for x402 Bazaar discovery and listed at https://api.wsystem.dev/.well-known/x402.

Key facts

Network: Base mainnet (eip155:8453), asset USDC. Facilitator: facilitator.payai.network.
Discovery: /.well-known/x402 manifest, OpenAPI x-payment-info, Bazaar extension on each route.
Clients: x402 SDKs (TypeScript/Python), x402-fetch, x402-axios, and agent wallets that support x402.

Examples

Python (x402 SDK) – full example in the GitHub x402 guide

# pip install "x402[requests,evm]" eth-account
from eth_account import Account
from x402 import x402ClientSync
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client
from x402.http.clients import x402_requests
client = x402ClientSync()
register_exact_evm_client(client, EthAccountSigner(Account.from_key(KEY)))
# see github.com/zifengw/eu-business-data-mcp/blob/main/docs/x402-agents.md

Discovery

curl https://api.wsystem.dev/.well-known/x402

Pricing

Channel	Price
GET /verify, /eori, /company, /sanctions/screen	$0.01
POST /verify/batch, /company/batch, /eori/batch, /sanctions/screen/batch	$0.10 per request
POST /kyb/check	$0.045

Questions and answers

What is x402?

An open protocol that uses HTTP 402 Payment Required so clients, including AI agents, can pay per request with stablecoins without accounts.

Do I need x402 for small volumes?

No; 20 calls per day per IP are free.

Facts and competitor details checked 2026-10-17. W System Hungary Kft. is the maker of this product. Not affiliated with the European Commission. Not legal or tax advice.