EU compliance & on-chain pre-flight tools for AI agents

Pay per call in USDC. No account, no API key, no subscription, no minimum. Also an MCP server, so an agent can simply use the tools.

An agent calls an endpoint, gets HTTP 402 Payment Required with the exact price, pays a fraction of a cent in USDC on Base, repeats the call and gets the answer. Every answer carries a signed receipt that verifies offline.

Catalog: https://eucompliance.tools · /.well-known/x402 · /llms.txt

Add it to your agent (30 seconds)

Claude Code

claude mcp add --transport http eucompliance https://mcp.eucompliance.tools/mcp

Claude Desktop / Cursor / any MCP client — add to the config:

{
  "mcpServers": {
    "eucompliance": {
      "type": "http",
      "url": "https://mcp.eucompliance.tools/mcp"
    }
  }
}

Nothing to sign up for. Two tools are free (VAT ID and IBAN validation, 5000/day); the rest are paid per call and an agent with a wallet settles them over x402 by itself. Ask it "validate VAT ID ATU16170006" and it works immediately.

Related MCP server: eu-tools-mcp

What the tools answer

On-chain pre-flight — for agents that transact

A failed transaction costs the full gas of the attempt. These calls cost a fraction of it.

EU compliance — for agents that onboard, invoice or pay

General purpose

Validate an e-invoice in one call

Check a UBL or CII invoice (XRechnung, ZUGFeRD / Factur-X, Peppol BIS) against the complete official EN 16931 Schematron — the same rule set the official validators use, run unmodified — plus totals arithmetic and VAT category rules. Every finding comes back with its official BR- code and severity, and the result is signed so it can be attached to the document as validation evidence.

No wallet needed to try it — examples/validate_einvoice.py runs against the free tier and catches a deliberately broken sample out of the box:

pip install requests
python examples/validate_einvoice.py                 # broken sample → BR-02, BR-06, BR-CO-26 …
python examples/validate_einvoice.py my-invoice.xml  # your UBL/CII XML
python examples/validate_einvoice.py zugferd.pdf     # or a ZUGFeRD / Factur-X PDF

For volume it is one x402 call at /x402/einvoice ($0.10) — see examples/pay_and_call.py.

Try it without paying anything

Free, 5 calls a day per address, no signup:

curl "https://api.eucompliance.tools/free/vat-rules?supplier=AT&customer=DE&b2b=true&type=service"
curl "https://api.eucompliance.tools/free/sanctions?name=Some%20Company%20Ltd"

Or get a key with 100 free calls covering every tool at https://api.eucompliance.tools/kaufen — email in, key out, no card.

Verify any answer without trusting us

Every response carries a receipt: the result hash, the issue time and an EIP-191 signature. Checking it needs no network and no trust in the issuer:

pip install eucompliance-verify

from eucompliance_verify import verify_receipt, PaymentPolicy

result = verify_receipt(response_json)          # recomputes the hash, recovers the signer
policy = PaymentPolicy(max_age_hours=24)
if not policy.check(response_json).allowed:
    raise RuntimeError("do not release this payment")

Source: eucompliance-verify (MIT). Conformance fixtures for the VAT engine, public domain: eu-vat-conformance.

Paying

x402 v2, scheme exact, network eip155:8453 (Base mainnet), asset USDC. The payer needs no ETH — gas is sponsored via EIP-3009, with Coinbase CDP as facilitator. Call any endpoint without payment to receive the challenge containing the exact price and payment address.

Prefer an invoice? The operator holds an Austrian trade licence and a VAT ID and can bill normally — see the signup page.

Who runs this

eucompliance.tools, operated from Vienna, Austria.

Two things about the origin, because they explain why the tools are shaped the way they are:

The VAT engine was not built for a market — it was built because we issue reverse-charge invoices ourselves every week and nothing off the shelf produced the codes our accountant, and from 2026 the EU e-invoicing mandates, require. Every rule in it is one we file under. The conformance fixtures are public so you can check that claim rather than believe it.

The on-chain tooling came out of running an agent wallet and getting tired of transactions that failed for reasons the receipt did not explain. The pre-flight check is the thing we wanted to exist.

Operator: Patrick Kaufmann, sole proprietor in Vienna, Austria (trade licence, Austrian VAT ID) — which is why an ordinary invoice is an option alongside per-call USDC. On-chain identity: ERC-8004 agent #60255 on Base.

MIT licensed. No telemetry, no tracking, no key required to look.