Validate a European Union VAT number against the official VIES (VAT Information Exchange System) register in real time. Confirms whether the VAT identifier is currently registered for intra-EU trade and, when the member state discloses them, returns the registered business name and address. Covers the 27 EU member states (Greece as EL) plus Northern Ireland (XI); Great Britain (GB) is not in VIES. Pass either a full identifier (vat=DE811569869) or country + number. Returns {valid, countryCode, vatNumber, name, address, requestDate, reason}. When a member-state register is temporarily down, returns a retryable 503 rather than a false negative. Data from the European Commission VIES service.
/api/tax/vatPAYMENT-SIGNATURE.The vat API is a pay-per-call tax endpoint built for AI agents and autonomous software. Validate a European Union VAT number against the official VIES (VAT Information Exchange System) register in real time.
There is no signup and no API key. An agent (or any HTTP client) hits the endpoint, receives an x402 "402 Payment Required" challenge, signs a sub-cent USDC payment on Base or Solana, and retries — the data comes back on the paid request. That makes it a drop-in vat data source for an agent tool-use loop, an MCP host, or a backend that needs tax data on demand without onboarding to yet another vendor portal.
| Name | Type | Description |
|---|---|---|
vat | string | Full VAT identifier: 2-letter country prefix + number, e.g. "DE811569869" or "NL810433941B01" (spaces/dots/hyphens allowed). min 3 chars · max 20 chars |
country | string | 2-letter VAT country prefix, e.g. "DE". Greece is EL (GR also accepted); Northern Ireland is XI. Use with number. min 2 chars · max 2 chars |
number | string | The VAT number without the country prefix, e.g. "811569869". Use with country. min 2 chars · max 18 chars |
# 1. Probe with no auth → 402 envelope with PaymentRequirements curl -sS 'https://2s.io/api/tax/vat?vat=xxx&country=xx&number=xx' # 2. Sign + retry with PAYMENT-SIGNATURE: curl -sS 'https://2s.io/api/tax/vat?vat=xxx&country=xx&number=xx' \ -H 'PAYMENT-SIGNATURE: <base64-json-payload>' # Or use the canonical runner (handles probe → sign → retry): # EVM_PRIVATE_KEY=0x... node --env-file=.env.local \ # --experimental-strip-types scripts/x402-pay.ts \ # 'https://2s.io/api/tax/vat?vat=xxx&country=xx&number=xx'
import { TwoS } from '@2sio/sdk'
const client = new TwoS({
privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})
const result = await client.tax.vat({
"vat": "xxx",
"country": "xx",
"number": "xx"
})
console.log('endpoint:', result.endpoint)
console.log('cost:', result.costUsd, 'USDC')
console.log('tx:', result.settlement?.txHash)
console.log('data:', result.data)import os
from twosio import TwoS
client = TwoS(private_key=os.environ["EVM_PRIVATE_KEY"])
result = client.tax.vat(vat="xxx", country="xx", number="xx")
print("endpoint:", result.endpoint)
print("cost:", result.cost_usd, "USDC")
print("tx:", (result.settlement or {}).get("tx_hash"))
print("data:", result.data)// 1. Add @2sio/mcp to your MCP host config (Claude Desktop example below).
// EVM_PRIVATE_KEY funds x402 payments per call.
// claude_desktop_config.json
{
"mcpServers": {
"2sio": {
"command": "npx",
"args": ["-y", "@2sio/mcp"],
"env": { "EVM_PRIVATE_KEY": "0x..." }
}
}
}
// 2. Once the server is running, agents call this tool via standard MCP:
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "tax.vat",
"arguments": {
"vat": "xxx",
"country": "xx",
"number": "xx"
}
}
}| Field | Type | Description |
|---|---|---|
ok | boolean | one of: true |
items | array | |
total | integer | Total matching rows upstream; null when unknown. |
source | object |
{
"ok": true,
"items": [
{
"input": "example",
"valid": false,
"countryCode": "example",
"vatNumber": "example",
"name": "example",
"address": "example",
"requestDate": "example",
"reason": "example"
}
],
"total": 1,
"source": {
"provider": "example",
"url": "example",
"license": "example"
}
}