contix herramientas is answering right now. Last checked 3 min ago. It exposes 6 tools.
Free no-auth tools for Spain: validate IBAN, EU VAT check (VIES), Modelo 303 sums, Veri*factu dates.
Uptime history
32 days of history · worst day 99%
32 days agonow
100.0%
Uptime 24h
91 of 91 checks
6
Tools
read from the server
131 ms
Response time
average over 24h
open, no key
Access
streamable-http
What changed 6
Every tool that appeared, vanished or quietly changed what it asks for. Recorded since 4 October 2026. No other catalogue keeps this.
22 Oct
4 tool descriptions were rewritten
calculate_modelo_303, calculate_vat, get_obligation_dates and 1 more
4 Oct
2 tools appeared
calculate_vat, validate_spanish_tax_id
Nothing serious here today
Today is the operative word: we check contix herramientas every 15 minutes and re-read its code on every release. Watch it and you find out the day that stops being true.
Connect this server
Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 3 min ago.
run in your terminal
claude mcp add herramientas --transport http https://api.contix.es/api/v1/mcp/herramientasSettings → Connectors → Add custom connector, then paste this address
https://api.contix.es/api/v1/mcp/herramientas~/.codex/config.toml
[mcp_servers.herramientas]
url = "https://api.contix.es/api/v1/mcp/herramientas".cursor/mcp.json
{
"mcpServers": {
"herramientas": {
"url": "https://api.contix.es/api/v1/mcp/herramientas"
}
}
}.vscode/mcp.json
{
"servers": {
"herramientas": {
"type": "http",
"url": "https://api.contix.es/api/v1/mcp/herramientas"
}
}
}Available tools 6
Read directly from the server with tools/list, grouped by what they act on.
If a tool disappears, we record the date.
calculate
calculate_modelo_303
Add up the boxes (casillas) of the Spanish quarterly VAT return Modelo 303 with the formulas printed on the official AEAT form: 27, 45, 46, 64, 66, 87, 69 and 71. Input are the tax amounts (cuotas) per box, e.g. {"09": 17430, "29": 9870}. It only sums what it is given: it does not decide which rate or deduction applies and it is not a tax return. To compute the 303 from an existing contix account's own invoices and gastos instead of typed-in boxes, use get_modelo with model 303.
calculate_vat
Compute the taxable base, VAT (IVA) amount, optional recargo de equivalencia and optional IRPF withholding from an amount. By default `importe` is the taxable base (sin IVA). With incluye_iva=true, `importe` is the TOTAL with VAT already included and the base is derived backwards (quitar IVA / reverse VAT). It only applies the rates it is given: it does NOT decide which VAT or IRPF rate applies to a case. Returns base_imponible, cuota_iva, recargo_importe, retencion_irpf, total_con_iva and total_factura (total after subtracting the IRPF withholding).
validate
validate_iban
Check whether an IBAN is well formed: country length (SWIFT IBAN registry) and ISO 13616 check digits. For Spanish IBANs also the two account check digits (DC) and the bank (entidad) with its BIC from the Banco de España registry. A 20-digit Spanish account number (CCC) is converted to its IBAN. Pure arithmetic: it does NOT confirm that the account exists or who owns it.
validate_spanish_tax_id
Two modes in one input. If `valor` is only 1-8 digits, computes the DNI check letter and returns the full 8-digit-plus-letter DNI (digits are left-padded with zeros). If `valor` is a full document, validates its check character: DNI (8 digits + letter), NIE (X/Y/Z + 7 digits + letter) or CIF (entity letter + 7 digits + check digit or letter, with the entity type per Orden EHA/451/2008). Tolerates spaces, dots, dashes and an ES prefix. Pure arithmetic: it does NOT confirm the document exists, is active or belongs to the person who gave it. In validation mode, returns valido (true/false) and, when it does not match, the correct check character (letra_correcta / control_correcto).
obligation
get_obligation_dates
Deadlines from the published Spanish rules: Veri*factu (RD 1007/2023, dates of RD-ley 15/2025) and mandatory B2B e-invoicing (RD 238/2026, counted from the ministerial order, provisional while the order is a draft). Information about the rules, not advice. Returns a date (or null) and explanatory text for each obligation (verifactu, factura_electronica and, where it applies, estados_facturas).
vat
check_vat_number
Look up an EU VAT number in the European Commission's VIES registry. Returns what the registry says: whether the number exists and, where the member state publishes it, the name and address. It draws NO tax conclusion. VIES is often down; that is reported as disponible=false, which is NOT the same as an invalid number.
Endpoints
| URL | Transport | State | Latency | Checked |
|---|---|---|---|---|
| https://api.contix.es/api/v1/mcp/herramientas | streamable-http | answering | 108 ms | 3 min ago |
Alternatives to contix herramientas
same job, measured the same wayCommerce Validators
by scienceswarm
Commerce validators: live EU VAT (VIES), EORI, email/MX lookups; IBAN/ABA/GTIN checksums; VAT rates.
Checksum Validator
by apished
Validates Luhn, IBAN, ISBN, EAN/UPC, SWIFT/BIC, and EU VAT checksums and formats.
Veridigit
by qinisolabs
Verified IBAN, card, ISBN-13 & VIN validation for AI agents — checksums, not guesses.
E
EU Counterparty Check (VIES + Peppol)
by douglasgouvea
Validate EU VAT numbers in VIES and check Peppol e-invoicing, with source and date on every fact
B
Barcode Tools (decode, render, GTIN validate)
by appvantagelabs2-a11y
Decode, render, validate barcodes: QR, DataMatrix, EAN, UPC, PDF417. All tools free, no auth.
AI Vat Number Validation
by iwebdevelopment
AI VAT Number Validation: hosted MCP server for EU VAT number checks via VIES.
Zovo VAT Number Check
by theluckystrike
Run a VAT number check for EU tax identifiers in VIES and get a dated XLSX validation log.
WinkelFactuur
by winkelfactuur
Free EU VAT, IBAN and bol.com commission tools for marketplace sellers
contix herramientas — questions
Answers built from our own checks of this server.
What can contix herramientas do?
It exposes 6 tools, read directly from the server on our last check. Among them: calculate_modelo_303, calculate_vat, check_vat_number, get_obligation_dates, validate_iban, validate_spanish_tax_id. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README.
How MCP servers expose tools in the first place →
What is contix herramientas mostly used for?
Its tools cluster around validate and calculate. That is what this server is built to work with — the grouping comes from the actual tool names, not from a category we assigned.
Is contix herramientas working right now?
We send a real MCP handshake every 15 minutes. Over the last 24 hours 91 of 91 checks got a reply (100.0%), average response time 131 ms. The bar chart above shows every period we have measured.
How do I connect contix herramientas?
Copy the ready config from this page. We generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each in the form that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.
Does contix herramientas need an API key?
No. contix herramientas completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 6 of them are readable on this page. This is what we observed, not what the docs claim.
How fast is contix herramientas?
It answers our handshake in 131 ms on average, which is faster than 86% of all working MCP servers we measure. That puts it in the quick quarter of the ecosystem. The comparison comes from our own checks across the whole registry, every 15 minutes.