VeriFactu

Name: VeriFactu
Author: ArceeDev

by ArceeDevversion 0.1.0i★ –iComputer or cloud

Registry nameio.github.ArceeDev/verifactu-mcp

Install

Overview

Description from the maker (original English)

Audit VERI*FACTU hash chains, build the AEAT tax QR, build and validate Facturae 3.2.2 invoices.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi3 of 3 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Computer or cloud
Transport: stdio, Streamable HTTP
Category: Accounting, finance & tax
You need to fill in: KEYFLINT_LICENSE

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 3 of 3 passed
Runs on the maker’s server: what you ask it goes through their server.
You fill in yourself: KEYFLINT_LICENSE

Values marked secret are keys to your account. Never share them or paste them into a chat.

You need

Runs in the cloudNothing to install; it connects over the internet
PyPIPython’s uv installed (for the uvx command)

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Works in Claude on the web, desktop and mobile:

Open Settings → Connectors
Press Add custom connector
Paste the address below and press Add
If it asks you to sign in, sign in with the maker

https://mcp.keyflint.dev/verifactu/mcp

Or run it on your computer

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "verifactu": {
      "command": "uvx",
      "args": [
        "verifactu-keyflint-mcp"
      ],
      "env": {
        "KEYFLINT_LICENSE": "your-value"
      }
    }
  }
}

Run this in your terminal

claude mcp add --transport http verifactu https://mcp.keyflint.dev/verifactu/mcp

Or run it on your computer

claude mcp add verifactu --env KEYFLINT_LICENSE=your-value -- uvx verifactu-keyflint-mcp

Fill in the empty values before running it.

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "verifactu": {
      "url": "https://mcp.keyflint.dev/verifactu/mcp"
    }
  }
}

Or run it on your computer

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "verifactu": {
      "command": "uvx",
      "args": [
        "verifactu-keyflint-mcp"
      ],
      "env": {
        "KEYFLINT_LICENSE": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "verifactu": {
      "type": "http",
      "url": "https://mcp.keyflint.dev/verifactu/mcp"
    }
  }
}

Or run it on your computer

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "verifactu": {
      "type": "stdio",
      "command": "uvx",
      "args": [
        "verifactu-keyflint-mcp"
      ],
      "env": {
        "KEYFLINT_LICENSE": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

ChatGPT connects only to servers on the internet:

Open ChatGPT on the web → Settings → Connectors (Apps)
Press Create or Add (some plans need Developer mode under Advanced first)
Paste the address below, give it a name and save
If it asks you to sign in, sign in with the maker

https://mcp.keyflint.dev/verifactu/mcp

Menu names can differ slightly by plan and over time.

Your choice stays on this device in a cookie; no account needed.

Values you fill in

KEYFLINT_LICENSE secret required env
Your KeyFlint license (LIC-...). Get one, free trial included, at https://mcp.keyflint.dev

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

The server asks you to sign in before it lists its tools.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 7, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account ArceeDev, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
✓ Pass
Endpoint responds
Responded in 84 ms (HTTP 401)
✓ Pass
Sign-in with OAuth
Declares OAuth sign-in, so your AI app can take you to log in
… Not checked yet
No hidden instructions in tool descriptions
Not checked yet; we read the tool list when we check the endpoint

Compared with others in Accounting, finance & taxi

More stars than 0% of the other 2902 servers in this category
Published to the registry more recently than 95% of the other 2902 servers in this category
Basic checks equal to or better than 100% of the other 2902 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is VeriFactu safe?

It passed 3 of 3 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

You need to fill in: KEYFLINT_LICENSE

Does it run on my computer or in the cloud?

Either way works: install it on your computer or connect to the cloud version.

Is it still maintained?

The GitHub repo last changed –, and the latest version (0.1.0) reached the registry yesterday.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. It connects by URL, so apps that accept remote MCP servers work too, such as ChatGPT in developer mode.

What can I use instead?

In the same category: Finance Toolkit, SolidInvoice, Korea Tax Calculator

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

Finance Toolkit

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500+ transparent financial methods calculated from raw statements, not third-party endpoints.

Computer or cloud★ 5,496MITUpdated yesterday

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SolidInvoice

by SolidInvoice

Create and send invoices and quotes, manage clients, and track payments in SolidInvoice.

Runs in the cloud★ 981MITUpdated 8 days ago

Install

Korea Tax Calculator

by UpstageAI

Korean tax calculation and tax-audit judgment MCP: 96 tools with statutory citations.

Runs on your computer★ 97MITUpdated yesterday

Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

verifactu-mcp

On PyPI as verifactu-keyflint-mcp (the name verifactu-mcp belongs to another project).

MCP server for Spanish invoicing compliance, built for AI agents working for gestorías, accountants and invoicing-software teams. Offline and stateless: nothing is stored and nothing is sent to the AEAT.

**Audit VERI\*FACTU chains**: recompute the SHA-256 fingerprint (*huella*) of every record (alta and anulación) exactly as the AEAT specifies, and check that each record links to the previous one. Works on JSON records or on the XML any invoicing program exports (validated against the official SuministroLR.xsd).
AEAT tax QR: URL and PNG/SVG image (error correction M) for VERI\*FACTU and non-VERI\*FACTU systems, production or test portal, with the printing rules.
Facturae 3.2.2: build an invoice from plain data (totals, VAT breakdown, IRPF withholding, recargo de equivalencia, DIR3 codes for FACe, IBAN) and validate any Facturae file: official XSD, the arithmetic FACe checks, NIFs, DIR3 roles and signature presence.

The fingerprint code is tested against the three reference vectors published by the AEAT.

Tools

Tool	Credits	What it does
`validate_invoice_chain`	3	Audit a chain of records (JSON, up to 20,000): fingerprints, links, PrimerRegistro, duplicates, cancellations of unknown invoices, timestamps, NIF/date/amount/TipoFactura formats. `continues_from` audits a chain in pieces.
`validate_verifactu_xml`	3	Same audit on exported XML (`RegFactuSistemaFacturacion`, SOAP envelope or any XML with `RegistroAlta`/`RegistroAnulacion`), plus XSD validation.
`verifactu_hash`	1	Fingerprint of one record, with the exact string hashed.
`generate_verifactu_qr`	1	Tax QR URL + image + printing rules.
`build_facturae`	3	Facturae 3.2.2 XML (unsigned) from plain invoice data, XSD-validated.
`validate_facturae`	2	XSD + arithmetic + NIF + DIR3 + signature check of a Facturae file.
`verifactu_calendar`	free	Deadlines in force and what is pending in the BOE, with sources.
`check_qr_url`, `validate_nif`, `pricing`, `credits_balance`	free	Helpers.

Unreadable or invalid input is never charged; a tool that fails after charging is refunded.

Install

Claude Desktop / Claude Code / Cursor (mcpServers entry):

"verifactu": { "command": "uvx", "args": ["--from", "verifactu-keyflint-mcp", "verifactu-mcp"], "env": { "KEYFLINT_LICENSE": "LIC-..." } } }

Hosted (one server, many buyers): verifactu-mcp --http or the Dockerfile; each request carries Authorization: Bearer LIC-....

Environment: KEYFLINT_LICENSE, KEYFLINT_URL, KEYFLINT_PUBLIC_KEYS, KEYFLINT_CHECKOUT_URL, VERIFACTU_PRICES (e.g. validate_invoice_chain=5,build_facturae=4), VERIFACTU_MAX_BYTES (default 10 MB).

Visual cards (MCP Apps)

In Claude, ChatGPT, VS Code and Goose every paid tool and credits_balance renders as an interactive card in the chat: credit balance with a refill bar and a buy button, or a result summary (key figures, issues, table preview and credits charged). It is the ui://verifactu/card.html resource, self-contained with no network access. Other clients keep getting the same JSON as before.

Legal status (checked 2026-11-05)

VERI\*FACTU (RD 1007/2023, Orden HAC/1177/2024; dates from RD-ley 15/2025): 1 Jan 2027 for corporate income tax payers, 1 Jul 2027 for everyone else. Hacienda announced on 5 Oct 2026 a further delay to October 2028, not yet published in the BOE. Taxpayers on SII and the foral territories are out of scope.
Mandatory B2B e-invoicing (RD 238/2026, Orden HAC/1028/2026): 6 Oct 2027 for turnover above 8 M EUR, 6 Oct 2028 for the rest; EN 16931 in UBL, CII, EDIFACT or Facturae.
Facturae with XAdES signature is mandatory for invoices to public administrations through FACe.

verifactu_calendar returns this with sources. Always confirm in the BOE.

Scope and limits

Not an invoicing system (SIF): it keeps no records, sends nothing to the AEAT and does not replace the producer's *declaración responsable*. Use it to check what a SIF produced, or to prepare data.
build_facturae produces unsigned XML. Sign it (XAdES-EPES) with the issuer's certificate before sending to FACe or a B2B platform. Corrective invoices (InvoiceClass OR) and batches are validated but not built yet.
If a stored fingerprint only matches after removing trailing zeros from the amounts, it is reported as a warning (correcta_sin_ceros): the record was generated with amounts written differently from the XML.

Sources

AEAT, *Detalle de las especificaciones técnicas para generación de la huella o hash de los registros de facturación* (reference vectors in tests/test_core.py).
AEAT, *Características del QR y especificaciones del servicio de cotejo*.
AEAT web service schemas SuministroLR.xsd / SuministroInformacion.xsd, and Facturaev3_2_2.xsd (facturae.gob.es), bundled in src/verifactu_mcp/schemas/ with the W3C xmldsig schema.

Development

pip install -e '.[test]'

pytest -q

Business Source License 1.1. Source available; production use needs a KeyFlint license (or must be non-commercial). Each version becomes Apache 2.0 four years after release. See LICENSE. The bundled XSD files belong to their publishers (AEAT, Ministerio de Hacienda, W3C).

VeriFactu

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

Or run it on your computer

Or run it on your computer

Or run it on your computer

Or run it on your computer

Values you fill in

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Accounting, finance & taxi

Common questions

Alternatives

Finance Toolkit

SolidInvoice

Korea Tax Calculator

README from the maker

verifactu-mcp

Tools

Install

Visual cards (MCP Apps)

Legal status (checked 2026-11-05)

Scope and limits

Sources

Development