invowerk

Name: invowerk
Author: invowerk-dev

by invowerk-devversion 1.0.1i★ –iRuns in the cloud

Registry namedev.invowerk/xrechnung-e-invoice-validator

Install

Overview

Description from the maker (original English)

E-invoice checker for ZUGFeRD, Factur-X, XRechnung and Peppol BIS. Free web tool, API and MCP.

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 checksi1 of 1 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: Runs in the cloud
Transport: Streamable HTTP
Category: Accounting, finance & tax
You need to fill in: X-API-Key

Install

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

Before you install

Basic checks: 1 of 1 passed
Runs on the maker’s server: what you ask it goes through their server.
You fill in yourself: X-API-Key

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

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

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

This address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.

Run this in your terminal

claude mcp add --transport http xrechnung-e-invoice-validator https://api.invowerk.dev/mcp/ --header 'X-API-Key: your-value'

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": {
    "xrechnung-e-invoice-validator": {
      "url": "https://api.invowerk.dev/mcp/",
      "headers": {
        "X-API-Key": "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": {
    "xrechnung-e-invoice-validator": {
      "type": "http",
      "url": "https://api.invowerk.dev/mcp/",
      "headers": {
        "X-API-Key": "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.

This address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.

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

Values you fill in

X-API-Key secret HTTP header
Optional API key; the anonymous tier works without it

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

What it can do

We have not read this server’s tool list yet; we check endpoints in rotation.

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 against the domain invowerk.dev (the registry checks domain ownership)
… 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
… Not checked yet
Endpoint responds
Not checked yet; we check endpoints in rotation
… Not checked yet
Sign-in with OAuth
Not checked yet; we check endpoints in rotation
… 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 1726 servers in this category
Published to the registry more recently than 55% of the other 1726 servers in this category
Basic checks equal to or better than 100% of the other 1726 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 invowerk safe?

It passed 1 of 1 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: X-API-Key

Does it run on my computer or in the cloud?

It runs in the maker’s cloud. Connect over the internet with nothing to install, but what you send passes through the maker’s servers.

Is it still maintained?

The GitHub repo last changed –, and the latest version (1.0.1) reached the registry 33 days ago.

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

by JerBouma

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

Computer or cloud★ 5,496MITUpdated today

Install

SolidInvoice

by SolidInvoice

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

Runs in the cloud★ 981MITUpdated 7 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.

invowerk

German e-invoices: create ZUGFeRD PDFs and XRechnung, check ZUGFeRD/Factur-X, XRechnung (KoSIT) and Peppol BIS. Free tool, API, MCP.

invowerk creates and checks e-invoices. In the browser it creates ZUGFeRD PDFs and XRechnung from a form and checks each file before download. It checks ZUGFeRD 2.5.2 and Factur-X 1.09.2 PDFs, XRechnung 3.0.2 (UBL and CII) and Peppol BIS Billing 3.0.21. XRechnung goes through the KoSIT validator; PDFs are also checked for PDF/A. Each check returns a report with the file's SHA-256, rule sets and result. Invoices are processed in memory, not stored. Free web tool; REST API and MCP server with 500 free credits a month.

Quickstart

Check an e-invoice in one call. The anonymous tier needs no key; add -H "X-API-Key: $INVOWERK_API_KEY" for your plan's limits.

curl -sO https://invowerk.dev/app-static/demo/beispiel-xrechnung.xml

curl -F file=@beispiel-xrechnung.xml https://api.invowerk.dev/v1/validate

"valid": true, "verdict_source": "official", "official_verdict": "valid", "scenario": {"config": "kosit-xrechnung", "name": "EN16931 XRechnung (UBL Invoice)"}, "detection": {"kind": "xml", "syntax": "ubl_invoice", "flavor": "xrechnung"}, "errors": {"format": [], "business_rules": [], "carrier": []}, "findings": [], "evidence": {"document_sha256": "259e3eff…", "checked_at": "2026-10-01T22:36:49Z"} }

The same call takes a ZUGFeRD or Factur-X PDF. A failed check is still HTTP 200, with valid: false and each problem in findings.

Use it from

MCP server

Streamable-HTTP endpoint: https://api.invowerk.dev/mcp/ — the anonymous tier works without a key; an API key raises the limits.

Claude Code:

claude mcp add --transport http invowerk https://api.invowerk.dev/mcp/

Claude Code: /plugin marketplace add invowerk-dev/invowerk then /plugin install invowerk@invowerk (set INVOWERK_API_KEY for your key).

Cursor / Windsurf / Cline / Claude Desktop:

"mcpServers": { "invowerk": { "url": "https://api.invowerk.dev/mcp/" } } }

One-click installs for every client: https://invowerk.dev/connect

Integrations (n8n, Zapier, Make, Dify, SDKs and templates): https://github.com/invowerk-dev/invowerk-integrations

Templates

Ready-made workflows: https://invowerk.dev/templates

API

Base URL https://api.invowerk.dev/ — authenticate with an X-API-Key header; anonymous calls work at a lower rate limit.

About the files here

.claude-plugin/ — Claude Code plugin, with this repo as its own marketplace.
.mcp.json — the MCP server the Claude Code plugin connects to.
gemini-extension.json — Gemini CLI extension manifest.
glama.json — Glama server claim (names the maintainer).
mcp.json — Agent Plugins 1.0 MCP server config.
plugin.json — Agent Plugins 1.0 plugin manifest.
server.json — the entry in the official MCP Registry.
skills/ — an Agent Skill (agentskills.io SKILL.md) for skill galleries.

invowerk

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

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

invowerk

Quickstart

Use it from

MCP server

Templates

Links

API

About the files here