invowerk

dev.invowerkv1.0.0Updated Oct 26, 2026

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

The publisher's own server: invowerk

VerifiedStreamable HTTPWeb executableDeveloper ToolsBusiness & Commerce

Overview

AI-generated overview

Remote MCP server that lets an assistant check and create German e-invoices (ZUGFeRD, Factur-X, XRechnung, Peppol BIS) and return validation reports.

What you can do
  • Validate e-invoice files: submit an XRechnung XML or a ZUGFeRD/Factur-X PDF and get a verdict with rule sets, findings and the file's SHA-256.
  • Run official checks: XRechnung goes through the KoSIT validator, and PDFs are also checked for PDF/A.
  • Create invoices: the web tool builds ZUGFeRD PDFs and XRechnung from a form and checks each file before download.
  • Work across formats: ZUGFeRD 2.5.2, Factur-X 1.09.2, XRechnung 3.0.2 (UBL and CII) and Peppol BIS Billing 3.0.21.
When to use it
Useful when you need to verify that a German e-invoice will be accepted before sending it, or when generating compliant ZUGFeRD or XRechnung documents as part of a billing workflow.
Requirements
Remote streamable-HTTP endpoint; no local install. The anonymous tier works without credentials; an X-API-Key header raises the limits. The free plan includes 500 credits a month.
Before you install
Invoice files are uploaded to a third-party service; the README says they are processed in memory and not stored, but they still leave your machine. A failed check still returns HTTP 200 with valid set to false, so results must be read from the body. Paid plans and limits are governed by the provider's pricing.

Installation

In SourceWeft

  1. Open invowerk in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/dev.invowerk%2Finvowerk/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

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

README

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. Uploaded 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.

sh
curl -sO https://invowerk.dev/app-static/demo/beispiel-xrechnung.xmlcurl -F [email protected] https://api.invowerk.dev/v1/validate
json
{  "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:

sh
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:

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

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

Integrations (Dify, Python SDK and templates): https://github.com/invowerk-dev/invowerk-integrations

Templates

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

Links

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.

Source: README.md at commit b581864

Tools

0
SourceWeft has not read this server's tools yet.

Version history

1
  1. v1.0.0LatestSep 28, 2026

Score

50% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts

    Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.

  • Auth declaredRequired10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts

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invowerk

dev.invowerkOfficial publisher

Validates, renders, parses, converts and generates European e-invoices (XRechnung, ZUGFeRD, Factur-X, Peppol BIS) against EN 16931 rules.

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