How do I install Invowerk?

Copy the http config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.

Does Invowerk need an API key?

No required environment variable is listed on this record.

When was Invowerk last checked?

Last checked 2026-10-21. E-invoice checker for ZUGFeRD, Factur-X, XRechnung and Peppol BIS. Free web tool, API and MCP.

Invowerk MCP server

Power your agent

Add this server

The publisher's own URL. Not a PlugMCP endpoint.

Add to Cursor Add in Claude Add to VS Code Run on PlugMCP

Host a copy with our keys and logs.

Server URL

https://api.invowerk.dev/mcp/

The Claude button above opens Claude with the name and URL filled in. You still confirm it there.

shClaude Code

1claude mcp add --transport http dev.invowerk-xrechnung-e-invoice-validator https://api.invowerk.dev/mcp/

Run in a terminal.

jsonClaude Desktop

1{2  "mcpServers": {3    "dev.invowerk-xrechnung-e-invoice-validator": {4      "command": "npx",5      "args": [6        "-y",7        "mcp-remote",8        "https://api.invowerk.dev/mcp/"9      ]10    }11  }12}

claude_desktop_config.json

Remote · HTTPPublisher installStep-by-step: add this in Claude

Remote URL or a command on your machine? How the two installs differ

Run on PlugMCP

Host a copy with our keys and logs.

A new server you create. It is not this listing's official endpoint. Use the publisher install when you want their URL and their credentials.

Launch

Server facts

Remote

Transport: http
Version: 1.0.1
Last checked

6 tools

Tools

tools/listVoice mode preview

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 [email protected] 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.

validate_invoice	Check an e-invoice against EN 16931 and German rules. Input: `invoice_base64` is the base64 of an XML invoice (UBL or CII) or a ZUGFeRD / Factur-X PDF, at most 4 MB decoded; or pass the file as a download link in `file`. `explain=true` adds an explanation to findings whose rule has one, in `lang` (
render_invoice	Render an XML e-invoice (UBL or CII, e.g. XRechnung) as a readable HTML page. invowerk uses the KoSIT XRechnung visualization. Use it to show a person what an e-invoice contains. Input: `invoice_base64` is the base64 of the XML, at most 4 MB decoded, or pass the file as a download link in `file`.
explain_errors	Explain rule codes in plain language. Works without an API key. Covers the codes of `validate_invoice` findings and hints: EN 16931, XRechnung, ZUGFeRD and invowerk's own hint codes (IW-*). Input: `codes` is a list of one or more codes, e.g. ["BR-CO-18", "BR-DE-21"]. Duplicates are removed. `lang`
generate_invoice	Create a valid EN 16931 e-invoice (UBL or CII XML) from JSON. Input: `invoice` is a JSON object keyed on EN 16931 Business Terms, the same schema as `POST /v1/generate`, at most 4 MB. Main fields: `syntax` ("ubl" default, or "cii"), `flavor` ("en16931" default, or "xrechnung", which requires `buyer
parse_invoice	Read an existing e-invoice into JSON keyed on EN 16931 Business Terms. The JSON is the input format of `generate_invoice`, so you can edit it and create the invoice again. Input: `invoice_base64` is the base64 of an XML invoice (UBL or CII) or a ZUGFeRD / Factur-X PDF, at most 4 MB decoded; or pas
convert_invoice	Convert an e-invoice to UBL or CII. The result is checked before it is returned. Input: `invoice_base64` is the base64 of an XML invoice or a ZUGFeRD / Factur-X PDF, at most 4 MB decoded; or pass the file as a download link in `file`. `target_syntax` is "ubl" or "cii". `target_flavor` is optional,

Invowerk

Add this server

Host a copy with our keys and logs.

Server facts

Tools

Questions

How do I install Invowerk?

Does Invowerk need an API key?

What transport does Invowerk use?

When was Invowerk last checked?

Documentation

invowerk

Quickstart

Use it from

MCP server

Templates

Links

API

About the files here