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NormAPI

by normapi.com · remote · local (npm) · no sign-in to list tools · v1.0.2 · published by com.normapi

Validate and generate German e-invoices (XRechnung, ZUGFeRD) against the official KoSIT rules.

Changes · 2
CompareRegistry entry

3 tools: 2 change things and 1 only read.

Scanned Oct 21, 2026

1 check matched something in the tool definitions. No finding is not a safety guarantee. How the checks work.

claude mcp add --transport http normapi https://normapi.com/mcp

Findings

Matches of fixed checks, with the text they matched.

1 warn
  • Warnexplain_rule

    The server marks "explain_rule" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

    Matched text

    annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":false}; The name "explain_rule" says "explain": a word for reading.

    What this check looks for

Tools

Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.

3 tools

Changes things 2Claude Code: ask
  • explain_ruleExplain one EN 16931 / XRechnung / Peppol business rule by its code (e.g.1 finding

    Why it is in this group

    • The name "explain_rule" says "explain": a word for reading.
    • The input takes a statement or command to run (input.code), which can change anything it can reach.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

    Findings

    • Warn

      The server marks "explain_rule" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

      Matched text

      annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":false}; The name "explain_rule" says "explain": a word for reading.

      What this check looks for
    Description, as the server wrote it
    Explain one EN 16931 / XRechnung / Peppol business rule by its code (e.g. BR-DE-15, BR-CO-10, PEPPOL-EN16931-R010): what it requires, why invoices typically break it, and how to fix it, with a link to the full page. Case does not matter. Schema findings (cvc-*) have no explanation.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • generate_invoiceProduce an XRechnung (`ubl` or `cii` XML) or a ZUGFeRD hybrid PDF (`zugferd`) from invoice data.No findings

    Why it is in this group

    • The name "generate_invoice" says "generate": a word for a change.
    Description, as the server wrote it
    Produce an XRechnung (`ubl` or `cii` XML) or a ZUGFeRD hybrid PDF (`zugferd`) from invoice data. Totals are computed server-side in decimal arithmetic, and the document is validated against the official rules before it is returned. Data the rules do not permit is refused with the broken rules and how to fix each. Needs the user's NormAPI account; each document counts against the monthly allowance (50 free).

    Annotations the server declares

    • readOnlyHint: false
    • destructiveHint: false
    • idempotentHint: false
    • openWorldHint: false
Only reads 1Claude Code: allow
  • validate_invoiceCheck an XRechnung (UBL or CII XML) or a ZUGFeRD/Factur-X PDF against the official KoSIT rules.No findings

    Why it is in this group

    • The name "validate_invoice" says "validate": a word for reading.
    Description, as the server wrote it
    Check an XRechnung (UBL or CII XML) or a ZUGFeRD/Factur-X PDF against the official KoSIT rules. Returns the verdict, the rule set version, and every finding; each business-rule finding comes with a plain-language meaning, cause and fix. Send the XML as text in `xml`, or the PDF base64-encoded in `pdfBase64` — exactly one. Free, no account needed, 5 MB at most.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Install

Pinned to version 1.0.2. Values in angle brackets are yours to fill in.

claude mcp add --transport http normapi https://normapi.com/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json
{
  "permissions": {
    "allow": [
      "mcp__normapi__validate_invoice"
    ],
    "ask": [
      "mcp__normapi__generate_invoice",
      "mcp__normapi__explain_rule"
    ],
    "deny": []
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as normapi. Review it before you use it.