# 402utils Factur-X / ZUGFeRD Invoice Validator

> 402utils Factur-X / ZUGFeRD Invoice Validator is a paid API for AI agents from 402utils.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Validates a Factur-X or ZUGFeRD invoice (PDF, CII XML, or URL) against PDF/A-3 structure, EN 16931 CII rules, arithmetic checks, and French Flux 2 requirements, returning a detailed rule-based compliance report.

## Facts

- Endpoint: POST https://402utils.com/v1/facturx-validate
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/402utils-factur-x-zugferd-invoice-validator-3a822cf4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_sk7ZxkedgYDAw9Xi51GGQ

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability 402utils-factur-x-zugferd-invoice-validator-3a822cf4 -d '<json body>'
```

Example prompt: Can you validate this Factur-X invoice PDF for me — here's the URL: https://example.com/invoice.pdf — and also give me a signed attestation I can keep for audit purposes?

## When to prefer this

Use this endpoint when you need a quick, paid, automated check of a Factur-X or ZUGFeRD e-invoice against EN 16931 CII rules, PDF/A-3 structure, arithmetic constraints, and French Flux 2 requirements — especially when you need an Ed25519-signed audit trail. Prefer this over manual validation tools when integrating compliance checks into automated invoicing workflows. Not suitable as a substitute for certified conformance testing bodies.

## Known failure modes

- Invalid or inaccessible URL returns an error fetching the document
- Malformed or non-CII XML causes a parse error
- Non-PDF/A-3 file causes structural validation failures
- Missing required fields in JSON body (none of url, xml, or pdfBase64 provided)
- Base64 decoding errors if pdfBase64 is malformed
- Service is heuristic/structural only — not a certified conformance authority

## How this service works

Validate a Factur-X / ZUGFeRD invoice: send PDF bytes, JSON { url } or { pdfBase64 }, or raw CII { xml }. Returns a rule-based report — PDF/A-3 structure, EN 16931 CII anchors, arithmetic rules (BR-CO) and French PA « Flux 2 » checks (BR-FR) — with the detected profile. Structural + heuristic, not a certified conformance service. ?attest=1 → Ed25519-signed audit trail.

## Output

A rule-based compliance report covering PDF/A-3 structural checks, EN 16931 CII anchor conformance, arithmetic (BR-CO) rules, and French public administration Flux 2 (BR-FR) checks, along with the detected Factur-X/ZUGFeRD profile. If attest=1 is passed, includes an Ed25519-signed audit trail of the validation result.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "format": "uri",
   "description": "Public http(s) URL of a Factur-X PDF or CII XML."
  },
  "xml": {
   "type": "string",
   "description": "Raw CII (CrossIndustryInvoice) XML to validate without a PDF wrapper."
  },
  "attest": {
   "type": "string",
   "description": "Set to 1 for an Ed25519-signed attestation of the result (audit trail)."
  },
  "pdfBase64": {
   "type": "string",
   "description": "Base64 of a Factur-X PDF (alternative to raw bytes)."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/402utils-factur-x-zugferd-invoice-validator-3a822cf4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 402utils.com](https://www.zero.xyz/host/402utils.com/llms.txt)