Peppol Validator for AI Agents

Why AI agents must validate invoices

What happens when validation fails

API endpoint

curl

curl -X POST https://peppolvalidator.com/api/v1/validate \
  -H "Content-Type: application/xml" \
  -d @invoice.xml

JavaScript / Node.js

const xml = fs.readFileSync("invoice.xml", "utf-8");

const res = await fetch("https://peppolvalidator.com/api/v1/validate", {
  method: "POST",
  headers: { "Content-Type": "application/xml" },
  body: xml,
});

const result = await res.json();
// result.status → "valid" | "invalid" | "error"
// result.errors → [{ rule, message, location }]

Python

import requests

with open("invoice.xml", "r") as f:
    xml = f.read()

res = requests.post(
    "https://peppolvalidator.com/api/v1/validate",
    data=xml,
    headers={"Content-Type": "application/xml"},
)

result = res.json()
print(result["status"])  # "valid" | "invalid" | "error"

Response format

What gets validated

See the full reference of all 311 validation rules with plain-language explanations and fixes.

MCP Server

Agent Skill: one-file integration

Download and place in your project. For Claude Code, use .claude/skills/. For other agents, use .agents/skills/.

.claude/skills/validating-peppol-invoices/SKILL.md

Or create the file manually with these contents:

---
name: validating-peppol-invoices
description: Validates Peppol UBL XML invoices and credit notes
  against EN16931 (CEN) and Peppol BIS Billing 3.0 schematron
  rules via the Peppol Validator API. Use when validating
  e-invoices, checking Peppol compliance, debugging UBL XML
  validation errors, or verifying invoices before sending via
  the Peppol network.
---

# Validating Peppol Invoices

POST XML to the Peppol Validator API and parse the JSON result.

## Endpoint

\`POST https://peppolvalidator.com/api/v1/validate\`

Send raw XML with \`Content-Type: application/xml\`:

```bash
curl -X POST https://peppolvalidator.com/api/v1/validate \
  -H "Content-Type: application/xml" \
  -d @invoice.xml
```

Returns JSON with status ("valid" / "invalid" / "error"),
errors, warnings, and invoice metadata.

What your agent can do with it

• •Validate XML invoices during development and flag issues inline
• •Run validation in CI/CD before deploying invoice generation code
• •Debug Peppol validation errors by examining rule IDs and XPath locations
• •Verify fixes by re-validating after code changes
• •Catch calculation mismatches, missing fields, and invalid code list values before they reach production
• •Generate valid test invoices by iterating on validation feedback

Common use cases

HTTP status codes

A 200 response means validation completed; check the status field for the result. Error codes (400, 500, 503) indicate request or server issues. See the developer docs for the full reference.

Common questions