Koskamo

xmlvalid MCP

An official MCP server provided by xmlvalid that allows AI agents to validate XML documents against various schemas (XSD, DTD, RelaxNG) and e-invoice standards (EN 16931, Peppol, XRechnung). It provides tools to validate documents, search schemas, and explain validation errors or business rules.

Endpoint and access

No sign-in to connect and list tools. Individual tools may still need a vendor account, credentials, or permissions; check the documented prerequisites.

xmlvalid MCP logo, by xmlvalidVendor evidenceStreamable HTTPNo sign-inEndpoint checked 2026-11-01Operated by xmlvalid
You need:Make a key under Dashboard → API keys (an account with a confirmed email)Needs your API key and counts as one API validation
MCP endpoint (Streamable HTTP)
https://xmlvalid.com/mcp
Vendor documentation

What you can do with it

  • Validate XML documents against XSD, DTD, or RelaxNG schemas
  • Check e-invoices against EN 16931, Peppol, or XRechnung rules
  • Search for available schemas in the public catalog
  • Explain specific XML error messages or business rule violations

Source and maintenance

Vendor evidenceRegistry 1.0.0

Protocol and capabilities

Server
xmlvalid 1.0.0
MCP protocol
2025-06-18
Tools
5 advertised
Resources
0 advertised
Resource templates
0 advertised
Prompts
0 advertised
Server-advertised capabilities
{
  "tools": {
    "listChanged": false
  },
  "prompts": {
    "listChanged": false
  },
  "resources": {
    "listChanged": false
  }
}

Server-provided instructions

Untrusted server output shown for inspection. It is not Koskamo guidance and is excluded from knowledge search.

xmlvalid validates XML and e-invoices: well-formedness, XSD, DTD and RelaxNG schemas, and the Schematron business rules of EN 16931, Peppol BIS, XRechnung, Factur-X and national e-invoicing formats. - validate_xml checks a document (its text or a URL) against a catalog schema, a saved schema or "auto" (the e-invoice profile the document names). It needs the API key the client connected with. - search_schemas finds the catalog slug for a format. - explain_error explains a parser or validator message (libxml2, Java's Xerces, .NET) and how to fix it. - explain_rule explains a business rule such as BR-CO-15. When a validation fails, fix the first errors first: later ones often follow from them, and business rules run only once the schema check passes.

Tools

5 advertised

validate_xml — Validate Xml
Advertised by the server during the last successful anonymous check.
Open-world

Validate an XML document with xmlvalid: well-formedness, an XSD, DTD or RelaxNG schema, and for e-invoices the Schematron business rules of EN 16931, Peppol BIS, XRechnung, Factur-X and national formats. Pass the document as `xml` (its text) or `url` (a public http(s) address), and a `schema`: a catalog slug from search_schemas, a saved schema ("@orders-v3"), or "auto" to use the e-invoice profile the document names. Without a schema only well-formedness is checked. Returns valid, errors and warnings with line, column, message, rule and a help_url explaining each. Counts as one API validation of the key's monthly quota.

validate_xml input schema
{
  "type": "object",
  "properties": {
    "url": {
      "type": "string",
      "description": "A public http(s) URL of the document, fetched by xmlvalid."
    },
    "xml": {
      "type": "string",
      "description": "The XML document itself. Use url instead for a document on the web."
    },
    "name": {
      "type": "string",
      "description": "A file name to show in the result, such as invoice-42.xml."
    },
    "wait": {
      "type": "integer",
      "default": 30,
      "maximum": 60,
      "minimum": 0,
      "description": "Seconds to wait for the result before returning a pending status to poll with get_validation."
    },
    "schema": {
      "type": "string",
      "description": "A catalog slug (see search_schemas), \"@<name>\" for a saved schema, or \"auto\" for the e-invoice profile the document names. Leave out to check well-formedness only."
    },
    "rules_version": {
      "type": "string",
      "description": "Pin Schematron rule sets to releases, as rule-set@version, comma-separated (peppol-bis-3-ubl@3.0.21): the call fails with rules_version_mismatch when one has moved on. The result's rule_sets lists the releases that ran."
    }
  }
}
validate_xml annotations
{
  "title": "Validate Xml",
  "openWorldHint": true
}
get_validation — Get Validation
Advertised by the server during the last successful anonymous check.
Advertised read-only

The status and result of a validation started with validate_xml that was still running when it returned (status "queued" or "running"). Results are kept for 24 hours.

get_validation input schema
{
  "type": "object",
  "required": [
    "id"
  ],
  "properties": {
    "id": {
      "type": "string",
      "description": "The id validate_xml returned."
    }
  }
}
get_validation annotations
{
  "title": "Get Validation",
  "readOnlyHint": true
}
search_schemas — Search Schemas
Advertised by the server during the last successful anonymous check.
Advertised read-only

Search xmlvalid's catalog of official XML schemas (UBL, CII, Peppol, XRechnung, Factur-X, ISO 20022, HL7, sitemaps…) by name, namespace, root element or area. Returns each schema's slug to pass to validate_xml, its version and the business rules it checks. No API key needed.

search_schemas input schema
{
  "type": "object",
  "properties": {
    "query": {
      "type": "string",
      "description": "Words to look for, such as \"peppol invoice\", \"xrechnung cii\" or \"pain.001\". Leave out to list the first schemas."
    }
  }
}
search_schemas annotations
{
  "title": "Search Schemas",
  "readOnlyHint": true
}
explain_error — Explain Error
Advertised by the server during the last successful anonymous check.
Advertised read-only

Explain an XML parsing or schema validation error message: what it means, why it happens and how to fix it, with an example. Understands libxml2 (xmllint, PHP, Python lxml, xmlvalid), Java (Xerces cvc-* codes, SAXParseException) and .NET (System.Xml) wording; paste the message as reported, stack trace prefix included. No API key needed.

explain_error input schema
{
  "type": "object",
  "required": [
    "message"
  ],
  "properties": {
    "message": {
      "type": "string",
      "description": "The error message, as the parser or validator reported it."
    }
  }
}
explain_error annotations
{
  "title": "Explain Error",
  "readOnlyHint": true
}
explain_rule — Explain Rule
Advertised by the server during the last successful anonymous check.
Advertised read-only

Explain an e-invoicing business rule by its id, such as BR-CO-15, BR-DE-1, PEPPOL-EN16931-R001 or a national CIUS rule: its message, level, the rule sets it belongs to, why invoices fail it and how to fix them. No API key needed.

explain_rule input schema
{
  "type": "object",
  "required": [
    "id"
  ],
  "properties": {
    "id": {
      "type": "string",
      "description": "The rule id as the validator reports it, such as BR-CO-15."
    }
  }
}
explain_rule annotations
{
  "title": "Explain Rule",
  "readOnlyHint": true
}

Prompts

0 advertised

No prompt definitions available.

Resources

0 advertised

No resource definitions available.

30-day availability

Aggregated from read-only remote checks; this is not a tool-execution or security guarantee.

Successful checks
1 of 1 (100%)
Average latency
3486 ms
95th percentile latency
3486 ms

Maintenance history

Public check and source-refresh events. Editorial and ownership records remain private.

  • · probe · passed · 3486 ms · metadata changed · 5 tool(s), 0 resource(s), 0 resource template(s), 0 prompt(s)

Connect from your client

Each snippet registers the same endpoint; pick the client you use.

This server is operated by the named third party. Listing and endpoint checks are not an endorsement or a security audit. Review the operator's permissions, terms, and data handling before connecting. How listings are checked and corrected.

Claude Code

Run this once in a terminal. It registers the remote server. Use --scope project to write .mcp.json for the repo.
Claude Code configuration
claude mcp add --transport http xmlvalid-mcp https://xmlvalid.com/mcp

Codex

Run this once. Codex stores MCP servers in ~/.codex/config.toml (or .codex/config.toml in a trusted project).
Codex configuration
codex mcp add xmlvalid-mcp --url https://xmlvalid.com/mcp

Cursor

Merge this server into .cursor/mcp.json in your project, then enable xmlvalid-mcp in your MCP settings.
Cursor configuration
{
  "mcpServers": {
    "xmlvalid-mcp": {
      "url": "https://xmlvalid.com/mcp"
    }
  }
}

Cline

Merge this into cline_mcp_settings.json (Cline → MCP Servers → Configure).
Cline configuration
{
  "mcpServers": {
    "xmlvalid-mcp": {
      "type": "streamableHttp",
      "url": "https://xmlvalid.com/mcp",
      "disabled": false
    }
  }
}

VS Code

Merge this server into .vscode/mcp.json. Use MCP: List Servers to start xmlvalid-mcp and inspect its tools.
VS Code configuration
{
  "servers": {
    "xmlvalid-mcp": {
      "type": "http",
      "url": "https://xmlvalid.com/mcp"
    }
  }
}

Gemini CLI

Run this once. It writes .gemini/settings.json in the current project; pass --scope user for ~/.gemini/settings.json.
Gemini CLI configuration
gemini mcp add --transport http xmlvalid-mcp https://xmlvalid.com/mcp

Claude Desktop

Merge this into claude_desktop_config.json (macOS: ~/Library/Application Support/Claude/, Windows: %APPDATA%\Claude\), then restart Claude Desktop.
Claude Desktop configuration
{
  "mcpServers": {
    "xmlvalid-mcp": {
      "url": "https://xmlvalid.com/mcp"
    }
  }
}

Windsurf

Merge this into ~/.codeium/windsurf/mcp_config.json, then refresh MCP in Cascade. Windsurf remote servers use serverUrl, not url.
Windsurf configuration
{
  "mcpServers": {
    "xmlvalid-mcp": {
      "serverUrl": "https://xmlvalid.com/mcp"
    }
  }
}

Let your agent find its tools

Find servers like xmlvalid MCP from your agent. Add Koskamo once to search the index for endpoints, access requirements, and client setup. Public discovery needs no key.

Do you run xmlvalid MCP?

Prove ownership with a DNS record, a well-known file, or your Official MCP Registry entry, and your edits publish immediately. Proofs are re-checked weekly; admins can still hide or remove a listing.

Claim this listing