Unfragile

The request "xsd" names an XML Schema definition language, not a product, so no source page describes XSD itself. The sources below are tools that work with XML or schemas: lxml can process XML in Python 8, and Cerberus validates data against schemas in Python 3. Please say which language or platform you use if you need a specific XSD validator.

A question back: Which language or platform do you need XSD validation for (for example Python, Java, or C#)?

1
lxmllxml.dewebsite read, tools not yet checked
lxml is a Python library for processing XML and HTML, built on libxml2 and libxslt, which are the C libraries that underpin XSD-capable XML tooling.
Website Docs
2
Cerberuspython-cerberus.orgverified and signed
Cerberus is a Python data validation library that checks data against a schema definition, though it validates Python dictionaries rather than XML documents.
Website Docs
for agents: validation · schema · normalization

Sources

3Cerberus — Data validation for Pythondocs.python-cerberus.org · read 2026-10-29
8lxml - Processing XML and HTML with Pythonlxml.de · read 2026-10-29

For agents: the 10 actions behind this answer

shuffle-json-data · shuffle-json-data verified and signed
Shuffle repetitive JSON objects safely by validating schema consistency before randomising entries.
document-api-endpoint · document-api-endpoint verified and signed
Document and type a Sentry API endpoint. Write or fix @extend_schema decorators, specify response TypedDicts, type request parameters, correct type drift between the declared schema and the runtime response, and validate the generated spec. Use when asked to "document an endpoint", "add OpenAPI docs
validation · Cerberus verified and signed
· async-std website read, tools not yet checked
A Rust library for easy and understandable async programming
· aio-libs Aiobotocore website read, tools not yet checked
parsing · ANTLR 3 Runtime verified and signed
cloudforce-one-validate-email-rule · Cloudflare API verified and signed
Validate an email rule
· lxml website read, tools not yet checked
lxml - the most feature-rich and easy-to-use library for processing XML and HTML in the Python language
· aio-libs Aiohttp website read, tools not yet checked
XML · beautifulsoup4 verified and signed

Labels are the instruments' verdict and are never changed by ranking. Agents and robots get this same answer as JSON at /api/v1/find?q=…&answer=1 and through the MCP server.