Welcome to SaxonC-HE

This is the official Saxonica Python wheel package for Saxon, an XML document processor. SaxonC provides APIs to run XSLT 3.0 transformations, XQuery 3.1 queries, XPath 3.1, and XML Schema validation.

Important security note

SaxonC is affected by the eMudhra CA compromise, because it contains its own CA Cert bundle, separate from Python's own mechanisms like certifi.

This bundle comes from GraalVM, where Oracle have issued the CVE-2026-91403 and CVE-2026-114820 advisories.

These relate to the compromised eMudhra certificates. The 12.10.1 and 13.1.1 release adopts the mitigation recommended in CVE-2026-114820: they have been rebuilt with updates that remove the set of impacted root CA certificates related to eMudhra.

Users should upgrade from vulnerable versions immediately.

Vulnerable versions are SaxonC 12.6 to, and including, 12.10, 13.0, and 13.1. Versions 12.5 and prior are not vulnerable because they predate the compromised certificates.

If you cannot upgrade, and your workflows access should not access remote URIs (through <xsl:import>, fn:doc(), or other mechanisms) then you can prevent HTTP/HTTPS resource access by restricting Saxon with the ALLOWED_PROTOCOLS configuration option. See the documentation at https://www.saxonica.com/saxon-c/documentation13/index.html#!configuration and https://www.saxonica.com/documentation13/index.html#!configuration/config-features.

If you must access remote HTTPS URIs, then no mitigation is possible, and you should upgrade as soon as possible.

SaxonC-HE

The SaxonC release comes in separate wheels for the three product editions:

• saxonche (SaxonC-HE: open-source Home Edition)
• saxoncpe (SaxonC-PE: Professional Edition)
• saxoncee (SaxonC-EE: Enterprise Edition)

SaxonC-PE and SaxonC-EE are commercial products that require a valid license key. Licenses can be purchased from the Saxonica online store. Alternatively a 30-day evaluation license is available free of charge. By downloading the software, you are agreeing to our terms and conditions.

For full documentation for the latest SaxonC release, see the SaxonC 12 documentation.

Why choose SaxonC?

The main reason for using SaxonC in preference to other XML tools available for Python is that it supports all the latest W3C standards: XSLT 3.0, XPath 3.1, XQuery 3.1, and XSD 1.1. It even includes experimental support for the draft 4.0 specifications currently under development.

About SaxonC

SaxonC is a version of Saxon developed by compiling the Java source code to native executables that run on the C/C++ platform, with extensions for PHP and Python. All features of Saxon have been ported, other than those (such as collations) that are necessarily platform dependent. In particular, SaxonC provides processing in XSLT, XQuery and XPath, and Schema validation. It therefore makes these processing capabilities available to a plethora of other languages that are strongly coupled to C/C++ such as PHP, Perl, Python, and Ruby.

About Saxonica

Saxon is developed by Saxonica, a company created in 2004 by Michael Kay, who was the editor of the XSLT 2.0 and 3.0 specifications in W3C. The original Saxon product on the Java platform has been continually developed for over 20 years, and has acquired a reputation for standards conformance, performance, and reliability.

Installation

pip install saxonche

Getting started

Either import the whole API:

from saxonche import *

Or specific modules:

from saxonche import PySaxonProcessor

The SaxonC API includes classes for constructing XDM data models and for a variety of processors. For full details see the SaxonC Python API documentation.

The following short example shows how to get the Saxon version from the PySaxonProcessor:

from saxonche import PySaxonProcessor

proc = PySaxonProcessor(license=False)
print(proc.version)

It will print something like this:

SaxonC-HE 12.10.1 from Saxonica

Note: license=False requests the open-source version of Saxon, whereas license=True requests the commercial product - which requires a license file. SaxonC looks for the license key in the directory identified by the environment variable SAXONC_HOME. To explicitly set the location of the license key, create a licensed PySaxonProcessor and set the licenseFileLocation property on it before doing anything else:

from saxoncee import PySaxonProcessor

proc = PySaxonProcessor(license=True)
proc.set_configuration_property("http://saxon.sf.net/feature/licenseFileLocation",
                                    "/path/to/saxon-license.lic")
...

Example: Running a transformation

The following basic example shows how an XSLT stylesheet can be run against a source XML document in Python using SaxonC:

from saxonche import *

proc = PySaxonProcessor(license=False)
 
xsltproc = proc.new_xslt30_processor()
document = proc.parse_xml(xml_text="<doc><item>text1</item><item>text2</item><item>text3</item></doc>")
executable = xsltproc.compile_stylesheet(stylesheet_file="test.xsl")
output = executable.transform_to_string(xdm_node=document)
print(output)

For more Python examples, and further details about installing and configuring the product, see the SaxonC 12 documentation.

Using pylint on a project which uses saxonche

Because the saxonche is a C extension, you will need to either configure Pylint to load the module to avoid pylint errors like:

E0611: No name 'PySaxonProcessor' in module 'saxonche' (no-name-in-module)

$ pylint --extension-pkg-allow-list=saxonche  my_module.py

Support

All users are welcome to use the public support site for reporting issues and seeking help (registration required). In addition, many questions are asked and answered on StackOverflow: please use the saxon tag.

Acknowledgement

We learned a lot about how to create Python wheels for Saxon from the Saxonpy wheel package, which is a third-party project on github.