NOTE: This is an OASIS TC Open Repository <https://www.oasis- open.org/resources/open-repositories/>__. See the Governance section for more information.

The STIX Validator checks that STIX JSON content conforms to the requirements specified in the STIX 2.1 specification. In addition to checking conformance with the JSON schemas <https://github.com/oasis- open/cti-stix2-json-schemas>, the validator checks conformance with requirements that cannot be specified in JSON schema, as well as with established "best practices". This validator is non-normative; in cases of conflict with the STIX 2.1 specification, the specification takes precedence.

The STIX 2.1 specification contains two types of requirements: mandatory "MUST" requirements, and recommended "SHOULD" best practice requirements. The validator checks documents against the "MUST" requirements using JSON schemas. Some of these mandatory requirements cannot be implemented in JSON Schema, however, so the validator uses Python functions to check them. The "SHOULD" requirements are all checked by Python functions, and options may be used to ignore some or all of these recommended "best practices."

The only exception to this is the mandatory requirement that an object's 'type' be one of those defined by a STIX Object in the specification. This rules out custom objects, so this check was made optional.

The validator also color-codes its output to make it easier to tell at a glance whether validation passed.

The easiest way to install the STIX validator is with pip:

$ pip install stix2-validator

The validator comes with a bundled script which you can use to validate a JSON file containing STIX content:

$ stix2_validator <stix_file.json>

You can also use this library to integrate STIX validation into your own tools. You can validate a JSON file:

from stix2validator import validate_file, print_results

results = validate_file("stix_file.json")
print_results(results)

You can also validate a JSON string using validate_string(), or a Python dictionary representing a STIX object using validate_instance(). For more information, see the full documentation here.

This GitHub public repository ( https://github.com/oasis-open/cti-stix-validator ) was proposed <https://lists.oasis- open.org/archives/cti/201609/msg00001.html> and approved [bis] by the OASIS Cyber Threat Intelligence (CTI) TC <https://www.oasis- open.org/committees/cti/> as an OASIS TC Open Repository to support development of open source resources related to Technical Committee work.

While this TC Open Repository remains associated with the sponsor TC, its development priorities, leadership, intellectual property terms, participation rules, and other matters of governance are separate and distinct <https://github.com/oasis-open/cti-stix- validator/blob/master/CONTRIBUTING.md#governance-distinct-from-oasis- tc-process> from the OASIS TC Process and related policies.

All contributions made to this TC Open Repository are subject to open source license terms expressed in the BSD-3-Clause License <https://www.oasis-open.org/sites/www.oasis-open.org/files/BSD-3- Clause.txt>. That license was selected as the declared "Applicable License" <https://www.oasis-open.org/resources/open- repositories/licenses> when the TC Open Repository was created.

As documented in "Public Participation Invited" <https://github.com/oasis-open/cti-stix- validator/blob/master/CONTRIBUTING.md#public-participation-invited>, contributions to this OASIS TC Open Repository are invited from all parties, whether affiliated with OASIS or not. Participants must have a GitHub account, but no fees or OASIS membership obligations are required. Participation is expected to be consistent with the OASIS TC Open Repository Guidelines and Procedures <https://www.oasis- open.org/policies-guidelines/open-repositories>, the open source LICENSE <https://github.com/oasis-open/cti-stix- validator/blob/master/LICENSE> designated for this particular repository, and the requirement for an Individual Contributor License Agreement <https://www.oasis-open.org/resources/open- repositories/cla/individual-cla> that governs intellectual property.

TC Open Repository Maintainers <https://www.oasis- open.org/resources/open-repositories/maintainers-guide>__ are responsible for oversight of this project's community development activities, including evaluation of GitHub pull requests <https://github.com/oasis-open/cti-stix- validator/blob/master/CONTRIBUTING.md#fork-and-pull-collaboration- model> and preserving <https://www.oasis-open.org/policies- guidelines/open-repositories#repositoryManagement> open source principles of openness and fairness. Maintainers are recognized and trusted experts who serve to implement community goals and consensus design preferences.

Initially, the associated TC members have designated one or more persons to serve as Maintainer(s); subsequently, participating community members may select additional or substitute Maintainers, per consensus agreements <https://www.oasis-open.org/resources/open- repositories/maintainers-guide#additionalMaintainers>.

• Emily Ratliff; GitHub ID: https://github.com/ejratl; WWW: IBM
• Jason Keirstead; GitHub ID: https://github.com/JasonKeirstead; WWW: IBM
• Rich Piazza; GitHub ID: https://github.com/rpiazza; WWW: MITRE

• TC Open Repositories: Overview and Resources
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Questions or comments about this TC Open Repository's activities should be composed as GitHub issues or comments. If use of an issue/comment is not possible or appropriate, questions may be directed by email to the Maintainer(s) listed above. Please send general questions about TC Open Repository participation to OASIS Staff at repository-admin@oasis-open.org and any specific CLA-related questions to repository-cla@oasis-open.org.