What we have today

Guidance for using NIEM with JSON

Guidance and documentation on adopting Javascript Object Notation (JSON) as a second standard format for representing data based on the NIEM data model is available at https://niem.github.io/json/. Until recently, XML has been the single format for NIEM data.

The NIEM JSON documentation is designed to provide an easy introduction to the purpose of NIEM, the reasons to use NIEM with JSON data, and the developer knowledge needed to put NIEM JSON into practice. To date, it includes:

  • A NIEM JSON Tutorial
  • NIEM and JSON Frequently Asked Questions
  • A NIEM JSON Reference Guide

The NIEM JSON documentation is intended for:

  • Developers who know JSON but know nothing of NIEM or XML
  • Developers familiar with NIEM XML who need a JSON version of a data exchange
  • Data scientists wanting to understand or provide JSON data sources
  • Managers wondering if NIEM JSON is right for their project

Your feedback and ideas are welcome at https://github.com/NIEM/NIEM.github.io/issues or by email at information@niem.gov.

New in NIEM 4.0

To support NIEM-based JSON exchanges, NIEM has provided a default JSON-LD context for NIEM 4.0 namespaces. NIEM JSON leverages JSON-LD, enabling it to maintain consistency and to connect data across exchanges. The JSON-LD context is a JSON file that identifies, for every namespace for NIEM content, the namespace prefix and its corresponding namespace URI.


For those users who would like to leverage only the NIEM terms and definitions when building custom JSON objects for a lightweight exchange, the NIEM Program has launched Movement. Movement is an open source tool that offers a better way to search model content and simpler way to use it. The tool provides users an intuitive way to pick and choose NIEM model content and automatically export conventional JSON Schema for their simple exchanges.

To learn more about Movement, visit the Movement overview page.

Coming Soon

NIEM JSON is a work in progress. Technical specifications that will define NIEM JSON conformance targets to accompany the existing NIEM XML conformance targets are in development. The alpha version of the NIEM JSON specification is available for use and feedback. Open source tools in the planning stage will help developers switch between JSON and XML (and perhaps other serializations) by creating translators for runtime data and conversions for build-time artifacts.

Promoting open data through NIEM

JSON plays a significant role in the general trend toward open data. This is especially true today, as many organizations are required to report and submit data in the JSON format.

The development of NIEM JSON opens up a potential avenue for collaboration with open data. Open data is about making data freely available, readily accessible, reusable, and redistributable by anyone. NIEM shares these same traits—making data understandable, reusable, and consistent for data exchanges. The ability to leverage community, consensus based common models as data sets are released, not only increases external understanding of the data but also reduces the effort of data analysts assembling the sets.

Want to help?

What we have today for JSON is subject to change based on community feedback. Please help to review the content on this page (and the associated hyperlinks) and provide your feedback!