Credential Engine Technical Site

Welcome to the Credential Engine Technical Site where you will find complete documentation on our:

  • Credential Transparency Description Language open family of schemas
  • Data publishing tools including the Registry Publishing Assistant API
  • Credential Registry Handbook
  • Credential Registry Policy
  • Consuming services from the Registry
  • Learner and Worker Records Guide
  • Quick Start Guides
  • Other tools including those for mapping to the schemas, serializations.

To get started with using the Credential Registry data publishing and consuming tools, begin by setting up your Credential Engine account and let us know if you have any questions.

Technical Services and Advisory Group

Technical Services

We specialize in helping organizations define, implement, and derive value from general open data strategies as well as from the Credential Registry and other Credential Engine services. Our areas of focus include credentials, skills and competencies, education and career pathways, transfer value, and quality assurance.

Advisory Group

The TAG is open to anyone interested in participating with feedback on development of the CTDL and other Credential Engine technologies and services and with supporting alignment with other standards.


Developers are able to leverage the the Credential Registry API to build applications that can read or publish as much or as little information about credentials as they need to.

The Credential Engine project's developers are using Dublin Core Application Profiles process to create systems that communicate all virtually all aspects of credentials.

Use the CTDL Schemas

The Credential Transparency Description Language (CTDL) is available to use with data design, with interoperable learner/worker records, and for publishing information as linked data.

Explore the CTDL Handbook, Terms, Serializations, LER Guide, and other resources for using CTDL on this site.

Publishing Options

Credential Engine offers the following options for publishing to the Credential Registry:

  • Registry Assistant Publishing API
  • Manual Entry
  • Bulk Upload

For more information on setting up your account and getting started with any of the publishing methods, click here.

Search Options

Credential Engine offers a robust search API to enable developers to leverage the wealth of data contained in the registry, using the CTDL and CTDL-ASN schemas.

Credential Engine offers a way for non-technical participants to enable a credential search on their own website. The Credential Finder Widget can be customized to match your site's theme and your preferences for automatic filtering, so that the results it shows can be more closely tailored to your site's purposes.

Join Credential Engine

Visit the Credential Engine website to:

  1. Learn more about Credential Engine
  2. Subscribe to updates
  3. Become a participant or partner

Get started with Credential Engine today by:

  1. Create or Login to your Credential Engine account
  2. Get your organization approved to publish and/or consume
  3. Learn more about CTDL, the Registry, and the publishing and consuming APIs


September 2021 TAG Meeting
Posted on 9/30/2021


We hope you’re doing well! It’s been quite awhile since we’ve convened the Technical Advisory Group (TAG) but it’s time to ask you to spare a bit of your time. We’re conscientious of how busy you have been and we understand meeting fatigue. Thereby, we decided to take a break from our typical TAG schedule. However, we have some big updates and are looking forward to sharing them with you and getting your feedback.

The CTDL team has also been very busy participating with numerous spec development efforts and working with our many partners to extend the CTDL. We’ll ensure TAG members have a link to all of the meeting materials closer to the meeting date.


  • Contextualizing Skills and Competencies Task Group: New CTDL Terms Proposal
  • Expanding CTDL Learning Opportunity to specify Courses and Programs
  • Using CTDL to efficiently publish articulated transfer value

Please join us and if you have colleagues who may be interested, pass this email on to them to join the TAG and they’re welcome to join this meeting. We’ll have a couple more meetings with the TAG this year with the intent of them being highly informative and for getting feedback. We hope to see you soon!

Meeting Date: Thursday, September 16, 2021

Time: 12:00 pm ET / 11:00 am CT / 10:00 am MT / 9:00 am PT

Call for Participation in Credential Engine’s Task Group on Contextualizing Skills and Competencies
Posted on 5/28/2021

Clearly defining and communicating the skills and competencies for credentials, programs, and jobs can lead to more equitable learn-and-work ecosystems that recognize everyone’s specific abilities. In order to achieve this, we all need clearly written skills that are contextualized with additional information, providing a valuable currency across education, training, and employment. Open skills that are published on the web using Linked Open Data support connections among the skills, credentials, jobs, and more. The Credential Transparency Description Language (CTDL) and the Registry provide a freely available, shared Linked Open Data structure for publishing open skills and their rich connections to other data.

The CTDL already supports data structures for describing competencies and skills, competency frameworks, alignments among skills, and rich metadata for contextualizing competency frameworks and related information. The CTDL also provides structure for linking competencies to credentials, courses, programs, assessments, transfer value, education and career pathways, jobs, work roles, and learning and employment records. The next step in the evolution of CTDL is to support additional rich metadata for individual competencies and skills.

Credential Engine follows a clearly defined, open process to make significant updates to develop the Credential Transparency Description Language (CTDL). This process includes subject matter and technical experts forming short-term task groups to provide valuable input (typically 8-12 weeks). You are invited to join our new Contextualization of Skills and Competencies Task Group (CSCTG). The work of this task group supports the goals of the Open Skills Network, T3 Innovation Network, and other initiatives and organizations advancing the development, sharing, and reuse of skills and competencies as linked data.

The CSCTG will:

  1. Identify real-world use cases for individual skill and competency statement contextualization. The contextual information is important to correctly interpret the intent, purpose, use of, or authoritative sources for an individual skill or competency statement.
  2. Provide real examples of skill and competency statements with contextual information.
  3. Provide input to expand the CTDL domain model and create additional CTDL terms where necessary for the meaningful contextualization of individual skill and competency statements.

Who: The CSCTG is for subject matter experts who create, manage, reuse, share, consume, or align skill and competency statements across learning and work domains. For example, skills architects, curriculum developers, assessment developers, HR or other job information managers, military and industry training developers, and others who work with skills and competencies. We welcome managers of data specifications who would like to participate and align their data standards to the resultant use cases and CTDL terms. We also welcome product and service providers who support skills and competencies and want to incorporate CTDL into their solutions. Prior knowledge of CTDL is appreciated by not required.

When and Where: The CSCTG will kickoff on Thursday, June 24, 2021 and meet no more than six times, every other week for one hour, and conclude in August, 2021. The one-hour meetings will be held via Zoom.

Materials: Credential Engine will create and provide all resources needed for this work, based on CSCTG input, and share them for ongoing feedback between meetings. All feedback and materials are transparently available following an open process.

Outcomes: The final products of this work include the use cases, real-world examples as instance data, CTDL domain model and terms with definitions, and usage guidance. The products are all public information made available via the Credential Engine technical site and where appropriate, on github and available under open licenses. All subsequent updates to the CTDL will follow the Significant Update Policy. The policy requires formation of the Task Group, input by the Credential Engine Technical Advisory Group and other advisory group members and stakeholders, and a comment period. This efficient process ensures orderly changes that support and expand the durable, persistent value of CTDL Linked Open Data. Once this process is completed, the CTDL family of specifications will be updated along with the Credential Registry publishing and consuming tools. The tools include the open source Competency and Skills System (CaSS). The Registry and related tools and resources are freely available for stakeholders to publish competencies and skills, competency frameworks, and related data.

For more information:

Join the CSCTG

May 2021 CTDL and CTDL-ASN Releases are now Pending
Posted on 5/14/2021

This month's pending releases for CTDL and CTDL-ASN bring with them a few small adjustments as well as some larger changes, namely:

  • The return of ceterms:codedNotation to the Occupation, Job, WorkRole, and Task classes to handle cases where the identification code is not part of a known or referenceable source, or where it isn't useful to include such a source
  • The introduction of the ceterms:Organization class to accommodate organizations that are not exclusively/specifically Credentialing or Quality Assurance organizations (even if they exhibit one or both of those functions)

You can view the pending changes here:

As always, please leave feedback in our Github, Google Group, or by contacting Credential Engine directly.

These changes will be implemented in the live versions of CTDL and CTDL-ASN on Friday, May 28, 2021.

March 2021 Schemas Update Feedback Period
Posted on 3/22/2021

The CTDL family of schemas is now in the feedback period for the March 2021 Release.

This release has some minor improvements along with the beginnings of a significant change to the way that aggregate data is managed. Previously, CTDL required the use of three separate classes (ceterms:HoldersProfile, ceterms:EmploymentOutcomeProfile, and ceterms:EarningsProfile) in order to convey various aspects of aggregate data. These classes were initially sketched out in the earliest days of CTDL and much of the functionality originally envisioned for them has been implemented in the QData schema instead. As such, these three classes took on a "summary" role wherein several test cases showed that they all ultimately linked to the same qdata:DataSetProfile.

After much discussion, we have now created a new class, ceterms:AggregateDataProfile, and given it a combination of properties drawn from those three aggregate data classes to enable it to fill the same "summary" role, but with less complexity.

However, this consolidation of classes represents a large change in how this kind of data is handled, so in order to ensure compatibility, we have not yet deprecated the original three aggregate data classes. Instead, we have updated them to reference and strongly urge the use of ceterms:AggregateData instead. We will consider whether or not to deprecate these classes based on future feedback (or lack thereof).

For a detailed list of changes, see the following:

These changes are scheduled to go live to their respective schemas on March 26, 2021.

Follow Up Information: Final Review of Transfer Value and Education & Training to Jobs CTDL Term Proposals
Posted on 10/16/2020

Thanks to all who joined the October 14, 2020 meetings to review the new CTDL terms proposals for Transfer Value and Education and Training to Jobs. If you can provide feedback by Friday, October 30, 2020, it would be very helpful.

All meeting materials are available to you:

Please review and provide feedback on these documents. Please provide feedback using any of these options:

Backup materials for Transfer Value terms and Education & Training to Jobs are listed below.

Transfer Value

  1. Transfer Value Charter with Use Cases - This document is complete.
  2. Transfer Value GitHub Issues - The terms proposal is documented with multiple GitHub issues. Use the Terms proposal to provide suggestions. Otherwise, log into your GitHub account and add comments to related issues.
  3. Transfer Value CTDL JSON Examples - These are the examples from slides 10-14 available for review.
  4. Updates to CTDL terms are in Pending status during the feedback period through Nov 1, 2020.

Education & Training to Jobs

  1. Education & Training to Jobs Charter with Use Cases - This document is complete.
  2. Education & Training to Jobs Domain Model - Review and provide suggestions.
  3. Education & Training to Jobs GitHub Issues - The terms proposal is documented with multiple GitHub issues. Use the Terms proposal to provide suggestions. Otherwise, log into your GitHub account and add comments to related issues.
  4. Education & Training to Jobs CTDL JSON Examples - These are the examples from slides 21 - 22 available for review..
  5. Updates to CTDL terms are in Pending status during feedback period through Nov 1, 2020.

Thank you in advance for reviewing proposal materials and please let us know if you have any questions.