About the CTID

Last Updated on 7/20/2021


The Credential Transparency Description Language (CTDL) is available under a Creative Commons 4.0 International License for any organization to use with their information management systems. A CTID is a CTDL property for a unique identifier for all major objects in the Credential Registry such as credentials, learning opportunities (including programs and courses), assessments, organizations, competency frameworks, concept schemes, and others (see this section for a complete list). The CTID serves as the primary, unique identifier for all major objects in the Credential Registry.

CTID Structure

Each CTID is made up of a standard UUID prefixed with ce-. The standard 16 octets of a UUID are represented as 32 hexadecimal (base-16) digits, displayed in five groups separated by hyphens, in the form 8-4-4-4-12 for a total of 36 characters (32 hexadecimal characters and 4 hyphens). When the UUID is prefixed with ce-, there are a total of 34 hexadecimal characters and 5 hyphens for a total of 39 characters.

For example: ce-e8a41a52-6ff6-48f0-9872-889c87b093b7

UUIDs can be readily generated in most programming languages, and any organization can generate valid CTIDs. The recommended approach, in general, is to generate and store CTIDs as a field along with the relevant data. If you don't have a programmer to handle this, you can use this CTID Generator tool to generate CTIDs in bulk.

CTID-Based URI Structure

The URIs for top-level entities in the Credential Registry are constructed from a standard structure as follows:

  • The domain https://credentialengineregistry.org
  • Either /resources/ (for just the resource itself) or /graph/ (for the resource and its most immediately related objects)
  • The CTID itself

For Example: https://credentialengineregistry.org/resources/ce-e8a41a52-6ff6-48f0-9872-889c87b093b7

Credential Registry URIs resolve via any HTTP GET request (including those from a web browser) and provide the entire record for that CTID, using JSON-LD. For example, the click on the above URI to see all of the raw JSON-LD data for an Education Design Lab Credential in the Credential Registry.


CTID (CTDL Handbook):
CTID Documentation in the CTDL Handbook
CTID (CTDL Terms):
CTID Documentation in the CTDL Terms
CTDL Identifiers:
Identifier Documentation in the CTDL Handbook
Managing CTIDs:
Recommendations for managing CTIDs with other data when publishing using the Assistant API
CTID (CTDL Terms):
CTID Documentation in the CTDL Terms
JSON Linked Data Specification
Uniform Resource Locator

Contact Us

For more information, contact Credential Engine.