Authentication with the Value Set Authority Center (VSAC) SVS API
The VSAC API allows users and computer
programs to retrieve value set content and
metadata using the IHE Sharing Value Sets XML format.
You will need a UMLS Terminology Services
(UTS) account to use the VSAC SVS API.
You can either hard code API calls into your
computer program, or you can use various API applications.
The VSAC API offers a REST service to obtain
CAS Ticket Granting Tickets, or TGTs, and
Service Tickets, or STs.
In order to make API calls to the VSAC, do the following:
First, obtain a TGT using your UMLS
username and password by making a POST
request to https://vsac.nlm.nih.gov/vsac/ws/Ticket
This TGT is valid for 8 hours and it can be re-used to
make API calls to obtain single-use
Service Tickets that are necessary for each VSAC API call.
Second, obtain a single-use Service Ticket.
Use your TGT to make a POST request to
https://vsac.nlm.nih.gov/vsac/ws/Ticket/.
Specify the URL
http://umlsks.nlm.nih.gov
as the service in the POST request.
Each service ticket is good for 5 minutes but
expires after one call.
This concludes our tutorial.
For additional information on VSAC REST API,
go to the VSAC home page, click on the Help button and then
navigate to the VSAC API section under How to Use VSAC.
You can also send us your questions by clicking on the
Contact VSAC link on the upper right.
Thank you for watching!