SINGLE_USER or MULTI_USER.
This is an integration configuration choice, not an authentication method. It determines how your partner credentials relate to Meridian users and whether X-Meridian-User-Id is required on partner-authenticated requests.
Integration types at a glance
Exact request rules
The Meridian Accounts API applies these rules to partner-key requests:MULTI_USER: sendX-Meridian-User-Idto identify which Meridian user the request targetsSINGLE_USER: omitX-Meridian-User-Id; Meridian uses the single configured user for that partner key
How this affects token creation
When you callPOST /v1/auth/token, the integration type changes how Meridian determines the user:
SINGLE_USER: Meridian derives the user from the partner key configuration, soX-Meridian-User-Idmust not be sentMULTI_USER: your request must identify the target user withX-Meridian-User-Id
MULTI_USER also allows you to create or look up Meridian users and then mint access tokens for the correct user in the selected programId.
How this affects onboarding
SINGLE_USER and MULTI_USER do not change the program enrollment lifecycle, but they do change how you identify the user entering that lifecycle:
SINGLE_USER: onboarding operates on the one Meridian user already tied to the partner configurationMULTI_USER: onboarding operates on the specific Meridian user identified byX-Meridian-User-Id
MULTI_USER integrations, you should keep your own mapping between customer records, externalId, and Meridian userId. Persist the returned userId when the user is first created so later token requests can reuse that mapping.