The Lookup endpoint can be used to perform exact matching on hashed PII strings (including email addresses).
If there is a maintained record associated with the input string or ID, the maintained RampID is returned.
If a maintained record is not associated with the input string or ID, a derived RampID is returned.
All calls to the Lookup endpoint must be structured as batch request calls. Make a POST call to "https://us.identity.api.liveramp.com/v1/batch/lookup" and pass in a JSON array of URL strings that start with "/people/" and that contain the appropriate body parameters. You can pass in up to 1000 URL strings in a single batch call.
See The Lookup Endpoint for more information.