https://<your_api_key>:<your_api_token><subdomain>/v2/accounts/<your_sid>/lists/<listSid>/contacts Copy
This API allows you to add contacts within an already created list. The contacts should already exists in Campaigns or should be created using Create Contacts API.
This is a bulk API which supports maximum of 5000 contacts in one request.
ListSid
Mention contactsids you want to add to the list
“contact references”: [
“contact_sid”: <value>
“contact_sid”:<value>….
]