Plivo supports bulk call feature in our API. Please use the below API to make bulk calls.
The auth_id can be procured from your dashboard https://console.plivo.com/dashboard/
There are three mandatory requirements that must be met to make an outbound call
The phone number can be used as the caller id (with the country code).For example, a USA caller id number could be, 15677654321, where '1' is the country code.
Use the regular number(s) or sip endpoint(s) to call.
Regular number must be prefixed with country code but without the + sign.
Using REST API:
Multiple numbers can be sent by using a delimiter.
To make bulk calls please use the delimiter “<”
For Example, 15677654321<12077657621<12047657621..1
Regular number and SIP endpoints can be together to in a bulk call
For example, 5677654321<15673464321<sip: email@example.com
Every language has its own defined syntax to use for Bulk Calling.
The URL invoked by Plivo when the outbound call is answered.
To add additional options on the API, please refer https://www.plivo.com/docs/api/call/#arguments