Feature Request: Add XTS REST API Brokerage Integration for Indian Brokers

[rishabhv2003]

Description

Implement XTS API as a new Lean brokerage plugin.

Motivation and Context

All major Indian brokers provide algorithmic trading access through XTS REST APIs. Implementing this new brokerage will extend Lean’s brokerage ecosystem by enabling seamless integration with Indian markets, allowing users to deploy, test, and run algorithmic strategies using widely adopted broker infrastructure.