Simple Straddle Trading Automation

I need a lightweight, production-ready script that can place and manage a basic straddle on my Upstox, Fyers, and Shoonya accounts. The logic is straightforward: pick the closest premium strike, enter the ATM straddle, apply a fixed-amount stop-loss on each leg (no trailing), and square off every open position automatically at 3:15 p.m. IST.

Connectivity
• The tool must talk to all three brokers’ REST/WebSocket APIs.
• I should be able to fire the same trade on every account at once or pick any single account, so please build the “simultaneous vs. separate” toggle into the config file or UI.

Runtime environment
I already have an Oracle Cloud free-tier VPS and prefer the solution to run there headless. If you lean on Python, Node.js, or Go that’s fine—just keep the footprint light enough for the free tier. Cron, systemd, or Docker are all acceptable for scheduling.

Deliverables
1. Clean, well-commented source code with README.
2. Setup script or Dockerfile that lets me deploy in one step on a fresh VPS.
3. Parameter file where I can enter: API keys, lot size, fixed SL value, and enable/disable each broker.
4. Logging to a local file plus optional Telegram/e-mail alert on order fills and stop-loss hits.
5. Quick hand-off call or document outlining how to change strikes or add up to three more similar strategies in future.

Please quote for the entire package and list any extras I might need (paid APIs, exchange approvals, etc.) so there are no surprises later.