Visa Slot API Automation

I need a Python-based solution that books Indian visa appointment slots from Bangladesh by talking directly to the platform’s private or public APIs—no Selenium or headless browser tricks. The script must negotiate every step of the reservation flow, submit applicant data, pick the earliest available date/time, and confirm the booking, all while remaining resilient to site-side changes.

The site sits behind Cloudflare Turnstile. I already have a workable token-generation approach, so your code only has to integrate the token at the right moment and reuse it for subsequent calls.

Core expectations
• Clean, well-structured Python code that can run headless on a VPS or Lambda-style container.
• Functions for: session creation, authentication, slot calendar query, slot selection, form submission, and booking confirmation parsing.
• Environment file for keys, headers, and the Turnstile token injector so I can swap credentials without altering core logic.
• README with quick-start commands (pip install …, env vars, one-line run) and clear points where I plug in new passport details.

Acceptance Criteria
1. From a CLI command I pass traveller data and desired consulate; the script returns a JSON booking confirmation or a clear error string.
2. Re-run safety: duplicate submissions must be detected and suppressed.
3. All external dependencies limited to widely available PyPI libraries (requests, httpx, asyncio, etc.).

If you have prior experience reverse-engineering REST or GraphQL flows, especially on high-traffic sites protected by Cloudflare, you’ll finish this fast. Share one automation example you’ve delivered, the approach you took to map hidden endpoints, and your estimated turnaround time.