n8n / Telegram / OpenAI: autoposting with manual approval gate

Self-initiated sandbox workflow demo. No credentials and no live posting. Collected a secure demonstration pipeline: webhook → payload normalization → OpenAI draft → human approval → Telegram adapter. The live UI only runs a mock trace and does not call external APIs. An importable n8n JSON without keys has been added to the case; the workflow is inactive by default and contains configuration points, retries, budget/rate limits, and a separate warning regarding the availability of the Meta/TikTok API. Stack: n8n, webhook, OpenAI Responses API integration pattern, Telegram Bot API pattern, human-in-the-loop.