I need production-ready API modules that allow our in-house video generator to automatically publish finished clips to all our major social channels, including Instagram, LinkedIn, X/Twitter, and YouTube. The goal is to integrate seamless content posting directly from our website. Core Goals • Accept a pre-rendered MP4 from our service and publish it with a single call • Attach captions/subtitles when supplied • Respect each platform’s OAuth2 flow, and automatically store and refresh tokens • Return clear success/error payloads so our workflow can determine next steps Tech Context Our back end is Node.js with TypeScript, and we use Cloudinary for media storage. FFmpeg processes are handled in a Python FastAPI service. Acceptance Criteria 1. A self-contained module for each platform (Instagram Reels, Facebook Pages, LinkedIn Pages, X, YouTube) exposing `publishVideo()`, `refreshAuth()`, and `getStatus()` methods 2. An end-to-end demo script that uploads a sample video to each destination using sandbox/test accounts we provide 3. A README covering environment variables, rate-limit handling, and recovery strategies for failed uploads 4. Clean, well-commented code pushed to our private Git repo, plus a short Loom walkthrough