Post Writer

I built post-writer because cross-posting one formula to five platforms and grading every copy by likes measures the wrong number. X ranks replies and bookmarks. Threads ranks your reply-to-like ratio and lifts creator self-replies by 42%. Instagram ranks saves. LinkedIn ranks dwell and comments. So the structure and the call-to-action change per platform, because the KPI changes per platform. It is guidance-only: your agent reads SKILL.md, loads the recipe for the platform you named, installs matching exemplars from 74 metric-bearing real posts, and writes the post with its own model. Then five scripts grade it and exit 1 with printed numbers if it fails. The rule I did not expect to write is no-mechanics-mode — the all-time most-liked posts carry no hook, no CTA and no framework, so for emotional or reactive posts the skill switches its own machinery off. Composes with voice-builder, hook-generator and copy-engine.