Use when a Lottie file renders incorrectly after conversion to Popkorn, when debugging or fixing the converter (lottie2popkorn) or player rendering/animation, when implementing a missing Lottie capability, or when adding/fixing a DSL property in this repo. Covers triage of conversion bugs vs player bugs vs deliberate skips, the measurement tools, and the full add-a-property checklist.
Use when authoring or editing a Popkorn scene (.css DSL for @popkorn/player) — writing shapes, keyframe animations, symbols, motion paths, masks, or interactive scenes in this repo's CSS-subset animation language.
Use when writing or rewriting any public-facing Popkorn documentation — README, docs/*.md (CONCEPT, ARCHITECTURE, DSL, state-machines, getting-started, etc.), package READMEs, or landing/marketing copy. Sets the voice, tone, and positioning for prose meant for humans discovering the project, NOT for CLAUDE.md dev-notes. Trigger whenever the task is "improve/rewrite the docs", "make this read for public consumption", "this reads like dev notes / an LLM spec", "write the intro", or any doc that a newcomer or potential user will read. Also use to sanity-check existing doc prose against the house voice before committing.
Use when asked to check whether the repo docs are stale, sync docs with recent commits, audit CLAUDE.md/README/docs against git history, or verify documentation still matches the code after a batch of changes.