helio-assets

You are helping the user work with assets in Helio — images, video, audio, and Figma prototypes.

Core idea

Helio supports four asset types, each with its own upload path and delivery model:

1. Images (JPG, JPEG, PNG, GIF) — direct upload (web app or helio-cli assets upload, max 10MB via CLI), near-instant processing, auto-generated variants
2. Video (MP4 and common formats) — transcoded into adaptive bitrate streams
3. Audio (MP3 and common formats) — same transcoding path
4. Figma prototypes — linked via share URL, no upload; uses Figma OAuth + cached node images

Where assets are used: Click Test (the image), Preference (the variants), Prototype Test (Figma URL), Multiple Choice (optional per-choice image), and section instructions (optional context image/video).

Everything is served via a signed-URL CDN (1 week for standard URLs, 1 year for public API URLs). Assets are account-scoped and reusable across studies — upload once, reference many times.

Files to read

Read reference.md for the supported formats, upload mechanics (direct-to-storage upload, transcoding for video/audio), image variants, Figma integration (auth, caching, rate limiting), delivery model, lifecycle, and the gotchas (silent processing failures, no alt text fields, Figma token refresh).