Claude Opus 4.5 Built a Self-Documenting Video Entirely in Code Using AI Agents

Anthropic's Claude Opus 4.5, operating within Claude Code, produced a music video that documents its own creation process, starting from an open-source p5.js project called PDoomVideo. The core technical constraint requires every frame to be a pure function of elapsed time, eliminating randomness and state so frames can render out of order or be regenerated on demand. Narration timing was handled by syncing ElevenLabs audio timestamps to script cue words, while music beat grids were extracted from Suno exports using Whisper transcription and audio onset detection. Three subagents built separate video chapters in parallel, each working from a pre-written storyboard and animation guide, with a reviewer agent grading drafts and flagging specific errors. All intermediate artifacts — briefs, storyboard, reviewer notes, and draft frames — are preserved in the repository and appear within the video itself.