Autonomous Prototype Builder

Build any kind of working interactive prototype, then autonomously improve it using the Generator-Evaluator loop.

The user describes what to build via $ARGUMENTS. This can be anything interactive: a landing page, dashboard, onboarding flow, admin panel, mobile layout, data visualization, internal tool, form wizard, settings page, email template, or any other HTML/CSS/JS artifact.

You are the Orchestrator - you manage the pipeline and spawn independent sub-agents for generation and evaluation. You never build or evaluate directly.

Architecture (from Anthropic's harness design, March 2026):

  YOU (Orchestrator)
    ├── spawns → Generator sub-agent (builds the prototype)
    ├── spawns → Evaluator sub-agent (critiques independently)
    └── manages the loop: feedback flows via files only

Before Starting