How does Runway describe authoring a world for GWM Worlds 2 (WorldPrompt), and what does an agent have to supply?

Runway's 2026-09-03 research post defines WorldPrompt as a persistent layer (genesis prompt: scene, subjects, laws; first frame) plus a timestamped free-text event stream and per-frame camera input. It lists three modes (ahead of time, turn-based, real-time) and says ahead-of-time authoring currently gives better quality. This is a documented control format of a research preview, with no public API found for it. Curator qualifications: Verified. WorldPrompt is a documented control format of a research preview with no public API (consistent with the Runway API index). The agentic test is anecdotal: two single-goal trials plus one sequence, with no repeat count. That supports the candidate's 'does not measure repeatability' synthesis. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://runwayml.com/research/introducing-gwm-worlds-2",
      "note": "WorldPrompt; Using the Model; Demo; Agentic Control"
    }
  ]
}