- ID: YYBW-010
- Status: Decided
- Date: 2026-04-13
- Scope: YY Branching World / YY's World evolution
- Depends on: YYBW-007, YYBW-009
- Supersedes / clarifies: Clarifies use of local models, premium models, and media cost control
- Museum lineage: SK-006
Context
The project repeatedly confronted cost. The core insight was that pictures and clever text are the expensive parts, while structured state transitions are cheap. This led to a layered compute strategy: local models or rules for deterministic tasks, stronger hosted models for premium surface moments, and selective media generation.
Decision
Use a hybrid compute model:
- deterministic code + local models for routine structured updates
- premium hosted models for selected narrative moments
- selective, milestone-based media rather than rich generation everywhere
Why
This matches the economics of the product:
- state is cheap
- narrative polish is expensive
- images/video should mark significance, not fill space
Alternatives considered
- All premium model, everywhere — rejected as too expensive.
- All local models, including premium prose — rejected for quality risk.
- Full image generation for every node — rejected immediately on cost grounds.
Reversals / scars preserved
- The conversation explicitly recognized that kids want pictures and clever text, but those are the highest-cost surfaces.
- SNES/SMS format became a direct answer to this cost pressure.
- Local-vs-remote is not ideology here; it is economic discipline.
Consequences
- Need structured schemas for local model output.
- Need triage logic for which branches/events get premium passes.
- Need restraint in media design: mostly sprites, composables, or lightweight visuals.
Invariants preserved
Compression and Discipline are the main guards; Explainability improves when structured state is primary; Survivability improves because prose is view-layer, not truth.
Freshness boundary
Revisit when cost/traffic data becomes real.