What changed
Foundation Models framework, guided generation, tool calling, and app data context make model behavior part of normal app engineering.
The prototype bar drops, but prompt versions, output format, fallback behavior, and local performance become delivery concerns.
Why it matters
When a model becomes an SDK, the real differentiation is context design and acceptance criteria. Workflow signals matter when they shorten the path from demand to delivery, not merely when they add another tool name to the list.
indie developers, iOS SaaS, productivity tools, and vertical apps should use the signal to decide what must be clearer for users, buyers, or operators before the next page, workflow, or offer is shipped.
What to check
Start with one low-risk task using fixed inputs, structured outputs, and a clear failure message.
Keep the test narrow: one low-risk task or tool entry before connecting permissions, logs, failure handling, and human takeover to production.
What needs verifying
Without output checks, in-app models can turn a convincing demo into user-data or workflow errors. The original source remains linked so readers can separate the announcement from this site's interpretation.