assertPromptFileSourceSupport

function assertPromptFileSourceSupport(adapter, prompt): void;

Defined in: packages/ai/src/utilities/content-source.ts:108

Fail-closed preflight for media prompts and embedding inputs (generateImage / generateVideo / embed): throws when the input carries a { type: 'file' } source and the adapter hasn't declared supportsFileSources. Runs in the activity dispatcher — the same layer that validates modality — so an adapter that predates the file arm can never receive one. Walks a single part, an array of parts, and nested arrays (fused embedding items).