@ai-sdk/rsc/src/streamable-value/is-streamable-value.ts

[React Server Components](https://react.dev/reference/rsc/server-components) for the [AI SDK](https://ai-sdk.dev/docs):

import { STREAMABLE_VALUE_TYPE, StreamableValue } from './streamable-value';

export function isStreamableValue(value: unknown): value is StreamableValue {
  return (
    value != null &&
    typeof value === 'object' &&
    'type' in value &&
    value.type === STREAMABLE_VALUE_TYPE
  );
}