SvelteKit has something like this to facilitate loading data where some of the values are Promises. I don't think the format is documented for external consumpt

SvelteKit has something like this to facilitate loading data where some of the values are Promises. I don't think the format is documented for external consumption, but it basically does this: placeholders for values where the JSON value at that point is still loading, replaced by streaming the results as they complete. https://svelte.dev/docs/kit/load#Streaming-with-promises https://svelte.dev/docs/kit/load#Streaming-with-promises