How to specify a system instruction to gemini models?

[H1Mohamed]

As of what I know, google gemini models allow you to specify system instructions to guide the ai on how it should answer questions and how the tone should be, so I've wondered on how to specify it and other settings of the gemini models like json responses

if possible can you give me an example with the sveltekit api route

[lgrammel]

https://sdk.vercel.ai/docs/foundations/prompts#system-prompts (or system msgs)