To encourage JSON object output, a developer prefills assistant con…

Question

To encourage JSON object output, a developer prefills assistant content with '{'. This technique:

Accepted Answer

Can steer format but still requires server-side JSON validation — Prefill '{' nudges JSON shape; you still parse and validate like a grown-up API.

Answer

Is guaranteed to produce valid JSON always without validation

Answer

Deletes the user message

Answer

Sets topp automatically to 0

To encourage JSON object output, a developer prefills assistant content with '{'. This technique: