Generate the copy for a single-image creator brief from up to 3 of your products (index 0 is the hero): the kicker, signature and winning hooks, social proof, benefits, content ideas, and shop tagline.

This returns content without saving it — pass the result to POST /image-briefs to keep it as a draft. The portal streams this generation token by token; here it is collapsed into one response.

Each call spends model tokens, so Idempotency-Key is required and retries replay the first result rather than regenerating. Generation is non-deterministic — the same products give different copy each time.