Render Python

Stream NDJSON events as each slide completes.

Response is application/x-ndjson — one JSON object per line. Event types:

{"event": "started", "total": N} {"event": "slide_done", "completed": K, "total": N, "preview": {...}} {"event": "stitching"} {"event": "complete", "project_id": ..., "stitched_pptx_url": ..., "slide_previews": [...], "total_credits_charged": int, "total_slides": int, "total_duration_ms": int} {"event": "error", "status": int, "error": str} # fatal — no further events

Frontend consumes per-line so the UI can show "5/9 done" etc. before the full batch finishes (some slides take 60s+ when audit retries fire).

Errors that abort the whole request emit a single error event then end the stream. Per-slide failures emit a slide_done with status="failed" and the stream continues.