Kling 4.0

# One Idempotency-Key per request, made once and sent again with every resend of it
KEY=$(uuidgen)

# 1. Submit. max_cost_usd is your cap: the most this may cost (it lists at $0.54).
#    No id after a timeout, a 429 or a 5xx? Run step 1 again: the same $KEY never makes a second one.
RESP=$(curl -s https://api.revana.si/v1/generations \
  -H "Authorization: Bearer $REVANA_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $KEY" \
  -d '{
    "model": "kling-4.0",
    "input": {
      "prompt": "A slow dolly shot through a neon-lit night market in the rain, steam rising from food stalls",
      "resolution": "720p",
      "duration": 3,
      "aspect_ratio": "16:9",
      "audio": true
    },
    "max_cost_usd": 0.81
  }')
ID=$(echo "$RESP" | jq -r '.id // empty')
echo "${ID:-no id: ${RESP:-no answer}}"

# 2. Poll it until status is "succeeded" or "failed". A failed one is free; to try it again,
#    make a new key first (KEY=$(uuidgen)): the old one answers with the failure.
curl -s https://api.revana.si/v1/generations/${ID:?no id from step 1} \
  -H "Authorization: Bearer $REVANA_API_KEY"

# 3. Download the file once it has succeeded
curl -L https://api.revana.si/v1/generations/${ID:?no id from step 1}/content \
  -H "Authorization: Bearer $REVANA_API_KEY" \
  -o out.mp4