Kling 4.0 Flash
The fast, low-cost Kling 4.0: 3 to 20 seconds at 720p, always with sound, from text, a first frame, or up to 10 reference images.
Pricing per second of video
| Resolution | Per second |
|---|---|
| 720p | $0.1010 credits |
Billed in credits per second of video (100 credits = $1, rounded up to a whole credit). Charged once, only for the route that succeeds. Failed attempts cost $0.00.
Request
# One Idempotency-Key per request, made once and sent again with every resend of it
KEY=$(uuidgen)
# 1. Submit. max_cost_usd is your cap: the most this may cost (it lists at $0.30).
# 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: $KEY" \
-d '{
"model": "kling-4.0-flash",
"input": {
"prompt": "A slow dolly shot through a neon-lit night market in the rain, steam rising from food stalls",
"resolution": "720p",
"duration": 3,
"aspect_ratio": "16:9",
"audio": true
},
"max_cost_usd": 0.45
}')
ID=$(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.mp4Set REVANA_API_KEY to your key. Full reference in the quickstart.
Options
kling-4.0-flash2 routes
Every request starts on the cheapest route. If it fails, the job moves to the next one automatically.
About the Kling 4.0 Flash API
How much does the Kling 4.0 Flash API cost?
Kling 4.0 Flash costs $0.10 per second of video on Revana. You pay in prepaid credits, 100 credits to the dollar, with no subscription or monthly minimum. A generation that fails costs nothing.
How do I call Kling 4.0 Flash from code?
Send POST https://api.revana.si/v1/generations with {"model": "kling-4.0-flash", "input": {...}} and your Revana API key as a Bearer token, poll GET /v1/generations/{id} until it succeeds, then download GET /v1/generations/{id}/content. Every model on Revana takes the same request shape.
What happens if a Kling 4.0 Flash generation fails?
Revana has 2 routes for Kling 4.0 Flash. A job starts on the cheapest and moves to the next automatically if one fails. You are charged once, only for the route that delivers. A failed generation costs $0.00.
What can Kling 4.0 Flash do on Revana?
Kling 4.0 Flash supports text to video, image to video and reference to video, resolutions 720p, durations 3 to 20 seconds, aspect ratios 16:9, 9:16, 1:1, 21:9, generated audio and up to 10 input images. A value it does not offer is refused with 422 before anything is charged.
Can my AI agent use Kling 4.0 Flash?
Yes. Connect the Revana MCP server (https://revana.si/api/mcp) to Claude, ChatGPT, Cursor or Codex, or have the agent call the REST API. The agent can list models, get a free quote and generate on your credits.
Compare with similar models
- Kling 4.0 Kuaishou, from $0.08 per second of video
- Kling 3.0 Kuaishou, from $0.09 per second of video
- Kling 2.6 Pro Kuaishou, from $0.07 per second of video
- Kling 2.1 Master Kuaishou, from $0.20 per second of video
- Kling 2.1 Pro Kuaishou, from $0.07 per second of video
- Kling 2.1 Standard Kuaishou, from $0.04 per second of video
Also as markdown for agents. Every model and price: models.json.