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Pricing: $0.2419/second. Endpoint: POST /v1/models/bytedance/seedance/2.0/fast/text-to-video/runs.
Fast variant of Seedance 2.0 for quicker text-to-video generation with synchronized audio support.

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Overview

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Pricing

  • Base price: $0.2419/second
  • Note: Per second (720p)

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Seedance 2.0 Fast Text to Video API

Endpoint: POST /v1/models/bytedance/seedance/2.0/fast/text-to-video/runs

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Run the model

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Python

import requests

response = requests.post(
    "https://api.runflow.io/v1/models/bytedance/seedance/2.0/fast/text-to-video/runs",
    headers={"Authorization": "Bearer RUNFLOW_API_KEY"},
    json={
        "input": {
            "prompt": "A barista pours steaming latte art into a ceramic cup, close-up of milk swirling into a perfect rosetta pattern, espresso machine hissing, soft morning light through window"
        },
        "callback_url": "https://your-server.com/webhook"
    },
)

data = response.json()
print(data)

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Node.js

const response = await fetch(
  "https://api.runflow.io/v1/models/bytedance/seedance/2.0/fast/text-to-video/runs",
  {
    method: "POST",
    headers: {
      "Authorization": "Bearer RUNFLOW_API_KEY",
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
        "input": {
            "prompt": "A barista pours steaming latte art into a ceramic cup, close-up of milk swirling into a perfect rosetta pattern, espresso machine hissing, soft morning light through window"
        },
        "callback_url": "https://your-server.com/webhook"
    }),
  }
);

const data = await response.json();
console.log(data);

​
cURL

curl -X POST https://api.runflow.io/v1/models/bytedance/seedance/2.0/fast/text-to-video/runs \
  -H "Authorization: Bearer $RUNFLOW_API_KEY" \
  -H "Content-Type: application/json" \
  --data-binary @- <<'JSON'
{
    "input": {
        "prompt": "A barista pours steaming latte art into a ceramic cup, close-up of milk swirling into a perfect rosetta pattern, espresso machine hissing, soft morning light through window"
    },
    "callback_url": "https://your-server.com/webhook"
}
JSON

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Request parameters

ParameterTypeRequiredDescription
inputobjectrequiredModel input parameters. See “Input schema” below.
callback_urlstring | nulloptionalWebhook URL - POSTed when the run reaches a terminal state.
metadataobject | nulloptionalArbitrary key-value pairs attached to the run.

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Input schema

FieldTypeRequiredAllowed valuesDescription
promptstringrequiredAnyThe text prompt used to generate the video
aspect_ratiostringoptionalauto, 21:9, 16:9, 4:3, 1:1, 3:4, 9:16The aspect ratio of the generated video.
durationstringoptionalauto, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15Duration of the video in seconds. Supports 4 to 15 seconds, or auto.
resolutionstringoptional480p, 720pVideo resolution - 480p for faster generation, 720p for balance.
generate_audiobooleanoptionalAnyWhether to generate synchronized audio for the video.
seedintegeroptionalAnyRandom seed for reproducibility.
end_user_idstringoptionalAnyThe unique user ID of the end user.

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Output schema

FieldTypeDescription
outputsjsonUnified output array - one entry per generated artifact with url/type/width/height/duration/etc.
seedjsonThe seed used for generation.
nsfw_detectedjsontrue if the provider flagged output as NSFW, false if cleared, null if not checked.
timingjsonProvider timing info (inference_ms etc.), or null.

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Callback payload

When you provide a callback_url, Runflow POSTs to it once the run reaches a terminal state.
FieldTypeDescription
eventstringEvent type: “run.completed”, “run.failed”, or “run.cancelled”.
run_idstringThe unique identifier of the run.
statusstringTerminal status: “succeeded”, “failed”, or “cancelled”.
outputobject | nullThe run output. Null if the run failed or was cancelled.
duration_msnumber | nullTotal run duration in milliseconds.
created_atstring | nullISO 8601 timestamp when the run was created.
completed_atstring | nullISO 8601 timestamp when the run reached terminal state.
metadataobject | nullThe metadata object passed at run creation, if any.
  • Retries: 3 attempts with exponential backoff (1s, 2s). Retries on 5xx / network errors only.
  • Headers: Runflow-Request-Id is always sent. Runflow-Signature is sent if a signing secret is configured.

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Additional Resources

Browse all models

Browse the catalog.

Run lifecycle

Callbacks, polling, statuses.

Callbacks

Handle async results.

Pricing

How requests bill out.