# Flux 3 extend video

Needs prompt and video url. Served by fal.ai.

Flux 3 Extend Video, served by fal.ai. The OpenAPI schema for the blackforestlabs/flux-3/extend-video queue. Price: Your request will be charged at 0.41 $ per second of generated video at 720p, and 0.53 $ per second at 1080p. Queued execution; final USD charge comes from the unique billing event matching this exact endpoint and request_id. A missing receipt retains the reservation; no guessed final fee. Asynchronous: returns a request_id; poll fal/status and fetch fal/result with model "blackforestlabs/flux-3" and that request_id. Billed once, when the result is ready; a generation that fails is refunded.

- Tool ID: `fal/blackforestlabs-flux-3-extend-video`
- Name in the catalog: Flux 3 Extend Video
- Provider: [fal.ai](/providers/fal.md)
- Capability: [AI video generation](/tools/video-generation.md)
- Price: usage based, the maximum is shown before a run
- Authentication: an authorised Agentik workspace is required for execution, including zero-price tools.

## Pricing contract

The provider’s price, with no markup. Billed for measured usage.


```json
{
  "model": "per_unit",
  "amountUsd": 0.53,
  "unitsField": "duration",
  "unitsDefault": 5,
  "maxUnits": 20,
  "fractional": true,
  "multipliers": [
    {
      "when": {
        "field": "resolution",
        "equals": "720p"
      },
      "setUsd": 0.41
    },
    {
      "when": {
        "field": "resolution",
        "equals": "1080p"
      },
      "setUsd": 0.53
    }
  ]
}
```

Pricing source: [https://fal.ai/models/blackforestlabs/flux-3/extend-video](https://fal.ai/models/blackforestlabs/flux-3/extend-video). Your request will be charged at 0.41 $ per second of generated video at 720p, and 0.53 $ per second at 1080p. Queued execution; final USD charge comes from the unique billing event matching this exact endpoint and request_id. A missing receipt retains the reservation; no guessed final fee..

Price verification date: 2026-10-07.

## Complete input schema


```json
{
  "type": "object",
  "properties": {
    "aspect_ratio": {
      "type": "string",
      "title": "Aspect Ratio",
      "description": "Aspect ratio of the generated video. `auto` lets the model choose.",
      "enum": [
        "auto",
        "21:9",
        "2:1",
        "16:9",
        "4:3",
        "1:1",
        "3:4",
        "9:16"
      ],
      "default": "auto"
    },
    "duration": {
      "enum": [
        5,
        6,
        7,
        8,
        9,
        10,
        11,
        12,
        13,
        14,
        15,
        16,
        17,
        18,
        19,
        20
      ],
      "description": "Duration of the generated video in seconds. `auto` lets the model choose.",
      "title": "Duration",
      "type": "integer",
      "default": 5
    },
    "resolution": {
      "type": "string",
      "description": "Resolution of the generated video.",
      "title": "Resolution",
      "enum": [
        "720p",
        "1080p"
      ],
      "default": "720p"
    },
    "prompt": {
      "type": "string",
      "title": "Prompt",
      "description": "The text prompt describing how the video continues from the source clip's final frames."
    },
    "safety_tolerance": {
      "type": "integer",
      "title": "Safety Tolerance",
      "description": "The safety tolerance level for the generated video. 0 is the strictest and 4 is the most permissive.",
      "maximum": 4,
      "default": 2,
      "minimum": 0
    },
    "generate_audio": {
      "type": "boolean",
      "title": "Generate Audio",
      "description": "Whether to generate audio for the video.",
      "default": true
    },
    "video_url": {
      "type": "string",
      "description": "URL of the input video. MP4, under 50 MB and under 15 seconds.",
      "title": "Video URL"
    }
  },
  "required": [
    "prompt",
    "video_url"
  ],
  "additionalProperties": false
}
```

## Published example

This is the provider tool’s published example. Replace example values with the user’s requested inputs, respecting the schema; do not execute an example merely to test a connection.


```json
{
  "tool_id": "fal/blackforestlabs-flux-3-extend-video",
  "input": {
    "prompt": "The camera keeps tracking as the subject turns and smiles.",
    "video_url": "https://storage.googleapis.com/falserverless/example_inputs/flux-3-red-panda.mp4"
  }
}
```

## Execute and retrieve

Inspect again before execution, explain the price and obtain the required authority. Use MCP run_tool or POST /v1/run with this tool ID, valid input and an idempotency key. Save the returned run ID and follow the actual state. If Agentik answers that the tool is temporarily unavailable, do not retry it blindly; use discovery to propose an alternative.

This tool uses deferred settlement. Follow its returned task/run instructions; preserve the existing reservation until the result is reconciled.

A partial or uncertain result can still have consumed provider resources. Consult [billing](/docs/billing.md), [idempotency](/docs/idempotency.md) and [asynchronous results](/docs/async.md).

[Provider documentation](https://fal.ai/models/blackforestlabs/flux-3/extend-video)

[REST inspection](https://api.agentik.cc/v1/tools/fal/blackforestlabs-flux-3-extend-video) · [OpenAPI](/openapi.json) · [Connection guide](/connect.md)

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[HTML page](/providers/fal/blackforestlabs-flux-3-extend-video) · [Agent index](/llms.txt)