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The nx:genai function calls an external AI media generation provider during the render pipeline and injects the result into a specified layer before After Effects starts compositing. This lets you combine AI-generated content with your AE templates in a single job - no manual steps, no intermediate storage wrangling. The provider is called at render time, so the generated asset is always fresh and unique to each job.

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Parameters

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provider
string
required
The AI provider to call. Currently supported: fal
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key
string
required
API key for the provider. Use a secret reference to avoid embedding credentials directly - e.g. ${secret.FAL_KEY}
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model
string
required
The model identifier on the provider’s platform. The exact value depends on which model you want to use - refer to your provider’s model library for available options.
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type
string
required
Output type: video or image. Determines how the result is injected into the layer.
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layerName
string
required
The footage layer in your After Effects composition where the generated asset will be placed.
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data
object
required
Model-specific parameters passed directly to the provider’s API. The shape of this object varies by model - refer to your provider’s documentation for the full list of available fields.

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Example

The following example uses FAL.AI to generate a talking-head video of a character speaking a provided script, then injects it into a footage layer: 
{
  "type": "function",
  "name": "nx:genai",
  "params": {
    "provider": "fal",
    "key": "${secret.FAL_KEY}",
    "model": "infinitalk/single-text",
    "type": "video",
    "layerName": "var_video",
    "data": {
      "image_url": "https://example.com/character.jpg",
      "text_input": "A Victorian inventor journeys to the distant future, encountering the peaceful Eloi and the subterranean Morlocks.",
      "voice": "Eric",
      "prompt": "A young man with a beard records audio with a microphone. He appears engaged and expressive, suggesting a podcast or voiceover.",
      "num_frames": 721,
      "resolution": "720p",
      "acceleration": "high"
    }
  }
}
The data fields here are specific to the infinitalk/single-text model - a different model would expect a different set of parameters. Always consult the model’s documentation on the provider platform for the exact payload shape.

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Adaptive Composition Duration

Since AI-generated videos have variable lengths, use nx:layer-duration-set immediately after nx:genai in your assets array to automatically adjust the layer and composition duration to match the generated output: 
{
  "type": "function",
  "name": "nx:layer-duration-set",
  "params": {
    "layerName": "var_video"
  }
}

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Storing Your Provider Key as a Secret

Never embed provider API keys directly in a job payload. Store them as Nexrender secrets and reference them with the ${secret.NAME} syntax - see Secrets Management for details.