> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/ollm/opencomic-ai-bin/llms.txt
> Use this file to discover all available pages before exploring further.

# preload

> Preload models to daemon or download models

## Signature

```typescript theme={null}
OpenComicAI.preload(
  steps: OpenComicAIOptions[],
  downloading?: Downloading | false
): Promise<void>
```

## Description

Preload models before processing images. This method serves two purposes:

1. **Download models**: Ensures all required model files are downloaded and available locally before processing begins
2. **Daemon mode**: For `upscayl` models, spawns daemon processes that keep models loaded in memory, significantly improving processing speed for multiple images

Daemons are only used with compatible models (upscayl-based models) when `OpenComicAI.setConcurrentDaemons()` is set to a value greater than 0.

## Parameters

<ParamField path="steps" type="OpenComicAIOptions[]" required>
  Array of processing steps to preload. Each step specifies a model and its parameters.

  See [OpenComicAIOptions](/api/types#opencomicaioptions) for available options.
</ParamField>

<ParamField path="downloading" type="Downloading | false">
  Optional callbacks for monitoring model download progress. Pass `false` to disable download callbacks.

  See [Downloading](/api/types#downloading) for callback options.
</ParamField>

## Returns

<ResponseField name="Promise<void>" type="void">
  Returns a promise that resolves when all models are downloaded and daemons are started (if enabled).
</ResponseField>

## Daemon mode

When daemon mode is enabled (`upscayl` models only):

* Models are loaded into memory once and kept running
* Subsequent image processing is 3-7x faster
* Multiple daemons can run concurrently for parallel processing
* Daemons automatically shut down after the configured idle timeout

See the [README performance comparison](https://github.com/ollm/opencomic-ai-bin#daemon-comparative-performance) for benchmarks.

## Examples

### Basic preload

```typescript theme={null}
import OpenComicAI from 'opencomic-ai-bin';

OpenComicAI.setModelsPath('./models');

// Download models if not available
await OpenComicAI.preload([
  {
    model: 'realcugan',
    scale: 4,
    noise: 0,
  }
]);

// Now pipeline() will run immediately without downloading
await OpenComicAI.pipeline('./input.jpg', './output.jpg', [
  {
    model: 'realcugan',
    scale: 4,
    noise: 0,
  }
]);
```

### Preload with daemon mode

```typescript theme={null}
import OpenComicAI from 'opencomic-ai-bin';

OpenComicAI.setModelsPath('./models');

// Enable daemon mode with 3 concurrent daemons
OpenComicAI.setConcurrentDaemons(3);

// Set daemon idle timeout to 60 seconds
OpenComicAI.setDaemonIdleTimeout(60000);

// Preload model and start daemon
await OpenComicAI.preload([
  {
    model: 'realesrgan-x4plus-anime',
    scale: 4,
  }
]);

// Process multiple images with daemon (much faster)
for (let i = 0; i < 100; i++) {
  await OpenComicAI.pipeline(
    `./input-${i}.jpg`,
    `./output-${i}.jpg`,
    [{ model: 'realesrgan-x4plus-anime', scale: 4 }]
  );
}

// Close daemons when done
OpenComicAI.closeAllDaemons();
```

### Preload with download tracking

```typescript theme={null}
await OpenComicAI.preload(
  [
    {
      model: '1x_halftone_patch_060000_G',
    },
    {
      model: 'realcugan',
      scale: 4,
      noise: 0,
    }
  ],
  {
    start: () => {
      console.log('Starting model download...');
    },
    progress: (progress) => {
      console.log(`Downloading: ${Math.round(progress * 100)}%`);
    },
    end: () => {
      console.log('Download complete');
    },
  }
);
```

### Preload multiple models

```typescript theme={null}
import OpenComicAI from 'opencomic-ai-bin';

OpenComicAI.setModelsPath('./models');
OpenComicAI.setConcurrentDaemons(3);

// Preload all models you'll use
await OpenComicAI.preload([
  { model: '1x_halftone_patch_060000_G' },
  { model: 'realesrgan-x4plus-anime', scale: 4 },
  { model: 'ultrasharp-4x', scale: 4 },
]);

// All models are now ready for fast processing
```

## Related

* [pipeline](/api/pipeline) - Process images with loaded models
* [setConcurrentDaemons](/api/set-concurrent-daemons) - Configure daemon mode
* [setDaemonIdleTimeout](/api/set-daemon-idle-timeout) - Set daemon timeout
* [closeAllDaemons](/api/close-all-daemons) - Stop all daemons
* [OpenComicAIOptions](/api/types#opencomicaioptions) - Available step options