Is the `guidanceScale` parameter used when generating images? And what's the range?

Gemini API
,
1

Does anyone know if the guidanceScale parameter is used when making calls via the API?

    const response = await ai.models.generateImages({
      model: 'imagen-3.0-generate-002',
      prompt,
      config: {
        numberOfImages: 1,
        guidanceScale: 1
        aspectRatio: '1:1',
        outputMimeType: 'image/png'
      },
    });

I can see it defined here: js-genai/src/types.ts at main · googleapis/js-genai · GitHub

But there is no documentation for it, so I’m not sure what the range is. Is it -4 to 4? Is it 0 to 1? Maybe 1 to 100? I’ve tried a lot of generations with varying scales but it doesn’t seem to impact the generations that much.

On a similar note, a range in the docs for what the seed value can be would be super handy!