Control Types

Volta supports several control types. Each has different value semantics when sending actions via POST /action.

Button

A simple trigger. No value needed.

{
  "layoutId": "abc123",
  "lid": 1,
  "type": "Button"
}

Buttons are cumulative — each press increments an internal counter. The output receives both the count and a normalised 0–1 value.

Slider

A continuous value between 0 and 1.

{
  "layoutId": "abc123",
  "lid": 2,
  "type": "Slider",
  "value": 0.75
}

Tip

Debounce slider updates to ~10-20 per second for smooth performance without overloading the API.

Toggle

A boolean on/off switch.

{
  "layoutId": "abc123",
  "lid": 3,
  "type": "Toggle",
  "value": true
}

Index

A selector with multiple options. The value is a zero-based integer.

{
  "layoutId": "abc123",
  "lid": 4,
  "type": "Index",
  "value": 2
}

Index controls power several templates:

• Stickers — each index selects a different sticker image
• Multiple Choice — each index is a vote for a different option

The GET /layout/{layoutId} endpoint returns an options array for Index controls, containing labels and (for stickers) image URLs:

{
  "lid": 4,
  "type": "Index",
  "options": [
    { "index": 0, "label": "Sticker 1", "image": "https://..." },
    { "index": 1, "label": "Sticker 2", "image": "https://..." }
  ]
}

String

A free-text input.

{
  "layoutId": "abc123",
  "lid": 5,
  "type": "String",
  "value": "Hello from the crowd!"
}

XYPad

A 2D position input. Value is an array of two floats, each between 0 and 1.

{
  "layoutId": "abc123",
  "lid": 6,
  "type": "XYPad",
  "value": [0.5, 0.3]
}