Input

session.input delivers the physical controls on the glasses: button presses and touchpad gestures. The starter scaffold wires a button press to the display, so a short press shows a text wall.

src/background/index.ts

import { registerMiniapp } from "@mentra/miniapp/background";

registerMiniapp((session) => {
  session.input.onButtonPress((press) => {
    session.display.render([{type: "text", id: "msg", box: {x: 0, y: 0, w: 576, h: 288}, text: `${press.buttonId}: ${press.pressType}`}]);
  });
});

Button events only reach glasses that have a button. Declare a BUTTON hardware requirement in your manifest to gate the miniapp to those glasses.

Button presses

onButtonPress fires on every press of a physical button:

session.input.onButtonPress((press) => {
  if (press.pressType === "long") session.display.render([]);
});

Each ButtonPressData has:

Field	Type	Notes
`buttonId`	`string`	Which button fired.
`pressType`	`"short" \| "long"`	Press duration.

Touch gestures

onTouch subscribes to touchpad gestures. Pass a handler for every gesture, a single gesture name to filter, or an array of names for one subscription across several gestures.

// Every touch gesture.
session.input.onTouch((touch) => {
  session.display.render([{type: "text", id: "msg", box: {x: 0, y: 0, w: 576, h: 288}, text: touch.kind}]);
});

// One gesture.
session.input.onTouch("single_tap", () => {
  session.display.render([{type: "text", id: "msg", box: {x: 0, y: 0, w: 576, h: 288}, text: "Tap"}]);
});

// Several gestures, one subscription.
session.input.onTouch(["swipe_up", "swipe_down"], (touch) => {
  // touch.kind tells you which one.
});

Each TouchData has:

Field	Type	Notes
`kind`	`string`	The gesture. See the values below.

The gesture values the runtime reports:

`kind`	Gesture
`"single_tap"`	A single tap on the touchpad.
`"double_tap"`	Two quick taps.
`"triple_tap"`	Three quick taps.
`"long_press"`	A press and hold.
`"swipe_up"`	A swipe up.
`"swipe_down"`	A swipe down.

Glasses can send other kind strings, so kind is typed as string. Match the values you handle and ignore the rest.

Cleaning up

onButtonPress and every onTouch form return an unsubscribe function:

const off = session.input.onTouch("single_tap", handler);
off(); // stop listening

Calling onTouch with an array returns one unsubscribe function that drops all of the gestures it registered.

Getting Started

Core Concepts

UI Layer

Display

Audio & Speech

Sensors & Input

Camera

Phone & System

Data

Reference

Button presses

Touch gestures

Cleaning up

​Button presses

​Touch gestures

​Cleaning up

Button presses

Touch gestures

Cleaning up