Read text using voicevox

// ==UserScript==
// @name        Read Everything
// @namespace   Violentmonkey Scripts
// @include     *
// @grant       none
// @version     1.0
// @author      -
// ==/UserScript==

// requires voicevox to be running, eg
// C:\Users\<youruser>\AppData\Local\Programs\VOICEVOX\run.exe --host localhost --cors_policy_mod all

const host = 'http://localhost:50021'
const speaker = 0

document.body.addEventListener("keydown", (e) => {
  if (!(e.shiftKey && e.altKey)) return
  const text = getSelectionText()
  if (!text) return
  play(text)
})

const play = async (text) => {
  const audioQuery = await fetch(`${host}/audio_query?text=${text}&speaker=${speaker}`, {
    "method": "POST"
  })
  const meta = await audioQuery.json()

  const maybeWav = await fetch(`${host}/synthesis?speaker=${speaker}`, {
    "headers": {
      "content-type": "application/json",
    },
    "body": JSON.stringify(meta),
    "method": "POST",
  })
  const buffer = await maybeWav.arrayBuffer()
  const audioContext = new(window.AudioContext || window.webkitAudioContext)()
  const decodedAudio = await audioContext.decodeAudioData(buffer)
  const gain = audioContext.createGain()
  gain.connect(audioContext.destination)
  const playSound = audioContext.createBufferSource()
  playSound.buffer = decodedAudio
  playSound.connect(gain)
  playSound.start(0)
}

const getSelectionText = () => {
  let text = ""
  if (window.getSelection) {
    text = window.getSelection().toString()
  } else if (document.selection && document.selection.type != "Control") {
    text = document.selection.createRange().text
  }
  return text;
}