Google Speech Recognition with API key + google-auth-library

testApiKeyAndGoogleAuthLibrary.js

const fs = require('fs');
const { auth } = require('google-auth-library');

const API_KEY = 'ADD YOUR API KEY HERE';
const fileName = './audio.raw';

// Reads a local audio file and converts it to base64
const file = fs.readFileSync(fileName);
const audioBytes = file.toString('base64');

// The audio file's encoding, sample rate in hertz, and BCP-47 language code
const audio = {
  content: audioBytes,
};
const config = {
  encoding: 'LINEAR16',
  sampleRateHertz: 16000,
  languageCode: 'en-US',
};
const request = {
  audio: audio,
  config: config
};

const client = auth.fromAPIKey(API_KEY);
const url = 'https://speech.googleapis.com/v1/speech:recognize';

client.request({
  url,
  method: 'POST',
  data: request
})
.then(response => {
  const transcription = response.data.results
    .map(result => result.alternatives[0].transcript)
    .join('\n');
  console.log(`Transcription: ${transcription}`);
})
.catch(err => {
  console.log('err :', err);
});