speak.js

#!/usr/bin/env node

const fs = require('fs');
const { spawn } = require('child_process');

const TTS_API_BASE_URL = process.env.TTS_API_BASE_URL || 'https://api.openai.com/v1';
const TTS_API_KEY = process.env.TTS_API_KEY || process.env.OPENAI_API_KEY;
const TTS_MODEL = process.env.TTS_MODEL;
const TTS_VOICE = process.env.TTS_VOICE;
const TTS_LANG = process.env.TTS_LANG;

const TTS_AUDIO_FORMAT = process.env.TTS_AUDIO_FORMAT || 'mp3'
const TTS_DEBUG = process.env.TTS_DEBUG;


const speak = async (input) => {
    const model = TTS_MODEL || 'kokoro';
    const voice = TTS_VOICE || 'af_bella';
    const format = TTS_AUDIO_FORMAT;
    const lang = TTS_LANG;
    const response_format = format;
    const speed = 1.0;

    const body = { input, model, voice, format, response_format, speed, lang };
    const auth = (TTS_API_KEY) ? { 'Authorization': `Bearer ${TTS_API_KEY}` } : {};

    const url = `${TTS_API_BASE_URL}/audio/speech`;

    try {
        const timestamp = Date.now();
        TTS_DEBUG && console.log(`Generating audio from text: ${input.length} characters...`)
        const response = await fetch(url, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json', ...auth },
            body: JSON.stringify(body),
        });
        if (!response.ok) {
            throw new Error(`HTTP error with the status: ${response.status} ${response.statusText}`);
        }
        const buffer = await response.arrayBuffer();
        const elapsed = Date.now() - timestamp;
        TTS_DEBUG && console.log(`Audio generation took ${elapsed} ms.`);
        return buffer;
    } catch (e) {
        TTS_DEBUG && console.error(`Error`, e);
        throw e;
    }
};

(async () => {
    const args = process.argv.slice(2);
    let input = args.join(' ');
    if (input.trim().length <= 0) {
        const chunks = [];
        for await (const chunk of process.stdin) {
            chunks.push(chunk);
        }
        input = Buffer.concat(chunks).toString('utf8').trim();
    }

    if (input.trim().length <= 0) {
        console.log('Usage:');
        consolel.log()
        console.log('/speak.js "How are you?"');
        console.log('echo "Good morning" | ./speak.js');
        process.exit(1);
    }

    const filename = `${(new Date()).toISOString().slice(0, 16).replace(/[-:T]/g, '')}.${TTS_AUDIO_FORMAT}`;
    const buffer = await speak(input);
    fs.writeFileSync(filename, Buffer.from(buffer));
    TTS_DEBUG && console.log(`Saved ${buffer.byteLength} bytes to ${filename}`);

    const speaker = spawn('play', [filename]);
    speaker.on('error', (err) => {
        console.error(`Failed to play audio: ${err.message}`);
    });
})();