Sprachanwendungen mit ElevenLabs und Twilio bauen

If you’ve ever wanted to give your users a truly human‑like voice experience—whether it’s a customer‑support bot, an interactive story, or a language‑learning assistant—two services together can do the heavy lifting for you:

When you pair ElevenLabs’ high‑quality audio generation with Twilio’s call routing, you can spin up voice‑first applications in minutes instead of weeks. Below is a practical walkthrough that shows how to generate speech on the fly and pipe it straight into a phone call.

# Python dependencies pip install flask requests twilio Enter fullscreen mode Exit fullscreen mode 1️⃣ Generating Speech with ElevenLabs ElevenLabs exposes a simple REST endpoint: POST /v1/text-to-speech/{voice_id}. The request body contains the text you want spoken, and the response is an MP3 (or WAV) audio stream.

import requests ELEVEN_API_KEY = " YOUR_ELEVENLABS_API_KEY " VOICE_ID = " EXAMPLE_VOICE_ID " # you can list your voices via the API def generate_speech ( text: str ) -> bytes: url = f " https://api.elevenlabs.io/v1/text-to-speech/ { VOICE_ID } " headers = { " xi-api-key ": ELEVEN_API_KEY, " Content-Type ": " application/json " } payload = { " text ": text, " model_id ": " eleven_monolingual_v1 ", # default high‑quality model " voice_settings ": { " stability ": 0.75, " similarity_boost ": 0.85 } } response = requests. post ( url, json = payload, headers = headers ) response. raise_for_status () return response. content # binary MP3 data Enter fullscreen mode Exit fullscreen mode Pro tip: Use ElevenLabs’ voice cloning feature to create a custom voice that matches your brand. The process is documented in their UI, and once you have a voice_id you can plug it straight into the code above. Check out the official docs or sign up via the affiliate link: https://try.elevenlabs.io/kr07zfuqn1bp.

Twilio expects a URL that returns TwiML (Twilio Markup Language) to tell it what to do during a call. In our case, we’ll return a <Play> verb that points to a temporary URL serving the MP3 we just generated.

from flask import Flask, request, send_file, jsonify from twilio.twiml.voice_response import VoiceResponse import io import uuid app = Flask ( __name__ ) # In‑memory store for generated audio (good enough for a demo) audio_store = {} @app.route ( " /voice ", methods = [ " POST " ]) def voice (): # Extract the caller's speech or a preset prompt prompt = " Welcome to the ElevenLabs + Twilio demo. How can I help you today? " audio_bytes = generate_speech ( prompt ) # Store audio with a short‑lived UUID audio_id = str ( uuid. uuid4 ()) audio_store [ audio_id ] = audio_bytes # Build TwiML that plays the generated audio response = VoiceResponse () response. play ( url = f " { request. url_root } audio/ { audio_id } " ) return str ( response ) @app.route ( " /audio/<audio_id> ", methods = [ " GET " ]) def serve_audio ( audio_id ): audio = audio_store. get ( audio_id ) if not audio: return " Audio not found ", 404 # Return MP3 with proper MIME type return send_file ( io.

BytesIO ( audio ), mimetype = " audio/mpeg ", as_attachment = False, download_name = " speech.mp3 " ) Enter fullscreen mode Exit fullscreen mode Exposing the Flask app # Run the server locally flask run --port 5000 Enter fullscreen mode Exit fullscreen mode Then start an ngrok tunnel:

ngrok http 5000 Enter fullscreen mode Exit fullscreen mode Copy the HTTPS forwarding URL (e.g., https://abcd1234.ngrok.io ) – you’ll need it in the Twilio console.

https://abcd1234.ngrok.io/voice Enter fullscreen mode Exit fullscreen mode Save the changes. Now, whenever someone dials your Twilio number, Twilio will POST to /voice, your Flask app will generate speech via ElevenLabs, and the caller will hear the generated audio instantly.

If you want the caller to respond and have the system speak back, you can combine Twilio’s <Gather> with the same TTS pipeline:

@app.route ( " /voice ", methods = [ " POST " ]) def voice (): response = VoiceResponse () # Prompt the user response. say ( " Press 1 for sales, 2 for support, or say something after the beep. " ) # Gather DTMF or speech gather = response. gather ( input = " speech dtmf ", timeout = 5, speech_timeout = " auto ", action = " /process_input ", method = " POST " ) # Play a brief hold tone while waiting gather. play ( url = " https://api.twilio.com/cowbell.mp3 " ) return str ( response ) @app.route ( " /process_input ", methods = [ " POST " ]) def process_input (): user_input = request. form. get ( " SpeechResult " ) or request. form. get ( " Digits " ) if not user_input: reply = " I didn ' t catch that. Goodbye!

" else: reply = f " You said: { user_input }. Thanks for trying the demo. " audio_bytes = generate_speech ( reply ) audio_id = str ( uuid. uuid4 ()) audio_store [ audio_id ] = audio_bytes resp = VoiceResponse () resp. play ( url = f " { request. url_root } audio/ { audio_id } " ) resp. hangup () return str ( resp ) Enter fullscreen mode Exit fullscreen mode Now the call becomes a two‑way conversation, with ElevenLabs handling all the spoken responses.

If you just want to verify that ElevenLabs returns audio correctly, you can hit the endpoint directly:

curl -X POST "https://api.elevenlabs.io/v1/text-to-speech/EXAMPLE_VOICE_ID" \ -H "xi-api-key: YOUR_ELEVENLABS_API_KEY" \ -H "Content-Type: application/json" \ -d '{"text":"Hello from ElevenLabs!", "model_id":"eleven_monolingual_v1"}' \ --output speech.mp3 Enter fullscreen mode Exit fullscreen mode Play speech.mp3 locally—if it sounds natural, you’re ready to integrate with Twilio.

Ready to give your users a voice they’ll actually want to listen to? Grab your ElevenLabs API key (and a free trial) at https://try.elevenlabs.io/kr07zfuqn1bp, spin up the Flask app, point Twilio at your webhook, and start calling. Happy building!