Text-to-speech API for voice agents and voice bots
Build AI voice agents, phone bots, and conversational assistants with Soniox Text-to-Speech API. Stream natural speech as your LLM generates it, handle interruptions, speak critical details accurately, and give every interaction a consistent voice across 60+ languages. Pair with Soniox Speech-to-Text to complete the loop.
Trusted by teams building global voice products
Give every voice agent a voice people want to talk to
Soniox provides the voice layer for conversational AI. Turn generated text into natural speech for customer service bots, phone agents, AI assistants, receptionists, and other products that speak with users.
Customer service voice bots
Give automated support agents a natural voice for answering questions, checking orders, troubleshooting issues, and guiding customers through self-service.
Phone voice agents
Generate dynamic speech for inbound and outbound phone agents that need clear prompts, confirmations, and accurate readback of customer data.
Conversational AI agents
Turn LLM responses into natural speech as they are generated, so conversational agents can respond quickly and keep interactions flowing.
In-app voice assistants
Add spoken AI assistance to apps for onboarding, search, scheduling, task completion, navigation, and other hands-free interactions.
Scheduling and receptionist bots
Build voice bots that book appointments, answer routine questions, confirm details, and communicate naturally across languages.
Multilingual voice agents
Serve global users with one voice pipeline across 60+ languages while preserving a consistent agent or brand voice.
Text-to-speech built for voice bots and conversational AI
A voice bot does not just need speech that sounds natural. Its TTS layer has to work inside a live conversation, where every millisecond of delay, misread number, awkward interruption, or inconsistent voice affects the user experience.
Text-to-speech for voice agents should:
- Accept streaming LLM output so the agent can begin speaking before the full response has been generated.
- Support fast conversational turn-takingso users are not left waiting between their question and the agent's response.
- Handle barge-in cleanly when users interrupt or change direction during a conversation.
- Speak structured data faithfully, including phone numbers, addresses, confirmation codes, dates, prices, and account details.
- Maintain one consistent agent voice across conversations, topics, and languages.
- Work across 60+ languages without maintaining a different voice stack for every market.
Soniox Text-to-Speech API is designed around these requirements, giving developers one programmable voice layer for AI voice agents, voice bots, phone agents, and conversational applications.
Streaming text-to-speech for responsive voice agents
Start speaking while the LLM is still generating
Stream text tokens to Soniox as they arrive and begin receiving audio before the complete response is available. Voice agents can start speaking without waiting for a full sentence or answer.
Handle barge-in and interruptions
When your application detects that a user has interrupted, stop the current speech and generate the next response immediately. Keep conversational voice bots responsive instead of forcing users to wait.
Speak critical details correctly
Phone numbers, email addresses, order IDs, verification codes, dates, and other structured data are rendered faithfully, so voice agents can read important information back clearly.
Build multilingual voice bots with one API
Generate speech across 60+ languages and switch languages naturally within a conversation without changing TTS models or rebuilding your voice pipeline.
Keep the agent voice consistent
Give every response the same recognizable voice across turns, topics, and languages. Choose from 200+ studio-quality voices or use a cloned voice for your product or brand.
Built for conversational voice
Voice agents need more than natural speech. They need TTS that can accept streaming LLM output, begin playback quickly, handle changing turns, pronounce critical data correctly, and keep the same voice across languages. Soniox brings those capabilities together in one Text-to-Speech API.
Build the complete voice agent loop
Pair Soniox Text-to-Speech API with Soniox Speech-to-Text API to handle both sides of a spoken conversation. Your application owns the agent logic while Soniox provides real-time speech input and natural voice output.
Listen
Stream the user's speech through Soniox Speech-to-Text API and receive accurate real-time transcripts for your voice agent.
Think
Send the transcript to your LLM, workflow, tools, or business logic to determine what the voice agent should do and say next.
Speak
Stream the response through Soniox Text-to-Speech API and begin playback while the agent's response is still being generated.
Use Soniox in popular frameworks
Soniox integrates seamlessly with leading real-time communication platforms, AI frameworks, automation tools, and developer SDKs.
An open source framework and developer platform for building, testing, deploying, scaling, and observing agents in production.
Twilio is a cloud-based customer engagement platform (CPaaS) that provides APIs, allowing developers to integrate voice, messaging (SMS, WhatsApp), email, and authentication capabilities into applications.
Open-source development framework designed to build applications powered by large language models (LLMs).
The open-source AI toolkit designed to help developers build AI-powered applications and agents with React, Next.js, Vue, Svelte, Node.js, and more.
Open-source AI SDK with a unified interface across multiple providers. No vendor lock-in, no proprietary formats.
n8n is a powerful, low-code/pro-code workflow automation tool that connects various applications, APIs, and databases to automate tasks.
Build the next generation of voice products, from agents and wearables to dictation, translation, and real-time multilingual experiences.
Privacy and compliance, built right in
Never stored, never saved.
Audio stays in memory, everything is processed in real-time.
Built for privacy-critical use cases.
Adhering to leading global security, privacy, and compliance standards.
Trusted where privacy matters most.
Used in industries where speech is sensitive, from healthcare to enterprise.
Frequently asked questions about text-to-speech for voice agents
What is text-to-speech for an AI voice agent?
Text-to-speech is the voice-output layer of an AI voice agent. It converts the text generated by an LLM, dialogue system, or application into speech the user hears.
Soniox Text-to-Speech API supports streaming input and output, so a voice agent can begin speaking before its complete response has been generated.
Can I use Soniox for voice bot text-to-speech?
What should I look for in a voice agent TTS API?
Can Soniox stream voice directly from LLM output?
Can a voice bot handle users interrupting while it speaks?
Can a voice agent speak phone numbers, codes, and account details accurately?
Does Soniox support multilingual voice bots?
Can I choose or clone a voice for my AI agent?
Can I use Soniox for both speech-to-text and text-to-speech in a voice agent?
Yes. Use Soniox Speech-to-Text API to turn user speech into text and Soniox Text-to-Speech API to turn the agent's response back into natural speech.
Your application can connect both APIs through its LLM, tools, dialogue logic, and business workflows to build the complete conversational voice loop.
How do developers add Soniox TTS to a voice agent?
Give your voice agent a better voice
Build voice bots and AI voice agents with streaming speech, consistent voices, accurate data readback, and support for 60+ languages from Soniox Text-to-Speech API. Pair it with Soniox Speech-to-Text API for the complete conversational voice stack.
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