Use case · Developer infrastructure
Best voice infrastructure for developers
These are the building blocks you wire together yourself: APIs, SDKs and frameworks for speech, turn-taking and call control, rather than a finished agent. Pick these when you are building a voice product, not buying one off the shelf.
What to look for: Look for clear docs and SDKs, bring-your-own model and voice, low latency you can measure, and usage-based pricing that scales with your own product.
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The speed specialist whose fast, natural speech is what keeps a live phone agent feeling real rather than laggy.
Build a phone agent exactly the way you want it, choosing each part yourself, if you have a developer to hand.
The open-source real-time stack that carries voice-agent audio, plus a framework to wire your own STT, LLM and voice.
OpenAI's speech-to-speech model and API for building your own voice agent, billed by audio tokens, not by the minute.
Open-source Python framework where you pick every voice-agent part, free to self-host, with Daily's cloud for scaling.
A voice that picks up how the caller is feeling and answers in kind, for warmer and more human conversations.
Get the voice agent and the phone network it runs on from one provider, useful when you want billing in one place.
Enterprise text-to-speech built for high-stakes phone calls, where a mispronounced name loses the customer.
Fast, accurate speech-to-text to power high-volume voice apps, for teams happy to build on a developer API.
Enterprise speech-to-text with very broad language coverage and real on-prem options, for teams who self-host.
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Accurate streaming speech-to-text with built-in audio intelligence, for teams who want the listening half done well.
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