Voice

Moshi

Open speech-text foundation model for full-duplex spoken dialogue.

Fish Audio

Text-to-speech and voice cloning platform built on the open Fish Speech models.

Coqui TTS

Open-source deep learning toolkit for text-to-speech.

Kokoro

Open-weight 82M-parameter text-to-speech model with fast inference.

Inworld

Realtime TTS and voice APIs for consumer-facing AI applications.

Resemble AI

Voice cloning, speech synthesis, and deepfake detection for enterprises.

LM✓ Attested

LMNT

Low-latency streaming text-to-speech and voice cloning API.

Rime

Text-to-speech models built for high-volume, realtime business conversations.

Cartesia

Realtime speech models purpose-built for voice agents.

ElevenLabs

AI audio platform with realtime TTS, STT, and a conversational agents product.

NVIDIA Riva

GPU-accelerated speech AI microservices for self-hosted deployment.

whisper.cpp

Dependency-free C/C++ port of Whisper for local and edge inference.

faster-whisper

Optimized Whisper inference using CTranslate2.

OpenAI Whisper

Open-source general-purpose speech recognition model.

Soniox

Realtime multilingual speech recognition and translation APIs.

Speechmatics

Multilingual speech-to-text APIs for realtime and batch transcription.

Gladia

Realtime and batch speech-to-text API for voice platforms.

AssemblyAI

Speech recognition and audio intelligence APIs for voice applications.

Deepgram

Speech-to-text, text-to-speech, and voice agent APIs in one platform.

Silero VAD

Pre-trained open-source voice activity detector for speech pipelines.

Krisp

Noise cancellation and speech enhancement SDKs for calls and voice agents.

OpenAI Realtime API

Speech-to-speech API for low-latency voice agents on OpenAI's realtime models.

Telnyx Voice AI

Carrier-grade voice AI agents on Telnyx's own telephony network.

TW✓ Attested

Twilio ConversationRelay

Twilio Voice feature that connects phone calls to any LLM over WebSockets.

JA✓ Attested

Jambonz

Self-hostable open-source voice platform for building conversational AI on telephony.

TEN Framework

Open-source framework for realtime multimodal conversational AI agents.

Vocode

Open-source Python library for building voice-based LLM applications.

Daily

Realtime audio/video infrastructure and hosting for voice AI agents.

LiveKit Agents

Open-source framework and cloud platform for realtime voice AI agents.

Ultravox

Speech-native multimodal model and realtime platform for voice agents.

Bolna

Open-source framework and hosted platform for LLM-based voice agents.

Voiceflow

Collaborative platform for designing, building, and deploying conversational AI agents.

PolyAI

Enterprise voice assistants for customer service call handling.

Hume AI

Voice AI APIs focused on emotional expression, including the EVI speech-to-speech interface.

Millis AI

Low-latency voice agent platform with no-code and API options.

Synthflow

No-code and API-based platform for deploying AI phone agents.

Bland

Enterprise voice AI for automating phone calls at scale.

Retell AI

Platform for building AI voice agents that handle inbound and outbound phone calls.

Vapi

Developer platform for building and deploying phone and web voice AI agents.