The Voice Layer for AI Companions

Voice quality out of the box

Everything you need to make AI companions sound like people, not robots.

🎙

Sentence-Aware TTS

Text is chunked at natural sentence boundaries. No more robotic mid-thought pauses or fragment-synthesized audio.

🔌

Runtime Agnostic

Stable adapter contracts let you swap Pipecat for LiveKit without touching your companion code. No vendor lock-in.

🎭

Voice Character Profiles

Define voice personality in a single JSON file — TTS settings, slang, pronunciation, persona mode. Ship different characters with zero code changes.

😊

Emoji-to-Emotion

Emojis in your agent's output become emotion_state events. Your avatar reacts to sentiment automatically.

😂

Real Laughter

ElevenLabs v3 audio tags turn "haha" and "lol" into actual laughter. Four default slang dicts ship out of the box.

🧩

Modular Plugin Architecture

Every capability is an npm package. Compose only what you need — core, voice router, observability, avatar events.

🛑

Barge-In Detection

Users can interrupt at any time. Kith stops in-flight TTS immediately and signals the turn change.

👁

Avatar Event Bus

Normalized viseme_frame and emotion_state events drive your avatar — VRM, Canvas, Unity, whatever renderer you use.

📊

Built-in Observability

Span tracing, duplicate-send guards, and reconnect metrics. Diagnose production voice failures without guessing.

Sits beside your agent, not inside it

Kith owns the voice loop. You keep your agent, your persona, your memory, your tools.

your agent  ←→  @kithjs/core  ←→  runtime adapter  ←→  Pipecat | LiveKit
                     │
           voice router ─── slang, pronunciation, chunking
           observability ── traces, dup-send, reconnect
           avatar events ── viseme, emotion, turn state

Built for every companion use case

From gaming NPCs to therapy bots — if it talks, Kith makes it sound better.

AI CompanionsVirtual TutorsGame NPCsCustomer Support BotsTherapy CompanionsLanguage LearningVirtual InfluencersAccessibility ToolsInteractive StorytellingVoice AssistantsSocial Platform BotsFitness CoachesMeditation GuidesTravel CompanionsCreative Writing Partners