Get started
Use in a Waterr scenario
Toggle Utter on for any scenario. No code.
Bring your own agent
Point Utter at your OpenAI-compatible endpoint.
Developer API
Talk to the underlying engine over WebSocket.
Audio orchestration
Utter is one system with four cooperating layers. Kyutai’s open streaming STT and TTS foundations provide the low-latency audio substrate; Utter contributes the turn engine, the reasoning contract, the voice curation, and the meeting-level primitives that make the loop feel like a conversation instead of a transaction.
The Kyutai substrate gives us a low-latency streaming loop. What makes Utter Utter is what sits around it: the semantic turn engine that arbitrates the loop, the reasoning contract that lets any LLM slot in without breaking timing, the voice roster we’ve selected for meeting durability, and the meeting-level primitives — multi-agent handoff, participant memory, custom functions — the loop is designed to serve.
What you can build
Voice agents on your own LLM
Point Utter at any OpenAI-compatible endpoint. Your agent stays on your infra; Utter handles the audio.
Meeting-native experiences
Interviews, sales calls, coaching, clinical roleplay — with handoff, transcript, and analysis out of the box.
Multi-agent flows
Mid-call persona swaps via Multi-Agent.
Tool-using agents
Call your APIs mid-turn with Custom Functions.
BYOA (Bring Your Own Agent)
Utter’s reasoning layer is a contract, not a fixed model. Point it at:- Waterr’s default backbone — no configuration; use the framework as shipped.
- Your own OpenAI-compatible endpoint — configure a custom endpoint against Waterr’s MCS proxy and Utter routes reasoning to your model. Your agent stays on your infra; only the audio loop runs on Utter.
- A fine-tuned Utter checkpoint — see Fine-tuning.
Fine-tuning
Utter supports supervised fine-tuning on the reasoning layer for enterprise deployments. Typical use cases:- A support agent tuned on your product’s actual conversations
- A recruiter agent that follows your interview rubric to the letter
- A medical intake agent that speaks in the terminology of your specialty
- A voice register or refusal pattern specific to your brand
Dedicated & on-prem deployment
For customers with data-residency, latency, or compliance requirements, Utter is available as a dedicated deployment:- Dedicated cloud — Utter running in a single-tenant environment in your region of choice. No noisy-neighbor variance on latency; audit-friendly logging.
- On-premises — the full Utter stack (turn engine, reasoning layer, voice head) deployed inside your network. Voice data never leaves your infrastructure. Suitable for healthcare, finance, defense, and regulated public-sector workloads.
Numbers (Preview, honest)
Limitations
Being honest about the Preview cut:- English-first. Other languages work but quality varies by voice.
- 30-minute session cap. Longer sessions are on the roadmap; today they need to be re-established.
- Multi-agent handoff coverage varies by pipeline. See the Multi-Agent matrix for what’s supported today.
Related
- ORI-Realtime 1.5 — the developer API surface exposing Utter over WebSocket.
- Multi-Agent — mid-call persona handoffs.
- Custom Functions — tools Utter can call mid-turn.

