Models
Speech to Speech
The Speech to Speech API enables real-time voice conversations over WebSocket, billed by minute of audio plus a flat fee per text input message. Supports function calling with web search, X search, collections, MCP, and custom functions.
At a glance
| Details | |
|---|---|
| Modalities | Text, Audio → Text, Audio |
| Audio pricing | / minute or / hour |
| Text Input pricing | / message |
| Region | us-east-1 |
Pricing
The Speech to Speech API charges based on audio duration and text events sent without audio.
| Details | |
|---|---|
| Audio | / minute or / hour of audio sent or received |
| Text Input | per conversation.item.create event |
What counts as a text input message
Every conversation.item.create event you send from the client is billed at , with two exceptions:
function_call_outputitems (server-requested tool results) are not billed.Items whose content is
input_audiooraudioare billed by the audio meter instead.
response.create is not a billable event. It only asks the model to produce the next turn; any audio the model generates in that turn is billed under the audio meter above.
Rate Limits
| Details | |
|---|---|
| Concurrent sessions | per team |
| Max session duration | 120 minutes |
Capabilities
Function calling
Web search
X search
Collections search
Remote MCP tools
Availability
| Details | |
|---|---|
| Cluster | us-east-1 |
Documentation
Speech to Speech Guide — Getting started with real-time voice conversations
API Reference — WebSocket endpoint reference
Pricing — Full pricing overview
Last updated:September 12, 2026