---
title: "Create GPT Live session"
method: POST
path: "/live/sessions"
tags: ["Gateway"]
---

# Create GPT Live session

`POST /live/sessions`

## Request

- Base URL: `https://api.phaseo.app/v1`
- URL: `https://api.phaseo.app/v1/live/sessions`
- Auth: HTTP bearer

Creates a metered GPT Live voice session, which delegates reasoning to a Responses backend model, and returns relay connection details. Function tools run on your client: the relay forwards each `function_call` and accepts its `function_call_output` followed by `response.create`.

## Request body

- object
  - `type` 'live'
  - `model` 'openai/gpt-live-1', required
  - `provider` 'openai', required
  - `voice` 'alloy' | 'ash' | 'ballad' | 'beacon' | 'bossa' | 'cedar' | 'cinder' | 'coral' | 'delta' | 'echo' | 'gleam' | 'marin' | 'meridian' | 'quartz' | 'ripple' | 'sage' | 'shimmer' | 'stone' | 'tempo' | 'verse' | 'vesper' | 'willow'
  - `instructions` string
  - `source` 'api' | 'chat'
  - `metadata` object
  - `backend_model` 'openai/gpt-5.6-luna' | 'openai/gpt-5.6-terra'
  - `backend_settings` object
    - `instructions` string
    - `max_output_tokens` integer
    - `reasoning_effort` 'none' | 'low' | 'medium' | 'high' | 'xhigh'
    - `reasoning_summary` 'auto' | 'concise' | 'detailed'
    - `verbosity` 'low' | 'medium' | 'high'
    - `service_tier` 'default' | 'flex' | 'priority'
    - `web_search` boolean
    - `tools` object[]: Client-executed function tools, with unique names.
      - `type` 'function', required
      - `name` string, required
      - `description` string
      - `parameters` object
      - `strict` boolean
    - `tool_choice` 'auto' | 'none' | 'required'
    - `parallel_tool_calls` boolean

## Response `201`

GPT Live session created

- object
  - `id` string
  - `session_id` string
  - `provider` string
  - `model` string
  - `model_id` string
  - `voice` string, nullable
  - `status` string
  - `expires_at` string, date-time, nullable
  - `max_duration_seconds` integer
  - `idle_timeout_seconds` integer, nullable
  - `client_secret` string
  - `connect` object
    - `transport` string
    - `url` string
  - `billing` object

## Changes

- **2026-10-28** `165f6b629160`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/phaseo/apis/phaseo-gateway-api/changes/live/sessions/post.md)

---

[API](https://skmtc.dev/phaseo/apis/phaseo-gateway-api.md) - [All operations](https://skmtc.dev/phaseo/apis/phaseo-gateway-api/llms.txt) - [OpenAPI document](https://skmtc.dev/phaseo/apis/phaseo-gateway-api/revisions/5ca9bb220d25?raw)