Implementation:Openai Openai python Realtime Calls Override

Knowledge Sources	Openai_Openai_python
Domains	Realtime_API
Last Updated	2026-02-15 00:00 GMT

Overview

Concrete tool for Realtime API call creation with SDP/multipart handling provided by the openai-python SDK.

Description

The _realtime module provides _Calls and _AsyncCalls classes that override the generated Calls and AsyncCalls resource classes to implement correct behavior for the POST /realtime/calls endpoint. The create() method accepts an sdp string (Session Description Protocol offer) and an optional session parameter of type RealtimeSessionCreateRequestParam. When session is omitted, the method sends a plain application/sdp request with the SDP payload as raw bytes. When session is provided, it sends a multipart/form-data request containing two parts: the SDP data (as application/sdp) and the session configuration serialized as application/json. Both variants set the Accept header to application/sdp and return an HttpxBinaryResponseContent containing the SDP answer. This is custom code intended to eventually be replaced by auto-generated code from the OpenAPI spec.

Usage

Use these classes when initiating WebRTC-based Realtime API sessions that require SDP offer/answer negotiation, optionally with session configuration parameters.

Code Reference

Source Location

• Repository: openai-python
• File: src/openai/lib/_realtime.py
• Lines: 1-92

Signature

class _Calls(Calls):
    @override
    def create(
        self,
        *,
        sdp: str,
        session: RealtimeSessionCreateRequestParam | Omit = omit,
        extra_headers: Headers | None = None,
        extra_query: Query | None = None,
        extra_body: Body | None = None,
        timeout: float | httpx.Timeout | None | NotGiven = not_given,
    ) -> HttpxBinaryResponseContent: ...

class _AsyncCalls(AsyncCalls):
    @override
    async def create(
        self,
        *,
        sdp: str,
        session: RealtimeSessionCreateRequestParam | Omit = omit,
        extra_headers: Headers | None = None,
        extra_query: Query | None = None,
        extra_body: Body | None = None,
        timeout: float | httpx.Timeout | None | NotGiven = not_given,
    ) -> HttpxBinaryResponseContent: ...

Import

from openai.lib._realtime import _Calls, _AsyncCalls

I/O Contract

Inputs

Name	Type	Required	Description
sdp	str	Yes	The SDP (Session Description Protocol) offer string
session	RealtimeSessionCreateRequestParam or Omit	No	Optional session configuration; omit for SDP-only requests
extra_headers	Headers or None	No	Additional HTTP headers
extra_query	Query or None	No	Additional query parameters
extra_body	Body or None	No	Additional JSON body properties
timeout	float / httpx.Timeout / None / NotGiven	No	Request timeout override

Outputs

Name	Type	Description
create() result	HttpxBinaryResponseContent	The SDP answer from the Realtime API as binary content

Usage Examples

Basic Usage

from openai import OpenAI

client = OpenAI()

# Simple SDP-only call
sdp_offer = "v=0\r\no=- 0 0 IN IP4 127.0.0.1\r\n..."
response = client.realtime.calls.create(sdp=sdp_offer)
sdp_answer = response.content.decode("utf-8")

# Call with session configuration
response = client.realtime.calls.create(
    sdp=sdp_offer,
    session={
        "model": "gpt-4o-realtime-preview",
        "voice": "alloy",
    },
)

Related Pages

• Environment:Openai_Openai_python_Python_3_9_Plus