OpenAI Go SDK Realtime Voice Example

This example sends spoken audio to CLIProxyAPI and saves the model's spoken reply as a WAV file.

It uses the official github.com/openai/openai-go/v3 SDK to create a short-lived Realtime client secret. The official Go SDK currently exposes the Realtime REST resources but does not provide a WebSocket connection helper, so github.com/gorilla/websocket is used for the standard Realtime audio events.

Prerequisites

Start CLIProxyAPI with at least one working ChatGPT/Codex OAuth credential.
Configure a proxy API key in config.yaml.
Use Go 1.26 or newer.
Prepare a PCM WAV file with these exact properties:
- 24,000 Hz sample rate
- 16-bit signed PCM
- mono
- little-endian

Convert an existing recording with FFmpeg:

bash

ffmpeg -i recording.m4a -ar 24000 -ac 1 -c:a pcm_s16le question.wav

Run

bash

cd examples/realtime-openai-go

OPENAI_BASE_URL="http://127.0.0.1:8317/v1" \
OPENAI_API_KEY="your-proxy-api-key" \
OPENAI_REALTIME_MODEL="gpt-realtime-2.1" \
OPENAI_REALTIME_INPUT_WAV="question.wav" \
OPENAI_REALTIME_OUTPUT_WAV="response.wav" \
go run .

Expected output:

text

Loaded question.wav (2.4s, 115200 PCM bytes)
Connected to ws://127.0.0.1:8317/v1/realtime?model=gpt-realtime-2.1 using model gpt-realtime-2.1 and voice marin
Sent 2.4s of speech audio
Assistant transcript: The connection is working correctly.
Saved spoken response to response.wav (1.8s, 86400 PCM bytes)

Play the response:

bash

# macOS
afplay response.wav

# Linux
aplay response.wav

# Cross-platform with FFmpeg
ffplay -autoexit response.wav

Environment variables

Variable	Required	Default	Description
`OPENAI_API_KEY`	Yes	—	API key configured for CLIProxyAPI.
`OPENAI_REALTIME_INPUT_WAV`	Yes	—	Input speech WAV file. It must be 24kHz, 16-bit, mono PCM.
`OPENAI_REALTIME_OUTPUT_WAV`	No	`response.wav`	Destination for the spoken response.
`OPENAI_BASE_URL`	No	`http://127.0.0.1:8317/v1`	CLIProxyAPI OpenAI-compatible base URL. `/v1` is added when the URL has no path.
`OPENAI_REALTIME_MODEL`	No	`gpt-realtime-2.1`	Standard Realtime model name. CLIProxyAPI uses it for the upstream standard WebSocket while selecting a compatible Codex OAuth credential internally.
`OPENAI_REALTIME_VOICE`	No	`marin`	Realtime output voice. Other common values include `cedar`, `alloy`, `ash`, `coral`, and `echo`.
`OPENAI_REALTIME_INSTRUCTIONS`	No	Short spoken response instruction	Session instructions attached to the client secret.
`OPENAI_REALTIME_DEBUG`	No	`false`	Print every received Realtime server event.

Audio flow

The official OpenAI Go SDK calls POST /v1/realtime/client_secrets with an audio session configured for 24kHz PCM input and output.
The returned local ek_... credential authenticates the /v1/realtime WebSocket.
Input WAV samples are sent in 200ms input_audio_buffer.append chunks.
The client sends input_audio_buffer.commit and response.create.
Base64 response.output_audio.delta events are decoded and written to the output WAV.

The client secret returned by CLIProxyAPI is local to that proxy instance and is not valid against api.openai.com.

Test

bash

go test -race ./...

The test starts an in-process HTTP/WebSocket server and verifies client-secret configuration, input audio streaming, output audio decoding, and WAV generation.