Example

curl -X POST https://api.openai.com/v1/realtime/client_secrets \
  -H "Authorization: Bearer $OPENAI_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "expires_after": {
      "anchor": "created_at",
      "seconds": 600
    },
    "session": {
      "type": "realtime",
      "model": "gpt-realtime",
      "instructions": "You are a friendly assistant."
    }
  }'

Response

{
  "value": "ek_68af296e8e408191a1120ab6383263c2",
  "expires_at": 1756310470,
  "session": {
    "type": "realtime",
    "object": "realtime.session",
    "id": "sess_C9CiUVUzUzYIssh3ELY1d",
    "model": "gpt-realtime",
    "output_modalities": [
      "audio"
    ],
    "instructions": "You are a friendly assistant.",
    "tools": [],
    "tool_choice": "auto",
    "max_output_tokens": "inf",
    "tracing": null,
    "truncation": "auto",
    "prompt": null,
    "expires_at": 0,
    "audio": {
      "input": {
        "format": {
          "type": "audio/pcm",
          "rate": 24000
        },
        "transcription": null,
        "noise_reduction": null,
        "turn_detection": {
          "type": "server_vad",
        }
      },
      "output": {
        "format": {
          "type": "audio/pcm",
          "rate": 24000
        },
        "voice": "alloy",
        "speed": 1.0
      }
    },
    "include": null
  }
}