Realtime session object for the beta interface.

Fields

• :expires_at - optional - integer()
  Expiration timestamp for the session, in seconds since epoch.

• :id - optional - String.t()
  Unique identifier for the session that looks like sess_1234567890abcdef.

• :include - optional - [:"item.input_audio_transcription.logprobs"] | any()

• :input_audio_format - optional - :pcm16 | :g711_ulaw | :g711_alaw
  The format of input audio. Options are pcm16, g711_ulaw, or g711_alaw. For pcm16, input audio must be 16-bit PCM at a 24kHz sample rate, single channel (mono), and little-endian byte order.
  Allowed values: "pcm16", "g711_ulaw", "g711_alaw"
  Default: "pcm16"

• :input_audio_noise_reduction - optional - {:%{}, [], [{{:optional, [], [:type]}, {{:., [], [ExOpenAI.Components.NoiseReductionType, :t]}, [], []}}]}
  Configuration for input audio noise reduction. This can be set to null to turn off. Noise reduction filters audio added to the input audio buffer before it is sent to VAD and the model. Filtering the audio can improve VAD and turn detection accuracy (reducing false positives) and model performance by improving perception of the input audio.
  Default: nil

• :input_audio_transcription - optional - {:%{}, [], [{{:optional, [], [:language]}, {{:., [], [{:__aliases__, [alias: false], [:String]}, :t]}, [], []}}, {{:optional, [], [:model]}, {:|, [], [{{:., [], [{:__aliases__, [alias: false], [:String]}, :t]}, [], []}, {:|, [], [{:|, [], [{:|, [], [{:|, [], [:"whisper-1", :"gpt-4o-mini-transcribe"]}, :"gpt-4o-mini-transcribe-2025-12-15"]}, :"gpt-4o-transcribe"]}, :"gpt-4o-transcribe-diarize"]}]}}, {{:optional, [], [:prompt]}, {{:., [], [{:__aliases__, [alias: false], [:String]}, :t]}, [], []}}]} | any()

• :instructions - optional - String.t()
  The default system instructions (i.e. system message) prepended to model calls. This field allows the client to guide the model on desired responses. The model can be instructed on response content and format, (e.g. "be extremely succinct", "act friendly", "here are examples of good responses") and on audio behavior (e.g. "talk quickly", "inject emotion into your voice", "laugh frequently"). The instructions are not guaranteed to be followed by the model, but they provide guidance to the model on the desired behavior.

Note that the server sets default instructions which will be used if this field is not set and are visible in the session.created event at the start of the session.

• :max_response_output_tokens - optional - integer() | :inf
  Maximum number of output tokens for a single assistant response, inclusive of tool calls. Provide an integer between 1 and 4096 to limit output tokens, or inf for the maximum available tokens for a given model. Defaults to inf.

• :modalities - optional - any()
  The set of modalities the model can respond with. To disable audio, set this to ["text"].

• :model - optional - String.t() | :"gpt-realtime" | :"gpt-realtime-1.5" | :"gpt-realtime-2025-08-28" | :"gpt-4o-realtime-preview" | :"gpt-4o-realtime-preview-2024-10-01" | :"gpt-4o-realtime-preview-2024-12-17" | :"gpt-4o-realtime-preview-2025-06-03" | :"gpt-4o-mini-realtime-preview" | :"gpt-4o-mini-realtime-preview-2024-12-17" | :"gpt-realtime-mini" | :"gpt-realtime-mini-2025-10-06" | :"gpt-realtime-mini-2025-12-15" | :"gpt-audio-1.5" | :"gpt-audio-mini" | :"gpt-audio-mini-2025-10-06" | :"gpt-audio-mini-2025-12-15"
  The Realtime model used for this session.

• :object - optional - :"realtime.session"
  The object type. Always realtime.session.
  Allowed values: "realtime.session"

• :output_audio_format - optional - :pcm16 | :g711_ulaw | :g711_alaw
  The format of output audio. Options are pcm16, g711_ulaw, or g711_alaw. For pcm16, output audio is sampled at a rate of 24kHz.
  Allowed values: "pcm16", "g711_ulaw", "g711_alaw"
  Default: "pcm16"

• :prompt - optional - ExOpenAI.Components.Prompt.t() | any()

• :speed - optional - number()
  The speed of the model's spoken response. 1.0 is the default speed. 0.25 is the minimum speed. 1.5 is the maximum speed. This value can only be changed in between model turns, not while a response is in progress.
  Default: 1
  Constraints: minimum: 0.25, maximum: 1.5

• :temperature - optional - number()
  Sampling temperature for the model, limited to [0.6, 1.2]. For audio models a temperature of 0.8 is highly recommended for best performance.
  Default: 0.8

• :tool_choice - optional - String.t()
  How the model chooses tools. Options are auto, none, required, or specify a function.
  Default: "auto"

• :tools - optional - [ExOpenAI.Components.RealtimeFunctionTool.t()]
  Tools (functions) available to the model.

• :tracing - optional - :auto | {:%{}, [], [{{:optional, [], [:group_id]}, {{:., [], [{:__aliases__, [alias: false], [:String]}, :t]}, [], []}}, {{:optional, [], [:metadata]}, {:map, [], []}}, {{:optional, [], [:workflow_name]}, {{:., [], [{:__aliases__, [alias: false], [:String]}, :t]}, [], []}}]} | any()

• :turn_detection - optional - ExOpenAI.Components.RealtimeTurnDetection.t()

• :voice - optional - ExOpenAI.Components.VoiceIdsShared.t()
  The voice the model uses to respond. Voice cannot be changed during the session once the model has responded with audio at least once. Current voice options are alloy, ash, ballad, coral, echo, sage, shimmer, and verse.