Class DuplexSession

Readonly duplexModel

audioStream

• get audioStream(): ReadableStream<DuplexAudioFrame>

• Mono 24 kHz PCM output, retained across reconnects and closed on shutdown.

  Returns ReadableStream<DuplexAudioFrame>

capabilities

• get capabilities(): DuplexCapabilities

• Provider features declared by the owning model.

  Returns DuplexCapabilities

sessionId

• get sessionId(): undefined | string

• Provider session identifier. Changes when a replacement connection starts.

  Returns undefined | string

tools

• get tools(): ToolContext<unknown>

• Copy of the tools available to the backend Responses model.

  Returns ToolContext<unknown>

_appendItems

• _appendItems(items): Promise<void>

• Retain framework chat items for reconnects and send their context or tool results.

  Parameters

  • items: ChatItem[]

  Returns Promise<void>

_generateReply

• _generateReply(instructions?): void

• Prompt an immediate spoken reply to instructions or the newest typed user message.

  Parameters

  • Optional instructions: string

  Returns void

_updateInstructions

• _updateInstructions(instructions): Promise<void>

• Set the initial voice instructions. Changes after session.start are rejected.

  Parameters

  • instructions: string

  Returns Promise<void>

_updateOptions

• _updateOptions(options): void

• Update backend tool selection for this session and future reconnects.

  Parameters

  • options: {
        toolChoice?: null | llm.ToolChoice;
    }

    • Optional toolChoice?: null | llm.ToolChoice

  Returns void

_updateSession

• _updateSession(instructions?, chatCtx?, tools?): Promise<void>

• Apply the complete startup configuration before releasing a waiting provider connection.

  Parameters

  • Optional instructions: string
  • Optional chatCtx: ChatContext
  • Optional tools: ToolContext<unknown>

  Returns Promise<void>

appendCommentary

• appendCommentary(text, options?): void

• Give the model text to paraphrase aloud, or answer a client delegation. Capped at 500 tokens by the service.

  Parameters

  • text: string
  • options: {
        delegationId?: null | string;
    } = {}

    • Optional delegationId?: null | string

  Returns void

appendInstructions

• appendInstructions(text, options?): void

• Add a standing rule retained in reconnect history. The service caps each append at 500 tokens.

  Parameters

  • text: string
  • options: {
        delegationId?: null | string;
    } = {}

    • Optional delegationId?: null | string

  Returns void

appendThinking

• appendThinking(text, options?): void

• Add silent context retained in reconnect history. The service caps each append at 500 tokens.

  Parameters

  • text: string
  • options: {
        delegationId?: null | string;
    } = {}

    • Optional delegationId?: null | string

  Returns void

close

• close(): Promise<void>

• Mark the session closing, release configuration waits, and close provider resources.

  Returns Promise<void>

muteInput

• muteInput(): void

• Replace microphone input with silence while the model continues speaking. The state is remembered and re-applied to any session a reconnect opens.

  Returns void

pushAudio

• pushAudio(frame): void

• Buffer microphone audio, mixing to mono and resampling to 24 kHz as needed.

  Parameters

  • frame: AudioFrame

  Returns void

pushVideo

• pushVideo(_frame): void

• Feed an input video frame. Providers without video input can ignore it.

  Parameters

  • _frame: VideoFrame

  Returns void

sendEvent

• sendEvent(event): void

• Queue a wire event. Commands wait for session.started before being sent.

  Parameters

  • event: Record<string, unknown> | realtime.GPTLive.ClientEvent

  Returns void

unmuteInput

• unmuteInput(): void

• Restore microphone input.

  Returns void