Realtime

Domain Types

Audio Transcription

• type AudioTranscription struct{…}

  • Delay AudioTranscriptionDelay

    Controls how long the model waits before emitting transcription text. Higher values can improve transcription accuracy at the cost of latency. Only supported with gpt-realtime-whisper in GA Realtime sessions.

    • const AudioTranscriptionDelayMinimal AudioTranscriptionDelay = "minimal"

    • const AudioTranscriptionDelayLow AudioTranscriptionDelay = "low"

    • const AudioTranscriptionDelayMedium AudioTranscriptionDelay = "medium"

    • const AudioTranscriptionDelayHigh AudioTranscriptionDelay = "high"

    • const AudioTranscriptionDelayXhigh AudioTranscriptionDelay = "xhigh"

  • Language string

    The language of the input audio. Supplying the input language in ISO-639-1 (e.g. en) format will improve accuracy and latency.

  • Model AudioTranscriptionModel

    The model to use for transcription. Current options are whisper-1, gpt-4o-mini-transcribe, gpt-4o-mini-transcribe-2025-12-15, gpt-4o-transcribe, gpt-4o-transcribe-diarize, and gpt-realtime-whisper. Use gpt-4o-transcribe-diarize when you need diarization with speaker labels.

    • string

    • type AudioTranscriptionModel string

      The model to use for transcription. Current options are whisper-1, gpt-4o-mini-transcribe, gpt-4o-mini-transcribe-2025-12-15, gpt-4o-transcribe, gpt-4o-transcribe-diarize, and gpt-realtime-whisper. Use gpt-4o-transcribe-diarize when you need diarization with speaker labels.

      • const AudioTranscriptionModelWhisper1 AudioTranscriptionModel = "whisper-1"

      • const AudioTranscriptionModelGPT4oMiniTranscribe AudioTranscriptionModel = "gpt-4o-mini-transcribe"

      • const AudioTranscriptionModelGPT4oMiniTranscribe2025_12_15 AudioTranscriptionModel = "gpt-4o-mini-transcribe-2025-12-15"

      • const AudioTranscriptionModelGPT4oTranscribe AudioTranscriptionModel = "gpt-4o-transcribe"

      • const AudioTranscriptionModelGPT4oTranscribeDiarize AudioTranscriptionModel = "gpt-4o-transcribe-diarize"

      • const AudioTranscriptionModelGPTRealtimeWhisper AudioTranscriptionModel = "gpt-realtime-whisper"

  • Prompt string

    An optional text to guide the model's style or continue a previous audio segment. For whisper-1, the prompt is a list of keywords. For gpt-4o-transcribe models (excluding gpt-4o-transcribe-diarize), the prompt is a free text string, for example "expect words related to technology". Prompt is not supported with gpt-realtime-whisper in GA Realtime sessions.

Conversation Created Event

• type ConversationCreatedEvent struct{…}

  Returned when a conversation is created. Emitted right after session creation.

  • Conversation ConversationCreatedEventConversation

    The conversation resource.

    • ID string

      The unique ID of the conversation.

    • Object string

      The object type, must be realtime.conversation.

      • const ConversationCreatedEventConversationObjectRealtimeConversation ConversationCreatedEventConversationObject = "realtime.conversation"

  • EventID string

    The unique ID of the server event.

  • Type ConversationCreated

    The event type, must be conversation.created.

    • const ConversationCreatedConversationCreated ConversationCreated = "conversation.created"

Conversation Item

• type ConversationItemUnion interface{…}

  A single item within a Realtime conversation.

  • type RealtimeConversationItemSystemMessage struct{…}

    A system message in a Realtime conversation can be used to provide additional context or instructions to the model. This is similar but distinct from the instruction prompt provided at the start of a conversation, as system messages can be added at any point in the conversation. For major changes to the conversation's behavior, use instructions, but for smaller updates (e.g. "the user is now asking about a different topic"), use system messages.

    • Content []RealtimeConversationItemSystemMessageContent

      The content of the message.

      • Text string

        The text content.

      • Type string

        The content type. Always input_text for system messages.

        • const RealtimeConversationItemSystemMessageContentTypeInputText RealtimeConversationItemSystemMessageContentType = "input_text"

    • Role System

      The role of the message sender. Always system.

      • const SystemSystem System = "system"

    • Type Message

      The type of the item. Always message.

      • const MessageMessage Message = "message"

    • ID string

      The unique ID of the item. This may be provided by the client or generated by the server.

    • Object RealtimeConversationItemSystemMessageObject

      Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

      • const RealtimeConversationItemSystemMessageObjectRealtimeItem RealtimeConversationItemSystemMessageObject = "realtime.item"

    • Status RealtimeConversationItemSystemMessageStatus

      The status of the item. Has no effect on the conversation.

      • const RealtimeConversationItemSystemMessageStatusCompleted RealtimeConversationItemSystemMessageStatus = "completed"

      • const RealtimeConversationItemSystemMessageStatusIncomplete RealtimeConversationItemSystemMessageStatus = "incomplete"

      • const RealtimeConversationItemSystemMessageStatusInProgress RealtimeConversationItemSystemMessageStatus = "in_progress"

  • type RealtimeConversationItemUserMessage struct{…}

    A user message item in a Realtime conversation.

    • Content []RealtimeConversationItemUserMessageContent

      The content of the message.

      • Audio string

        Base64-encoded audio bytes (for input_audio), these will be parsed as the format specified in the session input audio type configuration. This defaults to PCM 16-bit 24kHz mono if not specified.

      • Detail string

        The detail level of the image (for input_image). auto will default to high.

        • const RealtimeConversationItemUserMessageContentDetailAuto RealtimeConversationItemUserMessageContentDetail = "auto"

        • const RealtimeConversationItemUserMessageContentDetailLow RealtimeConversationItemUserMessageContentDetail = "low"

        • const RealtimeConversationItemUserMessageContentDetailHigh RealtimeConversationItemUserMessageContentDetail = "high"

      • ImageURL string

        Base64-encoded image bytes (for input_image) as a data URI. For example data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAA.... Supported formats are PNG and JPEG.

      • Text string

        The text content (for input_text).

      • Transcript string

        Transcript of the audio (for input_audio). This is not sent to the model, but will be attached to the message item for reference.

      • Type string

        The content type (input_text, input_audio, or input_image).

        • const RealtimeConversationItemUserMessageContentTypeInputText RealtimeConversationItemUserMessageContentType = "input_text"

        • const RealtimeConversationItemUserMessageContentTypeInputAudio RealtimeConversationItemUserMessageContentType = "input_audio"

        • const RealtimeConversationItemUserMessageContentTypeInputImage RealtimeConversationItemUserMessageContentType = "input_image"

    • Role User

      The role of the message sender. Always user.

      • const UserUser User = "user"

    • Type Message

      The type of the item. Always message.

      • const MessageMessage Message = "message"

    • ID string

      The unique ID of the item. This may be provided by the client or generated by the server.

    • Object RealtimeConversationItemUserMessageObject

      Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

      • const RealtimeConversationItemUserMessageObjectRealtimeItem RealtimeConversationItemUserMessageObject = "realtime.item"

    • Status RealtimeConversationItemUserMessageStatus

      The status of the item. Has no effect on the conversation.

      • const RealtimeConversationItemUserMessageStatusCompleted RealtimeConversationItemUserMessageStatus = "completed"

      • const RealtimeConversationItemUserMessageStatusIncomplete RealtimeConversationItemUserMessageStatus = "incomplete"

      • const RealtimeConversationItemUserMessageStatusInProgress RealtimeConversationItemUserMessageStatus = "in_progress"

  • type RealtimeConversationItemAssistantMessage struct{…}

    An assistant message item in a Realtime conversation.

    • Content []RealtimeConversationItemAssistantMessageContent

      The content of the message.

      • Audio string

        Base64-encoded audio bytes, these will be parsed as the format specified in the session output audio type configuration. This defaults to PCM 16-bit 24kHz mono if not specified.

      • Text string

        The text content.

      • Transcript string

        The transcript of the audio content, this will always be present if the output type is audio.

      • Type string

        The content type, output_text or output_audio depending on the session output_modalities configuration.

        • const RealtimeConversationItemAssistantMessageContentTypeOutputText RealtimeConversationItemAssistantMessageContentType = "output_text"

        • const RealtimeConversationItemAssistantMessageContentTypeOutputAudio RealtimeConversationItemAssistantMessageContentType = "output_audio"

    • Role Assistant

      The role of the message sender. Always assistant.

      • const AssistantAssistant Assistant = "assistant"

    • Type Message

      The type of the item. Always message.

      • const MessageMessage Message = "message"

    • ID string

      The unique ID of the item. This may be provided by the client or generated by the server.

    • Object RealtimeConversationItemAssistantMessageObject

      Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

      • const RealtimeConversationItemAssistantMessageObjectRealtimeItem RealtimeConversationItemAssistantMessageObject = "realtime.item"

    • Status RealtimeConversationItemAssistantMessageStatus

      The status of the item. Has no effect on the conversation.

      • const RealtimeConversationItemAssistantMessageStatusCompleted RealtimeConversationItemAssistantMessageStatus = "completed"

      • const RealtimeConversationItemAssistantMessageStatusIncomplete RealtimeConversationItemAssistantMessageStatus = "incomplete"

      • const RealtimeConversationItemAssistantMessageStatusInProgress RealtimeConversationItemAssistantMessageStatus = "in_progress"

  • type RealtimeConversationItemFunctionCall struct{…}

    A function call item in a Realtime conversation.

    • Arguments string

      The arguments of the function call. This is a JSON-encoded string representing the arguments passed to the function, for example {"arg1": "value1", "arg2": 42}.

    • Name string

      The name of the function being called.

    • Type FunctionCall

      The type of the item. Always function_call.

      • const FunctionCallFunctionCall FunctionCall = "function_call"

    • ID string

      The unique ID of the item. This may be provided by the client or generated by the server.

    • CallID string

      The ID of the function call.

    • Object RealtimeConversationItemFunctionCallObject

      Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

      • const RealtimeConversationItemFunctionCallObjectRealtimeItem RealtimeConversationItemFunctionCallObject = "realtime.item"

    • Status RealtimeConversationItemFunctionCallStatus

      The status of the item. Has no effect on the conversation.

      • const RealtimeConversationItemFunctionCallStatusCompleted RealtimeConversationItemFunctionCallStatus = "completed"

      • const RealtimeConversationItemFunctionCallStatusIncomplete RealtimeConversationItemFunctionCallStatus = "incomplete"

      • const RealtimeConversationItemFunctionCallStatusInProgress RealtimeConversationItemFunctionCallStatus = "in_progress"

  • type RealtimeConversationItemFunctionCallOutput struct{…}

    A function call output item in a Realtime conversation.

    • CallID string

      The ID of the function call this output is for.

    • Output string

      The output of the function call, this is free text and can contain any information or simply be empty.

    • Type FunctionCallOutput

      The type of the item. Always function_call_output.

      • const FunctionCallOutputFunctionCallOutput FunctionCallOutput = "function_call_output"

    • ID string

      The unique ID of the item. This may be provided by the client or generated by the server.

    • Object RealtimeConversationItemFunctionCallOutputObject

      Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

      • const RealtimeConversationItemFunctionCallOutputObjectRealtimeItem RealtimeConversationItemFunctionCallOutputObject = "realtime.item"

    • Status RealtimeConversationItemFunctionCallOutputStatus

      The status of the item. Has no effect on the conversation.

      • const RealtimeConversationItemFunctionCallOutputStatusCompleted RealtimeConversationItemFunctionCallOutputStatus = "completed"

      • const RealtimeConversationItemFunctionCallOutputStatusIncomplete RealtimeConversationItemFunctionCallOutputStatus = "incomplete"

      • const RealtimeConversationItemFunctionCallOutputStatusInProgress RealtimeConversationItemFunctionCallOutputStatus = "in_progress"

  • type RealtimeMcpApprovalResponse struct{…}

    A Realtime item responding to an MCP approval request.

    • ID string

      The unique ID of the approval response.

    • ApprovalRequestID string

      The ID of the approval request being answered.

    • Approve bool

      Whether the request was approved.

    • Type McpApprovalResponse

      The type of the item. Always mcp_approval_response.

      • const McpApprovalResponseMcpApprovalResponse McpApprovalResponse = "mcp_approval_response"

    • Reason string

      Optional reason for the decision.

  • type RealtimeMcpListTools struct{…}

    A Realtime item listing tools available on an MCP server.

    • ServerLabel string

      The label of the MCP server.

    • Tools []RealtimeMcpListToolsTool

      The tools available on the server.

      • InputSchema any

        The JSON schema describing the tool's input.

      • Name string

        The name of the tool.

      • Annotations any

        Additional annotations about the tool.

      • Description string

        The description of the tool.

    • Type McpListTools

      The type of the item. Always mcp_list_tools.

      • const McpListToolsMcpListTools McpListTools = "mcp_list_tools"

    • ID string

      The unique ID of the list.

  • type RealtimeMcpToolCall struct{…}

    A Realtime item representing an invocation of a tool on an MCP server.

    • ID string

      The unique ID of the tool call.

    • Arguments string

      A JSON string of the arguments passed to the tool.

    • Name string

      The name of the tool that was run.

    • ServerLabel string

      The label of the MCP server running the tool.

    • Type McpCall

      The type of the item. Always mcp_call.

      • const McpCallMcpCall McpCall = "mcp_call"

    • ApprovalRequestID string

      The ID of an associated approval request, if any.

    • Error RealtimeMcpToolCallErrorUnion

      The error from the tool call, if any.

      • type RealtimeMcpProtocolError struct{…}

        • Code int64

        • Message string

        • Type ProtocolError

          • const ProtocolErrorProtocolError ProtocolError = "protocol_error"

      • type RealtimeMcpToolExecutionError struct{…}

        • Message string

        • Type ToolExecutionError

          • const ToolExecutionErrorToolExecutionError ToolExecutionError = "tool_execution_error"

      • type RealtimeMcphttpError struct{…}

        • Code int64

        • Message string

        • Type HTTPError

          • const HTTPErrorHTTPError HTTPError = "http_error"

    • Output string

      The output from the tool call.

  • type RealtimeMcpApprovalRequest struct{…}

    A Realtime item requesting human approval of a tool invocation.

    • ID string

      The unique ID of the approval request.

    • Arguments string

      A JSON string of arguments for the tool.

    • Name string

      The name of the tool to run.

    • ServerLabel string

      The label of the MCP server making the request.

    • Type McpApprovalRequest

      The type of the item. Always mcp_approval_request.

      • const McpApprovalRequestMcpApprovalRequest McpApprovalRequest = "mcp_approval_request"

Conversation Item Added

• type ConversationItemAdded struct{…}

  Sent by the server when an Item is added to the default Conversation. This can happen in several cases:

  • When the client sends a conversation.item.create event.
  • When the input audio buffer is committed. In this case the item will be a user message containing the audio from the buffer.
  • When the model is generating a Response. In this case the conversation.item.added event will be sent when the model starts generating a specific Item, and thus it will not yet have any content (and status will be in_progress).

  The event will include the full content of the Item (except when model is generating a Response) except for audio data, which can be retrieved separately with a conversation.item.retrieve event if necessary.

  • EventID string

    The unique ID of the server event.

  • Item ConversationItemUnion

    A single item within a Realtime conversation.

    • type RealtimeConversationItemSystemMessage struct{…}

      A system message in a Realtime conversation can be used to provide additional context or instructions to the model. This is similar but distinct from the instruction prompt provided at the start of a conversation, as system messages can be added at any point in the conversation. For major changes to the conversation's behavior, use instructions, but for smaller updates (e.g. "the user is now asking about a different topic"), use system messages.

      • Content []RealtimeConversationItemSystemMessageContent

        The content of the message.

        • Text string

          The text content.

        • Type string

          The content type. Always input_text for system messages.

          • const RealtimeConversationItemSystemMessageContentTypeInputText RealtimeConversationItemSystemMessageContentType = "input_text"

      • Role System

        The role of the message sender. Always system.

        • const SystemSystem System = "system"

      • Type Message

        The type of the item. Always message.

        • const MessageMessage Message = "message"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • Object RealtimeConversationItemSystemMessageObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemSystemMessageObjectRealtimeItem RealtimeConversationItemSystemMessageObject = "realtime.item"

      • Status RealtimeConversationItemSystemMessageStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemSystemMessageStatusCompleted RealtimeConversationItemSystemMessageStatus = "completed"

        • const RealtimeConversationItemSystemMessageStatusIncomplete RealtimeConversationItemSystemMessageStatus = "incomplete"

        • const RealtimeConversationItemSystemMessageStatusInProgress RealtimeConversationItemSystemMessageStatus = "in_progress"

    • type RealtimeConversationItemUserMessage struct{…}

      A user message item in a Realtime conversation.

      • Content []RealtimeConversationItemUserMessageContent

        The content of the message.

        • Audio string

          Base64-encoded audio bytes (for input_audio), these will be parsed as the format specified in the session input audio type configuration. This defaults to PCM 16-bit 24kHz mono if not specified.

        • Detail string

          The detail level of the image (for input_image). auto will default to high.

          • const RealtimeConversationItemUserMessageContentDetailAuto RealtimeConversationItemUserMessageContentDetail = "auto"

          • const RealtimeConversationItemUserMessageContentDetailLow RealtimeConversationItemUserMessageContentDetail = "low"

          • const RealtimeConversationItemUserMessageContentDetailHigh RealtimeConversationItemUserMessageContentDetail = "high"

        • ImageURL string

          Base64-encoded image bytes (for input_image) as a data URI. For example data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAA.... Supported formats are PNG and JPEG.

        • Text string

          The text content (for input_text).

        • Transcript string

          Transcript of the audio (for input_audio). This is not sent to the model, but will be attached to the message item for reference.

        • Type string

          The content type (input_text, input_audio, or input_image).

          • const RealtimeConversationItemUserMessageContentTypeInputText RealtimeConversationItemUserMessageContentType = "input_text"

          • const RealtimeConversationItemUserMessageContentTypeInputAudio RealtimeConversationItemUserMessageContentType = "input_audio"

          • const RealtimeConversationItemUserMessageContentTypeInputImage RealtimeConversationItemUserMessageContentType = "input_image"

      • Role User

        The role of the message sender. Always user.

        • const UserUser User = "user"

      • Type Message

        The type of the item. Always message.

        • const MessageMessage Message = "message"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • Object RealtimeConversationItemUserMessageObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemUserMessageObjectRealtimeItem RealtimeConversationItemUserMessageObject = "realtime.item"

      • Status RealtimeConversationItemUserMessageStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemUserMessageStatusCompleted RealtimeConversationItemUserMessageStatus = "completed"

        • const RealtimeConversationItemUserMessageStatusIncomplete RealtimeConversationItemUserMessageStatus = "incomplete"

        • const RealtimeConversationItemUserMessageStatusInProgress RealtimeConversationItemUserMessageStatus = "in_progress"

    • type RealtimeConversationItemAssistantMessage struct{…}

      An assistant message item in a Realtime conversation.

      • Content []RealtimeConversationItemAssistantMessageContent

        The content of the message.

        • Audio string

          Base64-encoded audio bytes, these will be parsed as the format specified in the session output audio type configuration. This defaults to PCM 16-bit 24kHz mono if not specified.

        • Text string

          The text content.

        • Transcript string

          The transcript of the audio content, this will always be present if the output type is audio.

        • Type string

          The content type, output_text or output_audio depending on the session output_modalities configuration.

          • const RealtimeConversationItemAssistantMessageContentTypeOutputText RealtimeConversationItemAssistantMessageContentType = "output_text"

          • const RealtimeConversationItemAssistantMessageContentTypeOutputAudio RealtimeConversationItemAssistantMessageContentType = "output_audio"

      • Role Assistant

        The role of the message sender. Always assistant.

        • const AssistantAssistant Assistant = "assistant"

      • Type Message

        The type of the item. Always message.

        • const MessageMessage Message = "message"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • Object RealtimeConversationItemAssistantMessageObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemAssistantMessageObjectRealtimeItem RealtimeConversationItemAssistantMessageObject = "realtime.item"

      • Status RealtimeConversationItemAssistantMessageStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemAssistantMessageStatusCompleted RealtimeConversationItemAssistantMessageStatus = "completed"

        • const RealtimeConversationItemAssistantMessageStatusIncomplete RealtimeConversationItemAssistantMessageStatus = "incomplete"

        • const RealtimeConversationItemAssistantMessageStatusInProgress RealtimeConversationItemAssistantMessageStatus = "in_progress"

    • type RealtimeConversationItemFunctionCall struct{…}

      A function call item in a Realtime conversation.

      • Arguments string

        The arguments of the function call. This is a JSON-encoded string representing the arguments passed to the function, for example {"arg1": "value1", "arg2": 42}.

      • Name string

        The name of the function being called.

      • Type FunctionCall

        The type of the item. Always function_call.

        • const FunctionCallFunctionCall FunctionCall = "function_call"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • CallID string

        The ID of the function call.

      • Object RealtimeConversationItemFunctionCallObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemFunctionCallObjectRealtimeItem RealtimeConversationItemFunctionCallObject = "realtime.item"

      • Status RealtimeConversationItemFunctionCallStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemFunctionCallStatusCompleted RealtimeConversationItemFunctionCallStatus = "completed"

        • const RealtimeConversationItemFunctionCallStatusIncomplete RealtimeConversationItemFunctionCallStatus = "incomplete"

        • const RealtimeConversationItemFunctionCallStatusInProgress RealtimeConversationItemFunctionCallStatus = "in_progress"

    • type RealtimeConversationItemFunctionCallOutput struct{…}

      A function call output item in a Realtime conversation.

      • CallID string

        The ID of the function call this output is for.

      • Output string

        The output of the function call, this is free text and can contain any information or simply be empty.

      • Type FunctionCallOutput

        The type of the item. Always function_call_output.

        • const FunctionCallOutputFunctionCallOutput FunctionCallOutput = "function_call_output"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • Object RealtimeConversationItemFunctionCallOutputObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemFunctionCallOutputObjectRealtimeItem RealtimeConversationItemFunctionCallOutputObject = "realtime.item"

      • Status RealtimeConversationItemFunctionCallOutputStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemFunctionCallOutputStatusCompleted RealtimeConversationItemFunctionCallOutputStatus = "completed"

        • const RealtimeConversationItemFunctionCallOutputStatusIncomplete RealtimeConversationItemFunctionCallOutputStatus = "incomplete"

        • const RealtimeConversationItemFunctionCallOutputStatusInProgress RealtimeConversationItemFunctionCallOutputStatus = "in_progress"

    • type RealtimeMcpApprovalResponse struct{…}

      A Realtime item responding to an MCP approval request.

      • ID string

        The unique ID of the approval response.

      • ApprovalRequestID string

        The ID of the approval request being answered.

      • Approve bool

        Whether the request was approved.

      • Type McpApprovalResponse

        The type of the item. Always mcp_approval_response.

        • const McpApprovalResponseMcpApprovalResponse McpApprovalResponse = "mcp_approval_response"

      • Reason string

        Optional reason for the decision.

    • type RealtimeMcpListTools struct{…}

      A Realtime item listing tools available on an MCP server.

      • ServerLabel string

        The label of the MCP server.

      • Tools []RealtimeMcpListToolsTool

        The tools available on the server.

        • InputSchema any

          The JSON schema describing the tool's input.

        • Name string

          The name of the tool.

        • Annotations any

          Additional annotations about the tool.

        • Description string

          The description of the tool.

      • Type McpListTools

        The type of the item. Always mcp_list_tools.

        • const McpListToolsMcpListTools McpListTools = "mcp_list_tools"

      • ID string

        The unique ID of the list.

    • type RealtimeMcpToolCall struct{…}

      A Realtime item representing an invocation of a tool on an MCP server.

      • ID string

        The unique ID of the tool call.

      • Arguments string

        A JSON string of the arguments passed to the tool.

      • Name string

        The name of the tool that was run.

      • ServerLabel string

        The label of the MCP server running the tool.

      • Type McpCall

        The type of the item. Always mcp_call.

        • const McpCallMcpCall McpCall = "mcp_call"

      • ApprovalRequestID string

        The ID of an associated approval request, if any.

      • Error RealtimeMcpToolCallErrorUnion

        The error from the tool call, if any.

        • type RealtimeMcpProtocolError struct{…}

          • Code int64

          • Message string

          • Type ProtocolError

            • const ProtocolErrorProtocolError ProtocolError = "protocol_error"

        • type RealtimeMcpToolExecutionError struct{…}

          • Message string

          • Type ToolExecutionError

            • const ToolExecutionErrorToolExecutionError ToolExecutionError = "tool_execution_error"

        • type RealtimeMcphttpError struct{…}

          • Code int64

          • Message string

          • Type HTTPError

            • const HTTPErrorHTTPError HTTPError = "http_error"

      • Output string

        The output from the tool call.

    • type RealtimeMcpApprovalRequest struct{…}

      A Realtime item requesting human approval of a tool invocation.

      • ID string

        The unique ID of the approval request.

      • Arguments string

        A JSON string of arguments for the tool.

      • Name string

        The name of the tool to run.

      • ServerLabel string

        The label of the MCP server making the request.

      • Type McpApprovalRequest

        The type of the item. Always mcp_approval_request.

        • const McpApprovalRequestMcpApprovalRequest McpApprovalRequest = "mcp_approval_request"

  • Type ConversationItemAdded

    The event type, must be conversation.item.added.

    • const ConversationItemAddedConversationItemAdded ConversationItemAdded = "conversation.item.added"

  • PreviousItemID string

    The ID of the item that precedes this one, if any. This is used to maintain ordering when items are inserted.

Conversation Item Create Event

• type ConversationItemCreateEvent struct{…}

  Add a new Item to the Conversation's context, including messages, function calls, and function call responses. This event can be used both to populate a "history" of the conversation and to add new items mid-stream, but has the current limitation that it cannot populate assistant audio messages.

  If successful, the server will respond with a conversation.item.created event, otherwise an error event will be sent.

  • Item ConversationItemUnion

    A single item within a Realtime conversation.

    • type RealtimeConversationItemSystemMessage struct{…}

      A system message in a Realtime conversation can be used to provide additional context or instructions to the model. This is similar but distinct from the instruction prompt provided at the start of a conversation, as system messages can be added at any point in the conversation. For major changes to the conversation's behavior, use instructions, but for smaller updates (e.g. "the user is now asking about a different topic"), use system messages.

      • Content []RealtimeConversationItemSystemMessageContent

        The content of the message.

        • Text string

          The text content.

        • Type string

          The content type. Always input_text for system messages.

          • const RealtimeConversationItemSystemMessageContentTypeInputText RealtimeConversationItemSystemMessageContentType = "input_text"

      • Role System

        The role of the message sender. Always system.

        • const SystemSystem System = "system"

      • Type Message

        The type of the item. Always message.

        • const MessageMessage Message = "message"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • Object RealtimeConversationItemSystemMessageObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemSystemMessageObjectRealtimeItem RealtimeConversationItemSystemMessageObject = "realtime.item"

      • Status RealtimeConversationItemSystemMessageStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemSystemMessageStatusCompleted RealtimeConversationItemSystemMessageStatus = "completed"

        • const RealtimeConversationItemSystemMessageStatusIncomplete RealtimeConversationItemSystemMessageStatus = "incomplete"

        • const RealtimeConversationItemSystemMessageStatusInProgress RealtimeConversationItemSystemMessageStatus = "in_progress"

    • type RealtimeConversationItemUserMessage struct{…}

      A user message item in a Realtime conversation.

      • Content []RealtimeConversationItemUserMessageContent

        The content of the message.

        • Audio string

          Base64-encoded audio bytes (for input_audio), these will be parsed as the format specified in the session input audio type configuration. This defaults to PCM 16-bit 24kHz mono if not specified.

        • Detail string

          The detail level of the image (for input_image). auto will default to high.

          • const RealtimeConversationItemUserMessageContentDetailAuto RealtimeConversationItemUserMessageContentDetail = "auto"

          • const RealtimeConversationItemUserMessageContentDetailLow RealtimeConversationItemUserMessageContentDetail = "low"

          • const RealtimeConversationItemUserMessageContentDetailHigh RealtimeConversationItemUserMessageContentDetail = "high"

        • ImageURL string

          Base64-encoded image bytes (for input_image) as a data URI. For example data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAA.... Supported formats are PNG and JPEG.

        • Text string

          The text content (for input_text).

        • Transcript string

          Transcript of the audio (for input_audio). This is not sent to the model, but will be attached to the message item for reference.

        • Type string

          The content type (input_text, input_audio, or input_image).

          • const RealtimeConversationItemUserMessageContentTypeInputText RealtimeConversationItemUserMessageContentType = "input_text"

          • const RealtimeConversationItemUserMessageContentTypeInputAudio RealtimeConversationItemUserMessageContentType = "input_audio"

          • const RealtimeConversationItemUserMessageContentTypeInputImage RealtimeConversationItemUserMessageContentType = "input_image"

      • Role User

        The role of the message sender. Always user.

        • const UserUser User = "user"

      • Type Message

        The type of the item. Always message.

        • const MessageMessage Message = "message"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • Object RealtimeConversationItemUserMessageObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemUserMessageObjectRealtimeItem RealtimeConversationItemUserMessageObject = "realtime.item"

      • Status RealtimeConversationItemUserMessageStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemUserMessageStatusCompleted RealtimeConversationItemUserMessageStatus = "completed"

        • const RealtimeConversationItemUserMessageStatusIncomplete RealtimeConversationItemUserMessageStatus = "incomplete"

        • const RealtimeConversationItemUserMessageStatusInProgress RealtimeConversationItemUserMessageStatus = "in_progress"

    • type RealtimeConversationItemAssistantMessage struct{…}

      An assistant message item in a Realtime conversation.

      • Content []RealtimeConversationItemAssistantMessageContent

        The content of the message.

        • Audio string

          Base64-encoded audio bytes, these will be parsed as the format specified in the session output audio type configuration. This defaults to PCM 16-bit 24kHz mono if not specified.

        • Text string

          The text content.

        • Transcript string

          The transcript of the audio content, this will always be present if the output type is audio.

        • Type string

          The content type, output_text or output_audio depending on the session output_modalities configuration.

          • const RealtimeConversationItemAssistantMessageContentTypeOutputText RealtimeConversationItemAssistantMessageContentType = "output_text"

          • const RealtimeConversationItemAssistantMessageContentTypeOutputAudio RealtimeConversationItemAssistantMessageContentType = "output_audio"

      • Role Assistant

        The role of the message sender. Always assistant.

        • const AssistantAssistant Assistant = "assistant"

      • Type Message

        The type of the item. Always message.

        • const MessageMessage Message = "message"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • Object RealtimeConversationItemAssistantMessageObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemAssistantMessageObjectRealtimeItem RealtimeConversationItemAssistantMessageObject = "realtime.item"

      • Status RealtimeConversationItemAssistantMessageStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemAssistantMessageStatusCompleted RealtimeConversationItemAssistantMessageStatus = "completed"

        • const RealtimeConversationItemAssistantMessageStatusIncomplete RealtimeConversationItemAssistantMessageStatus = "incomplete"

        • const RealtimeConversationItemAssistantMessageStatusInProgress RealtimeConversationItemAssistantMessageStatus = "in_progress"

    • type RealtimeConversationItemFunctionCall struct{…}

      A function call item in a Realtime conversation.

      • Arguments string

        The arguments of the function call. This is a JSON-encoded string representing the arguments passed to the function, for example {"arg1": "value1", "arg2": 42}.

      • Name string

        The name of the function being called.

      • Type FunctionCall

        The type of the item. Always function_call.

        • const FunctionCallFunctionCall FunctionCall = "function_call"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • CallID string

        The ID of the function call.

      • Object RealtimeConversationItemFunctionCallObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemFunctionCallObjectRealtimeItem RealtimeConversationItemFunctionCallObject = "realtime.item"

      • Status RealtimeConversationItemFunctionCallStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemFunctionCallStatusCompleted RealtimeConversationItemFunctionCallStatus = "completed"

        • const RealtimeConversationItemFunctionCallStatusIncomplete RealtimeConversationItemFunctionCallStatus = "incomplete"

        • const RealtimeConversationItemFunctionCallStatusInProgress RealtimeConversationItemFunctionCallStatus = "in_progress"

    • type RealtimeConversationItemFunctionCallOutput struct{…}

      A function call output item in a Realtime conversation.

      • CallID string

        The ID of the function call this output is for.

      • Output string

        The output of the function call, this is free text and can contain any information or simply be empty.

      • Type FunctionCallOutput

        The type of the item. Always function_call_output.

        • const FunctionCallOutputFunctionCallOutput FunctionCallOutput = "function_call_output"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • Object RealtimeConversationItemFunctionCallOutputObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemFunctionCallOutputObjectRealtimeItem RealtimeConversationItemFunctionCallOutputObject = "realtime.item"

      • Status RealtimeConversationItemFunctionCallOutputStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemFunctionCallOutputStatusCompleted RealtimeConversationItemFunctionCallOutputStatus = "completed"

        • const RealtimeConversationItemFunctionCallOutputStatusIncomplete RealtimeConversationItemFunctionCallOutputStatus = "incomplete"

        • const RealtimeConversationItemFunctionCallOutputStatusInProgress RealtimeConversationItemFunctionCallOutputStatus = "in_progress"

    • type RealtimeMcpApprovalResponse struct{…}

      A Realtime item responding to an MCP approval request.

      • ID string

        The unique ID of the approval response.

      • ApprovalRequestID string

        The ID of the approval request being answered.

      • Approve bool

        Whether the request was approved.

      • Type McpApprovalResponse

        The type of the item. Always mcp_approval_response.

        • const McpApprovalResponseMcpApprovalResponse McpApprovalResponse = "mcp_approval_response"

      • Reason string

        Optional reason for the decision.

    • type RealtimeMcpListTools struct{…}

      A Realtime item listing tools available on an MCP server.

      • ServerLabel string

        The label of the MCP server.

      • Tools []RealtimeMcpListToolsTool

        The tools available on the server.

        • InputSchema any

          The JSON schema describing the tool's input.

        • Name string

          The name of the tool.

        • Annotations any

          Additional annotations about the tool.

        • Description string

          The description of the tool.

      • Type McpListTools

        The type of the item. Always mcp_list_tools.

        • const McpListToolsMcpListTools McpListTools = "mcp_list_tools"

      • ID string

        The unique ID of the list.

    • type RealtimeMcpToolCall struct{…}

      A Realtime item representing an invocation of a tool on an MCP server.

      • ID string

        The unique ID of the tool call.

      • Arguments string

        A JSON string of the arguments passed to the tool.

      • Name string

        The name of the tool that was run.

      • ServerLabel string

        The label of the MCP server running the tool.

      • Type McpCall

        The type of the item. Always mcp_call.

        • const McpCallMcpCall McpCall = "mcp_call"

      • ApprovalRequestID string

        The ID of an associated approval request, if any.

      • Error RealtimeMcpToolCallErrorUnion

        The error from the tool call, if any.

        • type RealtimeMcpProtocolError struct{…}

          • Code int64

          • Message string

          • Type ProtocolError

            • const ProtocolErrorProtocolError ProtocolError = "protocol_error"

        • type RealtimeMcpToolExecutionError struct{…}

          • Message string

          • Type ToolExecutionError

            • const ToolExecutionErrorToolExecutionError ToolExecutionError = "tool_execution_error"

        • type RealtimeMcphttpError struct{…}

          • Code int64

          • Message string

          • Type HTTPError

            • const HTTPErrorHTTPError HTTPError = "http_error"

      • Output string

        The output from the tool call.

    • type RealtimeMcpApprovalRequest struct{…}

      A Realtime item requesting human approval of a tool invocation.

      • ID string

        The unique ID of the approval request.

      • Arguments string

        A JSON string of arguments for the tool.

      • Name string

        The name of the tool to run.

      • ServerLabel string

        The label of the MCP server making the request.

      • Type McpApprovalRequest

        The type of the item. Always mcp_approval_request.

        • const McpApprovalRequestMcpApprovalRequest McpApprovalRequest = "mcp_approval_request"

  • Type ConversationItemCreate

    The event type, must be conversation.item.create.

    • const ConversationItemCreateConversationItemCreate ConversationItemCreate = "conversation.item.create"

  • EventID string

    Optional client-generated ID used to identify this event.

  • PreviousItemID string

    The ID of the preceding item after which the new item will be inserted. If not set, the new item will be appended to the end of the conversation.

    If set to root, the new item will be added to the beginning of the conversation.

    If set to an existing ID, it allows an item to be inserted mid-conversation. If the ID cannot be found, an error will be returned and the item will not be added.

Conversation Item Created Event

• type ConversationItemCreatedEvent struct{…}

  Returned when a conversation item is created. There are several scenarios that produce this event:

  • The server is generating a Response, which if successful will produce either one or two Items, which will be of type message (role assistant) or type function_call.

  • The input audio buffer has been committed, either by the client or the server (in server_vad mode). The server will take the content of the input audio buffer and add it to a new user message Item.

  • The client has sent a conversation.item.create event to add a new Item to the Conversation.

  • EventID string

    The unique ID of the server event.

  • Item ConversationItemUnion

    A single item within a Realtime conversation.

    • type RealtimeConversationItemSystemMessage struct{…}

      A system message in a Realtime conversation can be used to provide additional context or instructions to the model. This is similar but distinct from the instruction prompt provided at the start of a conversation, as system messages can be added at any point in the conversation. For major changes to the conversation's behavior, use instructions, but for smaller updates (e.g. "the user is now asking about a different topic"), use system messages.

      • Content []RealtimeConversationItemSystemMessageContent

        The content of the message.

        • Text string

          The text content.

        • Type string

          The content type. Always input_text for system messages.

          • const RealtimeConversationItemSystemMessageContentTypeInputText RealtimeConversationItemSystemMessageContentType = "input_text"

      • Role System

        The role of the message sender. Always system.

        • const SystemSystem System = "system"

      • Type Message

        The type of the item. Always message.

        • const MessageMessage Message = "message"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • Object RealtimeConversationItemSystemMessageObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemSystemMessageObjectRealtimeItem RealtimeConversationItemSystemMessageObject = "realtime.item"

      • Status RealtimeConversationItemSystemMessageStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemSystemMessageStatusCompleted RealtimeConversationItemSystemMessageStatus = "completed"

        • const RealtimeConversationItemSystemMessageStatusIncomplete RealtimeConversationItemSystemMessageStatus = "incomplete"

        • const RealtimeConversationItemSystemMessageStatusInProgress RealtimeConversationItemSystemMessageStatus = "in_progress"

    • type RealtimeConversationItemUserMessage struct{…}

      A user message item in a Realtime conversation.

      • Content []RealtimeConversationItemUserMessageContent

        The content of the message.

        • Audio string

          Base64-encoded audio bytes (for input_audio), these will be parsed as the format specified in the session input audio type configuration. This defaults to PCM 16-bit 24kHz mono if not specified.

        • Detail string

          The detail level of the image (for input_image). auto will default to high.

          • const RealtimeConversationItemUserMessageContentDetailAuto RealtimeConversationItemUserMessageContentDetail = "auto"

          • const RealtimeConversationItemUserMessageContentDetailLow RealtimeConversationItemUserMessageContentDetail = "low"

          • const RealtimeConversationItemUserMessageContentDetailHigh RealtimeConversationItemUserMessageContentDetail = "high"

        • ImageURL string

          Base64-encoded image bytes (for input_image) as a data URI. For example data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAA.... Supported formats are PNG and JPEG.

        • Text string

          The text content (for input_text).

        • Transcript string

          Transcript of the audio (for input_audio). This is not sent to the model, but will be attached to the message item for reference.

        • Type string

          The content type (input_text, input_audio, or input_image).

          • const RealtimeConversationItemUserMessageContentTypeInputText RealtimeConversationItemUserMessageContentType = "input_text"

          • const RealtimeConversationItemUserMessageContentTypeInputAudio RealtimeConversationItemUserMessageContentType = "input_audio"

          • const RealtimeConversationItemUserMessageContentTypeInputImage RealtimeConversationItemUserMessageContentType = "input_image"

      • Role User

        The role of the message sender. Always user.

        • const UserUser User = "user"

      • Type Message

        The type of the item. Always message.

        • const MessageMessage Message = "message"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • Object RealtimeConversationItemUserMessageObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemUserMessageObjectRealtimeItem RealtimeConversationItemUserMessageObject = "realtime.item"

      • Status RealtimeConversationItemUserMessageStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemUserMessageStatusCompleted RealtimeConversationItemUserMessageStatus = "completed"

        • const RealtimeConversationItemUserMessageStatusIncomplete RealtimeConversationItemUserMessageStatus = "incomplete"

        • const RealtimeConversationItemUserMessageStatusInProgress RealtimeConversationItemUserMessageStatus = "in_progress"

    • type RealtimeConversationItemAssistantMessage struct{…}

      An assistant message item in a Realtime conversation.

      • Content []RealtimeConversationItemAssistantMessageContent

        The content of the message.

        • Audio string

          Base64-encoded audio bytes, these will be parsed as the format specified in the session output audio type configuration. This defaults to PCM 16-bit 24kHz mono if not specified.

        • Text string

          The text content.

        • Transcript string

          The transcript of the audio content, this will always be present if the output type is audio.

        • Type string

          The content type, output_text or output_audio depending on the session output_modalities configuration.

          • const RealtimeConversationItemAssistantMessageContentTypeOutputText RealtimeConversationItemAssistantMessageContentType = "output_text"

          • const RealtimeConversationItemAssistantMessageContentTypeOutputAudio RealtimeConversationItemAssistantMessageContentType = "output_audio"

      • Role Assistant

        The role of the message sender. Always assistant.

        • const AssistantAssistant Assistant = "assistant"

      • Type Message

        The type of the item. Always message.

        • const MessageMessage Message = "message"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • Object RealtimeConversationItemAssistantMessageObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemAssistantMessageObjectRealtimeItem RealtimeConversationItemAssistantMessageObject = "realtime.item"

      • Status RealtimeConversationItemAssistantMessageStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemAssistantMessageStatusCompleted RealtimeConversationItemAssistantMessageStatus = "completed"

        • const RealtimeConversationItemAssistantMessageStatusIncomplete RealtimeConversationItemAssistantMessageStatus = "incomplete"

        • const RealtimeConversationItemAssistantMessageStatusInProgress RealtimeConversationItemAssistantMessageStatus = "in_progress"

    • type RealtimeConversationItemFunctionCall struct{…}

      A function call item in a Realtime conversation.

      • Arguments string

        The arguments of the function call. This is a JSON-encoded string representing the arguments passed to the function, for example {"arg1": "value1", "arg2": 42}.

      • Name string

        The name of the function being called.

      • Type FunctionCall

        The type of the item. Always function_call.

        • const FunctionCallFunctionCall FunctionCall = "function_call"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • CallID string

        The ID of the function call.

      • Object RealtimeConversationItemFunctionCallObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemFunctionCallObjectRealtimeItem RealtimeConversationItemFunctionCallObject = "realtime.item"

      • Status RealtimeConversationItemFunctionCallStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemFunctionCallStatusCompleted RealtimeConversationItemFunctionCallStatus = "completed"

        • const RealtimeConversationItemFunctionCallStatusIncomplete RealtimeConversationItemFunctionCallStatus = "incomplete"

        • const RealtimeConversationItemFunctionCallStatusInProgress RealtimeConversationItemFunctionCallStatus = "in_progress"

    • type RealtimeConversationItemFunctionCallOutput struct{…}

      A function call output item in a Realtime conversation.

      • CallID string

        The ID of the function call this output is for.

      • Output string

        The output of the function call, this is free text and can contain any information or simply be empty.

      • Type FunctionCallOutput

        The type of the item. Always function_call_output.

        • const FunctionCallOutputFunctionCallOutput FunctionCallOutput = "function_call_output"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • Object RealtimeConversationItemFunctionCallOutputObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemFunctionCallOutputObjectRealtimeItem RealtimeConversationItemFunctionCallOutputObject = "realtime.item"

      • Status RealtimeConversationItemFunctionCallOutputStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemFunctionCallOutputStatusCompleted RealtimeConversationItemFunctionCallOutputStatus = "completed"

        • const RealtimeConversationItemFunctionCallOutputStatusIncomplete RealtimeConversationItemFunctionCallOutputStatus = "incomplete"

        • const RealtimeConversationItemFunctionCallOutputStatusInProgress RealtimeConversationItemFunctionCallOutputStatus = "in_progress"

    • type RealtimeMcpApprovalResponse struct{…}

      A Realtime item responding to an MCP approval request.

      • ID string

        The unique ID of the approval response.

      • ApprovalRequestID string

        The ID of the approval request being answered.

      • Approve bool

        Whether the request was approved.

      • Type McpApprovalResponse

        The type of the item. Always mcp_approval_response.

        • const McpApprovalResponseMcpApprovalResponse McpApprovalResponse = "mcp_approval_response"

      • Reason string

        Optional reason for the decision.

    • type RealtimeMcpListTools struct{…}

      A Realtime item listing tools available on an MCP server.

      • ServerLabel string

        The label of the MCP server.

      • Tools []RealtimeMcpListToolsTool

        The tools available on the server.

        • InputSchema any

          The JSON schema describing the tool's input.

        • Name string

          The name of the tool.

        • Annotations any

          Additional annotations about the tool.

        • Description string

          The description of the tool.

      • Type McpListTools

        The type of the item. Always mcp_list_tools.

        • const McpListToolsMcpListTools McpListTools = "mcp_list_tools"

      • ID string

        The unique ID of the list.

    • type RealtimeMcpToolCall struct{…}

      A Realtime item representing an invocation of a tool on an MCP server.

      • ID string

        The unique ID of the tool call.

      • Arguments string

        A JSON string of the arguments passed to the tool.

      • Name string

        The name of the tool that was run.

      • ServerLabel string

        The label of the MCP server running the tool.

      • Type McpCall

        The type of the item. Always mcp_call.

        • const McpCallMcpCall McpCall = "mcp_call"

      • ApprovalRequestID string

        The ID of an associated approval request, if any.

      • Error RealtimeMcpToolCallErrorUnion

        The error from the tool call, if any.

        • type RealtimeMcpProtocolError struct{…}

          • Code int64

          • Message string

          • Type ProtocolError

            • const ProtocolErrorProtocolError ProtocolError = "protocol_error"

        • type RealtimeMcpToolExecutionError struct{…}

          • Message string

          • Type ToolExecutionError

            • const ToolExecutionErrorToolExecutionError ToolExecutionError = "tool_execution_error"

        • type RealtimeMcphttpError struct{…}

          • Code int64

          • Message string

          • Type HTTPError

            • const HTTPErrorHTTPError HTTPError = "http_error"

      • Output string

        The output from the tool call.

    • type RealtimeMcpApprovalRequest struct{…}

      A Realtime item requesting human approval of a tool invocation.

      • ID string

        The unique ID of the approval request.

      • Arguments string

        A JSON string of arguments for the tool.

      • Name string

        The name of the tool to run.

      • ServerLabel string

        The label of the MCP server making the request.

      • Type McpApprovalRequest

        The type of the item. Always mcp_approval_request.

        • const McpApprovalRequestMcpApprovalRequest McpApprovalRequest = "mcp_approval_request"

  • Type ConversationItemCreated

    The event type, must be conversation.item.created.

    • const ConversationItemCreatedConversationItemCreated ConversationItemCreated = "conversation.item.created"

  • PreviousItemID string

    The ID of the preceding item in the Conversation context, allows the client to understand the order of the conversation. Can be null if the item has no predecessor.

Conversation Item Delete Event

• type ConversationItemDeleteEvent struct{…}

  Send this event when you want to remove any item from the conversation history. The server will respond with a conversation.item.deleted event, unless the item does not exist in the conversation history, in which case the server will respond with an error.

  • ItemID string

    The ID of the item to delete.

  • Type ConversationItemDelete

    The event type, must be conversation.item.delete.

    • const ConversationItemDeleteConversationItemDelete ConversationItemDelete = "conversation.item.delete"

  • EventID string

    Optional client-generated ID used to identify this event.

Conversation Item Deleted Event

• type ConversationItemDeletedEvent struct{…}

  Returned when an item in the conversation is deleted by the client with a conversation.item.delete event. This event is used to synchronize the server's understanding of the conversation history with the client's view.

  • EventID string

    The unique ID of the server event.

  • ItemID string

    The ID of the item that was deleted.

  • Type ConversationItemDeleted

    The event type, must be conversation.item.deleted.

    • const ConversationItemDeletedConversationItemDeleted ConversationItemDeleted = "conversation.item.deleted"

Conversation Item Done

• type ConversationItemDone struct{…}

  Returned when a conversation item is finalized.

  The event will include the full content of the Item except for audio data, which can be retrieved separately with a conversation.item.retrieve event if needed.

  • EventID string

    The unique ID of the server event.

  • Item ConversationItemUnion

    A single item within a Realtime conversation.

    • type RealtimeConversationItemSystemMessage struct{…}

      A system message in a Realtime conversation can be used to provide additional context or instructions to the model. This is similar but distinct from the instruction prompt provided at the start of a conversation, as system messages can be added at any point in the conversation. For major changes to the conversation's behavior, use instructions, but for smaller updates (e.g. "the user is now asking about a different topic"), use system messages.

      • Content []RealtimeConversationItemSystemMessageContent

        The content of the message.

        • Text string

          The text content.

        • Type string

          The content type. Always input_text for system messages.

          • const RealtimeConversationItemSystemMessageContentTypeInputText RealtimeConversationItemSystemMessageContentType = "input_text"

      • Role System

        The role of the message sender. Always system.

        • const SystemSystem System = "system"

      • Type Message

        The type of the item. Always message.

        • const MessageMessage Message = "message"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • Object RealtimeConversationItemSystemMessageObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemSystemMessageObjectRealtimeItem RealtimeConversationItemSystemMessageObject = "realtime.item"

      • Status RealtimeConversationItemSystemMessageStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemSystemMessageStatusCompleted RealtimeConversationItemSystemMessageStatus = "completed"

        • const RealtimeConversationItemSystemMessageStatusIncomplete RealtimeConversationItemSystemMessageStatus = "incomplete"

        • const RealtimeConversationItemSystemMessageStatusInProgress RealtimeConversationItemSystemMessageStatus = "in_progress"

    • type RealtimeConversationItemUserMessage struct{…}

      A user message item in a Realtime conversation.

      • Content []RealtimeConversationItemUserMessageContent

        The content of the message.

        • Audio string

          Base64-encoded audio bytes (for input_audio), these will be parsed as the format specified in the session input audio type configuration. This defaults to PCM 16-bit 24kHz mono if not specified.

        • Detail string

          The detail level of the image (for input_image). auto will default to high.

          • const RealtimeConversationItemUserMessageContentDetailAuto RealtimeConversationItemUserMessageContentDetail = "auto"

          • const RealtimeConversationItemUserMessageContentDetailLow RealtimeConversationItemUserMessageContentDetail = "low"

          • const RealtimeConversationItemUserMessageContentDetailHigh RealtimeConversationItemUserMessageContentDetail = "high"

        • ImageURL string

          Base64-encoded image bytes (for input_image) as a data URI. For example data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAA.... Supported formats are PNG and JPEG.

        • Text string

          The text content (for input_text).

        • Transcript string

          Transcript of the audio (for input_audio). This is not sent to the model, but will be attached to the message item for reference.

        • Type string

          The content type (input_text, input_audio, or input_image).

          • const RealtimeConversationItemUserMessageContentTypeInputText RealtimeConversationItemUserMessageContentType = "input_text"

          • const RealtimeConversationItemUserMessageContentTypeInputAudio RealtimeConversationItemUserMessageContentType = "input_audio"

          • const RealtimeConversationItemUserMessageContentTypeInputImage RealtimeConversationItemUserMessageContentType = "input_image"

      • Role User

        The role of the message sender. Always user.

        • const UserUser User = "user"

      • Type Message

        The type of the item. Always message.

        • const MessageMessage Message = "message"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • Object RealtimeConversationItemUserMessageObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemUserMessageObjectRealtimeItem RealtimeConversationItemUserMessageObject = "realtime.item"

      • Status RealtimeConversationItemUserMessageStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemUserMessageStatusCompleted RealtimeConversationItemUserMessageStatus = "completed"

        • const RealtimeConversationItemUserMessageStatusIncomplete RealtimeConversationItemUserMessageStatus = "incomplete"

        • const RealtimeConversationItemUserMessageStatusInProgress RealtimeConversationItemUserMessageStatus = "in_progress"

    • type RealtimeConversationItemAssistantMessage struct{…}

      An assistant message item in a Realtime conversation.

      • Content []RealtimeConversationItemAssistantMessageContent

        The content of the message.

        • Audio string

          Base64-encoded audio bytes, these will be parsed as the format specified in the session output audio type configuration. This defaults to PCM 16-bit 24kHz mono if not specified.

        • Text string

          The text content.

        • Transcript string

          The transcript of the audio content, this will always be present if the output type is audio.

        • Type string

          The content type, output_text or output_audio depending on the session output_modalities configuration.

          • const RealtimeConversationItemAssistantMessageContentTypeOutputText RealtimeConversationItemAssistantMessageContentType = "output_text"

          • const RealtimeConversationItemAssistantMessageContentTypeOutputAudio RealtimeConversationItemAssistantMessageContentType = "output_audio"

      • Role Assistant

        The role of the message sender. Always assistant.

        • const AssistantAssistant Assistant = "assistant"

      • Type Message

        The type of the item. Always message.

        • const MessageMessage Message = "message"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • Object RealtimeConversationItemAssistantMessageObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemAssistantMessageObjectRealtimeItem RealtimeConversationItemAssistantMessageObject = "realtime.item"

      • Status RealtimeConversationItemAssistantMessageStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemAssistantMessageStatusCompleted RealtimeConversationItemAssistantMessageStatus = "completed"

        • const RealtimeConversationItemAssistantMessageStatusIncomplete RealtimeConversationItemAssistantMessageStatus = "incomplete"

        • const RealtimeConversationItemAssistantMessageStatusInProgress RealtimeConversationItemAssistantMessageStatus = "in_progress"

    • type RealtimeConversationItemFunctionCall struct{…}

      A function call item in a Realtime conversation.

      • Arguments string

        The arguments of the function call. This is a JSON-encoded string representing the arguments passed to the function, for example {"arg1": "value1", "arg2": 42}.

      • Name string

        The name of the function being called.

      • Type FunctionCall

        The type of the item. Always function_call.

        • const FunctionCallFunctionCall FunctionCall = "function_call"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • CallID string

        The ID of the function call.

      • Object RealtimeConversationItemFunctionCallObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemFunctionCallObjectRealtimeItem RealtimeConversationItemFunctionCallObject = "realtime.item"

      • Status RealtimeConversationItemFunctionCallStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemFunctionCallStatusCompleted RealtimeConversationItemFunctionCallStatus = "completed"

        • const RealtimeConversationItemFunctionCallStatusIncomplete RealtimeConversationItemFunctionCallStatus = "incomplete"

        • const RealtimeConversationItemFunctionCallStatusInProgress RealtimeConversationItemFunctionCallStatus = "in_progress"

    • type RealtimeConversationItemFunctionCallOutput struct{…}

      A function call output item in a Realtime conversation.

      • CallID string

        The ID of the function call this output is for.

      • Output string

        The output of the function call, this is free text and can contain any information or simply be empty.

      • Type FunctionCallOutput

        The type of the item. Always function_call_output.

        • const FunctionCallOutputFunctionCallOutput FunctionCallOutput = "function_call_output"

      • ID string

        The unique ID of the item. This may be provided by the client or generated by the server.

      • Object RealtimeConversationItemFunctionCallOutputObject

        Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

        • const RealtimeConversationItemFunctionCallOutputObjectRealtimeItem RealtimeConversationItemFunctionCallOutputObject = "realtime.item"

      • Status RealtimeConversationItemFunctionCallOutputStatus

        The status of the item. Has no effect on the conversation.

        • const RealtimeConversationItemFunctionCallOutputStatusCompleted RealtimeConversationItemFunctionCallOutputStatus = "completed"

        • const RealtimeConversationItemFunctionCallOutputStatusIncomplete RealtimeConversationItemFunctionCallOutputStatus = "incomplete"

        • const RealtimeConversationItemFunctionCallOutputStatusInProgress RealtimeConversationItemFunctionCallOutputStatus = "in_progress"

    • type RealtimeMcpApprovalResponse struct{…}

      A Realtime item responding to an MCP approval request.

      • ID string

        The unique ID of the approval response.

      • ApprovalRequestID string

        The ID of the approval request being answered.

      • Approve bool

        Whether the request was approved.

      • Type McpApprovalResponse

        The type of the item. Always mcp_approval_response.

        • const McpApprovalResponseMcpApprovalResponse McpApprovalResponse = "mcp_approval_response"

      • Reason string

        Optional reason for the decision.

    • type RealtimeMcpListTools struct{…}

      A Realtime item listing tools available on an MCP server.

      • ServerLabel string

        The label of the MCP server.

      • Tools []RealtimeMcpListToolsTool

        The tools available on the server.

        • InputSchema any

          The JSON schema describing the tool's input.

        • Name string

          The name of the tool.

        • Annotations any

          Additional annotations about the tool.

        • Description string

          The description of the tool.

      • Type McpListTools

        The type of the item. Always mcp_list_tools.

        • const McpListToolsMcpListTools McpListTools = "mcp_list_tools"

      • ID string

        The unique ID of the list.

    • type RealtimeMcpToolCall struct{…}

      A Realtime item representing an invocation of a tool on an MCP server.

      • ID string

        The unique ID of the tool call.

      • Arguments string

        A JSON string of the arguments passed to the tool.

      • Name string

        The name of the tool that was run.

      • ServerLabel string

        The label of the MCP server running the tool.

      • Type McpCall

        The type of the item. Always mcp_call.

        • const McpCallMcpCall McpCall = "mcp_call"

      • ApprovalRequestID string

        The ID of an associated approval request, if any.

      • Error RealtimeMcpToolCallErrorUnion

        The error from the tool call, if any.

        • type RealtimeMcpProtocolError struct{…}

          • Code int64

          • Message string

          • Type ProtocolError

            • const ProtocolErrorProtocolError ProtocolError = "protocol_error"

        • type RealtimeMcpToolExecutionError struct{…}

          • Message string

          • Type ToolExecutionError

            • const ToolExecutionErrorToolExecutionError ToolExecutionError = "tool_execution_error"

        • type RealtimeMcphttpError struct{…}

          • Code int64

          • Message string

          • Type HTTPError

            • const HTTPErrorHTTPError HTTPError = "http_error"

      • Output string

        The output from the tool call.

    • type RealtimeMcpApprovalRequest struct{…}

      A Realtime item requesting human approval of a tool invocation.

      • ID string

        The unique ID of the approval request.

      • Arguments string

        A JSON string of arguments for the tool.

      • Name string

        The name of the tool to run.

      • ServerLabel string

        The label of the MCP server making the request.

      • Type McpApprovalRequest

        The type of the item. Always mcp_approval_request.

        • const McpApprovalRequestMcpApprovalRequest McpApprovalRequest = "mcp_approval_request"

  • Type ConversationItemDone

    The event type, must be conversation.item.done.

    • const ConversationItemDoneConversationItemDone ConversationItemDone = "conversation.item.done"

  • PreviousItemID string

    The ID of the item that precedes this one, if any. This is used to maintain ordering when items are inserted.

Conversation Item Input Audio Transcription Completed Event

• type ConversationItemInputAudioTranscriptionCompletedEvent struct{…}

  This event is the output of audio transcription for user audio written to the user audio buffer. Transcription begins when the input audio buffer is committed by the client or server (when VAD is enabled). Transcription runs asynchronously with Response creation, so this event may come before or after the Response events.

  Realtime API models accept audio natively, and thus input transcription is a separate process run on a separate ASR (Automatic Speech Recognition) model. The transcript may diverge somewhat from the model's interpretation, and should be treated as a rough guide.

  • ContentIndex int64

    The index of the content part containing the audio.

  • EventID string

    The unique ID of the server event.

  • ItemID string

    The ID of the item containing the audio that is being transcribed.

  • Transcript string

    The transcribed text.

  • Type ConversationItemInputAudioTranscriptionCompleted

    The event type, must be conversation.item.input_audio_transcription.completed.

    • const ConversationItemInputAudioTranscriptionCompletedConversationItemInputAudioTranscriptionCompleted ConversationItemInputAudioTranscriptionCompleted = "conversation.item.input_audio_transcription.completed"

  • Usage ConversationItemInputAudioTranscriptionCompletedEventUsageUnion

    Usage statistics for the transcription, this is billed according to the ASR model's pricing rather than the realtime model's pricing.

    • ConversationItemInputAudioTranscriptionCompletedEventUsageTranscriptTextUsageTokens

      • InputTokens int64

        Number of input tokens billed for this request.

      • OutputTokens int64

        Number of output tokens generated.

      • TotalTokens int64

        Total number of tokens used (input + output).

      • Type Tokens

        The type of the usage object. Always tokens for this variant.

        • const TokensTokens Tokens = "tokens"

      • InputTokenDetails ConversationItemInputAudioTranscriptionCompletedEventUsageTranscriptTextUsageTokensInputTokenDetails

        Details about the input tokens billed for this request.

        • AudioTokens int64

          Number of audio tokens billed for this request.

        • TextTokens int64

          Number of text tokens billed for this request.

    • ConversationItemInputAudioTranscriptionCompletedEventUsageTranscriptTextUsageDuration

      • Seconds float64

        Duration of the input audio in seconds.

      • Type Duration

        The type of the usage object. Always duration for this variant.

        • const DurationDuration Duration = "duration"

  • Logprobs []LogProbProperties

    The log probabilities of the transcription.

    • Token string

      The token that was used to generate the log probability.

    • Bytes []int64

      The bytes that were used to generate the log probability.

    • Logprob float64

      The log probability of the token.

Conversation Item Input Audio Transcription Delta Event

• type ConversationItemInputAudioTranscriptionDeltaEvent struct{…}

  Returned when the text value of an input audio transcription content part is updated with incremental transcription results.

  • EventID string

    The unique ID of the server event.

  • ItemID string

    The ID of the item containing the audio that is being transcribed.

  • Type ConversationItemInputAudioTranscriptionDelta

    The event type, must be conversation.item.input_audio_transcription.delta.

    • const ConversationItemInputAudioTranscriptionDeltaConversationItemInputAudioTranscriptionDelta ConversationItemInputAudioTranscriptionDelta = "conversation.item.input_audio_transcription.delta"

  • ContentIndex int64

    The index of the content part in the item's content array.

  • Delta string

    The text delta.

  • Logprobs []LogProbProperties

    The log probabilities of the transcription. These can be enabled by configurating the session with "include": ["item.input_audio_transcription.logprobs"]. Each entry in the array corresponds a log probability of which token would be selected for this chunk of transcription. This can help to identify if it was possible there were multiple valid options for a given chunk of transcription.

    • Token string

      The token that was used to generate the log probability.

    • Bytes []int64

      The bytes that were used to generate the log probability.

    • Logprob float64

      The log probability of the token.

Conversation Item Input Audio Transcription Failed Event

• type ConversationItemInputAudioTranscriptionFailedEvent struct{…}

  Returned when input audio transcription is configured, and a transcription request for a user message failed. These events are separate from other error events so that the client can identify the related Item.

  • ContentIndex int64

    The index of the content part containing the audio.

  • Error ConversationItemInputAudioTranscriptionFailedEventError

    Details of the transcription error.

    • Code string

      Error code, if any.

    • Message string

      A human-readable error message.

    • Param string

      Parameter related to the error, if any.

    • Type string

      The type of error.

  • EventID string

    The unique ID of the server event.

  • ItemID string

    The ID of the user message item.

  • Type ConversationItemInputAudioTranscriptionFailed

    The event type, must be conversation.item.input_audio_transcription.failed.

    • const ConversationItemInputAudioTranscriptionFailedConversationItemInputAudioTranscriptionFailed ConversationItemInputAudioTranscriptionFailed = "conversation.item.input_audio_transcription.failed"

Conversation Item Input Audio Transcription Segment

• type ConversationItemInputAudioTranscriptionSegment struct{…}

  Returned when an input audio transcription segment is identified for an item.

  • ID string

    The segment identifier.

  • ContentIndex int64

    The index of the input audio content part within the item.

  • End float64

    End time of the segment in seconds.

  • EventID string

    The unique ID of the server event.

  • ItemID string

    The ID of the item containing the input audio content.

  • Speaker string

    The detected speaker label for this segment.

  • Start float64

    Start time of the segment in seconds.

  • Text string

    The text for this segment.

  • Type ConversationItemInputAudioTranscriptionSegment

    The event type, must be conversation.item.input_audio_transcription.segment.

    • const ConversationItemInputAudioTranscriptionSegmentConversationItemInputAudioTranscriptionSegment ConversationItemInputAudioTranscriptionSegment = "conversation.item.input_audio_transcription.segment"

Conversation Item Retrieve Event

• type ConversationItemRetrieveEvent struct{…}

  Send this event when you want to retrieve the server's representation of a specific item in the conversation history. This is useful, for example, to inspect user audio after noise cancellation and VAD. The server will respond with a conversation.item.retrieved event, unless the item does not exist in the conversation history, in which case the server will respond with an error.

  • ItemID string

    The ID of the item to retrieve.

  • Type ConversationItemRetrieve

    The event type, must be conversation.item.retrieve.

    • const ConversationItemRetrieveConversationItemRetrieve ConversationItemRetrieve = "conversation.item.retrieve"

  • EventID string

    Optional client-generated ID used to identify this event.

Conversation Item Truncate Event

• type ConversationItemTruncateEvent struct{…}

  Send this event to truncate a previous assistant message’s audio. The server will produce audio faster than realtime, so this event is useful when the user interrupts to truncate audio that has already been sent to the client but not yet played. This will synchronize the server's understanding of the audio with the client's playback.

  Truncating audio will delete the server-side text transcript to ensure there is not text in the context that hasn't been heard by the user.

  If successful, the server will respond with a conversation.item.truncated event.

  • AudioEndMs int64

    Inclusive duration up to which audio is truncated, in milliseconds. If the audio_end_ms is greater than the actual audio duration, the server will respond with an error.

  • ContentIndex int64

    The index of the content part to truncate. Set this to 0.

  • ItemID string

    The ID of the assistant message item to truncate. Only assistant message items can be truncated.

  • Type ConversationItemTruncate

    The event type, must be conversation.item.truncate.

    • const ConversationItemTruncateConversationItemTruncate ConversationItemTruncate = "conversation.item.truncate"

  • EventID string

    Optional client-generated ID used to identify this event.

Conversation Item Truncated Event

• type ConversationItemTruncatedEvent struct{…}

  Returned when an earlier assistant audio message item is truncated by the client with a conversation.item.truncate event. This event is used to synchronize the server's understanding of the audio with the client's playback.

  This action will truncate the audio and remove the server-side text transcript to ensure there is no text in the context that hasn't been heard by the user.

  • AudioEndMs int64

    The duration up to which the audio was truncated, in milliseconds.

  • ContentIndex int64

    The index of the content part that was truncated.

  • EventID string

    The unique ID of the server event.

  • ItemID string

    The ID of the assistant message item that was truncated.

  • Type ConversationItemTruncated

    The event type, must be conversation.item.truncated.

    • const ConversationItemTruncatedConversationItemTruncated ConversationItemTruncated = "conversation.item.truncated"

Conversation Item With Reference

• type ConversationItemWithReference struct{…}

  The item to add to the conversation.

  • ID string

    For an item of type (message | function_call | function_call_output) this field allows the client to assign the unique ID of the item. It is not required because the server will generate one if not provided.

    For an item of type item_reference, this field is required and is a reference to any item that has previously existed in the conversation.

  • Arguments string

    The arguments of the function call (for function_call items).

  • CallID string

    The ID of the function call (for function_call and function_call_output items). If passed on a function_call_output item, the server will check that a function_call item with the same ID exists in the conversation history.

  • Content []ConversationItemWithReferenceContent

    The content of the message, applicable for message items.

    • Message items of role system support only input_text content

    • Message items of role user support input_text and input_audio content

    • Message items of role assistant support text content.

    • ID string

      ID of a previous conversation item to reference (for item_reference content types in response.create events). These can reference both client and server created items.

    • Audio string

      Base64-encoded audio bytes, used for input_audio content type.

    • Text string

      The text content, used for input_text and text content types.

    • Transcript string

      The transcript of the audio, used for input_audio content type.

    • Type string

      The content type (input_text, input_audio, item_reference, text).

      • const ConversationItemWithReferenceContentTypeInputText ConversationItemWithReferenceContentType = "input_text"

      • const ConversationItemWithReferenceContentTypeInputAudio ConversationItemWithReferenceContentType = "input_audio"

      • const ConversationItemWithReferenceContentTypeItemReference ConversationItemWithReferenceContentType = "item_reference"

      • const ConversationItemWithReferenceContentTypeText ConversationItemWithReferenceContentType = "text"

  • Name string

    The name of the function being called (for function_call items).

  • Object ConversationItemWithReferenceObject

    Identifier for the API object being returned - always realtime.item.

    • const ConversationItemWithReferenceObjectRealtimeItem ConversationItemWithReferenceObject = "realtime.item"

  • Output string

    The output of the function call (for function_call_output items).

  • Role ConversationItemWithReferenceRole

    The role of the message sender (user, assistant, system), only applicable for message items.

    • const ConversationItemWithReferenceRoleUser ConversationItemWithReferenceRole = "user"

    • const ConversationItemWithReferenceRoleAssistant ConversationItemWithReferenceRole = "assistant"

    • const ConversationItemWithReferenceRoleSystem ConversationItemWithReferenceRole = "system"

  • Status ConversationItemWithReferenceStatus

    The status of the item (completed, incomplete, in_progress). These have no effect on the conversation, but are accepted for consistency with the conversation.item.created event.

    • const ConversationItemWithReferenceStatusCompleted ConversationItemWithReferenceStatus = "completed"

    • const ConversationItemWithReferenceStatusIncomplete ConversationItemWithReferenceStatus = "incomplete"

    • const ConversationItemWithReferenceStatusInProgress ConversationItemWithReferenceStatus = "in_progress"

  • Type ConversationItemWithReferenceType

    The type of the item (message, function_call, function_call_output, item_reference).

    • const ConversationItemWithReferenceTypeMessage ConversationItemWithReferenceType = "message"

    • const ConversationItemWithReferenceTypeFunctionCall ConversationItemWithReferenceType = "function_call"

    • const ConversationItemWithReferenceTypeFunctionCallOutput ConversationItemWithReferenceType = "function_call_output"

    • const ConversationItemWithReferenceTypeItemReference ConversationItemWithReferenceType = "item_reference"

Input Audio Buffer Append Event

• type InputAudioBufferAppendEvent struct{…}

  Send this event to append audio bytes to the input audio buffer. The audio buffer is temporary storage you can write to and later commit. A "commit" will create a new user message item in the conversation history from the buffer content and clear the buffer. Input audio transcription (if enabled) will be generated when the buffer is committed.

  If VAD is enabled the audio buffer is used to detect speech and the server will decide when to commit. When Server VAD is disabled, you must commit the audio buffer manually. Input audio noise reduction operates on writes to the audio buffer.

  The client may choose how much audio to place in each event up to a maximum of 15 MiB, for example streaming smaller chunks from the client may allow the VAD to be more responsive. Unlike most other client events, the server will not send a confirmation response to this event.

  • Audio string

    Base64-encoded audio bytes. This must be in the format specified by the input_audio_format field in the session configuration.

  • Type InputAudioBufferAppend

    The event type, must be input_audio_buffer.append.

    • const InputAudioBufferAppendInputAudioBufferAppend InputAudioBufferAppend = "input_audio_buffer.append"

  • EventID string

    Optional client-generated ID used to identify this event.

Input Audio Buffer Clear Event

• type InputAudioBufferClearEvent struct{…}

  Send this event to clear the audio bytes in the buffer. The server will respond with an input_audio_buffer.cleared event.

  • Type InputAudioBufferClear

    The event type, must be input_audio_buffer.clear.

    • const InputAudioBufferClearInputAudioBufferClear InputAudioBufferClear = "input_audio_buffer.clear"

  • EventID string

    Optional client-generated ID used to identify this event.

Input Audio Buffer Cleared Event

• type InputAudioBufferClearedEvent struct{…}

  Returned when the input audio buffer is cleared by the client with a input_audio_buffer.clear event.

  • EventID string

    The unique ID of the server event.

  • Type InputAudioBufferCleared

    The event type, must be input_audio_buffer.cleared.

    • const InputAudioBufferClearedInputAudioBufferCleared InputAudioBufferCleared = "input_audio_buffer.cleared"

Input Audio Buffer Commit Event

• type InputAudioBufferCommitEvent struct{…}

  Send this event to commit the user input audio buffer, which will create a new user message item in the conversation. This event will produce an error if the input audio buffer is empty. When in Server VAD mode, the client does not need to send this event, the server will commit the audio buffer automatically.

  Committing the input audio buffer will trigger input audio transcription (if enabled in session configuration), but it will not create a response from the model. The server will respond with an input_audio_buffer.committed event.

  • Type InputAudioBufferCommit

    The event type, must be input_audio_buffer.commit.

    • const InputAudioBufferCommitInputAudioBufferCommit InputAudioBufferCommit = "input_audio_buffer.commit"

  • EventID string

    Optional client-generated ID used to identify this event.

Input Audio Buffer Committed Event

• type InputAudioBufferCommittedEvent struct{…}

  Returned when an input audio buffer is committed, either by the client or automatically in server VAD mode. The item_id property is the ID of the user message item that will be created, thus a conversation.item.created event will also be sent to the client.

  • EventID string

    The unique ID of the server event.

  • ItemID string

    The ID of the user message item that will be created.

  • Type InputAudioBufferCommitted

    The event type, must be input_audio_buffer.committed.

    • const InputAudioBufferCommittedInputAudioBufferCommitted InputAudioBufferCommitted = "input_audio_buffer.committed"

  • PreviousItemID string

    The ID of the preceding item after which the new item will be inserted. Can be null if the item has no predecessor.

Input Audio Buffer Dtmf Event Received Event

• type InputAudioBufferDtmfEventReceivedEvent struct{…}

  SIP Only: Returned when an DTMF event is received. A DTMF event is a message that represents a telephone keypad press (0–9, *, #, A–D). The event property is the keypad that the user press. The received_at is the UTC Unix Timestamp that the server received the event.

  • Event string

    The telephone keypad that was pressed by the user.

  • ReceivedAt int64

    UTC Unix Timestamp when DTMF Event was received by server.

  • Type InputAudioBufferDtmfEventReceived

    The event type, must be input_audio_buffer.dtmf_event_received.

    • const InputAudioBufferDtmfEventReceivedInputAudioBufferDtmfEventReceived InputAudioBufferDtmfEventReceived = "input_audio_buffer.dtmf_event_received"

Input Audio Buffer Speech Started Event

• type InputAudioBufferSpeechStartedEvent struct{…}

  Sent by the server when in server_vad mode to indicate that speech has been detected in the audio buffer. This can happen any time audio is added to the buffer (unless speech is already detected). The client may want to use this event to interrupt audio playback or provide visual feedback to the user.

  The client should expect to receive a input_audio_buffer.speech_stopped event when speech stops. The item_id property is the ID of the user message item that will be created when speech stops and will also be included in the input_audio_buffer.speech_stopped event (unless the client manually commits the audio buffer during VAD activation).

  • AudioStartMs int64

    Milliseconds from the start of all audio written to the buffer during the session when speech was first detected. This will correspond to the beginning of audio sent to the model, and thus includes the prefix_padding_ms configured in the Session.

  • EventID string

    The unique ID of the server event.

  • ItemID string

    The ID of the user message item that will be created when speech stops.

  • Type InputAudioBufferSpeechStarted

    The event type, must be input_audio_buffer.speech_started.

    • const InputAudioBufferSpeechStartedInputAudioBufferSpeechStarted InputAudioBufferSpeechStarted = "input_audio_buffer.speech_started"

Input Audio Buffer Speech Stopped Event

• type InputAudioBufferSpeechStoppedEvent struct{…}

  Returned in server_vad mode when the server detects the end of speech in the audio buffer. The server will also send an conversation.item.created event with the user message item that is created from the audio buffer.

  • AudioEndMs int64

    Milliseconds since the session started when speech stopped. This will correspond to the end of audio sent to the model, and thus includes the min_silence_duration_ms configured in the Session.

  • EventID string

    The unique ID of the server event.

  • ItemID string

    The ID of the user message item that will be created.

  • Type InputAudioBufferSpeechStopped

    The event type, must be input_audio_buffer.speech_stopped.

    • const InputAudioBufferSpeechStoppedInputAudioBufferSpeechStopped InputAudioBufferSpeechStopped = "input_audio_buffer.speech_stopped"

Input Audio Buffer Timeout Triggered

• type InputAudioBufferTimeoutTriggered struct{…}

  Returned when the Server VAD timeout is triggered for the input audio buffer. This is configured with idle_timeout_ms in the turn_detection settings of the session, and it indicates that there hasn't been any speech detected for the configured duration.

  The audio_start_ms and audio_end_ms fields indicate the segment of audio after the last model response up to the triggering time, as an offset from the beginning of audio written to the input audio buffer. This means it demarcates the segment of audio that was silent and the difference between the start and end values will roughly match the configured timeout.

  The empty audio will be committed to the conversation as an input_audio item (there will be a input_audio_buffer.committed event) and a model response will be generated. There may be speech that didn't trigger VAD but is still detected by the model, so the model may respond with something relevant to the conversation or a prompt to continue speaking.

  • AudioEndMs int64

    Millisecond offset of audio written to the input audio buffer at the time the timeout was triggered.

  • AudioStartMs int64

    Millisecond offset of audio written to the input audio buffer that was after the playback time of the last model response.

  • EventID string

    The unique ID of the server event.

  • ItemID string

    The ID of the item associated with this segment.

  • Type InputAudioBufferTimeoutTriggered

    The event type, must be input_audio_buffer.timeout_triggered.

    • const InputAudioBufferTimeoutTriggeredInputAudioBufferTimeoutTriggered InputAudioBufferTimeoutTriggered = "input_audio_buffer.timeout_triggered"

Log Prob Properties

• type LogProbProperties struct{…}

  A log probability object.

  • Token string

    The token that was used to generate the log probability.

  • Bytes []int64

    The bytes that were used to generate the log probability.

  • Logprob float64

    The log probability of the token.

Mcp List Tools Completed

• type McpListToolsCompleted struct{…}

  Returned when listing MCP tools has completed for an item.

  • EventID string

    The unique ID of the server event.

  • ItemID string

    The ID of the MCP list tools item.

  • Type McpListToolsCompleted

    The event type, must be mcp_list_tools.completed.

    • const McpListToolsCompletedMcpListToolsCompleted McpListToolsCompleted = "mcp_list_tools.completed"

Mcp List Tools Failed

• type McpListToolsFailed struct{…}

  Returned when listing MCP tools has failed for an item.

  • EventID string

    The unique ID of the server event.

  • ItemID string

    The ID of the MCP list tools item.

  • Type McpListToolsFailed

    The event type, must be mcp_list_tools.failed.

    • const McpListToolsFailedMcpListToolsFailed McpListToolsFailed = "mcp_list_tools.failed"

Mcp List Tools In Progress

• type McpListToolsInProgress struct{…}

  Returned when listing MCP tools is in progress for an item.

  • EventID string

    The unique ID of the server event.

  • ItemID string

    The ID of the MCP list tools item.

  • Type McpListToolsInProgress

    The event type, must be mcp_list_tools.in_progress.

    • const McpListToolsInProgressMcpListToolsInProgress McpListToolsInProgress = "mcp_list_tools.in_progress"

Noise Reduction Type

• type NoiseReductionType string

  Type of noise reduction. near_field is for close-talking microphones such as headphones, far_field is for far-field microphones such as laptop or conference room microphones.

  • const NoiseReductionTypeNearField NoiseReductionType = "near_field"

  • const NoiseReductionTypeFarField NoiseReductionType = "far_field"

Output Audio Buffer Clear Event

• type OutputAudioBufferClearEvent struct{…}

  WebRTC/SIP Only: Emit to cut off the current audio response. This will trigger the server to stop generating audio and emit a output_audio_buffer.cleared event. This event should be preceded by a response.cancel client event to stop the generation of the current response. Learn more.

  • Type OutputAudioBufferClear

    The event type, must be output_audio_buffer.clear.

    • const OutputAudioBufferClearOutputAudioBufferClear OutputAudioBufferClear = "output_audio_buffer.clear"

  • EventID string

    The unique ID of the client event used for error handling.

Rate Limits Updated Event

• type RateLimitsUpdatedEvent struct{…}

  Emitted at the beginning of a Response to indicate the updated rate limits. When a Response is created some tokens will be "reserved" for the output tokens, the rate limits shown here reflect that reservation, which is then adjusted accordingly once the Response is completed.

  • EventID string

    The unique ID of the server event.

  • RateLimits []RateLimitsUpdatedEventRateLimit

    List of rate limit information.

    • Limit int64

      The maximum allowed value for the rate limit.

    • Name string

      The name of the rate limit (requests, tokens).

      • const RateLimitsUpdatedEventRateLimitNameRequests RateLimitsUpdatedEventRateLimitName = "requests"

      • const RateLimitsUpdatedEventRateLimitNameTokens RateLimitsUpdatedEventRateLimitName = "tokens"

    • Remaining int64

      The remaining value before the limit is reached.

    • ResetSeconds float64

      Seconds until the rate limit resets.

  • Type RateLimitsUpdated

    The event type, must be rate_limits.updated.

    • const RateLimitsUpdatedRateLimitsUpdated RateLimitsUpdated = "rate_limits.updated"

Realtime Audio Config

• type RealtimeAudioConfig struct{…}

  Configuration for input and output audio.

  • Input RealtimeAudioConfigInput

    • Format RealtimeAudioFormatsUnion

      The format of the input audio.

      • type RealtimeAudioFormatsAudioPCM struct{…}

        The PCM audio format. Only a 24kHz sample rate is supported.

        • Rate int64

          The sample rate of the audio. Always 24000.

          • const RealtimeAudioFormatsAudioPCMRate24000 RealtimeAudioFormatsAudioPCMRate = 24000

        • Type string

          The audio format. Always audio/pcm.

          • const RealtimeAudioFormatsAudioPCMTypeAudioPCM RealtimeAudioFormatsAudioPCMType = "audio/pcm"

      • type RealtimeAudioFormatsAudioPCMU struct{…}

        The G.711 μ-law format.

        • Type string

          The audio format. Always audio/pcmu.

          • const RealtimeAudioFormatsAudioPCMUTypeAudioPCMU RealtimeAudioFormatsAudioPCMUType = "audio/pcmu"

      • type RealtimeAudioFormatsAudioPCMA struct{…}

        The G.711 A-law format.

        • Type string

          The audio format. Always audio/pcma.

          • const RealtimeAudioFormatsAudioPCMATypeAudioPCMA RealtimeAudioFormatsAudioPCMAType = "audio/pcma"

    • NoiseReduction RealtimeAudioConfigInputNoiseReduction

      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.

      • Type NoiseReductionType

        Type of noise reduction. near_field is for close-talking microphones such as headphones, far_field is for far-field microphones such as laptop or conference room microphones.

        • const NoiseReductionTypeNearField NoiseReductionType = "near_field"

        • const NoiseReductionTypeFarField NoiseReductionType = "far_field"

    • Transcription AudioTranscription

      Configuration for input audio transcription, defaults to off and can be set to null to turn off once on. Input audio transcription is not native to the model, since the model consumes audio directly. Transcription runs asynchronously through the /audio/transcriptions endpoint and should be treated as guidance of input audio content rather than precisely what the model heard. The client can optionally set the language and prompt for transcription, these offer additional guidance to the transcription service.

      • Delay AudioTranscriptionDelay

        Controls how long the model waits before emitting transcription text. Higher values can improve transcription accuracy at the cost of latency. Only supported with gpt-realtime-whisper in GA Realtime sessions.

        • const AudioTranscriptionDelayMinimal AudioTranscriptionDelay = "minimal"

        • const AudioTranscriptionDelayLow AudioTranscriptionDelay = "low"

        • const AudioTranscriptionDelayMedium AudioTranscriptionDelay = "medium"

        • const AudioTranscriptionDelayHigh AudioTranscriptionDelay = "high"

        • const AudioTranscriptionDelayXhigh AudioTranscriptionDelay = "xhigh"

      • Language string

        The language of the input audio. Supplying the input language in ISO-639-1 (e.g. en) format will improve accuracy and latency.

      • Model AudioTranscriptionModel

        The model to use for transcription. Current options are whisper-1, gpt-4o-mini-transcribe, gpt-4o-mini-transcribe-2025-12-15, gpt-4o-transcribe, gpt-4o-transcribe-diarize, and gpt-realtime-whisper. Use gpt-4o-transcribe-diarize when you need diarization with speaker labels.

        • string

        • type AudioTranscriptionModel string

          The model to use for transcription. Current options are whisper-1, gpt-4o-mini-transcribe, gpt-4o-mini-transcribe-2025-12-15, gpt-4o-transcribe, gpt-4o-transcribe-diarize, and gpt-realtime-whisper. Use gpt-4o-transcribe-diarize when you need diarization with speaker labels.

          • const AudioTranscriptionModelWhisper1 AudioTranscriptionModel = "whisper-1"

          • const AudioTranscriptionModelGPT4oMiniTranscribe AudioTranscriptionModel = "gpt-4o-mini-transcribe"

          • const AudioTranscriptionModelGPT4oMiniTranscribe2025_12_15 AudioTranscriptionModel = "gpt-4o-mini-transcribe-2025-12-15"

          • const AudioTranscriptionModelGPT4oTranscribe AudioTranscriptionModel = "gpt-4o-transcribe"

          • const AudioTranscriptionModelGPT4oTranscribeDiarize AudioTranscriptionModel = "gpt-4o-transcribe-diarize"

          • const AudioTranscriptionModelGPTRealtimeWhisper AudioTranscriptionModel = "gpt-realtime-whisper"

      • Prompt string

        An optional text to guide the model's style or continue a previous audio segment. For whisper-1, the prompt is a list of keywords. For gpt-4o-transcribe models (excluding gpt-4o-transcribe-diarize), the prompt is a free text string, for example "expect words related to technology". Prompt is not supported with gpt-realtime-whisper in GA Realtime sessions.

    • TurnDetection RealtimeAudioInputTurnDetectionUnion

      Configuration for turn detection, ether Server VAD or Semantic VAD. This can be set to null to turn off, in which case the client must manually trigger model response.

      Server VAD means that the model will detect the start and end of speech based on audio volume and respond at the end of user speech.

      Semantic VAD is more advanced and uses a turn detection model (in conjunction with VAD) to semantically estimate whether the user has finished speaking, then dynamically sets a timeout based on this probability. For example, if user audio trails off with "uhhm", the model will score a low probability of turn end and wait longer for the user to continue speaking. This can be useful for more natural conversations, but may have a higher latency.

      For gpt-realtime-whisper transcription sessions, turn detection must be set to null; VAD is not supported.

      • RealtimeAudioInputTurnDetectionServerVad

        • Type ServerVad

          Type of turn detection, server_vad to turn on simple Server VAD.

          • const ServerVadServerVad ServerVad = "server_vad"

        • CreateResponse bool

          Whether or not to automatically generate a response when a VAD stop event occurs. If interrupt_response is set to false this may fail to create a response if the model is already responding.

          If both create_response and interrupt_response are set to false, the model will never respond automatically but VAD events will still be emitted.

        • IdleTimeoutMs int64

          Optional timeout after which a model response will be triggered automatically. This is useful for situations in which a long pause from the user is unexpected, such as a phone call. The model will effectively prompt the user to continue the conversation based on the current context.

          The timeout value will be applied after the last model response's audio has finished playing, i.e. it's set to the response.done time plus audio playback duration.

          An input_audio_buffer.timeout_triggered event (plus events associated with the Response) will be emitted when the timeout is reached. Idle timeout is currently only supported for server_vad mode.

        • InterruptResponse bool

          Whether or not to automatically interrupt (cancel) any ongoing response with output to the default conversation (i.e. conversation of auto) when a VAD start event occurs. If true then the response will be cancelled, otherwise it will continue until complete.

          If both create_response and interrupt_response are set to false, the model will never respond automatically but VAD events will still be emitted.

        • PrefixPaddingMs int64

          Used only for server_vad mode. Amount of audio to include before the VAD detected speech (in milliseconds). Defaults to 300ms.

        • SilenceDurationMs int64

          Used only for server_vad mode. Duration of silence to detect speech stop (in milliseconds). Defaults to 500ms. With shorter values the model will respond more quickly, but may jump in on short pauses from the user.

        • Threshold float64

          Used only for server_vad mode. Activation threshold for VAD (0.0 to 1.0), this defaults to 0.5. A higher threshold will require louder audio to activate the model, and thus might perform better in noisy environments.

      • RealtimeAudioInputTurnDetectionSemanticVad

        • Type SemanticVad

          Type of turn detection, semantic_vad to turn on Semantic VAD.

          • const SemanticVadSemanticVad SemanticVad = "semantic_vad"

        • CreateResponse bool

          Whether or not to automatically generate a response when a VAD stop event occurs.

        • Eagerness string

          Used only for semantic_vad mode. The eagerness of the model to respond. low will wait longer for the user to continue speaking, high will respond more quickly. auto is the default and is equivalent to medium. low, medium, and high have max timeouts of 8s, 4s, and 2s respectively.

          • const RealtimeAudioInputTurnDetectionSemanticVadEagernessLow RealtimeAudioInputTurnDetectionSemanticVadEagerness = "low"

          • const RealtimeAudioInputTurnDetectionSemanticVadEagernessMedium RealtimeAudioInputTurnDetectionSemanticVadEagerness = "medium"

          • const RealtimeAudioInputTurnDetectionSemanticVadEagernessHigh RealtimeAudioInputTurnDetectionSemanticVadEagerness = "high"

          • const RealtimeAudioInputTurnDetectionSemanticVadEagernessAuto RealtimeAudioInputTurnDetectionSemanticVadEagerness = "auto"

        • InterruptResponse bool

          Whether or not to automatically interrupt any ongoing response with output to the default conversation (i.e. conversation of auto) when a VAD start event occurs.

  • Output RealtimeAudioConfigOutput

    • Format RealtimeAudioFormatsUnion

      The format of the output audio.

    • Speed float64

      The speed of the model's spoken response as a multiple of the original speed. 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.

      This parameter is a post-processing adjustment to the audio after it is generated, it's also possible to prompt the model to speak faster or slower.

    • Voice RealtimeAudioConfigOutputVoiceUnion

      The voice the model uses to respond. Supported built-in voices are alloy, ash, ballad, coral, echo, sage, shimmer, verse, marin, and cedar. You may also provide a custom voice object with an id, for example { "id": "voice_1234" }. Voice cannot be changed during the session once the model has responded with audio at least once. We recommend marin and cedar for best quality.

      • string

      • string

        • const RealtimeAudioConfigOutputVoiceString2Alloy RealtimeAudioConfigOutputVoiceString2 = "alloy"

        • const RealtimeAudioConfigOutputVoiceString2Ash RealtimeAudioConfigOutputVoiceString2 = "ash"

        • const RealtimeAudioConfigOutputVoiceString2Ballad RealtimeAudioConfigOutputVoiceString2 = "ballad"

        • const RealtimeAudioConfigOutputVoiceString2Coral RealtimeAudioConfigOutputVoiceString2 = "coral"

        • const RealtimeAudioConfigOutputVoiceString2Echo RealtimeAudioConfigOutputVoiceString2 = "echo"

        • const RealtimeAudioConfigOutputVoiceString2Sage RealtimeAudioConfigOutputVoiceString2 = "sage"

        • const RealtimeAudioConfigOutputVoiceString2Shimmer RealtimeAudioConfigOutputVoiceString2 = "shimmer"

        • const RealtimeAudioConfigOutputVoiceString2Verse RealtimeAudioConfigOutputVoiceString2 = "verse"

        • const RealtimeAudioConfigOutputVoiceString2Marin RealtimeAudioConfigOutputVoiceString2 = "marin"

        • const RealtimeAudioConfigOutputVoiceString2Cedar RealtimeAudioConfigOutputVoiceString2 = "cedar"

      • RealtimeAudioConfigOutputVoiceID

        • ID string

          The custom voice ID, e.g. voice_1234.

Realtime Audio Config Input

• type RealtimeAudioConfigInput struct{…}

  • Format RealtimeAudioFormatsUnion

    The format of the input audio.

    • type RealtimeAudioFormatsAudioPCM struct{…}

      The PCM audio format. Only a 24kHz sample rate is supported.

      • Rate int64

        The sample rate of the audio. Always 24000.

        • const RealtimeAudioFormatsAudioPCMRate24000 RealtimeAudioFormatsAudioPCMRate = 24000

      • Type string

        The audio format. Always audio/pcm.

        • const RealtimeAudioFormatsAudioPCMTypeAudioPCM RealtimeAudioFormatsAudioPCMType = "audio/pcm"

    • type RealtimeAudioFormatsAudioPCMU struct{…}

      The G.711 μ-law format.

      • Type string

        The audio format. Always audio/pcmu.

        • const RealtimeAudioFormatsAudioPCMUTypeAudioPCMU RealtimeAudioFormatsAudioPCMUType = "audio/pcmu"

    • type RealtimeAudioFormatsAudioPCMA struct{…}

      The G.711 A-law format.

      • Type string

        The audio format. Always audio/pcma.

        • const RealtimeAudioFormatsAudioPCMATypeAudioPCMA RealtimeAudioFormatsAudioPCMAType = "audio/pcma"

  • NoiseReduction RealtimeAudioConfigInputNoiseReduction

    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.

    • Type NoiseReductionType

      Type of noise reduction. near_field is for close-talking microphones such as headphones, far_field is for far-field microphones such as laptop or conference room microphones.

      • const NoiseReductionTypeNearField NoiseReductionType = "near_field"

      • const NoiseReductionTypeFarField NoiseReductionType = "far_field"

  • Transcription AudioTranscription

    Configuration for input audio transcription, defaults to off and can be set to null to turn off once on. Input audio transcription is not native to the model, since the model consumes audio directly. Transcription runs asynchronously through the /audio/transcriptions endpoint and should be treated as guidance of input audio content rather than precisely what the model heard. The client can optionally set the language and prompt for transcription, these offer additional guidance to the transcription service.

    • Delay AudioTranscriptionDelay

      Controls how long the model waits before emitting transcription text. Higher values can improve transcription accuracy at the cost of latency. Only supported with gpt-realtime-whisper in GA Realtime sessions.

      • const AudioTranscriptionDelayMinimal AudioTranscriptionDelay = "minimal"

      • const AudioTranscriptionDelayLow AudioTranscriptionDelay = "low"

      • const AudioTranscriptionDelayMedium AudioTranscriptionDelay = "medium"

      • const AudioTranscriptionDelayHigh AudioTranscriptionDelay = "high"

      • const AudioTranscriptionDelayXhigh AudioTranscriptionDelay = "xhigh"

    • Language string

      The language of the input audio. Supplying the input language in ISO-639-1 (e.g. en) format will improve accuracy and latency.

    • Model AudioTranscriptionModel

      The model to use for transcription. Current options are whisper-1, gpt-4o-mini-transcribe, gpt-4o-mini-transcribe-2025-12-15, gpt-4o-transcribe, gpt-4o-transcribe-diarize, and gpt-realtime-whisper. Use gpt-4o-transcribe-diarize when you need diarization with speaker labels.

      • string

      • type AudioTranscriptionModel string

        The model to use for transcription. Current options are whisper-1, gpt-4o-mini-transcribe, gpt-4o-mini-transcribe-2025-12-15, gpt-4o-transcribe, gpt-4o-transcribe-diarize, and gpt-realtime-whisper. Use gpt-4o-transcribe-diarize when you need diarization with speaker labels.

        • const AudioTranscriptionModelWhisper1 AudioTranscriptionModel = "whisper-1"

        • const AudioTranscriptionModelGPT4oMiniTranscribe AudioTranscriptionModel = "gpt-4o-mini-transcribe"

        • const AudioTranscriptionModelGPT4oMiniTranscribe2025_12_15 AudioTranscriptionModel = "gpt-4o-mini-transcribe-2025-12-15"

        • const AudioTranscriptionModelGPT4oTranscribe AudioTranscriptionModel = "gpt-4o-transcribe"

        • const AudioTranscriptionModelGPT4oTranscribeDiarize AudioTranscriptionModel = "gpt-4o-transcribe-diarize"

        • const AudioTranscriptionModelGPTRealtimeWhisper AudioTranscriptionModel = "gpt-realtime-whisper"

    • Prompt string

      An optional text to guide the model's style or continue a previous audio segment. For whisper-1, the prompt is a list of keywords. For gpt-4o-transcribe models (excluding gpt-4o-transcribe-diarize), the prompt is a free text string, for example "expect words related to technology". Prompt is not supported with gpt-realtime-whisper in GA Realtime sessions.

  • TurnDetection RealtimeAudioInputTurnDetectionUnion

    Configuration for turn detection, ether Server VAD or Semantic VAD. This can be set to null to turn off, in which case the client must manually trigger model response.

    Server VAD means that the model will detect the start and end of speech based on audio volume and respond at the end of user speech.

    Semantic VAD is more advanced and uses a turn detection model (in conjunction with VAD) to semantically estimate whether the user has finished speaking, then dynamically sets a timeout based on this probability. For example, if user audio trails off with "uhhm", the model will score a low probability of turn end and wait longer for the user to continue speaking. This can be useful for more natural conversations, but may have a higher latency.

    For gpt-realtime-whisper transcription sessions, turn detection must be set to null; VAD is not supported.

    • RealtimeAudioInputTurnDetectionServerVad

      • Type ServerVad

        Type of turn detection, server_vad to turn on simple Server VAD.

        • const ServerVadServerVad ServerVad = "server_vad"

      • CreateResponse bool

        Whether or not to automatically generate a response when a VAD stop event occurs. If interrupt_response is set to false this may fail to create a response if the model is already responding.

        If both create_response and interrupt_response are set to false, the model will never respond automatically but VAD events will still be emitted.

      • IdleTimeoutMs int64

        Optional timeout after which a model response will be triggered automatically. This is useful for situations in which a long pause from the user is unexpected, such as a phone call. The model will effectively prompt the user to continue the conversation based on the current context.

        The timeout value will be applied after the last model response's audio has finished playing, i.e. it's set to the response.done time plus audio playback duration.

        An input_audio_buffer.timeout_triggered event (plus events associated with the Response) will be emitted when the timeout is reached. Idle timeout is currently only supported for server_vad mode.

      • InterruptResponse bool

        Whether or not to automatically interrupt (cancel) any ongoing response with output to the default conversation (i.e. conversation of auto) when a VAD start event occurs. If true then the response will be cancelled, otherwise it will continue until complete.

        If both create_response and interrupt_response are set to false, the model will never respond automatically but VAD events will still be emitted.

      • PrefixPaddingMs int64

        Used only for server_vad mode. Amount of audio to include before the VAD detected speech (in milliseconds). Defaults to 300ms.

      • SilenceDurationMs int64

        Used only for server_vad mode. Duration of silence to detect speech stop (in milliseconds). Defaults to 500ms. With shorter values the model will respond more quickly, but may jump in on short pauses from the user.

      • Threshold float64

        Used only for server_vad mode. Activation threshold for VAD (0.0 to 1.0), this defaults to 0.5. A higher threshold will require louder audio to activate the model, and thus might perform better in noisy environments.

    • RealtimeAudioInputTurnDetectionSemanticVad

      • Type SemanticVad

        Type of turn detection, semantic_vad to turn on Semantic VAD.

        • const SemanticVadSemanticVad SemanticVad = "semantic_vad"

      • CreateResponse bool

        Whether or not to automatically generate a response when a VAD stop event occurs.

      • Eagerness string

        Used only for semantic_vad mode. The eagerness of the model to respond. low will wait longer for the user to continue speaking, high will respond more quickly. auto is the default and is equivalent to medium. low, medium, and high have max timeouts of 8s, 4s, and 2s respectively.

        • const RealtimeAudioInputTurnDetectionSemanticVadEagernessLow RealtimeAudioInputTurnDetectionSemanticVadEagerness = "low"

        • const RealtimeAudioInputTurnDetectionSemanticVadEagernessMedium RealtimeAudioInputTurnDetectionSemanticVadEagerness = "medium"

        • const RealtimeAudioInputTurnDetectionSemanticVadEagernessHigh RealtimeAudioInputTurnDetectionSemanticVadEagerness = "high"

        • const RealtimeAudioInputTurnDetectionSemanticVadEagernessAuto RealtimeAudioInputTurnDetectionSemanticVadEagerness = "auto"

      • InterruptResponse bool

        Whether or not to automatically interrupt any ongoing response with output to the default conversation (i.e. conversation of auto) when a VAD start event occurs.

Realtime Audio Config Output

• type RealtimeAudioConfigOutput struct{…}

  • Format RealtimeAudioFormatsUnion

    The format of the output audio.

    • type RealtimeAudioFormatsAudioPCM struct{…}

      The PCM audio format. Only a 24kHz sample rate is supported.

      • Rate int64

        The sample rate of the audio. Always 24000.

        • const RealtimeAudioFormatsAudioPCMRate24000 RealtimeAudioFormatsAudioPCMRate = 24000

      • Type string

        The audio format. Always audio/pcm.

        • const RealtimeAudioFormatsAudioPCMTypeAudioPCM RealtimeAudioFormatsAudioPCMType = "audio/pcm"

    • type RealtimeAudioFormatsAudioPCMU struct{…}

      The G.711 μ-law format.

      • Type string

        The audio format. Always audio/pcmu.

        • const RealtimeAudioFormatsAudioPCMUTypeAudioPCMU RealtimeAudioFormatsAudioPCMUType = "audio/pcmu"

    • type RealtimeAudioFormatsAudioPCMA struct{…}

      The G.711 A-law format.

      • Type string

        The audio format. Always audio/pcma.

        • const RealtimeAudioFormatsAudioPCMATypeAudioPCMA RealtimeAudioFormatsAudioPCMAType = "audio/pcma"

  • Speed float64

    The speed of the model's spoken response as a multiple of the original speed. 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.

    This parameter is a post-processing adjustment to the audio after it is generated, it's also possible to prompt the model to speak faster or slower.

  • Voice RealtimeAudioConfigOutputVoiceUnion

    The voice the model uses to respond. Supported built-in voices are alloy, ash, ballad, coral, echo, sage, shimmer, verse, marin, and cedar. You may also provide a custom voice object with an id, for example { "id": "voice_1234" }. Voice cannot be changed during the session once the model has responded with audio at least once. We recommend marin and cedar for best quality.

    • string

    • string

      • const RealtimeAudioConfigOutputVoiceString2Alloy RealtimeAudioConfigOutputVoiceString2 = "alloy"

      • const RealtimeAudioConfigOutputVoiceString2Ash RealtimeAudioConfigOutputVoiceString2 = "ash"

      • const RealtimeAudioConfigOutputVoiceString2Ballad RealtimeAudioConfigOutputVoiceString2 = "ballad"

      • const RealtimeAudioConfigOutputVoiceString2Coral RealtimeAudioConfigOutputVoiceString2 = "coral"

      • const RealtimeAudioConfigOutputVoiceString2Echo RealtimeAudioConfigOutputVoiceString2 = "echo"

      • const RealtimeAudioConfigOutputVoiceString2Sage RealtimeAudioConfigOutputVoiceString2 = "sage"

      • const RealtimeAudioConfigOutputVoiceString2Shimmer RealtimeAudioConfigOutputVoiceString2 = "shimmer"

      • const RealtimeAudioConfigOutputVoiceString2Verse RealtimeAudioConfigOutputVoiceString2 = "verse"

      • const RealtimeAudioConfigOutputVoiceString2Marin RealtimeAudioConfigOutputVoiceString2 = "marin"

      • const RealtimeAudioConfigOutputVoiceString2Cedar RealtimeAudioConfigOutputVoiceString2 = "cedar"

    • RealtimeAudioConfigOutputVoiceID

      • ID string

        The custom voice ID, e.g. voice_1234.

Realtime Audio Formats

• type RealtimeAudioFormatsUnion interface{…}

  The PCM audio format. Only a 24kHz sample rate is supported.

  • type RealtimeAudioFormatsAudioPCM struct{…}

    The PCM audio format. Only a 24kHz sample rate is supported.

    • Rate int64

      The sample rate of the audio. Always 24000.

      • const RealtimeAudioFormatsAudioPCMRate24000 RealtimeAudioFormatsAudioPCMRate = 24000

    • Type string

      The audio format. Always audio/pcm.

      • const RealtimeAudioFormatsAudioPCMTypeAudioPCM RealtimeAudioFormatsAudioPCMType = "audio/pcm"

  • type RealtimeAudioFormatsAudioPCMU struct{…}

    The G.711 μ-law format.

    • Type string

      The audio format. Always audio/pcmu.

      • const RealtimeAudioFormatsAudioPCMUTypeAudioPCMU RealtimeAudioFormatsAudioPCMUType = "audio/pcmu"

  • type RealtimeAudioFormatsAudioPCMA struct{…}

    The G.711 A-law format.

    • Type string

      The audio format. Always audio/pcma.

      • const RealtimeAudioFormatsAudioPCMATypeAudioPCMA RealtimeAudioFormatsAudioPCMAType = "audio/pcma"

Realtime Audio Input Turn Detection

• type RealtimeAudioInputTurnDetectionUnion interface{…}

  Configuration for turn detection, ether Server VAD or Semantic VAD. This can be set to null to turn off, in which case the client must manually trigger model response.

  Server VAD means that the model will detect the start and end of speech based on audio volume and respond at the end of user speech.

  Semantic VAD is more advanced and uses a turn detection model (in conjunction with VAD) to semantically estimate whether the user has finished speaking, then dynamically sets a timeout based on this probability. For example, if user audio trails off with "uhhm", the model will score a low probability of turn end and wait longer for the user to continue speaking. This can be useful for more natural conversations, but may have a higher latency.

  For gpt-realtime-whisper transcription sessions, turn detection must be set to null; VAD is not supported.

  • RealtimeAudioInputTurnDetectionServerVad

    • Type ServerVad

      Type of turn detection, server_vad to turn on simple Server VAD.

      • const ServerVadServerVad ServerVad = "server_vad"

    • CreateResponse bool

      Whether or not to automatically generate a response when a VAD stop event occurs. If interrupt_response is set to false this may fail to create a response if the model is already responding.

      If both create_response and interrupt_response are set to false, the model will never respond automatically but VAD events will still be emitted.

    • IdleTimeoutMs int64

      Optional timeout after which a model response will be triggered automatically. This is useful for situations in which a long pause from the user is unexpected, such as a phone call. The model will effectively prompt the user to continue the conversation based on the current context.

      The timeout value will be applied after the last model response's audio has finished playing, i.e. it's set to the response.done time plus audio playback duration.

      An input_audio_buffer.timeout_triggered event (plus events associated with the Response) will be emitted when the timeout is reached. Idle timeout is currently only supported for server_vad mode.

    • InterruptResponse bool

      Whether or not to automatically interrupt (cancel) any ongoing response with output to the default conversation (i.e. conversation of auto) when a VAD start event occurs. If true then the response will be cancelled, otherwise it will continue until complete.

      If both create_response and interrupt_response are set to false, the model will never respond automatically but VAD events will still be emitted.

    • PrefixPaddingMs int64

      Used only for server_vad mode. Amount of audio to include before the VAD detected speech (in milliseconds). Defaults to 300ms.

    • SilenceDurationMs int64

      Used only for server_vad mode. Duration of silence to detect speech stop (in milliseconds). Defaults to 500ms. With shorter values the model will respond more quickly, but may jump in on short pauses from the user.

    • Threshold float64

      Used only for server_vad mode. Activation threshold for VAD (0.0 to 1.0), this defaults to 0.5. A higher threshold will require louder audio to activate the model, and thus might perform better in noisy environments.

  • RealtimeAudioInputTurnDetectionSemanticVad

    • Type SemanticVad

      Type of turn detection, semantic_vad to turn on Semantic VAD.

      • const SemanticVadSemanticVad SemanticVad = "semantic_vad"

    • CreateResponse bool

      Whether or not to automatically generate a response when a VAD stop event occurs.

    • Eagerness string

      Used only for semantic_vad mode. The eagerness of the model to respond. low will wait longer for the user to continue speaking, high will respond more quickly. auto is the default and is equivalent to medium. low, medium, and high have max timeouts of 8s, 4s, and 2s respectively.

      • const RealtimeAudioInputTurnDetectionSemanticVadEagernessLow RealtimeAudioInputTurnDetectionSemanticVadEagerness = "low"

      • const RealtimeAudioInputTurnDetectionSemanticVadEagernessMedium RealtimeAudioInputTurnDetectionSemanticVadEagerness = "medium"

      • const RealtimeAudioInputTurnDetectionSemanticVadEagernessHigh RealtimeAudioInputTurnDetectionSemanticVadEagerness = "high"

      • const RealtimeAudioInputTurnDetectionSemanticVadEagernessAuto RealtimeAudioInputTurnDetectionSemanticVadEagerness = "auto"

    • InterruptResponse bool

      Whether or not to automatically interrupt any ongoing response with output to the default conversation (i.e. conversation of auto) when a VAD start event occurs.

Realtime Client Event

• type RealtimeClientEventUnion interface{…}

  A realtime client event.

  • type ConversationItemCreateEvent struct{…}

    Add a new Item to the Conversation's context, including messages, function calls, and function call responses. This event can be used both to populate a "history" of the conversation and to add new items mid-stream, but has the current limitation that it cannot populate assistant audio messages.

    If successful, the server will respond with a conversation.item.created event, otherwise an error event will be sent.

    • Item ConversationItemUnion

      A single item within a Realtime conversation.

      • type RealtimeConversationItemSystemMessage struct{…}

        A system message in a Realtime conversation can be used to provide additional context or instructions to the model. This is similar but distinct from the instruction prompt provided at the start of a conversation, as system messages can be added at any point in the conversation. For major changes to the conversation's behavior, use instructions, but for smaller updates (e.g. "the user is now asking about a different topic"), use system messages.

        • Content []RealtimeConversationItemSystemMessageContent

          The content of the message.

          • Text string

            The text content.

          • Type string

            The content type. Always input_text for system messages.

            • const RealtimeConversationItemSystemMessageContentTypeInputText RealtimeConversationItemSystemMessageContentType = "input_text"

        • Role System

          The role of the message sender. Always system.

          • const SystemSystem System = "system"

        • Type Message

          The type of the item. Always message.

          • const MessageMessage Message = "message"

        • ID string

          The unique ID of the item. This may be provided by the client or generated by the server.

        • Object RealtimeConversationItemSystemMessageObject

          Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

          • const RealtimeConversationItemSystemMessageObjectRealtimeItem RealtimeConversationItemSystemMessageObject = "realtime.item"

        • Status RealtimeConversationItemSystemMessageStatus

          The status of the item. Has no effect on the conversation.

          • const RealtimeConversationItemSystemMessageStatusCompleted RealtimeConversationItemSystemMessageStatus = "completed"

          • const RealtimeConversationItemSystemMessageStatusIncomplete RealtimeConversationItemSystemMessageStatus = "incomplete"

          • const RealtimeConversationItemSystemMessageStatusInProgress RealtimeConversationItemSystemMessageStatus = "in_progress"

      • type RealtimeConversationItemUserMessage struct{…}

        A user message item in a Realtime conversation.

        • Content []RealtimeConversationItemUserMessageContent

          The content of the message.

          • Audio string

            Base64-encoded audio bytes (for input_audio), these will be parsed as the format specified in the session input audio type configuration. This defaults to PCM 16-bit 24kHz mono if not specified.

          • Detail string

            The detail level of the image (for input_image). auto will default to high.

            • const RealtimeConversationItemUserMessageContentDetailAuto RealtimeConversationItemUserMessageContentDetail = "auto"

            • const RealtimeConversationItemUserMessageContentDetailLow RealtimeConversationItemUserMessageContentDetail = "low"

            • const RealtimeConversationItemUserMessageContentDetailHigh RealtimeConversationItemUserMessageContentDetail = "high"

          • ImageURL string

            Base64-encoded image bytes (for input_image) as a data URI. For example data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAA.... Supported formats are PNG and JPEG.

          • Text string

            The text content (for input_text).

          • Transcript string

            Transcript of the audio (for input_audio). This is not sent to the model, but will be attached to the message item for reference.

          • Type string

            The content type (input_text, input_audio, or input_image).

            • const RealtimeConversationItemUserMessageContentTypeInputText RealtimeConversationItemUserMessageContentType = "input_text"

            • const RealtimeConversationItemUserMessageContentTypeInputAudio RealtimeConversationItemUserMessageContentType = "input_audio"

            • const RealtimeConversationItemUserMessageContentTypeInputImage RealtimeConversationItemUserMessageContentType = "input_image"

        • Role User

          The role of the message sender. Always user.

          • const UserUser User = "user"

        • Type Message

          The type of the item. Always message.

          • const MessageMessage Message = "message"

        • ID string

          The unique ID of the item. This may be provided by the client or generated by the server.

        • Object RealtimeConversationItemUserMessageObject

          Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

          • const RealtimeConversationItemUserMessageObjectRealtimeItem RealtimeConversationItemUserMessageObject = "realtime.item"

        • Status RealtimeConversationItemUserMessageStatus

          The status of the item. Has no effect on the conversation.

          • const RealtimeConversationItemUserMessageStatusCompleted RealtimeConversationItemUserMessageStatus = "completed"

          • const RealtimeConversationItemUserMessageStatusIncomplete RealtimeConversationItemUserMessageStatus = "incomplete"

          • const RealtimeConversationItemUserMessageStatusInProgress RealtimeConversationItemUserMessageStatus = "in_progress"

      • type RealtimeConversationItemAssistantMessage struct{…}

        An assistant message item in a Realtime conversation.

        • Content []RealtimeConversationItemAssistantMessageContent

          The content of the message.

          • Audio string

            Base64-encoded audio bytes, these will be parsed as the format specified in the session output audio type configuration. This defaults to PCM 16-bit 24kHz mono if not specified.

          • Text string

            The text content.

          • Transcript string

            The transcript of the audio content, this will always be present if the output type is audio.

          • Type string

            The content type, output_text or output_audio depending on the session output_modalities configuration.

            • const RealtimeConversationItemAssistantMessageContentTypeOutputText RealtimeConversationItemAssistantMessageContentType = "output_text"

            • const RealtimeConversationItemAssistantMessageContentTypeOutputAudio RealtimeConversationItemAssistantMessageContentType = "output_audio"

        • Role Assistant

          The role of the message sender. Always assistant.

          • const AssistantAssistant Assistant = "assistant"

        • Type Message

          The type of the item. Always message.

          • const MessageMessage Message = "message"

        • ID string

          The unique ID of the item. This may be provided by the client or generated by the server.

        • Object RealtimeConversationItemAssistantMessageObject

          Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

          • const RealtimeConversationItemAssistantMessageObjectRealtimeItem RealtimeConversationItemAssistantMessageObject = "realtime.item"

        • Status RealtimeConversationItemAssistantMessageStatus

          The status of the item. Has no effect on the conversation.

          • const RealtimeConversationItemAssistantMessageStatusCompleted RealtimeConversationItemAssistantMessageStatus = "completed"

          • const RealtimeConversationItemAssistantMessageStatusIncomplete RealtimeConversationItemAssistantMessageStatus = "incomplete"

          • const RealtimeConversationItemAssistantMessageStatusInProgress RealtimeConversationItemAssistantMessageStatus = "in_progress"

      • type RealtimeConversationItemFunctionCall struct{…}

        A function call item in a Realtime conversation.

        • Arguments string

          The arguments of the function call. This is a JSON-encoded string representing the arguments passed to the function, for example {"arg1": "value1", "arg2": 42}.

        • Name string

          The name of the function being called.

        • Type FunctionCall

          The type of the item. Always function_call.

          • const FunctionCallFunctionCall FunctionCall = "function_call"

        • ID string

          The unique ID of the item. This may be provided by the client or generated by the server.

        • CallID string

          The ID of the function call.

        • Object RealtimeConversationItemFunctionCallObject

          Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

          • const RealtimeConversationItemFunctionCallObjectRealtimeItem RealtimeConversationItemFunctionCallObject = "realtime.item"

        • Status RealtimeConversationItemFunctionCallStatus

          The status of the item. Has no effect on the conversation.

          • const RealtimeConversationItemFunctionCallStatusCompleted RealtimeConversationItemFunctionCallStatus = "completed"

          • const RealtimeConversationItemFunctionCallStatusIncomplete RealtimeConversationItemFunctionCallStatus = "incomplete"

          • const RealtimeConversationItemFunctionCallStatusInProgress RealtimeConversationItemFunctionCallStatus = "in_progress"

      • type RealtimeConversationItemFunctionCallOutput struct{…}

        A function call output item in a Realtime conversation.

        • CallID string

          The ID of the function call this output is for.

        • Output string

          The output of the function call, this is free text and can contain any information or simply be empty.

        • Type FunctionCallOutput

          The type of the item. Always function_call_output.

          • const FunctionCallOutputFunctionCallOutput FunctionCallOutput = "function_call_output"

        • ID string

          The unique ID of the item. This may be provided by the client or generated by the server.

        • Object RealtimeConversationItemFunctionCallOutputObject

          Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

          • const RealtimeConversationItemFunctionCallOutputObjectRealtimeItem RealtimeConversationItemFunctionCallOutputObject = "realtime.item"

        • Status RealtimeConversationItemFunctionCallOutputStatus

          The status of the item. Has no effect on the conversation.

          • const RealtimeConversationItemFunctionCallOutputStatusCompleted RealtimeConversationItemFunctionCallOutputStatus = "completed"

          • const RealtimeConversationItemFunctionCallOutputStatusIncomplete RealtimeConversationItemFunctionCallOutputStatus = "incomplete"

          • const RealtimeConversationItemFunctionCallOutputStatusInProgress RealtimeConversationItemFunctionCallOutputStatus = "in_progress"

      • type RealtimeMcpApprovalResponse struct{…}

        A Realtime item responding to an MCP approval request.

        • ID string

          The unique ID of the approval response.

        • ApprovalRequestID string

          The ID of the approval request being answered.

        • Approve bool

          Whether the request was approved.

        • Type McpApprovalResponse

          The type of the item. Always mcp_approval_response.

          • const McpApprovalResponseMcpApprovalResponse McpApprovalResponse = "mcp_approval_response"

        • Reason string

          Optional reason for the decision.

      • type RealtimeMcpListTools struct{…}

        A Realtime item listing tools available on an MCP server.

        • ServerLabel string

          The label of the MCP server.

        • Tools []RealtimeMcpListToolsTool

          The tools available on the server.

          • InputSchema any

            The JSON schema describing the tool's input.

          • Name string

            The name of the tool.

          • Annotations any

            Additional annotations about the tool.

          • Description string

            The description of the tool.

        • Type McpListTools

          The type of the item. Always mcp_list_tools.

          • const McpListToolsMcpListTools McpListTools = "mcp_list_tools"

        • ID string

          The unique ID of the list.

      • type RealtimeMcpToolCall struct{…}

        A Realtime item representing an invocation of a tool on an MCP server.

        • ID string

          The unique ID of the tool call.

        • Arguments string

          A JSON string of the arguments passed to the tool.

        • Name string

          The name of the tool that was run.

        • ServerLabel string

          The label of the MCP server running the tool.

        • Type McpCall

          The type of the item. Always mcp_call.

          • const McpCallMcpCall McpCall = "mcp_call"

        • ApprovalRequestID string

          The ID of an associated approval request, if any.

        • Error RealtimeMcpToolCallErrorUnion

          The error from the tool call, if any.

          • type RealtimeMcpProtocolError struct{…}

            • Code int64

            • Message string

            • Type ProtocolError

              • const ProtocolErrorProtocolError ProtocolError = "protocol_error"

          • type RealtimeMcpToolExecutionError struct{…}

            • Message string

            • Type ToolExecutionError

              • const ToolExecutionErrorToolExecutionError ToolExecutionError = "tool_execution_error"

          • type RealtimeMcphttpError struct{…}

            • Code int64

            • Message string

            • Type HTTPError

              • const HTTPErrorHTTPError HTTPError = "http_error"

        • Output string

          The output from the tool call.

      • type RealtimeMcpApprovalRequest struct{…}

        A Realtime item requesting human approval of a tool invocation.

        • ID string

          The unique ID of the approval request.

        • Arguments string

          A JSON string of arguments for the tool.

        • Name string

          The name of the tool to run.

        • ServerLabel string

          The label of the MCP server making the request.

        • Type McpApprovalRequest

          The type of the item. Always mcp_approval_request.

          • const McpApprovalRequestMcpApprovalRequest McpApprovalRequest = "mcp_approval_request"

    • Type ConversationItemCreate

      The event type, must be conversation.item.create.

      • const ConversationItemCreateConversationItemCreate ConversationItemCreate = "conversation.item.create"

    • EventID string

      Optional client-generated ID used to identify this event.

    • PreviousItemID string

      The ID of the preceding item after which the new item will be inserted. If not set, the new item will be appended to the end of the conversation.

      If set to root, the new item will be added to the beginning of the conversation.

      If set to an existing ID, it allows an item to be inserted mid-conversation. If the ID cannot be found, an error will be returned and the item will not be added.

  • type ConversationItemDeleteEvent struct{…}

    Send this event when you want to remove any item from the conversation history. The server will respond with a conversation.item.deleted event, unless the item does not exist in the conversation history, in which case the server will respond with an error.

    • ItemID string

      The ID of the item to delete.

    • Type ConversationItemDelete

      The event type, must be conversation.item.delete.

      • const ConversationItemDeleteConversationItemDelete ConversationItemDelete = "conversation.item.delete"

    • EventID string

      Optional client-generated ID used to identify this event.

  • type ConversationItemRetrieveEvent struct{…}

    Send this event when you want to retrieve the server's representation of a specific item in the conversation history. This is useful, for example, to inspect user audio after noise cancellation and VAD. The server will respond with a conversation.item.retrieved event, unless the item does not exist in the conversation history, in which case the server will respond with an error.

    • ItemID string

      The ID of the item to retrieve.

    • Type ConversationItemRetrieve

      The event type, must be conversation.item.retrieve.

      • const ConversationItemRetrieveConversationItemRetrieve ConversationItemRetrieve = "conversation.item.retrieve"

    • EventID string

      Optional client-generated ID used to identify this event.

  • type ConversationItemTruncateEvent struct{…}

    Send this event to truncate a previous assistant message’s audio. The server will produce audio faster than realtime, so this event is useful when the user interrupts to truncate audio that has already been sent to the client but not yet played. This will synchronize the server's understanding of the audio with the client's playback.

    Truncating audio will delete the server-side text transcript to ensure there is not text in the context that hasn't been heard by the user.

    If successful, the server will respond with a conversation.item.truncated event.

    • AudioEndMs int64

      Inclusive duration up to which audio is truncated, in milliseconds. If the audio_end_ms is greater than the actual audio duration, the server will respond with an error.

    • ContentIndex int64

      The index of the content part to truncate. Set this to 0.

    • ItemID string

      The ID of the assistant message item to truncate. Only assistant message items can be truncated.

    • Type ConversationItemTruncate

      The event type, must be conversation.item.truncate.

      • const ConversationItemTruncateConversationItemTruncate ConversationItemTruncate = "conversation.item.truncate"

    • EventID string

      Optional client-generated ID used to identify this event.

  • type InputAudioBufferAppendEvent struct{…}

    Send this event to append audio bytes to the input audio buffer. The audio buffer is temporary storage you can write to and later commit. A "commit" will create a new user message item in the conversation history from the buffer content and clear the buffer. Input audio transcription (if enabled) will be generated when the buffer is committed.

    If VAD is enabled the audio buffer is used to detect speech and the server will decide when to commit. When Server VAD is disabled, you must commit the audio buffer manually. Input audio noise reduction operates on writes to the audio buffer.

    The client may choose how much audio to place in each event up to a maximum of 15 MiB, for example streaming smaller chunks from the client may allow the VAD to be more responsive. Unlike most other client events, the server will not send a confirmation response to this event.

    • Audio string

      Base64-encoded audio bytes. This must be in the format specified by the input_audio_format field in the session configuration.

    • Type InputAudioBufferAppend

      The event type, must be input_audio_buffer.append.

      • const InputAudioBufferAppendInputAudioBufferAppend InputAudioBufferAppend = "input_audio_buffer.append"

    • EventID string

      Optional client-generated ID used to identify this event.

  • type InputAudioBufferClearEvent struct{…}

    Send this event to clear the audio bytes in the buffer. The server will respond with an input_audio_buffer.cleared event.

    • Type InputAudioBufferClear

      The event type, must be input_audio_buffer.clear.

      • const InputAudioBufferClearInputAudioBufferClear InputAudioBufferClear = "input_audio_buffer.clear"

    • EventID string

      Optional client-generated ID used to identify this event.

  • type OutputAudioBufferClearEvent struct{…}

    WebRTC/SIP Only: Emit to cut off the current audio response. This will trigger the server to stop generating audio and emit a output_audio_buffer.cleared event. This event should be preceded by a response.cancel client event to stop the generation of the current response. Learn more.

    • Type OutputAudioBufferClear

      The event type, must be output_audio_buffer.clear.

      • const OutputAudioBufferClearOutputAudioBufferClear OutputAudioBufferClear = "output_audio_buffer.clear"

    • EventID string

      The unique ID of the client event used for error handling.

  • type InputAudioBufferCommitEvent struct{…}

    Send this event to commit the user input audio buffer, which will create a new user message item in the conversation. This event will produce an error if the input audio buffer is empty. When in Server VAD mode, the client does not need to send this event, the server will commit the audio buffer automatically.

    Committing the input audio buffer will trigger input audio transcription (if enabled in session configuration), but it will not create a response from the model. The server will respond with an input_audio_buffer.committed event.

    • Type InputAudioBufferCommit

      The event type, must be input_audio_buffer.commit.

      • const InputAudioBufferCommitInputAudioBufferCommit InputAudioBufferCommit = "input_audio_buffer.commit"

    • EventID string

      Optional client-generated ID used to identify this event.

  • type ResponseCancelEvent struct{…}

    Send this event to cancel an in-progress response. The server will respond with a response.done event with a status of response.status=cancelled. If there is no response to cancel, the server will respond with an error. It's safe to call response.cancel even if no response is in progress, an error will be returned the session will remain unaffected.

    • Type ResponseCancel

      The event type, must be response.cancel.

      • const ResponseCancelResponseCancel ResponseCancel = "response.cancel"

    • EventID string

      Optional client-generated ID used to identify this event.

    • ResponseID string

      A specific response ID to cancel - if not provided, will cancel an in-progress response in the default conversation.

  • type ResponseCreateEvent struct{…}

    This event instructs the server to create a Response, which means triggering model inference. When in Server VAD mode, the server will create Responses automatically.

    A Response will include at least one Item, and may have two, in which case the second will be a function call. These Items will be appended to the conversation history by default.

    The server will respond with a response.created event, events for Items and content created, and finally a response.done event to indicate the Response is complete.

    The response.create event includes inference configuration like instructions and tools. If these are set, they will override the Session's configuration for this Response only.

    Responses can be created out-of-band of the default Conversation, meaning that they can have arbitrary input, and it's possible to disable writing the output to the Conversation. Only one Response can write to the default Conversation at a time, but otherwise multiple Responses can be created in parallel. The metadata field is a good way to disambiguate multiple simultaneous Responses.

    Clients can set conversation to none to create a Response that does not write to the default Conversation. Arbitrary input can be provided with the input field, which is an array accepting raw Items and references to existing Items.

    • Type ResponseCreate

      The event type, must be response.create.

      • const ResponseCreateResponseCreate ResponseCreate = "response.create"

    • EventID string

      Optional client-generated ID used to identify this event.

    • Response RealtimeResponseCreateParamsResp

      Create a new Realtime response with these parameters

      • Audio RealtimeResponseCreateAudioOutput

        Configuration for audio input and output.

        • Output RealtimeResponseCreateAudioOutputOutput

          • Format RealtimeAudioFormatsUnion

            The format of the output audio.

            • type RealtimeAudioFormatsAudioPCM struct{…}

              The PCM audio format. Only a 24kHz sample rate is supported.

              • Rate int64

                The sample rate of the audio. Always 24000.

                • const RealtimeAudioFormatsAudioPCMRate24000 RealtimeAudioFormatsAudioPCMRate = 24000

              • Type string

                The audio format. Always audio/pcm.

                • const RealtimeAudioFormatsAudioPCMTypeAudioPCM RealtimeAudioFormatsAudioPCMType = "audio/pcm"

            • type RealtimeAudioFormatsAudioPCMU struct{…}

              The G.711 μ-law format.

              • Type string

                The audio format. Always audio/pcmu.

                • const RealtimeAudioFormatsAudioPCMUTypeAudioPCMU RealtimeAudioFormatsAudioPCMUType = "audio/pcmu"

            • type RealtimeAudioFormatsAudioPCMA struct{…}

              The G.711 A-law format.

              • Type string

                The audio format. Always audio/pcma.

                • const RealtimeAudioFormatsAudioPCMATypeAudioPCMA RealtimeAudioFormatsAudioPCMAType = "audio/pcma"

          • Voice RealtimeResponseCreateAudioOutputOutputVoiceUnion

            The voice the model uses to respond. Supported built-in voices are alloy, ash, ballad, coral, echo, sage, shimmer, verse, marin, and cedar. You may also provide a custom voice object with an id, for example { "id": "voice_1234" }. Voice cannot be changed during the session once the model has responded with audio at least once. We recommend marin and cedar for best quality.

            • string

            • string

              • const RealtimeResponseCreateAudioOutputOutputVoiceString2Alloy RealtimeResponseCreateAudioOutputOutputVoiceString2 = "alloy"

              • const RealtimeResponseCreateAudioOutputOutputVoiceString2Ash RealtimeResponseCreateAudioOutputOutputVoiceString2 = "ash"

              • const RealtimeResponseCreateAudioOutputOutputVoiceString2Ballad RealtimeResponseCreateAudioOutputOutputVoiceString2 = "ballad"

              • const RealtimeResponseCreateAudioOutputOutputVoiceString2Coral RealtimeResponseCreateAudioOutputOutputVoiceString2 = "coral"

              • const RealtimeResponseCreateAudioOutputOutputVoiceString2Echo RealtimeResponseCreateAudioOutputOutputVoiceString2 = "echo"

              • const RealtimeResponseCreateAudioOutputOutputVoiceString2Sage RealtimeResponseCreateAudioOutputOutputVoiceString2 = "sage"

              • const RealtimeResponseCreateAudioOutputOutputVoiceString2Shimmer RealtimeResponseCreateAudioOutputOutputVoiceString2 = "shimmer"

              • const RealtimeResponseCreateAudioOutputOutputVoiceString2Verse RealtimeResponseCreateAudioOutputOutputVoiceString2 = "verse"

              • const RealtimeResponseCreateAudioOutputOutputVoiceString2Marin RealtimeResponseCreateAudioOutputOutputVoiceString2 = "marin"

              • const RealtimeResponseCreateAudioOutputOutputVoiceString2Cedar RealtimeResponseCreateAudioOutputOutputVoiceString2 = "cedar"

            • RealtimeResponseCreateAudioOutputOutputVoiceID

              • ID string

                The custom voice ID, e.g. voice_1234.

      • Conversation RealtimeResponseCreateParamsConversation

        Controls which conversation the response is added to. Currently supports auto and none, with auto as the default value. The auto value means that the contents of the response will be added to the default conversation. Set this to none to create an out-of-band response which will not add items to default conversation.

        • string

        • RealtimeResponseCreateParamsConversation

          • const RealtimeResponseCreateParamsConversationAuto RealtimeResponseCreateParamsConversation = "auto"

          • const RealtimeResponseCreateParamsConversationNone RealtimeResponseCreateParamsConversation = "none"

      • Input []ConversationItemUnion

        Input items to include in the prompt for the model. Using this field creates a new context for this Response instead of using the default conversation. An empty array [] will clear the context for this Response. Note that this can include references to items that previously appeared in the session using their id.

        • type RealtimeConversationItemSystemMessage struct{…}

          A system message in a Realtime conversation can be used to provide additional context or instructions to the model. This is similar but distinct from the instruction prompt provided at the start of a conversation, as system messages can be added at any point in the conversation. For major changes to the conversation's behavior, use instructions, but for smaller updates (e.g. "the user is now asking about a different topic"), use system messages.

        • type RealtimeConversationItemUserMessage struct{…}

          A user message item in a Realtime conversation.

        • type RealtimeConversationItemAssistantMessage struct{…}

          An assistant message item in a Realtime conversation.

        • type RealtimeConversationItemFunctionCall struct{…}

          A function call item in a Realtime conversation.

        • type RealtimeConversationItemFunctionCallOutput struct{…}

          A function call output item in a Realtime conversation.

        • type RealtimeMcpApprovalResponse struct{…}

          A Realtime item responding to an MCP approval request.

        • type RealtimeMcpListTools struct{…}

          A Realtime item listing tools available on an MCP server.

        • type RealtimeMcpToolCall struct{…}

          A Realtime item representing an invocation of a tool on an MCP server.

        • type RealtimeMcpApprovalRequest struct{…}

          A Realtime item requesting human approval of a tool invocation.

      • Instructions string

        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.

      • MaxOutputTokens RealtimeResponseCreateParamsMaxOutputTokensUnionResp

        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.

        • int64

        • Inf

          • const InfInf Inf = "inf"

      • Metadata Metadata

        Set of 16 key-value pairs that can be attached to an object. This can be useful for storing additional information about the object in a structured format, and querying for objects via API or the dashboard.

        Keys are strings with a maximum length of 64 characters. Values are strings with a maximum length of 512 characters.

      • OutputModalities []string

        The set of modalities the model used to respond, currently the only possible values are [\"audio\"], [\"text\"]. Audio output always include a text transcript. Setting the output to mode text will disable audio output from the model.

        • const RealtimeResponseCreateParamsOutputModalityText RealtimeResponseCreateParamsOutputModality = "text"

        • const RealtimeResponseCreateParamsOutputModalityAudio RealtimeResponseCreateParamsOutputModality = "audio"

      • ParallelToolCalls bool

        Whether the model may call multiple tools in parallel. Only supported by reasoning Realtime models such as gpt-realtime-2.

      • Prompt ResponsePrompt

        Reference to a prompt template and its variables. Learn more.

        • ID string

          The unique identifier of the prompt template to use.

        • Variables map[string, ResponsePromptVariableUnion]

          Optional map of values to substitute in for variables in your prompt. The substitution values can either be strings, or other Response input types like images or files.

          • string

          • type ResponseInputText struct{…}

            A text input to the model.

            • Text string

              The text input to the model.

            • Type InputText

              The type of the input item. Always input_text.

              • const InputTextInputText InputText = "input_text"

          • type ResponseInputImage struct{…}

            An image input to the model. Learn about image inputs.

            • Detail ResponseInputImageDetail

              The detail level of the image to be sent to the model. One of high, low, auto, or original. Defaults to auto.

              • const ResponseInputImageDetailLow ResponseInputImageDetail = "low"

              • const ResponseInputImageDetailHigh ResponseInputImageDetail = "high"

              • const ResponseInputImageDetailAuto ResponseInputImageDetail = "auto"

              • const ResponseInputImageDetailOriginal ResponseInputImageDetail = "original"

            • Type InputImage

              The type of the input item. Always input_image.

              • const InputImageInputImage InputImage = "input_image"

            • FileID string

              The ID of the file to be sent to the model.

            • ImageURL string

              The URL of the image to be sent to the model. A fully qualified URL or base64 encoded image in a data URL.

          • type ResponseInputFile struct{…}

            A file input to the model.

            • Type InputFile

              The type of the input item. Always input_file.

              • const InputFileInputFile InputFile = "input_file"

            • Detail ResponseInputFileDetail

              The detail level of the file to be sent to the model. Use low for the default rendering behavior, or high to render the file at higher quality. Defaults to low.

              • const ResponseInputFileDetailLow ResponseInputFileDetail = "low"

              • const ResponseInputFileDetailHigh ResponseInputFileDetail = "high"

            • FileData string

              The content of the file to be sent to the model.

            • FileID string

              The ID of the file to be sent to the model.

            • FileURL string

              The URL of the file to be sent to the model.

            • Filename string

              The name of the file to be sent to the model.

        • Version string

          Optional version of the prompt template.

      • Reasoning RealtimeReasoning

        Configuration for reasoning-capable Realtime models such as gpt-realtime-2.

        • Effort RealtimeReasoningEffort

          Constrains effort on reasoning for reasoning-capable Realtime models such as gpt-realtime-2.

          • const RealtimeReasoningEffortMinimal RealtimeReasoningEffort = "minimal"

          • const RealtimeReasoningEffortLow RealtimeReasoningEffort = "low"

          • const RealtimeReasoningEffortMedium RealtimeReasoningEffort = "medium"

          • const RealtimeReasoningEffortHigh RealtimeReasoningEffort = "high"

          • const RealtimeReasoningEffortXhigh RealtimeReasoningEffort = "xhigh"

      • ToolChoice RealtimeResponseCreateParamsToolChoiceUnionResp

        How the model chooses tools. Provide one of the string modes or force a specific function/MCP tool.

        • type ToolChoiceOptions string

          Controls which (if any) tool is called by the model.

          none means the model will not call any tool and instead generates a message.

          auto means the model can pick between generating a message or calling one or more tools.

          required means the model must call one or more tools.

          • const ToolChoiceOptionsNone ToolChoiceOptions = "none"

          • const ToolChoiceOptionsAuto ToolChoiceOptions = "auto"

          • const ToolChoiceOptionsRequired ToolChoiceOptions = "required"

        • type ToolChoiceFunction struct{…}

          Use this option to force the model to call a specific function.

          • Name string

            The name of the function to call.

          • Type Function

            For function calling, the type is always function.

            • const FunctionFunction Function = "function"

        • type ToolChoiceMcp struct{…}

          Use this option to force the model to call a specific tool on a remote MCP server.

          • ServerLabel string

            The label of the MCP server to use.

          • Type Mcp

            For MCP tools, the type is always mcp.

            • const McpMcp Mcp = "mcp"

          • Name string

            The name of the tool to call on the server.

      • Tools []RealtimeResponseCreateParamsToolUnionResp

        Tools available to the model.

        • type RealtimeFunctionTool struct{…}

          • Description string

            The description of the function, including guidance on when and how to call it, and guidance about what to tell the user when calling (if anything).

          • Name string

            The name of the function.

          • Parameters any

            Parameters of the function in JSON Schema.

          • Type RealtimeFunctionToolType

            The type of the tool, i.e. function.

            • const RealtimeFunctionToolTypeFunction RealtimeFunctionToolType = "function"

        • type RealtimeResponseCreateMcpTool struct{…}

          Give the model access to additional tools via remote Model Context Protocol (MCP) servers. Learn more about MCP.

          • ServerLabel string

            A label for this MCP server, used to identify it in tool calls.

          • Type Mcp

            The type of the MCP tool. Always mcp.

            • const McpMcp Mcp = "mcp"

          • AllowedTools RealtimeResponseCreateMcpToolAllowedToolsUnion

            List of allowed tool names or a filter object.

            • []string

            • RealtimeResponseCreateMcpToolAllowedToolsMcpToolFilter

              • ReadOnly bool

                Indicates whether or not a tool modifies data or is read-only. If an MCP server is annotated with readOnlyHint, it will match this filter.

              • ToolNames []string

                List of allowed tool names.

          • Authorization string

            An OAuth access token that can be used with a remote MCP server, either with a custom MCP server URL or a service connector. Your application must handle the OAuth authorization flow and provide the token here.

          • ConnectorID RealtimeResponseCreateMcpToolConnectorID

            Identifier for service connectors, like those available in ChatGPT. One of server_url, connector_id, or tunnel_id must be provided. Learn more about service connectors here.

            Currently supported connector_id values are:

            • Dropbox: connector_dropbox

            • Gmail: connector_gmail

            • Google Calendar: connector_googlecalendar

            • Google Drive: connector_googledrive

            • Microsoft Teams: connector_microsoftteams

            • Outlook Calendar: connector_outlookcalendar

            • Outlook Email: connector_outlookemail

            • SharePoint: connector_sharepoint

            • const RealtimeResponseCreateMcpToolConnectorIDConnectorDropbox RealtimeResponseCreateMcpToolConnectorID = "connector_dropbox"

            • const RealtimeResponseCreateMcpToolConnectorIDConnectorGmail RealtimeResponseCreateMcpToolConnectorID = "connector_gmail"

            • const RealtimeResponseCreateMcpToolConnectorIDConnectorGooglecalendar RealtimeResponseCreateMcpToolConnectorID = "connector_googlecalendar"

            • const RealtimeResponseCreateMcpToolConnectorIDConnectorGoogledrive RealtimeResponseCreateMcpToolConnectorID = "connector_googledrive"

            • const RealtimeResponseCreateMcpToolConnectorIDConnectorMicrosoftteams RealtimeResponseCreateMcpToolConnectorID = "connector_microsoftteams"

            • const RealtimeResponseCreateMcpToolConnectorIDConnectorOutlookcalendar RealtimeResponseCreateMcpToolConnectorID = "connector_outlookcalendar"

            • const RealtimeResponseCreateMcpToolConnectorIDConnectorOutlookemail RealtimeResponseCreateMcpToolConnectorID = "connector_outlookemail"

            • const RealtimeResponseCreateMcpToolConnectorIDConnectorSharepoint RealtimeResponseCreateMcpToolConnectorID = "connector_sharepoint"

          • DeferLoading bool

            Whether this MCP tool is deferred and discovered via tool search.

          • Headers map[string, string]

            Optional HTTP headers to send to the MCP server. Use for authentication or other purposes.

          • RequireApproval RealtimeResponseCreateMcpToolRequireApprovalUnion

            Specify which of the MCP server's tools require approval.

            • RealtimeResponseCreateMcpToolRequireApprovalMcpToolApprovalFilter

              • Always RealtimeResponseCreateMcpToolRequireApprovalMcpToolApprovalFilterAlways

                A filter object to specify which tools are allowed.

                • ReadOnly bool

                  Indicates whether or not a tool modifies data or is read-only. If an MCP server is annotated with readOnlyHint, it will match this filter.

                • ToolNames []string

                  List of allowed tool names.

              • Never RealtimeResponseCreateMcpToolRequireApprovalMcpToolApprovalFilterNever

                A filter object to specify which tools are allowed.

                • ReadOnly bool

                  Indicates whether or not a tool modifies data or is read-only. If an MCP server is annotated with readOnlyHint, it will match this filter.

                • ToolNames []string

                  List of allowed tool names.

            • string

              • const RealtimeResponseCreateMcpToolRequireApprovalMcpToolApprovalSettingAlways RealtimeResponseCreateMcpToolRequireApprovalMcpToolApprovalSetting = "always"

              • const RealtimeResponseCreateMcpToolRequireApprovalMcpToolApprovalSettingNever RealtimeResponseCreateMcpToolRequireApprovalMcpToolApprovalSetting = "never"

          • ServerDescription string

            Optional description of the MCP server, used to provide more context.

          • ServerURL string

            The URL for the MCP server. One of server_url, connector_id, or tunnel_id must be provided.

          • TunnelID string

            The Secure MCP Tunnel ID to use instead of a direct server URL. One of server_url, connector_id, or tunnel_id must be provided.

  • type SessionUpdateEvent struct{…}

    Send this event to update the session’s configuration. The client may send this event at any time to update any field except for voice and model. voice can be updated only if there have been no other audio outputs yet.

    When the server receives a session.update, it will respond with a session.updated event showing the full, effective configuration. Only the fields that are present in the session.update are updated. To clear a field like instructions, pass an empty string. To clear a field like tools, pass an empty array. To clear a field like turn_detection, pass null.

    • Session SessionUpdateEventSessionUnion

      Update the Realtime session. Choose either a realtime session or a transcription session.

      • type RealtimeSessionCreateRequest struct{…}

        Realtime session object configuration.

        • Type Realtime

          The type of session to create. Always realtime for the Realtime API.

          • const RealtimeRealtime Realtime = "realtime"

        • Audio RealtimeAudioConfig

          Configuration for input and output audio.

          • Input RealtimeAudioConfigInput

            • Format RealtimeAudioFormatsUnion

              The format of the input audio.

            • NoiseReduction RealtimeAudioConfigInputNoiseReduction

              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.

              • Type NoiseReductionType

                Type of noise reduction. near_field is for close-talking microphones such as headphones, far_field is for far-field microphones such as laptop or conference room microphones.

                • const NoiseReductionTypeNearField NoiseReductionType = "near_field"

                • const NoiseReductionTypeFarField NoiseReductionType = "far_field"

            • Transcription AudioTranscription

              Configuration for input audio transcription, defaults to off and can be set to null to turn off once on. Input audio transcription is not native to the model, since the model consumes audio directly. Transcription runs asynchronously through the /audio/transcriptions endpoint and should be treated as guidance of input audio content rather than precisely what the model heard. The client can optionally set the language and prompt for transcription, these offer additional guidance to the transcription service.

              • Delay AudioTranscriptionDelay

                Controls how long the model waits before emitting transcription text. Higher values can improve transcription accuracy at the cost of latency. Only supported with gpt-realtime-whisper in GA Realtime sessions.

                • const AudioTranscriptionDelayMinimal AudioTranscriptionDelay = "minimal"

                • const AudioTranscriptionDelayLow AudioTranscriptionDelay = "low"

                • const AudioTranscriptionDelayMedium AudioTranscriptionDelay = "medium"

                • const AudioTranscriptionDelayHigh AudioTranscriptionDelay = "high"

                • const AudioTranscriptionDelayXhigh AudioTranscriptionDelay = "xhigh"

              • Language string

                The language of the input audio. Supplying the input language in ISO-639-1 (e.g. en) format will improve accuracy and latency.

              • Model AudioTranscriptionModel

                The model to use for transcription. Current options are whisper-1, gpt-4o-mini-transcribe, gpt-4o-mini-transcribe-2025-12-15, gpt-4o-transcribe, gpt-4o-transcribe-diarize, and gpt-realtime-whisper. Use gpt-4o-transcribe-diarize when you need diarization with speaker labels.

                • string

                • type AudioTranscriptionModel string

                  The model to use for transcription. Current options are whisper-1, gpt-4o-mini-transcribe, gpt-4o-mini-transcribe-2025-12-15, gpt-4o-transcribe, gpt-4o-transcribe-diarize, and gpt-realtime-whisper. Use gpt-4o-transcribe-diarize when you need diarization with speaker labels.

                  • const AudioTranscriptionModelWhisper1 AudioTranscriptionModel = "whisper-1"

                  • const AudioTranscriptionModelGPT4oMiniTranscribe AudioTranscriptionModel = "gpt-4o-mini-transcribe"

                  • const AudioTranscriptionModelGPT4oMiniTranscribe2025_12_15 AudioTranscriptionModel = "gpt-4o-mini-transcribe-2025-12-15"

                  • const AudioTranscriptionModelGPT4oTranscribe AudioTranscriptionModel = "gpt-4o-transcribe"

                  • const AudioTranscriptionModelGPT4oTranscribeDiarize AudioTranscriptionModel = "gpt-4o-transcribe-diarize"

                  • const AudioTranscriptionModelGPTRealtimeWhisper AudioTranscriptionModel = "gpt-realtime-whisper"

              • Prompt string

                An optional text to guide the model's style or continue a previous audio segment. For whisper-1, the prompt is a list of keywords. For gpt-4o-transcribe models (excluding gpt-4o-transcribe-diarize), the prompt is a free text string, for example "expect words related to technology". Prompt is not supported with gpt-realtime-whisper in GA Realtime sessions.

            • TurnDetection RealtimeAudioInputTurnDetectionUnion

              Configuration for turn detection, ether Server VAD or Semantic VAD. This can be set to null to turn off, in which case the client must manually trigger model response.

              Server VAD means that the model will detect the start and end of speech based on audio volume and respond at the end of user speech.

              Semantic VAD is more advanced and uses a turn detection model (in conjunction with VAD) to semantically estimate whether the user has finished speaking, then dynamically sets a timeout based on this probability. For example, if user audio trails off with "uhhm", the model will score a low probability of turn end and wait longer for the user to continue speaking. This can be useful for more natural conversations, but may have a higher latency.

              For gpt-realtime-whisper transcription sessions, turn detection must be set to null; VAD is not supported.

              • RealtimeAudioInputTurnDetectionServerVad

                • Type ServerVad

                  Type of turn detection, server_vad to turn on simple Server VAD.

                  • const ServerVadServerVad ServerVad = "server_vad"

                • CreateResponse bool

                  Whether or not to automatically generate a response when a VAD stop event occurs. If interrupt_response is set to false this may fail to create a response if the model is already responding.

                  If both create_response and interrupt_response are set to false, the model will never respond automatically but VAD events will still be emitted.

                • IdleTimeoutMs int64

                  Optional timeout after which a model response will be triggered automatically. This is useful for situations in which a long pause from the user is unexpected, such as a phone call. The model will effectively prompt the user to continue the conversation based on the current context.

                  The timeout value will be applied after the last model response's audio has finished playing, i.e. it's set to the response.done time plus audio playback duration.

                  An input_audio_buffer.timeout_triggered event (plus events associated with the Response) will be emitted when the timeout is reached. Idle timeout is currently only supported for server_vad mode.

                • InterruptResponse bool

                  Whether or not to automatically interrupt (cancel) any ongoing response with output to the default conversation (i.e. conversation of auto) when a VAD start event occurs. If true then the response will be cancelled, otherwise it will continue until complete.

                  If both create_response and interrupt_response are set to false, the model will never respond automatically but VAD events will still be emitted.

                • PrefixPaddingMs int64

                  Used only for server_vad mode. Amount of audio to include before the VAD detected speech (in milliseconds). Defaults to 300ms.

                • SilenceDurationMs int64

                  Used only for server_vad mode. Duration of silence to detect speech stop (in milliseconds). Defaults to 500ms. With shorter values the model will respond more quickly, but may jump in on short pauses from the user.

                • Threshold float64

                  Used only for server_vad mode. Activation threshold for VAD (0.0 to 1.0), this defaults to 0.5. A higher threshold will require louder audio to activate the model, and thus might perform better in noisy environments.

              • RealtimeAudioInputTurnDetectionSemanticVad

                • Type SemanticVad

                  Type of turn detection, semantic_vad to turn on Semantic VAD.

                  • const SemanticVadSemanticVad SemanticVad = "semantic_vad"

                • CreateResponse bool

                  Whether or not to automatically generate a response when a VAD stop event occurs.

                • Eagerness string

                  Used only for semantic_vad mode. The eagerness of the model to respond. low will wait longer for the user to continue speaking, high will respond more quickly. auto is the default and is equivalent to medium. low, medium, and high have max timeouts of 8s, 4s, and 2s respectively.

                  • const RealtimeAudioInputTurnDetectionSemanticVadEagernessLow RealtimeAudioInputTurnDetectionSemanticVadEagerness = "low"

                  • const RealtimeAudioInputTurnDetectionSemanticVadEagernessMedium RealtimeAudioInputTurnDetectionSemanticVadEagerness = "medium"

                  • const RealtimeAudioInputTurnDetectionSemanticVadEagernessHigh RealtimeAudioInputTurnDetectionSemanticVadEagerness = "high"

                  • const RealtimeAudioInputTurnDetectionSemanticVadEagernessAuto RealtimeAudioInputTurnDetectionSemanticVadEagerness = "auto"

                • InterruptResponse bool

                  Whether or not to automatically interrupt any ongoing response with output to the default conversation (i.e. conversation of auto) when a VAD start event occurs.

          • Output RealtimeAudioConfigOutput

            • Format RealtimeAudioFormatsUnion

              The format of the output audio.

            • Speed float64

              The speed of the model's spoken response as a multiple of the original speed. 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.

              This parameter is a post-processing adjustment to the audio after it is generated, it's also possible to prompt the model to speak faster or slower.

            • Voice RealtimeAudioConfigOutputVoiceUnion

              The voice the model uses to respond. Supported built-in voices are alloy, ash, ballad, coral, echo, sage, shimmer, verse, marin, and cedar. You may also provide a custom voice object with an id, for example { "id": "voice_1234" }. Voice cannot be changed during the session once the model has responded with audio at least once. We recommend marin and cedar for best quality.

              • string

              • string

                • const RealtimeAudioConfigOutputVoiceString2Alloy RealtimeAudioConfigOutputVoiceString2 = "alloy"

                • const RealtimeAudioConfigOutputVoiceString2Ash RealtimeAudioConfigOutputVoiceString2 = "ash"

                • const RealtimeAudioConfigOutputVoiceString2Ballad RealtimeAudioConfigOutputVoiceString2 = "ballad"

                • const RealtimeAudioConfigOutputVoiceString2Coral RealtimeAudioConfigOutputVoiceString2 = "coral"

                • const RealtimeAudioConfigOutputVoiceString2Echo RealtimeAudioConfigOutputVoiceString2 = "echo"

                • const RealtimeAudioConfigOutputVoiceString2Sage RealtimeAudioConfigOutputVoiceString2 = "sage"

                • const RealtimeAudioConfigOutputVoiceString2Shimmer RealtimeAudioConfigOutputVoiceString2 = "shimmer"

                • const RealtimeAudioConfigOutputVoiceString2Verse RealtimeAudioConfigOutputVoiceString2 = "verse"

                • const RealtimeAudioConfigOutputVoiceString2Marin RealtimeAudioConfigOutputVoiceString2 = "marin"

                • const RealtimeAudioConfigOutputVoiceString2Cedar RealtimeAudioConfigOutputVoiceString2 = "cedar"

              • RealtimeAudioConfigOutputVoiceID

                • ID string

                  The custom voice ID, e.g. voice_1234.

        • Include []string

          Additional fields to include in server outputs.

          item.input_audio_transcription.logprobs: Include logprobs for input audio transcription.

          • const RealtimeSessionCreateRequestIncludeItemInputAudioTranscriptionLogprobs RealtimeSessionCreateRequestInclude = "item.input_audio_transcription.logprobs"

        • Instructions string

          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.

        • MaxOutputTokens RealtimeSessionCreateRequestMaxOutputTokensUnion

          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.

          • int64

          • Inf

            • const InfInf Inf = "inf"

        • Model RealtimeSessionCreateRequestModel

          The Realtime model used for this session.

          • string

          • RealtimeSessionCreateRequestModel

            • const RealtimeSessionCreateRequestModelGPTRealtime RealtimeSessionCreateRequestModel = "gpt-realtime"

            • const RealtimeSessionCreateRequestModelGPTRealtime1_5 RealtimeSessionCreateRequestModel = "gpt-realtime-1.5"

            • const RealtimeSessionCreateRequestModelGPTRealtime2 RealtimeSessionCreateRequestModel = "gpt-realtime-2"

            • const RealtimeSessionCreateRequestModelGPTRealtime2025_08_28 RealtimeSessionCreateRequestModel = "gpt-realtime-2025-08-28"

            • const RealtimeSessionCreateRequestModelGPT4oRealtimePreview RealtimeSessionCreateRequestModel = "gpt-4o-realtime-preview"

            • const RealtimeSessionCreateRequestModelGPT4oRealtimePreview2024_10_01 RealtimeSessionCreateRequestModel = "gpt-4o-realtime-preview-2024-10-01"

            • const RealtimeSessionCreateRequestModelGPT4oRealtimePreview2024_12_17 RealtimeSessionCreateRequestModel = "gpt-4o-realtime-preview-2024-12-17"

            • const RealtimeSessionCreateRequestModelGPT4oRealtimePreview2025_06_03 RealtimeSessionCreateRequestModel = "gpt-4o-realtime-preview-2025-06-03"

            • const RealtimeSessionCreateRequestModelGPT4oMiniRealtimePreview RealtimeSessionCreateRequestModel = "gpt-4o-mini-realtime-preview"

            • const RealtimeSessionCreateRequestModelGPT4oMiniRealtimePreview2024_12_17 RealtimeSessionCreateRequestModel = "gpt-4o-mini-realtime-preview-2024-12-17"

            • const RealtimeSessionCreateRequestModelGPTRealtimeMini RealtimeSessionCreateRequestModel = "gpt-realtime-mini"

            • const RealtimeSessionCreateRequestModelGPTRealtimeMini2025_10_06 RealtimeSessionCreateRequestModel = "gpt-realtime-mini-2025-10-06"

            • const RealtimeSessionCreateRequestModelGPTRealtimeMini2025_12_15 RealtimeSessionCreateRequestModel = "gpt-realtime-mini-2025-12-15"

            • const RealtimeSessionCreateRequestModelGPTAudio1_5 RealtimeSessionCreateRequestModel = "gpt-audio-1.5"

            • const RealtimeSessionCreateRequestModelGPTAudioMini RealtimeSessionCreateRequestModel = "gpt-audio-mini"

            • const RealtimeSessionCreateRequestModelGPTAudioMini2025_10_06 RealtimeSessionCreateRequestModel = "gpt-audio-mini-2025-10-06"

            • const RealtimeSessionCreateRequestModelGPTAudioMini2025_12_15 RealtimeSessionCreateRequestModel = "gpt-audio-mini-2025-12-15"

        • OutputModalities []string

          The set of modalities the model can respond with. It defaults to ["audio"], indicating that the model will respond with audio plus a transcript. ["text"] can be used to make the model respond with text only. It is not possible to request both text and audio at the same time.

          • const RealtimeSessionCreateRequestOutputModalityText RealtimeSessionCreateRequestOutputModality = "text"

          • const RealtimeSessionCreateRequestOutputModalityAudio RealtimeSessionCreateRequestOutputModality = "audio"

        • ParallelToolCalls bool

          Whether the model may call multiple tools in parallel. Only supported by reasoning Realtime models such as gpt-realtime-2.

        • Prompt ResponsePrompt

          Reference to a prompt template and its variables. Learn more.

        • Reasoning RealtimeReasoning

          Configuration for reasoning-capable Realtime models such as gpt-realtime-2.

        • ToolChoice RealtimeToolChoiceConfigUnion

          How the model chooses tools. Provide one of the string modes or force a specific function/MCP tool.

          • type ToolChoiceOptions string

            Controls which (if any) tool is called by the model.

            none means the model will not call any tool and instead generates a message.

            auto means the model can pick between generating a message or calling one or more tools.

            required means the model must call one or more tools.

          • type ToolChoiceFunction struct{…}

            Use this option to force the model to call a specific function.

          • type ToolChoiceMcp struct{…}

            Use this option to force the model to call a specific tool on a remote MCP server.

        • Tools RealtimeToolsConfig

          Tools available to the model.

          • type RealtimeFunctionTool struct{…}

          • RealtimeToolsConfigUnionMcp

            • ServerLabel string

              A label for this MCP server, used to identify it in tool calls.

            • Type Mcp

              The type of the MCP tool. Always mcp.

              • const McpMcp Mcp = "mcp"

            • AllowedTools RealtimeToolsConfigUnionMcpAllowedTools

              List of allowed tool names or a filter object.

              • []string

              • RealtimeToolsConfigUnionMcpAllowedToolsMcpToolFilter

                • ReadOnly bool

                  Indicates whether or not a tool modifies data or is read-only. If an MCP server is annotated with readOnlyHint, it will match this filter.

                • ToolNames []string

                  List of allowed tool names.

            • Authorization string

              An OAuth access token that can be used with a remote MCP server, either with a custom MCP server URL or a service connector. Your application must handle the OAuth authorization flow and provide the token here.

            • ConnectorID string

              Identifier for service connectors, like those available in ChatGPT. One of server_url, connector_id, or tunnel_id must be provided. Learn more about service connectors here.

              Currently supported connector_id values are:

              • Dropbox: connector_dropbox

              • Gmail: connector_gmail

              • Google Calendar: connector_googlecalendar

              • Google Drive: connector_googledrive

              • Microsoft Teams: connector_microsoftteams

              • Outlook Calendar: connector_outlookcalendar

              • Outlook Email: connector_outlookemail

              • SharePoint: connector_sharepoint

              • const RealtimeToolsConfigUnionMcpConnectorIDConnectorDropbox RealtimeToolsConfigUnionMcpConnectorID = "connector_dropbox"

              • const RealtimeToolsConfigUnionMcpConnectorIDConnectorGmail RealtimeToolsConfigUnionMcpConnectorID = "connector_gmail"

              • const RealtimeToolsConfigUnionMcpConnectorIDConnectorGooglecalendar RealtimeToolsConfigUnionMcpConnectorID = "connector_googlecalendar"

              • const RealtimeToolsConfigUnionMcpConnectorIDConnectorGoogledrive RealtimeToolsConfigUnionMcpConnectorID = "connector_googledrive"

              • const RealtimeToolsConfigUnionMcpConnectorIDConnectorMicrosoftteams RealtimeToolsConfigUnionMcpConnectorID = "connector_microsoftteams"

              • const RealtimeToolsConfigUnionMcpConnectorIDConnectorOutlookcalendar RealtimeToolsConfigUnionMcpConnectorID = "connector_outlookcalendar"

              • const RealtimeToolsConfigUnionMcpConnectorIDConnectorOutlookemail RealtimeToolsConfigUnionMcpConnectorID = "connector_outlookemail"

              • const RealtimeToolsConfigUnionMcpConnectorIDConnectorSharepoint RealtimeToolsConfigUnionMcpConnectorID = "connector_sharepoint"

            • DeferLoading bool

              Whether this MCP tool is deferred and discovered via tool search.

            • Headers map[string, string]

              Optional HTTP headers to send to the MCP server. Use for authentication or other purposes.

            • RequireApproval RealtimeToolsConfigUnionMcpRequireApproval

              Specify which of the MCP server's tools require approval.

              • RealtimeToolsConfigUnionMcpRequireApprovalMcpToolApprovalFilter

                • Always RealtimeToolsConfigUnionMcpRequireApprovalMcpToolApprovalFilterAlways

                  A filter object to specify which tools are allowed.

                  • ReadOnly bool

                    Indicates whether or not a tool modifies data or is read-only. If an MCP server is annotated with readOnlyHint, it will match this filter.

                  • ToolNames []string

                    List of allowed tool names.

                • Never RealtimeToolsConfigUnionMcpRequireApprovalMcpToolApprovalFilterNever

                  A filter object to specify which tools are allowed.

                  • ReadOnly bool

                    Indicates whether or not a tool modifies data or is read-only. If an MCP server is annotated with readOnlyHint, it will match this filter.

                  • ToolNames []string

                    List of allowed tool names.

              • string

                • const RealtimeToolsConfigUnionMcpRequireApprovalMcpToolApprovalSettingAlways RealtimeToolsConfigUnionMcpRequireApprovalMcpToolApprovalSetting = "always"

                • const RealtimeToolsConfigUnionMcpRequireApprovalMcpToolApprovalSettingNever RealtimeToolsConfigUnionMcpRequireApprovalMcpToolApprovalSetting = "never"

            • ServerDescription string

              Optional description of the MCP server, used to provide more context.

            • ServerURL string

              The URL for the MCP server. One of server_url, connector_id, or tunnel_id must be provided.

            • TunnelID string

              The Secure MCP Tunnel ID to use instead of a direct server URL. One of server_url, connector_id, or tunnel_id must be provided.

        • Tracing RealtimeTracingConfigUnion

          Realtime API can write session traces to the Traces Dashboard. Set to null to disable tracing. Once tracing is enabled for a session, the configuration cannot be modified.

          auto will create a trace for the session with default values for the workflow name, group id, and metadata.

          • Auto

            • const AutoAuto Auto = "auto"

          • RealtimeTracingConfigTracingConfiguration

            • GroupID string

              The group id to attach to this trace to enable filtering and grouping in the Traces Dashboard.

            • Metadata any

              The arbitrary metadata to attach to this trace to enable filtering in the Traces Dashboard.

            • WorkflowName string

              The name of the workflow to attach to this trace. This is used to name the trace in the Traces Dashboard.

        • Truncation RealtimeTruncationUnion

          When the number of tokens in a conversation exceeds the model's input token limit, the conversation be truncated, meaning messages (starting from the oldest) will not be included in the model's context. A 32k context model with 4,096 max output tokens can only include 28,224 tokens in the context before truncation occurs.

          Clients can configure truncation behavior to truncate with a lower max token limit, which is an effective way to control token usage and cost.

          Truncation will reduce the number of cached tokens on the next turn (busting the cache), since messages are dropped from the beginning of the context. However, clients can also configure truncation to retain messages up to a fraction of the maximum context size, which will reduce the need for future truncations and thus improve the cache rate.

          Truncation can be disabled entirely, which means the server will never truncate but would instead return an error if the conversation exceeds the model's input token limit.

          • type RealtimeTruncationRealtimeTruncationStrategy string

            The truncation strategy to use for the session. auto is the default truncation strategy. disabled will disable truncation and emit errors when the conversation exceeds the input token limit.

            • const RealtimeTruncationRealtimeTruncationStrategyAuto RealtimeTruncationRealtimeTruncationStrategy = "auto"

            • const RealtimeTruncationRealtimeTruncationStrategyDisabled RealtimeTruncationRealtimeTruncationStrategy = "disabled"

          • type RealtimeTruncationRetentionRatio struct{…}

            Retain a fraction of the conversation tokens when the conversation exceeds the input token limit. This allows you to amortize truncations across multiple turns, which can help improve cached token usage.

            • RetentionRatio float64

              Fraction of post-instruction conversation tokens to retain (0.0 - 1.0) when the conversation exceeds the input token limit. Setting this to 0.8 means that messages will be dropped until 80% of the maximum allowed tokens are used. This helps reduce the frequency of truncations and improve cache rates.

            • Type RetentionRatio

              Use retention ratio truncation.

              • const RetentionRatioRetentionRatio RetentionRatio = "retention_ratio"

            • TokenLimits RealtimeTruncationRetentionRatioTokenLimits

              Optional custom token limits for this truncation strategy. If not provided, the model's default token limits will be used.

              • PostInstructions int64

                Maximum tokens allowed in the conversation after instructions (which including tool definitions). For example, setting this to 5,000 would mean that truncation would occur when the conversation exceeds 5,000 tokens after instructions. This cannot be higher than the model's context window size minus the maximum output tokens.

      • type RealtimeTranscriptionSessionCreateRequest struct{…}

        Realtime transcription session object configuration.

        • Type Transcription

          The type of session to create. Always transcription for transcription sessions.

          • const TranscriptionTranscription Transcription = "transcription"

        • Audio RealtimeTranscriptionSessionAudio

          Configuration for input and output audio.

          • Input RealtimeTranscriptionSessionAudioInput

            • Format RealtimeAudioFormatsUnion

              The PCM audio format. Only a 24kHz sample rate is supported.

            • NoiseReduction RealtimeTranscriptionSessionAudioInputNoiseReduction

              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.

              • Type NoiseReductionType

                Type of noise reduction. near_field is for close-talking microphones such as headphones, far_field is for far-field microphones such as laptop or conference room microphones.

            • Transcription AudioTranscription

              Configuration for input audio transcription, defaults to off and can be set to null to turn off once on. Input audio transcription is not native to the model, since the model consumes audio directly. Transcription runs asynchronously through the /audio/transcriptions endpoint and should be treated as guidance of input audio content rather than precisely what the model heard. The client can optionally set the language and prompt for transcription, these offer additional guidance to the transcription service.

            • TurnDetection RealtimeTranscriptionSessionAudioInputTurnDetectionUnion

              Configuration for turn detection, ether Server VAD or Semantic VAD. This can be set to null to turn off, in which case the client must manually trigger model response.

              Server VAD means that the model will detect the start and end of speech based on audio volume and respond at the end of user speech.

              Semantic VAD is more advanced and uses a turn detection model (in conjunction with VAD) to semantically estimate whether the user has finished speaking, then dynamically sets a timeout based on this probability. For example, if user audio trails off with "uhhm", the model will score a low probability of turn end and wait longer for the user to continue speaking. This can be useful for more natural conversations, but may have a higher latency.

              For gpt-realtime-whisper transcription sessions, turn detection must be set to null; VAD is not supported.

              • RealtimeTranscriptionSessionAudioInputTurnDetectionServerVad

                • Type ServerVad

                  Type of turn detection, server_vad to turn on simple Server VAD.

                  • const ServerVadServerVad ServerVad = "server_vad"

                • CreateResponse bool

                  Whether or not to automatically generate a response when a VAD stop event occurs. If interrupt_response is set to false this may fail to create a response if the model is already responding.

                  If both create_response and interrupt_response are set to false, the model will never respond automatically but VAD events will still be emitted.

                • IdleTimeoutMs int64

                  Optional timeout after which a model response will be triggered automatically. This is useful for situations in which a long pause from the user is unexpected, such as a phone call. The model will effectively prompt the user to continue the conversation based on the current context.

                  The timeout value will be applied after the last model response's audio has finished playing, i.e. it's set to the response.done time plus audio playback duration.

                  An input_audio_buffer.timeout_triggered event (plus events associated with the Response) will be emitted when the timeout is reached. Idle timeout is currently only supported for server_vad mode.

                • InterruptResponse bool

                  Whether or not to automatically interrupt (cancel) any ongoing response with output to the default conversation (i.e. conversation of auto) when a VAD start event occurs. If true then the response will be cancelled, otherwise it will continue until complete.

                  If both create_response and interrupt_response are set to false, the model will never respond automatically but VAD events will still be emitted.

                • PrefixPaddingMs int64

                  Used only for server_vad mode. Amount of audio to include before the VAD detected speech (in milliseconds). Defaults to 300ms.

                • SilenceDurationMs int64

                  Used only for server_vad mode. Duration of silence to detect speech stop (in milliseconds). Defaults to 500ms. With shorter values the model will respond more quickly, but may jump in on short pauses from the user.

                • Threshold float64

                  Used only for server_vad mode. Activation threshold for VAD (0.0 to 1.0), this defaults to 0.5. A higher threshold will require louder audio to activate the model, and thus might perform better in noisy environments.

              • RealtimeTranscriptionSessionAudioInputTurnDetectionSemanticVad

                • Type SemanticVad

                  Type of turn detection, semantic_vad to turn on Semantic VAD.

                  • const SemanticVadSemanticVad SemanticVad = "semantic_vad"

                • CreateResponse bool

                  Whether or not to automatically generate a response when a VAD stop event occurs.

                • Eagerness string

                  Used only for semantic_vad mode. The eagerness of the model to respond. low will wait longer for the user to continue speaking, high will respond more quickly. auto is the default and is equivalent to medium. low, medium, and high have max timeouts of 8s, 4s, and 2s respectively.

                  • const RealtimeTranscriptionSessionAudioInputTurnDetectionSemanticVadEagernessLow RealtimeTranscriptionSessionAudioInputTurnDetectionSemanticVadEagerness = "low"

                  • const RealtimeTranscriptionSessionAudioInputTurnDetectionSemanticVadEagernessMedium RealtimeTranscriptionSessionAudioInputTurnDetectionSemanticVadEagerness = "medium"

                  • const RealtimeTranscriptionSessionAudioInputTurnDetectionSemanticVadEagernessHigh RealtimeTranscriptionSessionAudioInputTurnDetectionSemanticVadEagerness = "high"

                  • const RealtimeTranscriptionSessionAudioInputTurnDetectionSemanticVadEagernessAuto RealtimeTranscriptionSessionAudioInputTurnDetectionSemanticVadEagerness = "auto"

                • InterruptResponse bool

                  Whether or not to automatically interrupt any ongoing response with output to the default conversation (i.e. conversation of auto) when a VAD start event occurs.

        • Include []string

          Additional fields to include in server outputs.

          item.input_audio_transcription.logprobs: Include logprobs for input audio transcription.

          • const RealtimeTranscriptionSessionCreateRequestIncludeItemInputAudioTranscriptionLogprobs RealtimeTranscriptionSessionCreateRequestInclude = "item.input_audio_transcription.logprobs"

    • Type SessionUpdate

      The event type, must be session.update.

      • const SessionUpdateSessionUpdate SessionUpdate = "session.update"

    • EventID string

      Optional client-generated ID used to identify this event. This is an arbitrary string that a client may assign. It will be passed back if there is an error with the event, but the corresponding session.updated event will not include it.

Realtime Conversation Item Assistant Message

• type RealtimeConversationItemAssistantMessage struct{…}

  An assistant message item in a Realtime conversation.

  • Content []RealtimeConversationItemAssistantMessageContent

    The content of the message.

    • Audio string

      Base64-encoded audio bytes, these will be parsed as the format specified in the session output audio type configuration. This defaults to PCM 16-bit 24kHz mono if not specified.

    • Text string

      The text content.

    • Transcript string

      The transcript of the audio content, this will always be present if the output type is audio.

    • Type string

      The content type, output_text or output_audio depending on the session output_modalities configuration.

      • const RealtimeConversationItemAssistantMessageContentTypeOutputText RealtimeConversationItemAssistantMessageContentType = "output_text"

      • const RealtimeConversationItemAssistantMessageContentTypeOutputAudio RealtimeConversationItemAssistantMessageContentType = "output_audio"

  • Role Assistant

    The role of the message sender. Always assistant.

    • const AssistantAssistant Assistant = "assistant"

  • Type Message

    The type of the item. Always message.

    • const MessageMessage Message = "message"

  • ID string

    The unique ID of the item. This may be provided by the client or generated by the server.

  • Object RealtimeConversationItemAssistantMessageObject

    Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

    • const RealtimeConversationItemAssistantMessageObjectRealtimeItem RealtimeConversationItemAssistantMessageObject = "realtime.item"

  • Status RealtimeConversationItemAssistantMessageStatus

    The status of the item. Has no effect on the conversation.

    • const RealtimeConversationItemAssistantMessageStatusCompleted RealtimeConversationItemAssistantMessageStatus = "completed"

    • const RealtimeConversationItemAssistantMessageStatusIncomplete RealtimeConversationItemAssistantMessageStatus = "incomplete"

    • const RealtimeConversationItemAssistantMessageStatusInProgress RealtimeConversationItemAssistantMessageStatus = "in_progress"

Realtime Conversation Item Function Call

• type RealtimeConversationItemFunctionCall struct{…}

  A function call item in a Realtime conversation.

  • Arguments string

    The arguments of the function call. This is a JSON-encoded string representing the arguments passed to the function, for example {"arg1": "value1", "arg2": 42}.

  • Name string

    The name of the function being called.

  • Type FunctionCall

    The type of the item. Always function_call.

    • const FunctionCallFunctionCall FunctionCall = "function_call"

  • ID string

    The unique ID of the item. This may be provided by the client or generated by the server.

  • CallID string

    The ID of the function call.

  • Object RealtimeConversationItemFunctionCallObject

    Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

    • const RealtimeConversationItemFunctionCallObjectRealtimeItem RealtimeConversationItemFunctionCallObject = "realtime.item"

  • Status RealtimeConversationItemFunctionCallStatus

    The status of the item. Has no effect on the conversation.

    • const RealtimeConversationItemFunctionCallStatusCompleted RealtimeConversationItemFunctionCallStatus = "completed"

    • const RealtimeConversationItemFunctionCallStatusIncomplete RealtimeConversationItemFunctionCallStatus = "incomplete"

    • const RealtimeConversationItemFunctionCallStatusInProgress RealtimeConversationItemFunctionCallStatus = "in_progress"

Realtime Conversation Item Function Call Output

• type RealtimeConversationItemFunctionCallOutput struct{…}

  A function call output item in a Realtime conversation.

  • CallID string

    The ID of the function call this output is for.

  • Output string

    The output of the function call, this is free text and can contain any information or simply be empty.

  • Type FunctionCallOutput

    The type of the item. Always function_call_output.

    • const FunctionCallOutputFunctionCallOutput FunctionCallOutput = "function_call_output"

  • ID string

    The unique ID of the item. This may be provided by the client or generated by the server.

  • Object RealtimeConversationItemFunctionCallOutputObject

    Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

    • const RealtimeConversationItemFunctionCallOutputObjectRealtimeItem RealtimeConversationItemFunctionCallOutputObject = "realtime.item"

  • Status RealtimeConversationItemFunctionCallOutputStatus

    The status of the item. Has no effect on the conversation.

    • const RealtimeConversationItemFunctionCallOutputStatusCompleted RealtimeConversationItemFunctionCallOutputStatus = "completed"

    • const RealtimeConversationItemFunctionCallOutputStatusIncomplete RealtimeConversationItemFunctionCallOutputStatus = "incomplete"

    • const RealtimeConversationItemFunctionCallOutputStatusInProgress RealtimeConversationItemFunctionCallOutputStatus = "in_progress"

Realtime Conversation Item System Message

• type RealtimeConversationItemSystemMessage struct{…}

  A system message in a Realtime conversation can be used to provide additional context or instructions to the model. This is similar but distinct from the instruction prompt provided at the start of a conversation, as system messages can be added at any point in the conversation. For major changes to the conversation's behavior, use instructions, but for smaller updates (e.g. "the user is now asking about a different topic"), use system messages.

  • Content []RealtimeConversationItemSystemMessageContent

    The content of the message.

    • Text string

      The text content.

    • Type string

      The content type. Always input_text for system messages.

      • const RealtimeConversationItemSystemMessageContentTypeInputText RealtimeConversationItemSystemMessageContentType = "input_text"

  • Role System

    The role of the message sender. Always system.

    • const SystemSystem System = "system"

  • Type Message

    The type of the item. Always message.

    • const MessageMessage Message = "message"

  • ID string

    The unique ID of the item. This may be provided by the client or generated by the server.

  • Object RealtimeConversationItemSystemMessageObject

    Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

    • const RealtimeConversationItemSystemMessageObjectRealtimeItem RealtimeConversationItemSystemMessageObject = "realtime.item"

  • Status RealtimeConversationItemSystemMessageStatus

    The status of the item. Has no effect on the conversation.

    • const RealtimeConversationItemSystemMessageStatusCompleted RealtimeConversationItemSystemMessageStatus = "completed"

    • const RealtimeConversationItemSystemMessageStatusIncomplete RealtimeConversationItemSystemMessageStatus = "incomplete"

    • const RealtimeConversationItemSystemMessageStatusInProgress RealtimeConversationItemSystemMessageStatus = "in_progress"

Realtime Conversation Item User Message

• type RealtimeConversationItemUserMessage struct{…}

  A user message item in a Realtime conversation.

  • Content []RealtimeConversationItemUserMessageContent

    The content of the message.

    • Audio string

      Base64-encoded audio bytes (for input_audio), these will be parsed as the format specified in the session input audio type configuration. This defaults to PCM 16-bit 24kHz mono if not specified.

    • Detail string

      The detail level of the image (for input_image). auto will default to high.

      • const RealtimeConversationItemUserMessageContentDetailAuto RealtimeConversationItemUserMessageContentDetail = "auto"

      • const RealtimeConversationItemUserMessageContentDetailLow RealtimeConversationItemUserMessageContentDetail = "low"

      • const RealtimeConversationItemUserMessageContentDetailHigh RealtimeConversationItemUserMessageContentDetail = "high"

    • ImageURL string

      Base64-encoded image bytes (for input_image) as a data URI. For example data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAA.... Supported formats are PNG and JPEG.

    • Text string

      The text content (for input_text).

    • Transcript string

      Transcript of the audio (for input_audio). This is not sent to the model, but will be attached to the message item for reference.

    • Type string

      The content type (input_text, input_audio, or input_image).

      • const RealtimeConversationItemUserMessageContentTypeInputText RealtimeConversationItemUserMessageContentType = "input_text"

      • const RealtimeConversationItemUserMessageContentTypeInputAudio RealtimeConversationItemUserMessageContentType = "input_audio"

      • const RealtimeConversationItemUserMessageContentTypeInputImage RealtimeConversationItemUserMessageContentType = "input_image"

  • Role User

    The role of the message sender. Always user.

    • const UserUser User = "user"

  • Type Message

    The type of the item. Always message.

    • const MessageMessage Message = "message"

  • ID string

    The unique ID of the item. This may be provided by the client or generated by the server.

  • Object RealtimeConversationItemUserMessageObject

    Identifier for the API object being returned - always realtime.item. Optional when creating a new item.

    • const RealtimeConversationItemUserMessageObjectRealtimeItem RealtimeConversationItemUserMessageObject = "realtime.item"

  • Status RealtimeConversationItemUserMessageStatus

    The status of the item. Has no effect on the conversation.

    • const RealtimeConversationItemUserMessageStatusCompleted RealtimeConversationItemUserMessageStatus = "completed"

    • const RealtimeConversationItemUserMessageStatusIncomplete RealtimeConversationItemUserMessageStatus = "incomplete"

    • const RealtimeConversationItemUserMessageStatusInProgress RealtimeConversationItemUserMessageStatus = "in_progress"

Realtime Error

• type RealtimeError struct{…}

  Details of the error.

  • Message string

    A human-readable error message.

  • Type string

    The type of error (e.g., "invalid_request_error", "server_error").

  • Code string

    Error code, if any.

  • EventID string

    The event_id of the client event that caused the error, if applicable.

  • Param string

    Parameter related to the error, if any.

Realtime Error Event

• type RealtimeErrorEvent struct{…}

  Returned when an error occurs, which could be a client problem or a server problem. Most errors are recoverable and the session will stay open, we recommend to implementors to monitor and log error messages by default.

  • Error RealtimeError

    Details of the error.

    • Message string

      A human-readable error message.

    • Type string

      The type of error (e.g., "invalid_request_error", "server_error").

    • Code string

      Error code, if any.

    • EventID string

      The event_id of the client event that caused the error, if applicable.

    • Param string

      Parameter related to the error, if any.

  • EventID string

    The unique ID of the server event.

  • Type Error

    The event type, must be error.

    • const ErrorError Error = "error"

Realtime Function Tool

• type RealtimeFunctionTool struct{…}

  • Description string

    The description of the function, including guidance on when and how to call it, and guidance about what to tell the user when calling (if anything).

  • Name string

    The name of the function.

  • Parameters any

    Parameters of the function in JSON Schema.

  • Type RealtimeFunctionToolType

    The type of the tool, i.e. function.

    • const RealtimeFunctionToolTypeFunction RealtimeFunctionToolType = "function"

Realtime Mcp Approval Request

• type RealtimeMcpApprovalRequest struct{…}

  A Realtime item requesting human approval of a tool invocation.

  • ID string

    The unique ID of the approval request.

  • Arguments string

    A JSON string of arguments for the tool.

  • Name string

    The name of the tool to run.

  • ServerLabel string

    The label of the MCP server making the request.

  • Type McpApprovalRequest

    The type of the item. Always mcp_approval_request.

    • const McpApprovalRequestMcpApprovalRequest McpApprovalRequest = "mcp_approval_request"

Realtime Mcp Approval Response

• type RealtimeMcpApprovalResponse struct{…}

  A Realtime item responding to an MCP approval request.

  • ID string

    The unique ID of the approval response.

  • ApprovalRequestID string

    The ID of the approval request being answered.

  • Approve bool

    Whether the request was approved.

  • Type McpApprovalResponse

    The type of the item. Always mcp_approval_response.

    • const McpApprovalResponseMcpApprovalResponse McpApprovalResponse = "mcp_approval_response"

  • Reason string

    Optional reason for the decision.

Realtime Mcp List Tools

• type RealtimeMcpListTools struct{…}

  A Realtime item listing tools available on an MCP server.

  • ServerLabel string

    The label of the MCP server.

  • Tools []RealtimeMcpListToolsTool

    The tools available on the server.

    • InputSchema any

      The JSON schema describing the tool's input.

    • Name string

      The name of the tool.

    • Annotations any

      Additional annotations about the tool.

    • Description string

      The description of the tool.

  • Type McpListTools

    The type of the item. Always mcp_list_tools.

    • const McpListToolsMcpListTools McpListTools = "mcp_list_tools"

  • ID string

    The unique ID of the list.

Realtime Mcp Protocol Error

• type RealtimeMcpProtocolError struct{…}

  • Code int64

  • Message string

  • Type ProtocolError

    • const ProtocolErrorProtocolError ProtocolError = "protocol_error"

Realtime Mcp Tool Call

• type RealtimeMcpToolCall struct{…}

  A Realtime item representing an invocation of a tool on an MCP server.

  • ID string

    The unique ID of the tool call.

  • Arguments string

    A JSON string of the arguments passed to the tool.

  • Name string

    The name of the tool that was run.

  • ServerLabel string

    The label of the MCP server running the tool.

  • Type McpCall

    The type of the item. Always mcp_call.

    • const McpCallMcpCall McpCall = "mcp_call"

  • ApprovalRequestID string

    The ID of an associated approval request, if any.

  • Error RealtimeMcpToolCallErrorUnion

    The error from the tool call, if any.

    • type RealtimeMcpProtocolError struct{…}

      • Code int64

      • Message string

      • Type ProtocolError

        • const ProtocolErrorProtocolError ProtocolError = "protocol_error"

    • type RealtimeMcpToolExecutionError struct{…}

      • Message string

      • Type ToolExecutionError

        • const ToolExecutionErrorToolExecutionError ToolExecutionError = "tool_execution_error"

    • type RealtimeMcphttpError struct{…}

      • Code int64

      • Message string

      • Type HTTPError

        • const HTTPErrorHTTPError HTTPError = "http_error"

  • Output string

    The output from the tool call.

Realtime Mcp Tool Execution Error

• type RealtimeMcpToolExecutionError struct{…}

  • Message string

  • Type ToolExecutionError

    • const ToolExecutionErrorToolExecutionError ToolExecutionError = "tool_execution_error"

Realtime Mcphttp Error

• type RealtimeMcphttpError struct{…}

  • Code int64

  • Message string

  • Type HTTPError

    • const HTTPErrorHTTPError HTTPError = "http_error"

Realtime Reasoning

• type RealtimeReasoning struct{…}

  Configuration for reasoning-capable Realtime models such as gpt-realtime-2.

  • Effort RealtimeReasoningEffort

    Constrains effort on reasoning for reasoning-capable Realtime models such as gpt-realtime-2.

    • const RealtimeReasoningEffortMinimal RealtimeReasoningEffort = "minimal"

    • const RealtimeReasoningEffortLow RealtimeReasoningEffort = "low"

    • const RealtimeReasoningEffortMedium RealtimeReasoningEffort = "medium"

    • const RealtimeReasoningEffortHigh RealtimeReasoningEffort = "high"

    • const RealtimeReasoningEffortXhigh RealtimeReasoningEffort = "xhigh"