LocalAI Realtime API

x-generated: '2026-08-27'
x-method: derived
x-source: https://localai.io/features/openai-realtime
asyncapi: 3.0.0
info:
  title: LocalAI Realtime API
  version: 4.9.0
  description: |
    The LocalAI Realtime API — an OpenAI Realtime-compatible, low-latency, multi-modal (voice and text)
    conversation surface carried over WebSocket, with an alternative WebRTC transport negotiated through
    an SDP offer/answer handshake on the REST endpoint.

    PROVENANCE: LocalAI publishes no AsyncAPI document. This description is DERIVED from the provider's
    own Realtime API documentation at https://localai.io/features/openai-realtime and contains only event
    names quoted verbatim from that page. No event was invented, and no payload schema is asserted, because
    none is published — the message payloads below are declared as unconstrained objects rather than
    guessed. LocalAI has no webhook surface; this WebSocket channel and the backend-log stream are its
    entire event surface.
  license:
    name: MIT
    url: https://raw.githubusercontent.com/mudler/LocalAI/master/LICENSE
  externalDocs:
    url: https://localai.io/features/openai-realtime
servers:
  instance:
    host: '{localai-host}:8080'
    protocol: ws
    description: >-
      A self-hosted LocalAI instance. The documented default address is localhost:8080. Realtime requires
      a pipeline model configuration naming vad, transcription, llm and tts components.
    variables:
      localai-host:
        default: localhost
        description: The host running LocalAI.
channels:
  realtime:
    address: /v1/realtime
    title: Realtime session
    description: >-
      WebSocket channel. Connect as ws://<host>:8080/v1/realtime?model=<model>. Carries the OpenAI
      Realtime event vocabulary in both directions.
    parameters:
      model:
        description: Name of a pipeline model configuration (query parameter, not a path parameter).
    messages:
      sessionCreated:
        $ref: '#/components/messages/sessionCreated'
      sessionUpdate:
        $ref: '#/components/messages/sessionUpdate'
      responseCreate:
        $ref: '#/components/messages/responseCreate'
      responseCreated:
        $ref: '#/components/messages/responseCreated'
      responseDone:
        $ref: '#/components/messages/responseDone'
      responseOutputAudioDelta:
        $ref: '#/components/messages/responseOutputAudioDelta'
      responseOutputAudioTranscriptDelta:
        $ref: '#/components/messages/responseOutputAudioTranscriptDelta'
      conversationItemCreate:
        $ref: '#/components/messages/conversationItemCreate'
      conversationItemDelete:
        $ref: '#/components/messages/conversationItemDelete'
      conversationItemTruncate:
        $ref: '#/components/messages/conversationItemTruncate'
      conversationItemSpeaker:
        $ref: '#/components/messages/conversationItemSpeaker'
      conversationItemInputAudioTranscriptionDelta:
        $ref: '#/components/messages/conversationItemInputAudioTranscriptionDelta'
      conversationItemInputAudioTranscriptionFailed:
        $ref: '#/components/messages/conversationItemInputAudioTranscriptionFailed'
      inputAudioBufferClear:
        $ref: '#/components/messages/inputAudioBufferClear'
  backendLogs:
    address: /ws/backend-logs/{modelId}
    title: Backend log stream
    description: >-
      WebSocket channel streaming backend logs for one model. Declared in the published Swagger document
      as GET /ws/backend-logs/{modelId}. Admin-only when authentication is enabled. No message schema is
      published, so none is asserted here.
    parameters:
      modelId:
        description: Identifier of the model whose backend logs to stream.
    messages:
      logLine:
        $ref: '#/components/messages/logLine'
operations:
  sendClientEvent:
    action: send
    channel:
      $ref: '#/channels/realtime'
    title: Client events
    description: Events the client sends into a realtime session.
    messages:
    - $ref: '#/channels/realtime/messages/sessionUpdate'
    - $ref: '#/channels/realtime/messages/responseCreate'
    - $ref: '#/channels/realtime/messages/conversationItemCreate'
    - $ref: '#/channels/realtime/messages/conversationItemDelete'
    - $ref: '#/channels/realtime/messages/conversationItemTruncate'
    - $ref: '#/channels/realtime/messages/inputAudioBufferClear'
  receiveServerEvent:
    action: receive
    channel:
      $ref: '#/channels/realtime'
    title: Server events
    description: Events LocalAI emits back over the session.
    messages:
    - $ref: '#/channels/realtime/messages/sessionCreated'
    - $ref: '#/channels/realtime/messages/responseCreated'
    - $ref: '#/channels/realtime/messages/responseDone'
    - $ref: '#/channels/realtime/messages/responseOutputAudioDelta'
    - $ref: '#/channels/realtime/messages/responseOutputAudioTranscriptDelta'
    - $ref: '#/channels/realtime/messages/conversationItemSpeaker'
    - $ref: '#/channels/realtime/messages/conversationItemInputAudioTranscriptionDelta'
    - $ref: '#/channels/realtime/messages/conversationItemInputAudioTranscriptionFailed'
  receiveBackendLogs:
    action: receive
    channel:
      $ref: '#/channels/backendLogs'
    title: Backend log lines
components:
  messages:
    sessionCreated:
      name: session.created
      title: Session created
      payload:
        $ref: '#/components/schemas/undocumentedEvent'
    sessionUpdate:
      name: session.update
      title: Update session configuration
      payload:
        $ref: '#/components/schemas/undocumentedEvent'
    responseCreate:
      name: response.create
      title: Request a response
      description: >-
        Setting `conversation` to `none` creates a response outside the default conversation; the reply is
        not added to conversation history, which makes it usable as a side channel during a spoken turn.
      payload:
        $ref: '#/components/schemas/undocumentedEvent'
    responseCreated:
      name: response.created
      payload:
        $ref: '#/components/schemas/undocumentedEvent'
    responseDone:
      name: response.done
      payload:
        $ref: '#/components/schemas/undocumentedEvent'
    responseOutputAudioDelta:
      name: response.output_audio.delta
      title: Audio chunk
      description: >-
        Emitted per audio chunk when pipeline.streaming.tts is enabled and the TTS backend supports
        streaming synthesis; otherwise one unary delta is emitted for the whole utterance.
      payload:
        $ref: '#/components/schemas/undocumentedEvent'
    responseOutputAudioTranscriptDelta:
      name: response.output_audio_transcript.delta
      description: Emitted as LLM tokens stream when pipeline.streaming.llm is enabled.
      payload:
        $ref: '#/components/schemas/undocumentedEvent'
    conversationItemCreate:
      name: conversation.item.create
      payload:
        $ref: '#/components/schemas/undocumentedEvent'
    conversationItemDelete:
      name: conversation.item.delete
      payload:
        $ref: '#/components/schemas/undocumentedEvent'
    conversationItemTruncate:
      name: conversation.item.truncate
      payload:
        $ref: '#/components/schemas/undocumentedEvent'
    conversationItemSpeaker:
      name: conversation.item.speaker
      payload:
        $ref: '#/components/schemas/undocumentedEvent'
    conversationItemInputAudioTranscriptionDelta:
      name: conversation.item.input_audio_transcription.delta
      description: Streams transcript text deltas of the user's speech when pipeline.streaming.transcription is enabled.
      payload:
        $ref: '#/components/schemas/undocumentedEvent'
    conversationItemInputAudioTranscriptionFailed:
      name: conversation.item.input_audio_transcription.failed
      payload:
        $ref: '#/components/schemas/undocumentedEvent'
    inputAudioBufferClear:
      name: input_audio_buffer.clear
      payload:
        $ref: '#/components/schemas/undocumentedEvent'
    logLine:
      name: backendLogLine
      payload:
        $ref: '#/components/schemas/undocumentedEvent'
  schemas:
    undocumentedEvent:
      type: object
      description: >-
        No payload schema is published for this event. LocalAI documents the event NAMES and the transport
        but not the message bodies, deferring to the OpenAI Realtime API specification it emulates. The
        shape is deliberately left unconstrained rather than guessed.
      additionalProperties: true