Deepgram Voice Agent API

asyncapi: 2.6.0
info:
  title: Deepgram Voice Agent Events
  description: >-
    The Deepgram Voice Agent API is an end-to-end solution that combines
    speech-to-text, LLM orchestration, and text-to-speech into a single
    real-time WebSocket API. It simplifies building conversational voice
    agents by handling barge-in detection, turn-taking prediction, function
    calling, and mid-session control. The client sends a settings
    configuration message after connection, followed by audio frames, and
    receives agent audio responses along with lifecycle and control events.
  version: '1.0'
  contact:
    name: Deepgram Support
    url: https://developers.deepgram.com
servers:
  production:
    url: 'wss://agent.deepgram.com/v1/agent/converse'
    protocol: wss
    description: >-
      Deepgram production WebSocket server for the Voice Agent API. Connect
      and send a Settings message to configure the agent before sending
      audio data.
    security:
      - bearerAuth: []
channels:
  /v1/agent/converse:
    description: >-
      WebSocket channel for the Voice Agent API. After connecting, the
      client sends a Settings message to configure the agent's listen
      (STT), think (LLM), and speak (TTS) providers, followed by binary
      audio frames. The server responds with agent audio, transcription
      events, and lifecycle messages.
    publish:
      operationId: sendAgentInput
      summary: Send input to the voice agent
      description: >-
        Client sends settings configuration, audio frames, function call
        results, and control messages to the voice agent.
      message:
        oneOf:
          - $ref: '#/components/messages/Settings'
          - $ref: '#/components/messages/AudioInput'
          - $ref: '#/components/messages/UpdateInstructions'
          - $ref: '#/components/messages/UpdateSpeak'
          - $ref: '#/components/messages/InjectAgentMessage'
          - $ref: '#/components/messages/FunctionCallResponse'
          - $ref: '#/components/messages/AgentKeepAlive'
    subscribe:
      operationId: receiveAgentOutput
      summary: Receive output from the voice agent
      description: >-
        Server sends agent audio responses, transcription results, function
        call requests, and agent lifecycle events.
      message:
        oneOf:
          - $ref: '#/components/messages/AgentAudioData'
          - $ref: '#/components/messages/UserStartedSpeaking'
          - $ref: '#/components/messages/AgentStartedSpeaking'
          - $ref: '#/components/messages/AgentThinking'
          - $ref: '#/components/messages/ConversationText'
          - $ref: '#/components/messages/FunctionCallRequest'
          - $ref: '#/components/messages/FunctionCalling'
          - $ref: '#/components/messages/Welcome'
          - $ref: '#/components/messages/AgentError'
components:
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: >-
        Deepgram API key passed as a token query parameter or Authorization
        header when establishing the WebSocket connection.
  messages:
    Settings:
      name: Settings
      title: Settings
      summary: Agent session configuration
      description: >-
        Initialization message sent immediately after opening the WebSocket
        and before sending any audio. Configures the agent's audio format,
        STT (listen), LLM (think), and TTS (speak) providers, agent
        instructions, and optional context.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/SettingsPayload'
    AudioInput:
      name: AudioInput
      title: Audio Input
      summary: User audio data
      description: >-
        Binary WebSocket message containing raw audio data from the user's
        microphone in the encoding configured in the Settings message.
      contentType: application/octet-stream
      payload:
        type: string
        format: binary
        description: >-
          Raw binary audio from the user.
    UpdateInstructions:
      name: UpdateInstructions
      title: Update Instructions
      summary: Update agent instructions mid-session
      description: >-
        Updates the agent's system instructions during an active session
        without restarting the connection.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/UpdateInstructionsPayload'
    UpdateSpeak:
      name: UpdateSpeak
      title: Update Speak Settings
      summary: Update TTS settings mid-session
      description: >-
        Updates the text-to-speech provider settings during an active
        session.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/UpdateSpeakPayload'
    InjectAgentMessage:
      name: InjectAgentMessage
      title: Inject Agent Message
      summary: Inject a message into the agent conversation
      description: >-
        Injects a text message into the agent's conversation context,
        allowing external events to influence the conversation flow.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/InjectAgentMessagePayload'
    FunctionCallResponse:
      name: FunctionCallResponse
      title: Function Call Response
      summary: Response to a function call request
      description: >-
        Sends the result of a function call back to the agent after the
        client has executed the requested function.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/FunctionCallResponsePayload'
    AgentKeepAlive:
      name: AgentKeepAlive
      title: Keep Alive
      summary: Keep the agent connection alive
      description: >-
        Keeps the WebSocket connection alive during periods of inactivity.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/KeepAlivePayload'
    AgentAudioData:
      name: AgentAudioData
      title: Agent Audio Data
      summary: Agent speech audio
      description: >-
        Binary WebSocket message containing synthesized speech audio from
        the agent in the encoding configured in the Settings message.
      contentType: application/octet-stream
      payload:
        type: string
        format: binary
        description: >-
          Raw binary audio from the agent's TTS output.
    UserStartedSpeaking:
      name: UserStartedSpeaking
      title: User Started Speaking
      summary: User speech activity detected
      description: >-
        Event indicating that the user has started speaking, which may
        trigger barge-in behavior to interrupt the agent.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/UserStartedSpeakingPayload'
    AgentStartedSpeaking:
      name: AgentStartedSpeaking
      title: Agent Started Speaking
      summary: Agent has begun speaking
      description: >-
        Event indicating that the agent has started generating and sending
        audio output.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/AgentStartedSpeakingPayload'
    AgentThinking:
      name: AgentThinking
      title: Agent Thinking
      summary: Agent is processing a response
      description: >-
        Event indicating that the agent's LLM is generating a response to
        the user's input.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/AgentThinkingPayload'
    ConversationText:
      name: ConversationText
      title: Conversation Text
      summary: Transcript of conversation
      description: >-
        Text transcript of the conversation including both user speech
        transcriptions and agent response text.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/ConversationTextPayload'
    FunctionCallRequest:
      name: FunctionCallRequest
      title: Function Call Request
      summary: Agent requests a function call
      description: >-
        The agent's LLM has determined that a function should be called.
        The client must execute the function and return the result via
        a FunctionCallResponse message.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/FunctionCallRequestPayload'
    FunctionCalling:
      name: FunctionCalling
      title: Function Calling
      summary: Agent is invoking a function
      description: >-
        Event indicating that the agent is in the process of calling a
        function.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/FunctionCallingPayload'
    Welcome:
      name: Welcome
      title: Welcome
      summary: Connection established
      description: >-
        Welcome message sent by the server after the WebSocket connection
        is established and the Settings message has been processed.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/WelcomePayload'
    AgentError:
      name: AgentError
      title: Error
      summary: Agent error event
      description: >-
        Error event indicating an issue with the voice agent session.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/AgentErrorPayload'
  schemas:
    SettingsPayload:
      type: object
      required:
        - type
      properties:
        type:
          type: string
          const: Settings
          description: >-
            Message type identifier.
        audio:
          type: object
          properties:
            input:
              type: object
              properties:
                encoding:
                  type: string
                  description: >-
                    Audio encoding format for input audio from the user.
                sample_rate:
                  type: integer
                  description: >-
                    Sample rate in Hertz for input audio.
              description: >-
                Input audio configuration.
            output:
              type: object
              properties:
                encoding:
                  type: string
                  description: >-
                    Audio encoding format for output audio from the agent.
                sample_rate:
                  type: integer
                  description: >-
                    Sample rate in Hertz for output audio.
                container:
                  type: string
                  description: >-
                    Container format for output audio.
              description: >-
                Output audio configuration.
          description: >-
            Audio format configuration for both input and output.
        agent:
          type: object
          properties:
            listen:
              type: object
              properties:
                model:
                  type: string
                  description: >-
                    Speech-to-text model to use for transcription.
                language:
                  type: string
                  description: >-
                    Language for speech recognition.
              description: >-
                STT provider configuration.
            think:
              type: object
              properties:
                provider:
                  type: object
                  properties:
                    type:
                      type: string
                      description: >-
                        LLM provider type such as open_ai, anthropic, or
                        deepgram.
                  description: >-
                    LLM provider settings.
                model:
                  type: string
                  description: >-
                    LLM model identifier.
                instructions:
                  type: string
                  description: >-
                    System instructions for the agent's behavior.
                functions:
                  type: array
                  items:
                    $ref: '#/components/schemas/FunctionDefinition'
                  description: >-
                    Functions available for the agent to call.
              description: >-
                LLM provider configuration.
            speak:
              type: object
              properties:
                model:
                  type: string
                  description: >-
                    Text-to-speech model or voice to use.
              description: >-
                TTS provider configuration.
          description: >-
            Agent provider configuration for listen, think, and speak.
        context:
          type: object
          properties:
            messages:
              type: array
              items:
                type: object
                properties:
                  role:
                    type: string
                    description: >-
                      Role of the message sender.
                  content:
                    type: string
                    description: >-
                      Content of the message.
              description: >-
                Initial conversation context messages.
            replay:
              type: boolean
              description: >-
                Whether to replay context messages to the user.
          description: >-
            Optional initial conversation context.
    FunctionDefinition:
      type: object
      properties:
        name:
          type: string
          description: >-
            Name of the function.
        description:
          type: string
          description: >-
            Description of what the function does.
        parameters:
          type: object
          description: >-
            JSON Schema defining the function's parameters.
    UpdateInstructionsPayload:
      type: object
      required:
        - type
        - instructions
      properties:
        type:
          type: string
          const: UpdateInstructions
          description: >-
            Message type identifier.
        instructions:
          type: string
          description: >-
            New system instructions for the agent.
    UpdateSpeakPayload:
      type: object
      required:
        - type
      properties:
        type:
          type: string
          const: UpdateSpeak
          description: >-
            Message type identifier.
        model:
          type: string
          description: >-
            New text-to-speech model or voice.
    InjectAgentMessagePayload:
      type: object
      required:
        - type
        - message
      properties:
        type:
          type: string
          const: InjectAgentMessage
          description: >-
            Message type identifier.
        message:
          type: string
          description: >-
            Text message to inject into the conversation.
    FunctionCallResponsePayload:
      type: object
      required:
        - type
        - function_call_id
        - output
      properties:
        type:
          type: string
          const: FunctionCallResponse
          description: >-
            Message type identifier.
        function_call_id:
          type: string
          description: >-
            Identifier of the function call being responded to.
        output:
          type: string
          description: >-
            String result of the function execution.
    KeepAlivePayload:
      type: object
      required:
        - type
      properties:
        type:
          type: string
          const: KeepAlive
          description: >-
            Message type identifier.
    UserStartedSpeakingPayload:
      type: object
      properties:
        type:
          type: string
          const: UserStartedSpeaking
          description: >-
            Message type identifier.
    AgentStartedSpeakingPayload:
      type: object
      properties:
        type:
          type: string
          const: AgentStartedSpeaking
          description: >-
            Message type identifier.
        total_latency:
          type: number
          format: float
          description: >-
            Total latency in seconds from user input to agent response.
        tts_latency:
          type: number
          format: float
          description: >-
            Text-to-speech processing latency in seconds.
        ttt_latency:
          type: number
          format: float
          description: >-
            Text-to-text (LLM) processing latency in seconds.
    AgentThinkingPayload:
      type: object
      properties:
        type:
          type: string
          const: AgentThinking
          description: >-
            Message type identifier.
    ConversationTextPayload:
      type: object
      properties:
        type:
          type: string
          const: ConversationText
          description: >-
            Message type identifier.
        role:
          type: string
          enum:
            - user
            - assistant
          description: >-
            Role of the speaker in the conversation.
        content:
          type: string
          description: >-
            Text content of the conversation turn.
    FunctionCallRequestPayload:
      type: object
      properties:
        type:
          type: string
          const: FunctionCallRequest
          description: >-
            Message type identifier.
        function_call_id:
          type: string
          description: >-
            Unique identifier for this function call.
        function_name:
          type: string
          description: >-
            Name of the function to call.
        input:
          type: object
          additionalProperties: true
          description: >-
            Arguments to pass to the function.
    FunctionCallingPayload:
      type: object
      properties:
        type:
          type: string
          const: FunctionCalling
          description: >-
            Message type identifier.
    WelcomePayload:
      type: object
      properties:
        type:
          type: string
          const: Welcome
          description: >-
            Message type identifier.
        session_id:
          type: string
          description: >-
            Unique identifier for this agent session.
    AgentErrorPayload:
      type: object
      properties:
        type:
          type: string
          const: Error
          description: >-
            Message type identifier.
        description:
          type: string
          description: >-
            Human-readable error description.
        message:
          type: string
          description: >-
            Error message.