Synthflow Calls API

openapi: 3.2.0
info:
  title: PLATFORM Calls API
  version: 1.0.0
servers:
- url: https://api.synthflow.ai/v2
  description: Global
- url: https://api.us.synthflow.ai/v2
  description: United States
- url: https://api.eu.synthflow.ai/v2
  description: European Union
tags:
- name: Calls
paths:
  /calls:
    post:
      operationId: voice-call
      summary: Make a call
      description: Initiates a real-time phone call through the AI agent.
      tags:
      - Calls
      parameters:
      - name: Authorization
        in: header
        description: Bearer authentication
        required: true
        schema:
          type: string
      responses:
        '200':
          description: '200'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/voice-call_Response_200'
        '400':
          description: '400'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Voice-callRequestBadRequestError'
      requestBody:
        content:
          application/json:
            schema:
              type: object
              properties:
                model_id:
                  $ref: '#/components/schemas/model_id'
                phone:
                  type: string
                  description: Call recipient's phone number.
                from_phone_number:
                  type: string
                  description: Optional outbound caller ID. Must match a phone number attached to the outbound agent.
                name:
                  type: string
                  description: Call recipient's name.
                custom_variables:
                  type: array
                  items:
                    $ref: '#/components/schemas/CallsPostRequestBodyContentApplicationJsonSchemaCustomVariablesItems'
                  description: Key-value pairs of pre-call variables, called custom variables in the API, that you can dynamically inject into the prompt. [Learn more](/variables#pre-call-variables).
                lead_email:
                  type: string
                  description: The customer's email that can be used to book an appointment.
                lead_timezone:
                  type: string
                  description: The customer's time zone that can be used to book an appointment. For a list of all available time zones, see [Time zones](/time-zones).
                prompt:
                  type: string
                  description: The prompt that the agent will use.
                greeting:
                  type: string
                  description: The greeting the agent will use.
              required:
              - model_id
              - phone
              - name
    get:
      operationId: list-calls
      summary: List calls
      description: Returns a paginated list of calls for the specified model. You can optionally filter by time window, status, duration range, or phone number.
      tags:
      - Calls
      parameters:
      - name: model_id
        in: query
        description: The calls for the specified model ID will be returned
        required: true
        schema:
          type: string
      - name: limit
        in: query
        description: How many calls will be displayed in every page, default is 20
        required: false
        schema:
          type: integer
      - name: offset
        in: query
        description: Index of the first call to be returned.
        required: false
        schema:
          type: integer
      - name: from_date
        in: query
        description: 'Begin timestamp (milliseconds since epoch) of the call. Available after the call starts. Example: 1732546200000'
        required: false
        schema:
          type: integer
          format: int64
      - name: to_date
        in: query
        description: 'End timestamp (milliseconds since epoch) of the call. Available after the call ends. Example: 1732546200000'
        required: false
        schema:
          type: integer
          format: int64
      - name: call_status
        in: query
        description: Status of call.
        required: false
        schema:
          type: string
      - name: duration_min
        in: query
        description: Only retrieve calls with duration greater than or equal to this value (seconds).
        required: false
        schema:
          type: integer
      - name: duration_max
        in: query
        description: Only retrieve calls with duration less than or equal to this value (seconds).
        required: false
        schema:
          type: integer
      - name: lead_phone_number
        in: query
        description: Phone number of the caller or callee (E.164 format preferred) and URL-encode the leading "+" (e.g. %2B14155552671)
        required: false
        schema:
          type: string
      - name: Authorization
        in: header
        description: Bearer authentication
        required: true
        schema:
          type: string
      responses:
        '200':
          description: '200'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/list-calls_Response_200'
        '400':
          description: '400'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/List-callsRequestBadRequestError'
  /calls/outbound-test-ws-media:
    post:
      operationId: start-ws-media-call
      summary: Start a WebSocket media call
      description: Starts an outbound test call and returns a short-lived WebSocket URL for streaming call audio.
      tags:
      - Calls
      parameters:
      - name: Authorization
        in: header
        description: Bearer authentication
        required: true
        schema:
          type: string
      responses:
        '200':
          description: WebSocket media call created.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/start-ws-media-call_Response_200'
        '400':
          description: Invalid request.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Start-ws-media-callRequestBadRequestError'
        '401':
          description: Missing or invalid API credentials.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Start-ws-media-callRequestUnauthorizedError'
        '502':
          description: Room join failed.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Start-ws-media-callRequestBadGatewayError'
        '503':
          description: WebSocket media is not enabled in this environment.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Start-ws-media-callRequestServiceUnavailableError'
      requestBody:
        content:
          application/json:
            schema:
              type: object
              properties:
                modelId:
                  type: string
                  format: uuid
                  description: Agent model UUID.
                fromPhoneNumber:
                  type: string
                  description: Caller ID for the test call.
                toPhoneNumber:
                  type: string
                  description: Destination phone number.
                leadName:
                  type: string
                  description: Lead display name.
                agentVersion:
                  type: string
                  description: Agent version to use. Set to `draft` to test the draft version, pass a version UUID, or omit for the live version.
                wsMediaCodec:
                  $ref: '#/components/schemas/CallsOutboundTestWsMediaPostRequestBodyContentApplicationJsonSchemaWsMediaCodec'
                  default: opus
                  description: Codec to use for the WebSocket media stream. `l16` is raw big-endian 16-bit PCM at 16 kHz.
                wsMediaFraming:
                  $ref: '#/components/schemas/CallsOutboundTestWsMediaPostRequestBodyContentApplicationJsonSchemaWsMediaFraming'
                  default: rtp
                  description: Wire format for the WebSocket media stream. `rtp` (default) sends full RTP packets; `payload` sends raw codec payloads (RTP header stripped), which is simpler for external AI/STT/TTS clients. Use `payload` with `pcma`/`pcmu` — avoid `payload` with `opus` (see the integration guide for why).
                wsMediaServerName:
                  type: string
                  default: ''
                  description: Media node the client reached, taken from the `server-name` in the `server_info` message. Provide it to start the call on that exact node and receive a `sid` to bind over the open WebSocket (connect-then-bind). Omit it only for the legacy single-node flow that returns a ready-to-use `wsMediaUrl`.
              required:
              - modelId
              - fromPhoneNumber
              - toPhoneNumber
  /calls/outbound-test-ws-media/base-url:
    get:
      operationId: get-ws-media-base-url
      summary: Get the WebSocket media base URL
      description: Returns the region-correct WebSocket base URL (no session id) for the connect-then-bind flow. Connect to this URL first, read the `server_info` message, then start the call with `wsMediaServerName` set to the `server-name` you received. This call is stateless and does not start or reserve a call.
      tags:
      - Calls
      parameters:
      - name: Authorization
        in: header
        description: Bearer authentication
        required: true
        schema:
          type: string
      responses:
        '200':
          description: Base URL issued.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/get-ws-media-base-url_Response_200'
        '401':
          description: Missing or invalid API credentials.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Get-ws-media-base-urlRequestUnauthorizedError'
        '503':
          description: WebSocket media is not enabled in this environment.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Get-ws-media-base-urlRequestServiceUnavailableError'
  /calls/{call_id}:
    get:
      operationId: get-phone-call
      summary: Get a call
      description: Retrieve the transcript and other metadata for a phone call.
      tags:
      - Calls
      parameters:
      - name: call_id
        in: path
        required: true
        schema:
          $ref: '#/components/schemas/call_id'
      - name: Authorization
        in: header
        description: Bearer authentication
        required: true
        schema:
          type: string
      responses:
        '200':
          description: '200'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/get-phone-call_Response_200'
        '400':
          description: '400'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Get-phone-callRequestBadRequestError'
        '404':
          description: '404'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Get-phone-callRequestNotFoundError'
components:
  schemas:
    CallsGetResponsesContentApplicationJsonSchemaResponse:
      type: object
      properties:
        pagination:
          $ref: '#/components/schemas/CallsGetResponsesContentApplicationJsonSchemaResponsePagination'
          description: Pagination information for the response
        calls:
          type: array
          items:
            $ref: '#/components/schemas/CallsGetResponsesContentApplicationJsonSchemaResponseCallsItems'
      title: CallsGetResponsesContentApplicationJsonSchemaResponse
    CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsExecutedActions:
      type: object
      properties: {}
      description: Actions that were executed during the call.
      title: CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsExecutedActions
    model_id:
      type: string
      description: Agent ID. You can find it on the agent’s page in your dashboard.
      title: model_id
    get-ws-media-base-url_Response_200:
      type: object
      properties:
        wsMediaBaseUrl:
          type: string
          format: uri
          description: Secure WebSocket base URL for streaming call audio, without a session id.
      required:
      - wsMediaBaseUrl
      title: get-ws-media-base-url_Response_200
    CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsStatus:
      type: string
      enum:
      - pending
      - ringing
      - in-progress
      - completed
      - no-answer
      - busy
      - failed
      - canceled
      - user-canceled
      - hangup_on_voicemail
      - left_voicemail
      - spam
      - paused
      - registered
      description: The current status of the call.
      title: CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsStatus
    CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsCollectedVariables:
      type: object
      properties:
        value:
          description: The collected value of the variable (string, number, boolean, or null if not collected).
        collected:
          type: boolean
          description: Whether this variable was successfully collected.
      title: CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsCollectedVariables
    CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsPromptVariables:
      type: object
      properties: {}
      description: Prompt variables.
      title: CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsPromptVariables
    Get-ws-media-base-urlRequestUnauthorizedError:
      type: object
      properties: {}
      title: Get-ws-media-base-urlRequestUnauthorizedError
    Get-ws-media-base-urlRequestServiceUnavailableError:
      type: object
      properties: {}
      title: Get-ws-media-base-urlRequestServiceUnavailableError
    Start-ws-media-callRequestBadGatewayError:
      type: object
      properties:
        callId:
          type: string
          description: Call ID, if a call was created before the room join failed.
        error:
          type: string
      title: Start-ws-media-callRequestBadGatewayError
    CallsPostResponsesContentApplicationJsonSchemaResponse:
      type: object
      properties:
        answer:
          type: string
        call_id:
          type: string
      title: CallsPostResponsesContentApplicationJsonSchemaResponse
    CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsTelephonyDisconnectReason:
      type: string
      enum:
      - unknown
      - callee_hangup
      - caller_hangup
      - error
      - forbidden
      description: The reason the telephony connection was disconnected.
      title: CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsTelephonyDisconnectReason
    voice-call_Response_200:
      type: object
      properties:
        status:
          type: string
        response:
          $ref: '#/components/schemas/CallsPostResponsesContentApplicationJsonSchemaResponse'
        eta:
          type: integer
          description: How long it will take to initialize the call, in seconds.
      title: voice-call_Response_200
    start-ws-media-call_Response_200:
      type: object
      properties:
        callId:
          type: string
          description: Call ID for looking up the call later.
        sid:
          type: string
          description: 'Session id for connect-then-bind. Returned when `wsMediaServerName` is set; send it as `{ "type": "bind", "sid": "..." }` over the WebSocket you already opened to attach your connection to the call. Empty for the legacy single-node flow.'
        wsMediaUrl:
          type: string
          format: uri
          description: Short-lived WebSocket URL with the session id attached. Used directly by the legacy single-node flow; connect-then-bind clients ignore it and bind `sid` over the base URL connection instead.
      required:
      - callId
      - wsMediaUrl
      title: start-ws-media-call_Response_200
    list-calls_Response_200:
      type: object
      properties:
        status:
          $ref: '#/components/schemas/status'
        response:
          $ref: '#/components/schemas/CallsGetResponsesContentApplicationJsonSchemaResponse'
      title: list-calls_Response_200
    CallsPostRequestBodyContentApplicationJsonSchemaCustomVariablesItems:
      type: object
      properties:
        key:
          type: string
        value:
          type: string
      title: CallsPostRequestBodyContentApplicationJsonSchemaCustomVariablesItems
    CallsGetResponsesContentApplicationJsonSchemaResponseCallsItemsTelephonyHangup:
      type: string
      enum:
      - caller
      - callee
      title: CallsGetResponsesContentApplicationJsonSchemaResponseCallsItemsTelephonyHangup
    call_id:
      type: string
      description: Call ID. You can find it on the logs page in your dashboard.
      title: call_id
    Start-ws-media-callRequestBadRequestError:
      type: object
      properties: {}
      title: Start-ws-media-callRequestBadRequestError
    List-callsRequestBadRequestError:
      type: object
      properties: {}
      title: List-callsRequestBadRequestError
    Get-phone-callRequestNotFoundError:
      type: object
      properties:
        detail:
          $ref: '#/components/schemas/CallsCallIdGetResponsesContentApplicationJsonSchemaDetail'
      title: Get-phone-callRequestNotFoundError
    CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsTypeOfCall:
      type: string
      enum:
      - inbound
      - outbound
      description: Call type.
      title: CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsTypeOfCall
    CallsGetResponsesContentApplicationJsonSchemaResponseCallsItemsExecutedActions:
      type: object
      properties: {}
      description: Actions executed during the call
      title: CallsGetResponsesContentApplicationJsonSchemaResponseCallsItemsExecutedActions
    get-phone-call_Response_200:
      type: object
      properties:
        status:
          $ref: '#/components/schemas/status'
        response:
          $ref: '#/components/schemas/CallsCallIdGetResponsesContentApplicationJsonSchemaResponse'
      title: get-phone-call_Response_200
    CallsCallIdGetResponsesContentApplicationJsonSchemaDetail:
      type: object
      properties:
        status:
          type: string
        description:
          type: string
        request_id:
          type: string
        category:
          type: string
      required:
      - status
      - description
      - request_id
      - category
      title: CallsCallIdGetResponsesContentApplicationJsonSchemaDetail
    Start-ws-media-callRequestServiceUnavailableError:
      type: object
      properties: {}
      title: Start-ws-media-callRequestServiceUnavailableError
    Get-phone-callRequestBadRequestError:
      type: object
      properties:
        detail:
          $ref: '#/components/schemas/CallsCallIdGetResponsesContentApplicationJsonSchemaDetail'
      title: Get-phone-callRequestBadRequestError
    CallsCallIdGetResponsesContentApplicationJsonSchemaResponsePagination:
      type: object
      properties:
        total_records:
          type: integer
          description: The total number of call records matching the query.
        limit:
          type: integer
          description: The maximum number of records returned per request.
        offset:
          type: integer
          description: The number of records skipped from the beginning of the results.
      description: Pagination information for the results.
      title: CallsCallIdGetResponsesContentApplicationJsonSchemaResponsePagination
    CallsGetResponsesContentApplicationJsonSchemaResponseCallsItemsTelephonyDisconnectReason:
      type: string
      enum:
      - unknown
      - callee_hangup
      - caller_hangup
      - error
      - forbidden
      title: CallsGetResponsesContentApplicationJsonSchemaResponseCallsItemsTelephonyDisconnectReason
    CallsGetResponsesContentApplicationJsonSchemaResponsePagination:
      type: object
      properties:
        total_records:
          type: integer
          description: Total number of call records
        limit:
          type: integer
          description: Maximum number of records per page
        offset:
          type: integer
          description: Starting index for the current page
      description: Pagination information for the response
      title: CallsGetResponsesContentApplicationJsonSchemaResponsePagination
    CallsGetResponsesContentApplicationJsonSchemaResponseCallsItems:
      type: object
      properties:
        call_id:
          $ref: '#/components/schemas/call_id'
        model_id:
          $ref: '#/components/schemas/model_id'
        duration:
          type: integer
          description: Duration of the call in seconds
        end_call_reason:
          type: string
          description: Reason why the call ended
        judge_results:
          oneOf:
          - description: Any type
          - type: 'null'
          description: Results from call quality judging
        lead_phone_number:
          type: string
          description: Phone number of the lead
        agents_used:
          type: array
          items:
            type: string
          description: List of agents used during the call
        executed_actions:
          $ref: '#/components/schemas/CallsGetResponsesContentApplicationJsonSchemaResponseCallsItemsExecutedActions'
          description: Actions executed during the call
        recording_url:
          type:
          - string
          - 'null'
        type_of_call:
          type: string
          description: Type of call (inbound or outbound)
        recording_duration:
          type:
          - string
          - 'null'
          description: Duration of the recording
        transcript:
          type:
          - string
          - 'null'
        error_message:
          type:
          - string
          - 'null'
          description: Error message if the call failed
        call_status:
          type: string
          description: Status of the call
        start_time:
          type: string
          description: Timestamp when the call started (milliseconds since epoch)
        lead_name:
          type:
          - string
          - 'null'
          description: Name of the lead
        name:
          type:
          - string
          - 'null'
          description: Name of the call recipient
        labels:
          type: array
          items:
            type: string
          description: Labels associated with the call
        agent_phone_number:
          type: string
          description: Phone number used by the agent
        deployment_type:
          type:
          - string
          - 'null'
          description: Type of deployment
        timezone:
          type:
          - string
          - 'null'
          description: Timezone for the call
        telephony_hangup:
          oneOf:
          - $ref: '#/components/schemas/CallsGetResponsesContentApplicationJsonSchemaResponseCallsItemsTelephonyHangup'
          - type: 'null'
        telephony_disconnect_reason:
          oneOf:
          - $ref: '#/components/schemas/CallsGetResponsesContentApplicationJsonSchemaResponseCallsItemsTelephonyDisconnectReason'
          - type: 'null'
        telephony_duration:
          type:
          - integer
          - 'null'
        telephony_start:
          type:
          - string
          - 'null'
          format: date
        telephony_end:
          type:
          - string
          - 'null'
          format: date
        campaign_type:
          type: string
        phone_number_from:
          type: string
        phone_number_to:
          type: string
        collected_variables:
          type: object
          additionalProperties:
            type: object
            additionalProperties:
              $ref: '#/components/schemas/CallsGetResponsesContentApplicationJsonSchemaResponseCallsItemsCollectedVariables'
          description: Collected variables (slots) from the conversation flow, keyed by agent ID. May be null if not available.
      title: CallsGetResponsesContentApplicationJsonSchemaResponseCallsItems
    CallsGetResponsesContentApplicationJsonSchemaResponseCallsItemsCollectedVariables:
      type: object
      properties:
        value:
          description: The collected value of the variable (string, number, boolean, or null if not collected).
        collected:
          type: boolean
          description: Whether this variable was successfully collected.
      title: CallsGetResponsesContentApplicationJsonSchemaResponseCallsItemsCollectedVariables
    CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsTelephonyHangup:
      type: string
      enum:
      - caller
      - callee
      description: Indicates which party ended the call.
      title: CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsTelephonyHangup
    status:
      type: string
      description: Whether the request was successful.
      title: status
    Start-ws-media-callRequestUnauthorizedError:
      type: object
      properties: {}
      title: Start-ws-media-callRequestUnauthorizedError
    CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsEndCallReason:
      type: string
      enum:
      - human_pick_up_cut_off
      - voicemail
      - voicemail_cut_off
      - voicemail_message_left
      - agent_ended_call
      - human_ended_call
      - custom_end_call
      - user_canceled
      - timeout
      - error
      description: The reason the call ended from the AI agent's perspective.
      title: CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsEndCallReason
    CallsCallIdGetResponsesContentApplicationJsonSchemaResponse:
      type: object
      properties:
        pagination:
          $ref: '#/components/schemas/CallsCallIdGetResponsesContentApplicationJsonSchemaResponsePagination'
          description: Pagination information for the results.
        calls:
          type: array
          items:
            $ref: '#/components/schemas/CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItems'
      title: CallsCallIdGetResponsesContentApplicationJsonSchemaResponse
    CallsOutboundTestWsMediaPostRequestBodyContentApplicationJsonSchemaWsMediaCodec:
      type: string
      enum:
      - opus
      - pcma
      - pcmu
      - l16
      default: opus
      description: Codec to use for the WebSocket media stream. `l16` is raw big-endian 16-bit PCM at 16 kHz.
      title: CallsOutboundTestWsMediaPostRequestBodyContentApplicationJsonSchemaWsMediaCodec
    Voice-callRequestBadRequestError:
      type: object
      properties: {}
      title: Voice-callRequestBadRequestError
    CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItems:
      type: object
      properties:
        call_id:
          $ref: '#/components/schemas/call_id'
        model_id:
          $ref: '#/components/schemas/model_id'
        campaign_type:
          type: string
          description: Campaign type.
        phone_number_from:
          type: string
          description: The caller's phone number.
        phone_number_to:
          type: string
          description: The call recipient's phone number.
        name:
          type: string
          description: Recipient's name.
        transcript:
          type: string
          description: Call transcript.
        duration:
          type: integer
          description: The duration of the call in seconds.
        recording_url:
          type:
          - string
          - 'null'
          description: The URL of the call recording, or `null` if no recording is available.
        end_call_reason:
          $ref: '#/components/schemas/CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsEndCallReason'
          description: The reason the call ended from the AI agent's perspective.
        custom_end_call_reason:
          type:
          - string
          - 'null'
          description: The specific user-defined reason that triggered call termination. Only present when end_call_reason is custom_end_call.
        error_message:
          type: string
          description: Error message if the call encountered an error, or an empty string if no error occurred.
        executed_actions:
          $ref: '#/components/schemas/CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsExecutedActions'
          description: Actions that were executed during the call.
        prompt_variables:
          $ref: '#/components/schemas/CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsPromptVariables'
          description: Prompt variables.
        type_of_call:
          $ref: '#/components/schemas/CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsTypeOfCall'
          description: Call type.
        start_time:
          type: string
          description: The scheduled start time for the call as a UNIX timestamp in milliseconds.
        timezone:
          type: string
          description: The timezone of the call. For a list of all available time zones, see the available [timezones](/time-zones).
        telephony_hangup:
          $ref: '#/components/schemas/CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsTelephonyHangup'
          description: Indicates which party ended the call.
        telephony_disconnect_reason:
          $ref: '#/components/schemas/CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsTelephonyDisconnectReason'
          description: The reason the telephony connection was disconnected.
        telephony_duration:
          type: integer
          description: The total duration of the telephony connection in milliseconds.
        telephony_ringing_duration:
          type: integer
          description: The duration the phone was ringing before the call was answered, in milliseconds.
        telephony_start:
          type: string
          format: date-time
          description: The timestamp when the telephony connection started (ISO 8601 format).
        telephony_end:
          type: string
          format: date-time
          description: The timestamp when the telephony connection ended (ISO 8601 format).
        status:
          $ref: '#/components/schemas/CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsStatus'
          description: The current status of the call.
        collected_variables:
          type: object
          additionalProperties:
            type: object
            additionalProperties:
              $ref: '#/components/schemas/CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItemsCollectedVariables'
          description: Collected variables (slots) from the conversation flow, keyed by agent ID. May be null if not available.
      title: CallsCallIdGetResponsesContentApplicationJsonSchemaResponseCallsItems
    CallsOutboundTestWsMediaPostRequestBodyContentApplicationJsonSchemaWsMediaFraming:
      type: string
      enum:
      - rtp
      - payload
      default: rtp
      description: Wire format for the WebSocket media stream. `rtp` (default) sends full RTP packets; `payload` sends raw codec payloads (RTP header stripped), which is simpler for external AI/STT/TTS clients. Use `payload` with `pcma`/`pcmu` — avoid `payload` with `opus` (see the integration guide for why).
      title: CallsOutboundTestWsMediaPostRequestBodyContentApplicationJsonSchemaWsMediaFraming
  securitySchemes:
    sec0:
      type: http
      scheme: bearer